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NIH launches 5-year, $10 million study on acute flaccid myelitis
Researchers at the University of Alabama at Birmingham will lead a 5-year, federally-funded study of acute flaccid myelitis (AFM) – a rare pediatric neurologic disease.
The National Institute of Allergy and Infectious Diseases (NIAID) awarded the $10 million grant to primary investigator David Kimberlin, MD, a UAB professor of pediatrics. Carlos Pardo-Villamizar, MD, professor of neurology and pathology at Johns Hopkins University, Baltimore, is the co-principal investigator.
The university will organize and implement the international, multisite study. Its primary goal is to examine the incidence and distribution of AFM, and its pathogenesis and progression. Enrollment is expected to commence next fall. Investigators will enroll children with symptoms of AFM and follow them for 1 year. Household contacts of the subjects will serve as comparators.
In addition to collecting data about risk factors and disease progression, the researchers will collect clinical specimens, including blood and cerebrospinal fluid. More details about the design and study sites will be released then, according to a press statement issued by NIAID.
AFM targets spinal nerves and often develops after a mild respiratory illness. The disease mounted a global epidemic comeback in 2014, primarily affecting children; it has occurred concurrently with enterovirus outbreaks.
“Growing epidemiological evidence suggests that enterovirus-D68 [EV-D68] could play a role,” the statement noted. “Most people who become infected with EV-D68 are asymptomatic or experience mild, cold-like symptoms. Researchers and physicians are working to understand if there is a connection between these viral outbreaks and AFM, and if so, why some children but not others experience this sudden muscle weakness and paralysis.”
The study will draw on the expertise of the AFM Task Force, established last fall. The group comprises physicians, scientists, and public health experts from diverse disciplines and institutions who will assist in the ongoing investigation.
The AFM natural history study is funded under contract HHSN272201600018C.
Researchers at the University of Alabama at Birmingham will lead a 5-year, federally-funded study of acute flaccid myelitis (AFM) – a rare pediatric neurologic disease.
The National Institute of Allergy and Infectious Diseases (NIAID) awarded the $10 million grant to primary investigator David Kimberlin, MD, a UAB professor of pediatrics. Carlos Pardo-Villamizar, MD, professor of neurology and pathology at Johns Hopkins University, Baltimore, is the co-principal investigator.
The university will organize and implement the international, multisite study. Its primary goal is to examine the incidence and distribution of AFM, and its pathogenesis and progression. Enrollment is expected to commence next fall. Investigators will enroll children with symptoms of AFM and follow them for 1 year. Household contacts of the subjects will serve as comparators.
In addition to collecting data about risk factors and disease progression, the researchers will collect clinical specimens, including blood and cerebrospinal fluid. More details about the design and study sites will be released then, according to a press statement issued by NIAID.
AFM targets spinal nerves and often develops after a mild respiratory illness. The disease mounted a global epidemic comeback in 2014, primarily affecting children; it has occurred concurrently with enterovirus outbreaks.
“Growing epidemiological evidence suggests that enterovirus-D68 [EV-D68] could play a role,” the statement noted. “Most people who become infected with EV-D68 are asymptomatic or experience mild, cold-like symptoms. Researchers and physicians are working to understand if there is a connection between these viral outbreaks and AFM, and if so, why some children but not others experience this sudden muscle weakness and paralysis.”
The study will draw on the expertise of the AFM Task Force, established last fall. The group comprises physicians, scientists, and public health experts from diverse disciplines and institutions who will assist in the ongoing investigation.
The AFM natural history study is funded under contract HHSN272201600018C.
Researchers at the University of Alabama at Birmingham will lead a 5-year, federally-funded study of acute flaccid myelitis (AFM) – a rare pediatric neurologic disease.
The National Institute of Allergy and Infectious Diseases (NIAID) awarded the $10 million grant to primary investigator David Kimberlin, MD, a UAB professor of pediatrics. Carlos Pardo-Villamizar, MD, professor of neurology and pathology at Johns Hopkins University, Baltimore, is the co-principal investigator.
The university will organize and implement the international, multisite study. Its primary goal is to examine the incidence and distribution of AFM, and its pathogenesis and progression. Enrollment is expected to commence next fall. Investigators will enroll children with symptoms of AFM and follow them for 1 year. Household contacts of the subjects will serve as comparators.
In addition to collecting data about risk factors and disease progression, the researchers will collect clinical specimens, including blood and cerebrospinal fluid. More details about the design and study sites will be released then, according to a press statement issued by NIAID.
AFM targets spinal nerves and often develops after a mild respiratory illness. The disease mounted a global epidemic comeback in 2014, primarily affecting children; it has occurred concurrently with enterovirus outbreaks.
“Growing epidemiological evidence suggests that enterovirus-D68 [EV-D68] could play a role,” the statement noted. “Most people who become infected with EV-D68 are asymptomatic or experience mild, cold-like symptoms. Researchers and physicians are working to understand if there is a connection between these viral outbreaks and AFM, and if so, why some children but not others experience this sudden muscle weakness and paralysis.”
The study will draw on the expertise of the AFM Task Force, established last fall. The group comprises physicians, scientists, and public health experts from diverse disciplines and institutions who will assist in the ongoing investigation.
The AFM natural history study is funded under contract HHSN272201600018C.
Study refines ALS risk among first-degree relatives of patients with disease
, according to a recent Irish population–based study.
Among first-degree relatives of individuals with ALS whose genetic status was unknown, the lifetime risk of developing ALS was 1.4%, compared with 0.3% in the general population (P less than .001).
Overall, lifetime heritability for the 1,117 patients in the heritability study cohort was 52.3% (95% confidence interval, 42.9%-61.7%). The highest heritability was seen in mother-daughter dyads; here, the concordance rate for ALS was 2.6% and the heritability estimate was 66.2% (95% CI, 58.5%-73.9%), “pointing to a previously unrecognized sex-mediated association with disease heritability,” Marie Ryan, MD, and coauthors at Trinity College Dublin wrote in JAMA Neurology.
For the purposes of this study, heritability was defined as “the proportion of variance in liability that is attributable to additive genetic factors,” explained the investigators. Their model was applied to 1,123 Irish patients with incident ALS over a 10-year study period, drawing on a national database. Complete medical histories were available for both parents of every individual in the cohort, and the investigators identified 32 parent-offspring dyads with ALS.
In their assessment of “liability” for ALS, Dr. Ryan and colleagues accounted for age-specific and sex-specific ALS incidence rates, using a well-delineated United States reference population. They also took into account competing mortality risks that might intervene before an individual developed ALS.
Although mother-daughter dyads yielded the highest heritability estimates, heritability was also elevated among father-son dyads, at 50.1% (95% CI, 42.0%-59.4%). Opposite-sex dyads (mother-son and father-daughter) yielded similar, and lower, heritability estimates of 34%-38%. Dr. Ryan and coinvestigators acknowledged that female sex hormones might play a role in mediating risk for ALS, but the contribution and mechanism are currently unknown.
The investigators identified 674 patients in the cohort who had been tested for C9orf72; large repeat expansions in the GGGGCC segment of this gene are known to cause ALS. In all, 69 patients were C9orf72 positive, and 14 of these individuals (20.3%) reported that one parent had ALS. Among the entire cohort, 23 of the 32 patients with parents who also had ALS had C9orf72 testing, and 14 of 23 (60.9%) were positive. This discrepancy, wrote Dr. Ryan and coauthors, suggests that “genetic anticipation or pleiotropic effects may have masked the clinical phenotype in their parents.”
Parents were a mean 69.6 years old at the time of diagnosis, and offspring were a mean 52.0 years old; 56% of patients in the study cohort were male.
“[I]n our study, ALS heritability was assessed for the first time in a population in whom genetic mutations have been excluded,” wrote Dr. Ryan and coinvestigators. “We have found that, in the absence of known ALS-associated genetic mutations in the proband, first-degree relatives of individuals with ALS remain at increased risk of developing ALS compared with the general population.”
Dr. Ryan and one coauthor reported receiving funding from Science Foundation Ireland, and one coauthor reported receiving book royalties from Taylor & Francis, and fees from Cytokinetics and Wave Pharmaceuticals. The study was funded by Science Foundation Ireland and the Motor Neurone Disease Association.
SOURCE: Ryan M et al. JAMA Neurol. 2019 Jul 22. doi: 10.1001/jamaneurol.2019.2044.
, according to a recent Irish population–based study.
Among first-degree relatives of individuals with ALS whose genetic status was unknown, the lifetime risk of developing ALS was 1.4%, compared with 0.3% in the general population (P less than .001).
Overall, lifetime heritability for the 1,117 patients in the heritability study cohort was 52.3% (95% confidence interval, 42.9%-61.7%). The highest heritability was seen in mother-daughter dyads; here, the concordance rate for ALS was 2.6% and the heritability estimate was 66.2% (95% CI, 58.5%-73.9%), “pointing to a previously unrecognized sex-mediated association with disease heritability,” Marie Ryan, MD, and coauthors at Trinity College Dublin wrote in JAMA Neurology.
For the purposes of this study, heritability was defined as “the proportion of variance in liability that is attributable to additive genetic factors,” explained the investigators. Their model was applied to 1,123 Irish patients with incident ALS over a 10-year study period, drawing on a national database. Complete medical histories were available for both parents of every individual in the cohort, and the investigators identified 32 parent-offspring dyads with ALS.
In their assessment of “liability” for ALS, Dr. Ryan and colleagues accounted for age-specific and sex-specific ALS incidence rates, using a well-delineated United States reference population. They also took into account competing mortality risks that might intervene before an individual developed ALS.
Although mother-daughter dyads yielded the highest heritability estimates, heritability was also elevated among father-son dyads, at 50.1% (95% CI, 42.0%-59.4%). Opposite-sex dyads (mother-son and father-daughter) yielded similar, and lower, heritability estimates of 34%-38%. Dr. Ryan and coinvestigators acknowledged that female sex hormones might play a role in mediating risk for ALS, but the contribution and mechanism are currently unknown.
The investigators identified 674 patients in the cohort who had been tested for C9orf72; large repeat expansions in the GGGGCC segment of this gene are known to cause ALS. In all, 69 patients were C9orf72 positive, and 14 of these individuals (20.3%) reported that one parent had ALS. Among the entire cohort, 23 of the 32 patients with parents who also had ALS had C9orf72 testing, and 14 of 23 (60.9%) were positive. This discrepancy, wrote Dr. Ryan and coauthors, suggests that “genetic anticipation or pleiotropic effects may have masked the clinical phenotype in their parents.”
Parents were a mean 69.6 years old at the time of diagnosis, and offspring were a mean 52.0 years old; 56% of patients in the study cohort were male.
“[I]n our study, ALS heritability was assessed for the first time in a population in whom genetic mutations have been excluded,” wrote Dr. Ryan and coinvestigators. “We have found that, in the absence of known ALS-associated genetic mutations in the proband, first-degree relatives of individuals with ALS remain at increased risk of developing ALS compared with the general population.”
Dr. Ryan and one coauthor reported receiving funding from Science Foundation Ireland, and one coauthor reported receiving book royalties from Taylor & Francis, and fees from Cytokinetics and Wave Pharmaceuticals. The study was funded by Science Foundation Ireland and the Motor Neurone Disease Association.
SOURCE: Ryan M et al. JAMA Neurol. 2019 Jul 22. doi: 10.1001/jamaneurol.2019.2044.
, according to a recent Irish population–based study.
Among first-degree relatives of individuals with ALS whose genetic status was unknown, the lifetime risk of developing ALS was 1.4%, compared with 0.3% in the general population (P less than .001).
Overall, lifetime heritability for the 1,117 patients in the heritability study cohort was 52.3% (95% confidence interval, 42.9%-61.7%). The highest heritability was seen in mother-daughter dyads; here, the concordance rate for ALS was 2.6% and the heritability estimate was 66.2% (95% CI, 58.5%-73.9%), “pointing to a previously unrecognized sex-mediated association with disease heritability,” Marie Ryan, MD, and coauthors at Trinity College Dublin wrote in JAMA Neurology.
For the purposes of this study, heritability was defined as “the proportion of variance in liability that is attributable to additive genetic factors,” explained the investigators. Their model was applied to 1,123 Irish patients with incident ALS over a 10-year study period, drawing on a national database. Complete medical histories were available for both parents of every individual in the cohort, and the investigators identified 32 parent-offspring dyads with ALS.
In their assessment of “liability” for ALS, Dr. Ryan and colleagues accounted for age-specific and sex-specific ALS incidence rates, using a well-delineated United States reference population. They also took into account competing mortality risks that might intervene before an individual developed ALS.
Although mother-daughter dyads yielded the highest heritability estimates, heritability was also elevated among father-son dyads, at 50.1% (95% CI, 42.0%-59.4%). Opposite-sex dyads (mother-son and father-daughter) yielded similar, and lower, heritability estimates of 34%-38%. Dr. Ryan and coinvestigators acknowledged that female sex hormones might play a role in mediating risk for ALS, but the contribution and mechanism are currently unknown.
The investigators identified 674 patients in the cohort who had been tested for C9orf72; large repeat expansions in the GGGGCC segment of this gene are known to cause ALS. In all, 69 patients were C9orf72 positive, and 14 of these individuals (20.3%) reported that one parent had ALS. Among the entire cohort, 23 of the 32 patients with parents who also had ALS had C9orf72 testing, and 14 of 23 (60.9%) were positive. This discrepancy, wrote Dr. Ryan and coauthors, suggests that “genetic anticipation or pleiotropic effects may have masked the clinical phenotype in their parents.”
Parents were a mean 69.6 years old at the time of diagnosis, and offspring were a mean 52.0 years old; 56% of patients in the study cohort were male.
“[I]n our study, ALS heritability was assessed for the first time in a population in whom genetic mutations have been excluded,” wrote Dr. Ryan and coinvestigators. “We have found that, in the absence of known ALS-associated genetic mutations in the proband, first-degree relatives of individuals with ALS remain at increased risk of developing ALS compared with the general population.”
Dr. Ryan and one coauthor reported receiving funding from Science Foundation Ireland, and one coauthor reported receiving book royalties from Taylor & Francis, and fees from Cytokinetics and Wave Pharmaceuticals. The study was funded by Science Foundation Ireland and the Motor Neurone Disease Association.
SOURCE: Ryan M et al. JAMA Neurol. 2019 Jul 22. doi: 10.1001/jamaneurol.2019.2044.
FROM JAMA NEUROLOGY
Novel genetic therapy reduces key protein in Huntington’s disease
according to a study published in the New England Journal of Medicine.
Huntington’s disease is an autosomal-dominant neurodegenerative disease caused by CAG trinucleotide repeat expansion in HTT, resulting in a mutant huntingtin protein. No disease-modifying treatment currently exists. The experimental therapy tested in this trial, developed by Ionis Pharmaceuticals and licensed to Roche as HTTRx, is an antisense oligonucleotide that inhibits HTT messenger RNA signaling specific to the production of the mutant huntingtin protein implicated in Huntington’s disease. Whether HTTRx, which is delivered intrathecally, can produce functional or cognitive improvement is yet unclear, as this randomized, double-blinded, multiple-ascending-dose, placebo-controlled trial, which enrolled 46 patients in Canada, Germany, and the United Kingdom, was primarily a safety study.
For the phase 1-2a trial, lead author Sarah J. Tabrizi, MB, ChB, PhD, of University College London and colleagues assigned patients with early Huntington’s disease to monthly intrathecal injections of one of five different doses of HTTRx (10, 30, 60, 90 or 120 mg), or placebo. Most patients (n = 34) received active drug. After the 85-day treatment period, in which four doses were delivered, patients were followed for 4 months.
The treatment groups saw a mean dose-dependent reduction from baseline in the concentration of CSF mutant huntingtin of between –20% and –42% at 28 days post dosing, while the placebo arm saw an increase of a mean 10%. The most common adverse events seen in the trial were procedure-related pain and headache following spinal puncture.
Other endpoints in the study included concentrations of mutant huntingtin in plasma, the effect of treatment on other neurodegenerative biomarkers, and cognitive scores.
The median peak plasma concentrations of HTTRx were reached within 4 hours after the bolus intrathecal administration and declined to less than 30% of the peak concentration by 24 hours after administration. There was no evidence of accumulation of concentration in plasma 24 hours after dose administration.
Functional, cognitive, psychiatric, and neurologic clinical outcomes were generally unchanged at the dose-group level during the trial, and no meaningful differences were observed between patients who received placebo and patients who received active treatment, regardless of the dose level.
An open-label, follow-up study in the same group of patients, all of whom have been assigned to the 120-mg dose monthly or every other month, is expected to end in October 2019. While the extension study is also mainly a safety study, it will also look at biomarkers and cognitive scores over a longer treatment period.
The study was funded by Ionis Pharmaceuticals and F. Hoffmann–La Roche, and most of the authors, including Dr. Tabrizi, reported financial relationships with one or both entities.
SOURCE: Tabrizi SJ et al. N Eng J Med. 2019:380;2307-16.
according to a study published in the New England Journal of Medicine.
Huntington’s disease is an autosomal-dominant neurodegenerative disease caused by CAG trinucleotide repeat expansion in HTT, resulting in a mutant huntingtin protein. No disease-modifying treatment currently exists. The experimental therapy tested in this trial, developed by Ionis Pharmaceuticals and licensed to Roche as HTTRx, is an antisense oligonucleotide that inhibits HTT messenger RNA signaling specific to the production of the mutant huntingtin protein implicated in Huntington’s disease. Whether HTTRx, which is delivered intrathecally, can produce functional or cognitive improvement is yet unclear, as this randomized, double-blinded, multiple-ascending-dose, placebo-controlled trial, which enrolled 46 patients in Canada, Germany, and the United Kingdom, was primarily a safety study.
For the phase 1-2a trial, lead author Sarah J. Tabrizi, MB, ChB, PhD, of University College London and colleagues assigned patients with early Huntington’s disease to monthly intrathecal injections of one of five different doses of HTTRx (10, 30, 60, 90 or 120 mg), or placebo. Most patients (n = 34) received active drug. After the 85-day treatment period, in which four doses were delivered, patients were followed for 4 months.
The treatment groups saw a mean dose-dependent reduction from baseline in the concentration of CSF mutant huntingtin of between –20% and –42% at 28 days post dosing, while the placebo arm saw an increase of a mean 10%. The most common adverse events seen in the trial were procedure-related pain and headache following spinal puncture.
Other endpoints in the study included concentrations of mutant huntingtin in plasma, the effect of treatment on other neurodegenerative biomarkers, and cognitive scores.
The median peak plasma concentrations of HTTRx were reached within 4 hours after the bolus intrathecal administration and declined to less than 30% of the peak concentration by 24 hours after administration. There was no evidence of accumulation of concentration in plasma 24 hours after dose administration.
Functional, cognitive, psychiatric, and neurologic clinical outcomes were generally unchanged at the dose-group level during the trial, and no meaningful differences were observed between patients who received placebo and patients who received active treatment, regardless of the dose level.
An open-label, follow-up study in the same group of patients, all of whom have been assigned to the 120-mg dose monthly or every other month, is expected to end in October 2019. While the extension study is also mainly a safety study, it will also look at biomarkers and cognitive scores over a longer treatment period.
The study was funded by Ionis Pharmaceuticals and F. Hoffmann–La Roche, and most of the authors, including Dr. Tabrizi, reported financial relationships with one or both entities.
SOURCE: Tabrizi SJ et al. N Eng J Med. 2019:380;2307-16.
according to a study published in the New England Journal of Medicine.
Huntington’s disease is an autosomal-dominant neurodegenerative disease caused by CAG trinucleotide repeat expansion in HTT, resulting in a mutant huntingtin protein. No disease-modifying treatment currently exists. The experimental therapy tested in this trial, developed by Ionis Pharmaceuticals and licensed to Roche as HTTRx, is an antisense oligonucleotide that inhibits HTT messenger RNA signaling specific to the production of the mutant huntingtin protein implicated in Huntington’s disease. Whether HTTRx, which is delivered intrathecally, can produce functional or cognitive improvement is yet unclear, as this randomized, double-blinded, multiple-ascending-dose, placebo-controlled trial, which enrolled 46 patients in Canada, Germany, and the United Kingdom, was primarily a safety study.
For the phase 1-2a trial, lead author Sarah J. Tabrizi, MB, ChB, PhD, of University College London and colleagues assigned patients with early Huntington’s disease to monthly intrathecal injections of one of five different doses of HTTRx (10, 30, 60, 90 or 120 mg), or placebo. Most patients (n = 34) received active drug. After the 85-day treatment period, in which four doses were delivered, patients were followed for 4 months.
The treatment groups saw a mean dose-dependent reduction from baseline in the concentration of CSF mutant huntingtin of between –20% and –42% at 28 days post dosing, while the placebo arm saw an increase of a mean 10%. The most common adverse events seen in the trial were procedure-related pain and headache following spinal puncture.
Other endpoints in the study included concentrations of mutant huntingtin in plasma, the effect of treatment on other neurodegenerative biomarkers, and cognitive scores.
The median peak plasma concentrations of HTTRx were reached within 4 hours after the bolus intrathecal administration and declined to less than 30% of the peak concentration by 24 hours after administration. There was no evidence of accumulation of concentration in plasma 24 hours after dose administration.
Functional, cognitive, psychiatric, and neurologic clinical outcomes were generally unchanged at the dose-group level during the trial, and no meaningful differences were observed between patients who received placebo and patients who received active treatment, regardless of the dose level.
An open-label, follow-up study in the same group of patients, all of whom have been assigned to the 120-mg dose monthly or every other month, is expected to end in October 2019. While the extension study is also mainly a safety study, it will also look at biomarkers and cognitive scores over a longer treatment period.
The study was funded by Ionis Pharmaceuticals and F. Hoffmann–La Roche, and most of the authors, including Dr. Tabrizi, reported financial relationships with one or both entities.
SOURCE: Tabrizi SJ et al. N Eng J Med. 2019:380;2307-16.
FROM THE NEW ENGLAND JOURNAL OF MEDICINE
Mutant huntingtin and neurofilament light are potential biomarkers in Huntington’s disease
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. These biomarkers appear to reflect the earliest detectable changes in the natural history of Huntington’s disease, but the longitudinal prognostic value of changes in these biomarkers requires further investigation, the researchers said.
Huntington’s disease has a long prodromal phase and is associated with long survival. Investigators still need well-validated biomarkers of disease progression, prognosis, and pharmacodynamics to aid drug development, said Filipe B. Rodrigues, MD, clinical research fellow at University College London. After several years of study, Dr. Rodrigues and colleagues found mutant huntingtin and neurofilament light (NfL) to be the most promising potential biomarkers in Huntington’s disease. They sought to understand how these two biomarkers compare with each other, what their predictive ability is, and how they change longitudinally.
To this end, Dr. Rodrigues and colleagues designed the HD-CSF study, a prospective, observational, longitudinal cohort study with a 2-year follow-up. They recruited 20 healthy controls, 20 patients with premanifest Huntington’s disease, and 40 patients with manifest Huntington’s disease. All participants underwent regular clinical assessments and standardized collections of cerebrospinal fluid (CSF) and blood. They also had the option of undergoing brain MRI scans.
The investigators analyzed their data using multiple linear regression models, Pearson’s correlations, receiver operating characteristic curves, and sample size calculations. They used an event-based model to evaluate the temporal sequence of changes in Huntington’s disease-related biomarkers.
Dr. Rodrigues and colleagues first observed that all three biomarkers successfully distinguished between healthy controls, patients with premanifest Huntington’s disease, and patients with Huntington’s disease. Mutant huntingtin, the pathogenic agent in Huntington’s disease, discriminated perfectly between healthy controls and mutation carriers, as the researchers had expected. CSF and plasma levels of NfL also discriminated well between healthy controls and mutation carriers. These biomarkers had areas under the ROC curve greater than 0.9. NfL in plasma and CSF also distinguished well between patients with premanifest Huntington’s disease and those with manifest Huntington’s disease, with areas under the curve greater than 0.9. Their discriminative ability in this regard was significantly better than that of mutant huntingtin.
When the researchers examined the relationship between the three biomarkers, they found that CSF levels of NfL were strongly correlated in a linear fashion with plasma levels of NfL. CSF levels of mutant huntingtin were moderately associated with CSF levels of NfL.
Levels of all three biomarkers increased significantly as the disease progressed and were associated with all clinical scales and imaging measures. CSF and plasma levels of NfL had superior predictive ability for clinical and imaging measures, compared with mutant huntingtin. CSF and plasma NfL were associated with brain volume, but mutant huntingtin was not.
All three biomarkers were stable during a 6-week period. Dr. Rodrigues and colleagues calculated sample sizes for a two-arm interventional trial involving various hypothetical therapeutic effects. They found that the required sample sizes were small enough to be incorporated easily into ongoing and future clinical trials.
In silico modeling suggested among the markers measured in the HD-CSF study, the three biofluid biomarkers were the first factors to be altered in the course of Huntington’s disease. Alterations in the biomarkers were followed by changes in imaging markers, and then by changes in clinical markers (for example, motor and cognitive function).
Finally, Dr. Rodrigues and colleagues found preliminary evidence that levels of NfL in CSF and plasma increase over time at different rates in patients with Huntington’s disease, compared with healthy controls. NfL appears to be more useful than mutant huntingtin for evaluating the rate of disease progression than for gauging response to treatment, said Dr. Rodrigues. “If [we] can prove that we can assess response to treatment by measuring NfL, I think that would be great.”
The investigators are currently analyzing the longitudinal predictive value of changes in these biomarkers. They also have begun analyzing other markers such as tau and brain-derived neurotrophic factor.
This study was funded by the Medical Research Council UK, the CHDI Foundation, and F. Hoffmann-La Roche.
This article was updated 6/18/19.
SOURCE: Rodrigues FB et al. AAN 2019, Abstract S16.003.
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. These biomarkers appear to reflect the earliest detectable changes in the natural history of Huntington’s disease, but the longitudinal prognostic value of changes in these biomarkers requires further investigation, the researchers said.
Huntington’s disease has a long prodromal phase and is associated with long survival. Investigators still need well-validated biomarkers of disease progression, prognosis, and pharmacodynamics to aid drug development, said Filipe B. Rodrigues, MD, clinical research fellow at University College London. After several years of study, Dr. Rodrigues and colleagues found mutant huntingtin and neurofilament light (NfL) to be the most promising potential biomarkers in Huntington’s disease. They sought to understand how these two biomarkers compare with each other, what their predictive ability is, and how they change longitudinally.
To this end, Dr. Rodrigues and colleagues designed the HD-CSF study, a prospective, observational, longitudinal cohort study with a 2-year follow-up. They recruited 20 healthy controls, 20 patients with premanifest Huntington’s disease, and 40 patients with manifest Huntington’s disease. All participants underwent regular clinical assessments and standardized collections of cerebrospinal fluid (CSF) and blood. They also had the option of undergoing brain MRI scans.
The investigators analyzed their data using multiple linear regression models, Pearson’s correlations, receiver operating characteristic curves, and sample size calculations. They used an event-based model to evaluate the temporal sequence of changes in Huntington’s disease-related biomarkers.
Dr. Rodrigues and colleagues first observed that all three biomarkers successfully distinguished between healthy controls, patients with premanifest Huntington’s disease, and patients with Huntington’s disease. Mutant huntingtin, the pathogenic agent in Huntington’s disease, discriminated perfectly between healthy controls and mutation carriers, as the researchers had expected. CSF and plasma levels of NfL also discriminated well between healthy controls and mutation carriers. These biomarkers had areas under the ROC curve greater than 0.9. NfL in plasma and CSF also distinguished well between patients with premanifest Huntington’s disease and those with manifest Huntington’s disease, with areas under the curve greater than 0.9. Their discriminative ability in this regard was significantly better than that of mutant huntingtin.
When the researchers examined the relationship between the three biomarkers, they found that CSF levels of NfL were strongly correlated in a linear fashion with plasma levels of NfL. CSF levels of mutant huntingtin were moderately associated with CSF levels of NfL.
Levels of all three biomarkers increased significantly as the disease progressed and were associated with all clinical scales and imaging measures. CSF and plasma levels of NfL had superior predictive ability for clinical and imaging measures, compared with mutant huntingtin. CSF and plasma NfL were associated with brain volume, but mutant huntingtin was not.
All three biomarkers were stable during a 6-week period. Dr. Rodrigues and colleagues calculated sample sizes for a two-arm interventional trial involving various hypothetical therapeutic effects. They found that the required sample sizes were small enough to be incorporated easily into ongoing and future clinical trials.
In silico modeling suggested among the markers measured in the HD-CSF study, the three biofluid biomarkers were the first factors to be altered in the course of Huntington’s disease. Alterations in the biomarkers were followed by changes in imaging markers, and then by changes in clinical markers (for example, motor and cognitive function).
Finally, Dr. Rodrigues and colleagues found preliminary evidence that levels of NfL in CSF and plasma increase over time at different rates in patients with Huntington’s disease, compared with healthy controls. NfL appears to be more useful than mutant huntingtin for evaluating the rate of disease progression than for gauging response to treatment, said Dr. Rodrigues. “If [we] can prove that we can assess response to treatment by measuring NfL, I think that would be great.”
The investigators are currently analyzing the longitudinal predictive value of changes in these biomarkers. They also have begun analyzing other markers such as tau and brain-derived neurotrophic factor.
This study was funded by the Medical Research Council UK, the CHDI Foundation, and F. Hoffmann-La Roche.
This article was updated 6/18/19.
SOURCE: Rodrigues FB et al. AAN 2019, Abstract S16.003.
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. These biomarkers appear to reflect the earliest detectable changes in the natural history of Huntington’s disease, but the longitudinal prognostic value of changes in these biomarkers requires further investigation, the researchers said.
Huntington’s disease has a long prodromal phase and is associated with long survival. Investigators still need well-validated biomarkers of disease progression, prognosis, and pharmacodynamics to aid drug development, said Filipe B. Rodrigues, MD, clinical research fellow at University College London. After several years of study, Dr. Rodrigues and colleagues found mutant huntingtin and neurofilament light (NfL) to be the most promising potential biomarkers in Huntington’s disease. They sought to understand how these two biomarkers compare with each other, what their predictive ability is, and how they change longitudinally.
To this end, Dr. Rodrigues and colleagues designed the HD-CSF study, a prospective, observational, longitudinal cohort study with a 2-year follow-up. They recruited 20 healthy controls, 20 patients with premanifest Huntington’s disease, and 40 patients with manifest Huntington’s disease. All participants underwent regular clinical assessments and standardized collections of cerebrospinal fluid (CSF) and blood. They also had the option of undergoing brain MRI scans.
The investigators analyzed their data using multiple linear regression models, Pearson’s correlations, receiver operating characteristic curves, and sample size calculations. They used an event-based model to evaluate the temporal sequence of changes in Huntington’s disease-related biomarkers.
Dr. Rodrigues and colleagues first observed that all three biomarkers successfully distinguished between healthy controls, patients with premanifest Huntington’s disease, and patients with Huntington’s disease. Mutant huntingtin, the pathogenic agent in Huntington’s disease, discriminated perfectly between healthy controls and mutation carriers, as the researchers had expected. CSF and plasma levels of NfL also discriminated well between healthy controls and mutation carriers. These biomarkers had areas under the ROC curve greater than 0.9. NfL in plasma and CSF also distinguished well between patients with premanifest Huntington’s disease and those with manifest Huntington’s disease, with areas under the curve greater than 0.9. Their discriminative ability in this regard was significantly better than that of mutant huntingtin.
When the researchers examined the relationship between the three biomarkers, they found that CSF levels of NfL were strongly correlated in a linear fashion with plasma levels of NfL. CSF levels of mutant huntingtin were moderately associated with CSF levels of NfL.
Levels of all three biomarkers increased significantly as the disease progressed and were associated with all clinical scales and imaging measures. CSF and plasma levels of NfL had superior predictive ability for clinical and imaging measures, compared with mutant huntingtin. CSF and plasma NfL were associated with brain volume, but mutant huntingtin was not.
All three biomarkers were stable during a 6-week period. Dr. Rodrigues and colleagues calculated sample sizes for a two-arm interventional trial involving various hypothetical therapeutic effects. They found that the required sample sizes were small enough to be incorporated easily into ongoing and future clinical trials.
In silico modeling suggested among the markers measured in the HD-CSF study, the three biofluid biomarkers were the first factors to be altered in the course of Huntington’s disease. Alterations in the biomarkers were followed by changes in imaging markers, and then by changes in clinical markers (for example, motor and cognitive function).
Finally, Dr. Rodrigues and colleagues found preliminary evidence that levels of NfL in CSF and plasma increase over time at different rates in patients with Huntington’s disease, compared with healthy controls. NfL appears to be more useful than mutant huntingtin for evaluating the rate of disease progression than for gauging response to treatment, said Dr. Rodrigues. “If [we] can prove that we can assess response to treatment by measuring NfL, I think that would be great.”
The investigators are currently analyzing the longitudinal predictive value of changes in these biomarkers. They also have begun analyzing other markers such as tau and brain-derived neurotrophic factor.
This study was funded by the Medical Research Council UK, the CHDI Foundation, and F. Hoffmann-La Roche.
This article was updated 6/18/19.
SOURCE: Rodrigues FB et al. AAN 2019, Abstract S16.003.
REPORTING FROM AAN 2019
Key clinical point: Mutant huntingtin and plasma and cerebrospinal fluid levels of neurofilament light are useful potential biomarkers in Huntington’s disease.
Major finding: Levels of neurofilament light in plasma are correlated with those in cerebrospinal fluid.
Study details: A prospective, observational, longitudinal cohort study including 80 participants with and without Huntington’s disease.
Disclosures: This study was funded by the Medical Research Council UK, the CHDI Foundation, and F. Hoffmann-La Roche.
Source: Rodrigues FB et al. AAN 2019, Abstract S16.003.
Can an antisense oligonucleotide benefit patients with SOD1-ALS?
PHILADELPHIA – In patients with amyotrophic lateral sclerosis (ALS) caused by gain-of-toxic function mutations in the SOD1 gene, according to phase 1/2 trial results presented at the annual meeting of the American Academy of Neurology. Exploratory analyses suggest that the drug, known as tofersen (also known as BIIB067), may lessen declines in function, respiratory function, and strength. The treatment generally was safe and well tolerated, researchers said.
Most ALS cases are sporadic, but about 10% are genetic, of which approximately 20% are caused by SOD1 mutations. “Although SOD1-ALS disease progression is heterogeneous, the underlying pathophysiology, attributable to mutant SOD1 toxicity, is thought to be consistent across SOD1 mutation types,” said Timothy M. Miller, MD, PhD, of Washington University, St. Louis, and colleagues. “As such, effective reduction of SOD1 protein, irrespective of mutation, has the potential to alter the disease course of people with SOD1-ALS.”
Tofersen is an antisense oligonucleotide ribonuclease H1-mediated inhibitor of SOD1 messenger RNA. To study its safety, tolerability, pharmacokinetics, pharmacodynamics, and exploratory efficacy in patients with SOD1-ALS, investigators conducted a double-blind study. The investigators randomized 50 patients with ALS with a SOD1 mutation to 20 mg (n = 10), 40 mg (n = 9), 60 mg (n = 9), or 100 mg (n = 10) of tofersen or placebo (n = 12).
Patients received tofersen by intrathecal bolus over 1-3 minutes. They received a loading regimen on days 1, 15, and 29 and maintenance dosing on days 57 and 85. After the dosing period, patients completed a 12-week follow-up period.
Adverse events
All patients received at least one dose of the study treatment, and 48 received all treatments. Three patients died during the study. One patient in the 20-mg group died of pulmonary embolism, and one patient in both the 60-mg group and placebo group died of respiratory failure. Investigators considered the deaths secondary to ALS or other conditions and not drug related.
Most adverse events were mild or moderate. The most common adverse events among tofersen-treated patients were headache (n = 16), procedural pain (n = 14), and post–lumbar puncture syndrome (n = 13). Five patients who received tofersen and two who received placebo experienced serious adverse events; no serious adverse events occurred in the 100-mg dose group.
“A reduction from baseline in CSF SOD1 concentrations was observed in the tofersen 40-, 60-, and 100-mg cohorts with the maximal reduction observed in the 100 mg–treated group [37% vs. no reduction in the placebo group; P less than 0.002] at day 85,” the investigators reported.
Possible efficacy
In exploratory analyses, the 100-mg dose slowed decline on the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ASLFRS-R), compared with placebo. Mean change in ASLFRS-R from baseline to day 85 was –1.1 in patients who received 100 mg of tofersen, compared with –5.3 for patients who received placebo. Declines on measures of respiratory function and muscle strength also slowed. “Across clinical measures, separation from placebo was most apparent in participants with fast progressing disease,” the researchers said.
“Lower concentrations of the protein in the spinal fluid suggest that there were also lower concentrations in the brain and spinal cord,” Dr. Miller said in a news release. “Such reductions could lead to preservation of motor neurons and slow progression of the disease, but more study is needed to examine this further.”
The study was sponsored by Biogen, which is developing tofersen. Some of the study authors are Biogen employees. Dr. Miller is on Biogen’s medical advisory board and receives clinical research support from Biogen. In addition, he consults, has licensing agreements with, and is a principal investigator for other companies.
PHILADELPHIA – In patients with amyotrophic lateral sclerosis (ALS) caused by gain-of-toxic function mutations in the SOD1 gene, according to phase 1/2 trial results presented at the annual meeting of the American Academy of Neurology. Exploratory analyses suggest that the drug, known as tofersen (also known as BIIB067), may lessen declines in function, respiratory function, and strength. The treatment generally was safe and well tolerated, researchers said.
Most ALS cases are sporadic, but about 10% are genetic, of which approximately 20% are caused by SOD1 mutations. “Although SOD1-ALS disease progression is heterogeneous, the underlying pathophysiology, attributable to mutant SOD1 toxicity, is thought to be consistent across SOD1 mutation types,” said Timothy M. Miller, MD, PhD, of Washington University, St. Louis, and colleagues. “As such, effective reduction of SOD1 protein, irrespective of mutation, has the potential to alter the disease course of people with SOD1-ALS.”
Tofersen is an antisense oligonucleotide ribonuclease H1-mediated inhibitor of SOD1 messenger RNA. To study its safety, tolerability, pharmacokinetics, pharmacodynamics, and exploratory efficacy in patients with SOD1-ALS, investigators conducted a double-blind study. The investigators randomized 50 patients with ALS with a SOD1 mutation to 20 mg (n = 10), 40 mg (n = 9), 60 mg (n = 9), or 100 mg (n = 10) of tofersen or placebo (n = 12).
Patients received tofersen by intrathecal bolus over 1-3 minutes. They received a loading regimen on days 1, 15, and 29 and maintenance dosing on days 57 and 85. After the dosing period, patients completed a 12-week follow-up period.
Adverse events
All patients received at least one dose of the study treatment, and 48 received all treatments. Three patients died during the study. One patient in the 20-mg group died of pulmonary embolism, and one patient in both the 60-mg group and placebo group died of respiratory failure. Investigators considered the deaths secondary to ALS or other conditions and not drug related.
Most adverse events were mild or moderate. The most common adverse events among tofersen-treated patients were headache (n = 16), procedural pain (n = 14), and post–lumbar puncture syndrome (n = 13). Five patients who received tofersen and two who received placebo experienced serious adverse events; no serious adverse events occurred in the 100-mg dose group.
“A reduction from baseline in CSF SOD1 concentrations was observed in the tofersen 40-, 60-, and 100-mg cohorts with the maximal reduction observed in the 100 mg–treated group [37% vs. no reduction in the placebo group; P less than 0.002] at day 85,” the investigators reported.
Possible efficacy
In exploratory analyses, the 100-mg dose slowed decline on the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ASLFRS-R), compared with placebo. Mean change in ASLFRS-R from baseline to day 85 was –1.1 in patients who received 100 mg of tofersen, compared with –5.3 for patients who received placebo. Declines on measures of respiratory function and muscle strength also slowed. “Across clinical measures, separation from placebo was most apparent in participants with fast progressing disease,” the researchers said.
“Lower concentrations of the protein in the spinal fluid suggest that there were also lower concentrations in the brain and spinal cord,” Dr. Miller said in a news release. “Such reductions could lead to preservation of motor neurons and slow progression of the disease, but more study is needed to examine this further.”
The study was sponsored by Biogen, which is developing tofersen. Some of the study authors are Biogen employees. Dr. Miller is on Biogen’s medical advisory board and receives clinical research support from Biogen. In addition, he consults, has licensing agreements with, and is a principal investigator for other companies.
PHILADELPHIA – In patients with amyotrophic lateral sclerosis (ALS) caused by gain-of-toxic function mutations in the SOD1 gene, according to phase 1/2 trial results presented at the annual meeting of the American Academy of Neurology. Exploratory analyses suggest that the drug, known as tofersen (also known as BIIB067), may lessen declines in function, respiratory function, and strength. The treatment generally was safe and well tolerated, researchers said.
Most ALS cases are sporadic, but about 10% are genetic, of which approximately 20% are caused by SOD1 mutations. “Although SOD1-ALS disease progression is heterogeneous, the underlying pathophysiology, attributable to mutant SOD1 toxicity, is thought to be consistent across SOD1 mutation types,” said Timothy M. Miller, MD, PhD, of Washington University, St. Louis, and colleagues. “As such, effective reduction of SOD1 protein, irrespective of mutation, has the potential to alter the disease course of people with SOD1-ALS.”
Tofersen is an antisense oligonucleotide ribonuclease H1-mediated inhibitor of SOD1 messenger RNA. To study its safety, tolerability, pharmacokinetics, pharmacodynamics, and exploratory efficacy in patients with SOD1-ALS, investigators conducted a double-blind study. The investigators randomized 50 patients with ALS with a SOD1 mutation to 20 mg (n = 10), 40 mg (n = 9), 60 mg (n = 9), or 100 mg (n = 10) of tofersen or placebo (n = 12).
Patients received tofersen by intrathecal bolus over 1-3 minutes. They received a loading regimen on days 1, 15, and 29 and maintenance dosing on days 57 and 85. After the dosing period, patients completed a 12-week follow-up period.
Adverse events
All patients received at least one dose of the study treatment, and 48 received all treatments. Three patients died during the study. One patient in the 20-mg group died of pulmonary embolism, and one patient in both the 60-mg group and placebo group died of respiratory failure. Investigators considered the deaths secondary to ALS or other conditions and not drug related.
Most adverse events were mild or moderate. The most common adverse events among tofersen-treated patients were headache (n = 16), procedural pain (n = 14), and post–lumbar puncture syndrome (n = 13). Five patients who received tofersen and two who received placebo experienced serious adverse events; no serious adverse events occurred in the 100-mg dose group.
“A reduction from baseline in CSF SOD1 concentrations was observed in the tofersen 40-, 60-, and 100-mg cohorts with the maximal reduction observed in the 100 mg–treated group [37% vs. no reduction in the placebo group; P less than 0.002] at day 85,” the investigators reported.
Possible efficacy
In exploratory analyses, the 100-mg dose slowed decline on the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ASLFRS-R), compared with placebo. Mean change in ASLFRS-R from baseline to day 85 was –1.1 in patients who received 100 mg of tofersen, compared with –5.3 for patients who received placebo. Declines on measures of respiratory function and muscle strength also slowed. “Across clinical measures, separation from placebo was most apparent in participants with fast progressing disease,” the researchers said.
“Lower concentrations of the protein in the spinal fluid suggest that there were also lower concentrations in the brain and spinal cord,” Dr. Miller said in a news release. “Such reductions could lead to preservation of motor neurons and slow progression of the disease, but more study is needed to examine this further.”
The study was sponsored by Biogen, which is developing tofersen. Some of the study authors are Biogen employees. Dr. Miller is on Biogen’s medical advisory board and receives clinical research support from Biogen. In addition, he consults, has licensing agreements with, and is a principal investigator for other companies.
REPORTING FROM AAN 2019
Ruzurgi approved for Lambert-Eaton myasthenic syndrome in patients under age 17
Amifampridine (Ruzurgi) has been approved for the treatment of Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune neuromuscular disorder, in patients aged 6 to less than 17 years, according to a statement from the Food and Drug Administration.
The approval is the first for a LEMS treatment specifically for pediatric patients.
“This approval will provide a much-needed treatment option for pediatric patients with LEMS who have significant weakness and fatigue that can often cause great difficulties with daily activities,” Billy Dunn, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, said in the statement.
The prevalence of LEMS in pediatric patients is not known, but the overall prevalence of LEMS is estimated to be three per million individuals worldwide, according to the FDA press release.
Use of amifampridine in patients 6 to less than 17 years of age is supported by pharmacokinetic data in adult patients, pharmacokinetic modeling and simulation to identify the dosing regimen in pediatric patients, and safety data from pediatric patients 6 to less than 17 years of age.
A randomized, double-blind, placebo-controlled withdrawal study enrolled 32 adult patients who had taken amifampridine for at least 3 months. The study compared patients continuing on amifampridine with patients switched to placebo. Effectiveness was measured by the degree of change in a test that assessed the time it took the patient to rise from a chair, walk three meters, and return to the chair for three consecutive laps without pause. The patients who continued on amifampridine experienced less impairment compared with those switched to placebo. Effectiveness was also measured with a self-assessment scale for LEMS-related weakness. The scores indicated greater perceived weakening in the patients switched to placebo.
The most common side effects among amifampridine users were paresthesia, abdominal pain, indigestion, dizziness, and nausea. Side effects reported in pediatric patients were similar to those seen in adult patients. Seizures have been observed in patients without a history of seizures. Signs of hypersensitivity reactions include rash, hives, itching, fever, swelling, or trouble breathing.
The FDA granted this application Priority Review and Fast Track designations. Amifampridine also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.
The FDA granted the approval of amifampridine (Ruzurgi) to Jacobus Pharmaceutical Company.
Amifampridine (Ruzurgi) has been approved for the treatment of Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune neuromuscular disorder, in patients aged 6 to less than 17 years, according to a statement from the Food and Drug Administration.
The approval is the first for a LEMS treatment specifically for pediatric patients.
“This approval will provide a much-needed treatment option for pediatric patients with LEMS who have significant weakness and fatigue that can often cause great difficulties with daily activities,” Billy Dunn, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, said in the statement.
The prevalence of LEMS in pediatric patients is not known, but the overall prevalence of LEMS is estimated to be three per million individuals worldwide, according to the FDA press release.
Use of amifampridine in patients 6 to less than 17 years of age is supported by pharmacokinetic data in adult patients, pharmacokinetic modeling and simulation to identify the dosing regimen in pediatric patients, and safety data from pediatric patients 6 to less than 17 years of age.
A randomized, double-blind, placebo-controlled withdrawal study enrolled 32 adult patients who had taken amifampridine for at least 3 months. The study compared patients continuing on amifampridine with patients switched to placebo. Effectiveness was measured by the degree of change in a test that assessed the time it took the patient to rise from a chair, walk three meters, and return to the chair for three consecutive laps without pause. The patients who continued on amifampridine experienced less impairment compared with those switched to placebo. Effectiveness was also measured with a self-assessment scale for LEMS-related weakness. The scores indicated greater perceived weakening in the patients switched to placebo.
The most common side effects among amifampridine users were paresthesia, abdominal pain, indigestion, dizziness, and nausea. Side effects reported in pediatric patients were similar to those seen in adult patients. Seizures have been observed in patients without a history of seizures. Signs of hypersensitivity reactions include rash, hives, itching, fever, swelling, or trouble breathing.
The FDA granted this application Priority Review and Fast Track designations. Amifampridine also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.
The FDA granted the approval of amifampridine (Ruzurgi) to Jacobus Pharmaceutical Company.
Amifampridine (Ruzurgi) has been approved for the treatment of Lambert-Eaton myasthenic syndrome (LEMS), a rare autoimmune neuromuscular disorder, in patients aged 6 to less than 17 years, according to a statement from the Food and Drug Administration.
The approval is the first for a LEMS treatment specifically for pediatric patients.
“This approval will provide a much-needed treatment option for pediatric patients with LEMS who have significant weakness and fatigue that can often cause great difficulties with daily activities,” Billy Dunn, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research, said in the statement.
The prevalence of LEMS in pediatric patients is not known, but the overall prevalence of LEMS is estimated to be three per million individuals worldwide, according to the FDA press release.
Use of amifampridine in patients 6 to less than 17 years of age is supported by pharmacokinetic data in adult patients, pharmacokinetic modeling and simulation to identify the dosing regimen in pediatric patients, and safety data from pediatric patients 6 to less than 17 years of age.
A randomized, double-blind, placebo-controlled withdrawal study enrolled 32 adult patients who had taken amifampridine for at least 3 months. The study compared patients continuing on amifampridine with patients switched to placebo. Effectiveness was measured by the degree of change in a test that assessed the time it took the patient to rise from a chair, walk three meters, and return to the chair for three consecutive laps without pause. The patients who continued on amifampridine experienced less impairment compared with those switched to placebo. Effectiveness was also measured with a self-assessment scale for LEMS-related weakness. The scores indicated greater perceived weakening in the patients switched to placebo.
The most common side effects among amifampridine users were paresthesia, abdominal pain, indigestion, dizziness, and nausea. Side effects reported in pediatric patients were similar to those seen in adult patients. Seizures have been observed in patients without a history of seizures. Signs of hypersensitivity reactions include rash, hives, itching, fever, swelling, or trouble breathing.
The FDA granted this application Priority Review and Fast Track designations. Amifampridine also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.
The FDA granted the approval of amifampridine (Ruzurgi) to Jacobus Pharmaceutical Company.
Physical activity slows cognitive decline in patients with Parkinson’s disease
PHILADELPHIA – according to Sneha Mantri, MD, of Duke University in Durham, N.C., and colleagues, who presented the results of their study at the annual meeting of the American Academy of Neurology.
Physical activity is an important component of the management of Parkinson’s disease and is shown to mitigate cognitive decline among patients with moderate disease, said Dr. Mantri and colleagues. “Exercise levels in de novo and early disease may influence risk of future cognitive decline; early disease also presents an opportunity for early intervention and possible disease modification,” Dr. Mantri said.
Physical activity levels in early disease are known to be low, but the effects of activity on cognition are currently unclear. To assess the relationship between physical activity and cognition, Dr. Mantri and colleagues examined patients with Parkinson’s disease who were enrolled in the prospective Parkinson’s Progression Markers Initiative (PPMI) cohort. At annual study visits, participants completed the Physical Activity Scale for the Elderly (PASE), a validated self-reported questionnaire assessing household, leisure, and work activities over the previous 7 days. The researchers used a linear mixed-effects model to compare rates of change in the Montreal Cognitive Assessment (MoCA) according to PASE scores; covariates included age, sex, Unified Parkinson’s Disease Rating Scale (UPDRS) part III score, and baseline MoCA.
A total of 379 patients completed at least one PASE questionnaire over the course of the study. PASE scores in this cohort have been previously described (Mantri S et al. J Park Dis. 2018;8[1]:107-11). Although overall rates of cognitive decline are known to be modest in this early cohort, PASE over time has a significant effect on MoCA during follow-up (P = 0.02) which suggest that higher levels of activity throughout disease are associated with better cognitive performance.
Dr. Mantri had nothing to disclose. Among her coauthors, Dr. Tropea received personal compensation from Genzyme and Medtronics and research support from Sanofi. Dr. Morley had nothing to disclose.
SOURCE: Mantri S et al. AAN 2019, Abstract P2.8-021.
PHILADELPHIA – according to Sneha Mantri, MD, of Duke University in Durham, N.C., and colleagues, who presented the results of their study at the annual meeting of the American Academy of Neurology.
Physical activity is an important component of the management of Parkinson’s disease and is shown to mitigate cognitive decline among patients with moderate disease, said Dr. Mantri and colleagues. “Exercise levels in de novo and early disease may influence risk of future cognitive decline; early disease also presents an opportunity for early intervention and possible disease modification,” Dr. Mantri said.
Physical activity levels in early disease are known to be low, but the effects of activity on cognition are currently unclear. To assess the relationship between physical activity and cognition, Dr. Mantri and colleagues examined patients with Parkinson’s disease who were enrolled in the prospective Parkinson’s Progression Markers Initiative (PPMI) cohort. At annual study visits, participants completed the Physical Activity Scale for the Elderly (PASE), a validated self-reported questionnaire assessing household, leisure, and work activities over the previous 7 days. The researchers used a linear mixed-effects model to compare rates of change in the Montreal Cognitive Assessment (MoCA) according to PASE scores; covariates included age, sex, Unified Parkinson’s Disease Rating Scale (UPDRS) part III score, and baseline MoCA.
A total of 379 patients completed at least one PASE questionnaire over the course of the study. PASE scores in this cohort have been previously described (Mantri S et al. J Park Dis. 2018;8[1]:107-11). Although overall rates of cognitive decline are known to be modest in this early cohort, PASE over time has a significant effect on MoCA during follow-up (P = 0.02) which suggest that higher levels of activity throughout disease are associated with better cognitive performance.
Dr. Mantri had nothing to disclose. Among her coauthors, Dr. Tropea received personal compensation from Genzyme and Medtronics and research support from Sanofi. Dr. Morley had nothing to disclose.
SOURCE: Mantri S et al. AAN 2019, Abstract P2.8-021.
PHILADELPHIA – according to Sneha Mantri, MD, of Duke University in Durham, N.C., and colleagues, who presented the results of their study at the annual meeting of the American Academy of Neurology.
Physical activity is an important component of the management of Parkinson’s disease and is shown to mitigate cognitive decline among patients with moderate disease, said Dr. Mantri and colleagues. “Exercise levels in de novo and early disease may influence risk of future cognitive decline; early disease also presents an opportunity for early intervention and possible disease modification,” Dr. Mantri said.
Physical activity levels in early disease are known to be low, but the effects of activity on cognition are currently unclear. To assess the relationship between physical activity and cognition, Dr. Mantri and colleagues examined patients with Parkinson’s disease who were enrolled in the prospective Parkinson’s Progression Markers Initiative (PPMI) cohort. At annual study visits, participants completed the Physical Activity Scale for the Elderly (PASE), a validated self-reported questionnaire assessing household, leisure, and work activities over the previous 7 days. The researchers used a linear mixed-effects model to compare rates of change in the Montreal Cognitive Assessment (MoCA) according to PASE scores; covariates included age, sex, Unified Parkinson’s Disease Rating Scale (UPDRS) part III score, and baseline MoCA.
A total of 379 patients completed at least one PASE questionnaire over the course of the study. PASE scores in this cohort have been previously described (Mantri S et al. J Park Dis. 2018;8[1]:107-11). Although overall rates of cognitive decline are known to be modest in this early cohort, PASE over time has a significant effect on MoCA during follow-up (P = 0.02) which suggest that higher levels of activity throughout disease are associated with better cognitive performance.
Dr. Mantri had nothing to disclose. Among her coauthors, Dr. Tropea received personal compensation from Genzyme and Medtronics and research support from Sanofi. Dr. Morley had nothing to disclose.
SOURCE: Mantri S et al. AAN 2019, Abstract P2.8-021.
REPORTING FROM AAN 2019
Key clinical point: Physical activity is associated with slower cognitive decline in patients with de novo Parkinson’s disease.
Major finding: Higher scores on the Physical Activity Scale for the Elderly over time had a significant effect on cognitive function.
Study details: A prospective study of 379 patients enrolled in the Parkinson’s Progression Markers Initiative.
Disclosures: Dr. Mantri had no relevant financial disclosures. Among her coauthors, Dr. Tropea received personal compensation from Genzyme and Medtronics and research support from Sanofi. Dr. Morley had nothing to disclose.
Source: Mantri S et al. AAN 2019, Abstract P2.8-021.
Is pro soccer a risk factor for ALS?
according to Italian researchers who reviewed trading cards of about 25,000 male professional soccer players who played in Italy. The researchers then scanned news reports to find which of those players developed the rare neurologic disease. Players who developed ALS were a much younger age at diagnosis when compared with the general population, according to the researchers, who will present their findings at the annual meeting of the American Academy of Neurology.
While the findings might implicate professional-level soccer in the development of ALS, there could be other factors at work, said lead author Ettore Beghi, MD, of the Mario Negri Institute for Pharmacological Research, Milan. “Repeated traumatic events, heavy physical exercise, and substance use could also be factors in the increased ALS risk among soccer players,” Dr. Beghi said in a news release. “In addition, genetics may play a role.”
The ALS-related deaths of several Italian pro soccer players sparked suggestions that the disease and the sport could be somehow linked, according to Dr. Beghi and colleagues. To determine whether professional soccer players are at increased ALS risk, they reviewed the archives of the country’s major soccer card publisher from the years 1959 to 2000, recording the name, date, and place of birth; field position; and team history for the tens of thousands of players they identified.
News reports revealed that 33 players in that cohort developed ALS, compared with 17.6 cases that would be expected based on Italian general population estimates, according to Dr. Beghi and colleagues.
The number of cases per 100,000 person-years was 1.9 for all the soccer players, and 4.7 for those who were younger than 45 years at diagnosis, researchers said. In general, soccer players were younger at diagnosis, with a median age of ALS onset of 43.3 years, versus 62.5 years in the general population, they added.
These findings cannot be applied to those who play soccer below the professional level, since only professional athletes were studied, Dr. Beghi said. Moreover, the results should not be construed to suggest that people avoid playing soccer, he said, adding that the researchers had few specific details on the players’ ALS diagnoses.
Patients with ALS more often report head injuries, compared with the general population, while links between exercise and ALS have been found in some studies, but not others, according to the researchers.
“Clinical and experimental observations suggest an association between ALS and use of nonsteroidal anti-inflammatory agents and dietary supplements, including branched chain amino acids,” researchers added in the abstract for their report.
The study by Dr. Beghi and colleagues was supported by the Mario Negri Institute in Milan.
Source: Beghi E et al. AAN 2019, Abstract S1.001.
according to Italian researchers who reviewed trading cards of about 25,000 male professional soccer players who played in Italy. The researchers then scanned news reports to find which of those players developed the rare neurologic disease. Players who developed ALS were a much younger age at diagnosis when compared with the general population, according to the researchers, who will present their findings at the annual meeting of the American Academy of Neurology.
While the findings might implicate professional-level soccer in the development of ALS, there could be other factors at work, said lead author Ettore Beghi, MD, of the Mario Negri Institute for Pharmacological Research, Milan. “Repeated traumatic events, heavy physical exercise, and substance use could also be factors in the increased ALS risk among soccer players,” Dr. Beghi said in a news release. “In addition, genetics may play a role.”
The ALS-related deaths of several Italian pro soccer players sparked suggestions that the disease and the sport could be somehow linked, according to Dr. Beghi and colleagues. To determine whether professional soccer players are at increased ALS risk, they reviewed the archives of the country’s major soccer card publisher from the years 1959 to 2000, recording the name, date, and place of birth; field position; and team history for the tens of thousands of players they identified.
News reports revealed that 33 players in that cohort developed ALS, compared with 17.6 cases that would be expected based on Italian general population estimates, according to Dr. Beghi and colleagues.
The number of cases per 100,000 person-years was 1.9 for all the soccer players, and 4.7 for those who were younger than 45 years at diagnosis, researchers said. In general, soccer players were younger at diagnosis, with a median age of ALS onset of 43.3 years, versus 62.5 years in the general population, they added.
These findings cannot be applied to those who play soccer below the professional level, since only professional athletes were studied, Dr. Beghi said. Moreover, the results should not be construed to suggest that people avoid playing soccer, he said, adding that the researchers had few specific details on the players’ ALS diagnoses.
Patients with ALS more often report head injuries, compared with the general population, while links between exercise and ALS have been found in some studies, but not others, according to the researchers.
“Clinical and experimental observations suggest an association between ALS and use of nonsteroidal anti-inflammatory agents and dietary supplements, including branched chain amino acids,” researchers added in the abstract for their report.
The study by Dr. Beghi and colleagues was supported by the Mario Negri Institute in Milan.
Source: Beghi E et al. AAN 2019, Abstract S1.001.
according to Italian researchers who reviewed trading cards of about 25,000 male professional soccer players who played in Italy. The researchers then scanned news reports to find which of those players developed the rare neurologic disease. Players who developed ALS were a much younger age at diagnosis when compared with the general population, according to the researchers, who will present their findings at the annual meeting of the American Academy of Neurology.
While the findings might implicate professional-level soccer in the development of ALS, there could be other factors at work, said lead author Ettore Beghi, MD, of the Mario Negri Institute for Pharmacological Research, Milan. “Repeated traumatic events, heavy physical exercise, and substance use could also be factors in the increased ALS risk among soccer players,” Dr. Beghi said in a news release. “In addition, genetics may play a role.”
The ALS-related deaths of several Italian pro soccer players sparked suggestions that the disease and the sport could be somehow linked, according to Dr. Beghi and colleagues. To determine whether professional soccer players are at increased ALS risk, they reviewed the archives of the country’s major soccer card publisher from the years 1959 to 2000, recording the name, date, and place of birth; field position; and team history for the tens of thousands of players they identified.
News reports revealed that 33 players in that cohort developed ALS, compared with 17.6 cases that would be expected based on Italian general population estimates, according to Dr. Beghi and colleagues.
The number of cases per 100,000 person-years was 1.9 for all the soccer players, and 4.7 for those who were younger than 45 years at diagnosis, researchers said. In general, soccer players were younger at diagnosis, with a median age of ALS onset of 43.3 years, versus 62.5 years in the general population, they added.
These findings cannot be applied to those who play soccer below the professional level, since only professional athletes were studied, Dr. Beghi said. Moreover, the results should not be construed to suggest that people avoid playing soccer, he said, adding that the researchers had few specific details on the players’ ALS diagnoses.
Patients with ALS more often report head injuries, compared with the general population, while links between exercise and ALS have been found in some studies, but not others, according to the researchers.
“Clinical and experimental observations suggest an association between ALS and use of nonsteroidal anti-inflammatory agents and dietary supplements, including branched chain amino acids,” researchers added in the abstract for their report.
The study by Dr. Beghi and colleagues was supported by the Mario Negri Institute in Milan.
Source: Beghi E et al. AAN 2019, Abstract S1.001.
FROM AAN 2019
Myositis mimics: Clues for making the right diagnosis
A number of conditions can mimic myositis, but clues that can point to the correct diagnosis are often present in cases involving the mimics, according to Lisa Christopher-Stine, MD.
For example, elevated levels of certain muscle enzymes are an important source of diagnostic information, Dr. Christopher-Stine, director of the Johns Hopkins Myositis Center, Baltimore, said at the Winter Rheumatology Symposium sponsored by the American College of Rheumatology.
Isolated elevations in aldolase can be seen in connective tissue–associated interstitial lung disease or in patients with fascial edema, and aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase (LDH), and creatine kinase (CK) levels can also be helpful, she explained.
The latter can also be elevated in the absence of muscle disease, for example, in healthy individuals following exercise. CK peaks at 24 hours after exercise before returning to baseline by 72 hours. In an experimental setting, a threefold increase in CK levels has been seen at 8-24 hours after exercise, Dr. Christopher-Stine said.
“HyperCKemia”
Trauma from causes such as intramuscular injection, electromyography (EMG), major surgery, or biopsy can also lead to increased CK levels. Motor neuron disease can also cause such increases. In one study, 75% of patients with amyotrophic lateral sclerosis had a mean twofold increase in CK levels, she said.
Asymptomatic CK elevations may also represent presymptomatic myopathies, type 1 or 2 macro-CK, manual labor occupations, or they may be idiopathic.
Race can play a role in CK levels as well. Black people tend to have higher CK levels than white people, she said, noting that one study of more than 10,000 adults showed that black race was strongly associated with CK, and that body composition largely explained differences in CK by age, but not by race/ethnicity (Medicine. Aug 2016;95[33]:e4344).
“So elevated CK may not herald any discernible illness,” she said.
Dr. Christopher-Stine described a case involving an otherwise healthy 30-year-old man with a CK level of 695 IU/L that was found incidentally. He had a desk job, no recent travel, and denied weakness, myalgias, joint pain, dysphagia, shortness of breath, and fevers. In this case, the elevated CK was felt to be secondary to his African American race given that other causes were ruled out.
Another case involved a 72-year-old man with left-arm pain. A cardiac event was ruled out, and CK was found to be about 4,500 IU/L. He reported “flare-ups” of diffuse swelling of the hands and feet. X-rays showed concerning signs of erosions. His transaminases and electromyogram were normal; he reported no weakness or myalgia; and an MRI showed no muscle edema. He was diagnosed with macro-CK, which refers to CK with an increased molecular weight. A clue to this diagnosis is a normal liver function test. In some cases, muscle/brain CK levels (CK-MB) are elevated and higher than total CK, she noted.
She presented an algorithm for the diagnostic work-up of patients presenting with elevated CK of unclear significance. Her recommended approach involves repeat CK assessment and a closer look at family history, medication, drug/toxin history, examination for weakness and neurologic abnormalities, and additional lab assessments in those whose levels remain elevated. In those in whom a diagnosis is not identified, the algorithm calls for observation every 3 months – including physical examination and labs – in asymptomatic patients with levels at less than five times the upper limit of normal, and further evaluation, including EMG with nerve-conduction velocity testing, muscle biopsy, and MRI in those with (or who later develop) marked elevation greater than five times the upper limit of normal and/or symptoms.
Patient assessment
The physical examination should involve localization and quantification of weakness, and assessment for fever, rash, atrophy/wasting/scooping of forearms, fasciculations, cranial nerve involvement, Raynaud’s phenomenon, nailfold capillary changes, arthritis, calcinosis, “mechanic’s hands,” signs of other autoimmune diseases, and lung crackles. Initial laboratory testing should include HIV and hepatitis B and C testing; measurement of CK, AST, ALT, aldolase, thyroid-stimulating hormone, and magnesium levels; a comprehensive metabolic panel and complete blood count; and measurement of erythrocyte sedimentation rate and C-reactive protein.
“Weakness may be secondary to a neuropathy, myopathy, or a problem at the neuropathic junction. Many causes of weakness can be readily identified by careful history taking, focused physical examination, and directed laboratory evaluation,” she said.
Features pointing toward a diagnosis of myositis include characteristic rashes, gradual symptom onset, proximal limb and truncal weakness, other connective tissue disease features such as Raynaud’s and arthritis, and the presence of lung disease, including interstitial lung disease or unexplained infiltrates, she said.
Features pointing away from a diagnosis of myositis include a family history of a similar illness, weakness that is associated with eating or fasting, neurologic signs, cranial nerve involvement, fasciculations, severe muscle cramping, early atrophy, and creatine phosphokinase levels that are either less than 2 times or more than 100 times the upper limit of normal.
Among the conditions to consider in the presence of the features that point away from a myositis diagnosis are muscular dystrophies, metabolic myopathies, and toxic (drug-induced) myopathies, to name a few, Dr. Christopher-Stine said.
She described a number of other cases to illustrate the need for – and to help develop – a differential diagnosis in patients presenting with apparent myositis.
Muscular dystrophies
A 38-year-old woman with limited scleroderma and anti-PM/Scl autoantibodies developed proximal weakness over 9 months and was eventually unable to walk up a flight of stairs. She had heliotrope rash and Gottron’s sign, her serum CK was 723 IU/L, and EMG showed an irritable myopathy.
Muscle biopsy showed inflammation, and she was treated with prednisone, but this led to worsening weakness. She complained of prominent fatigue and double vision at the end of the day, and these symptoms did not improve with steroids.
Anti-AChR and anti-MuSK antibodies were negative, but she had a decrement on repetitive nerve stimulation testing.
She was treated with pyridostigmine and experienced near-complete resolution of her proximal weakness and double vision. A chest CT scan showed thymic hyperplasia; thymectomy was recommended.
In another case, a 19-year-old woman who complained of leg pain after exercise was found to have intact strength but asymmetric calf hypertrophy. Her CK level was 5,000 IU/L, and she was referred to rule out acute myositis.
A quadriceps biopsy was performed and showed abnormal dystrophin immunostaining but no inflammation. A molecular genetic analysis showed deletions in Xp21 and she was diagnosed as a manifesting carrier of Duchenne muscular dystrophy. It was recommended that she be evaluated for cardiomyopathy and receive genetic counseling.
A number of other cases presented by Dr. Christopher-Stine highlighted other muscular dystrophies that can mimic myositis, such as:
- Myotonic dystrophies. These are more often type 2 than type 1. Myotonia may be subtle, cataracts are seen early in all patients, and cardiac arrhythmias are common.
- Limb girdle muscular dystrophy type 2 B (dysferlinopathy). In the legs, this often affects the gastrocnemius muscle, and this will be visible on MRI. In the arms, it most often affects the biceps, sparing the deltoids. CKs are typically very high.
- Facioscapulohumeral muscular dystrophy (FSHD). This involves facial weakness, especially obicularis oris, in 95% of cases, as well as scapular weakness and winging, inflammation on muscle biopsy in 75% of cases, and typically is endomysial or perivascular.
Metabolic myopathies
Among metabolic myopathies that can mimic myositis are disorders of carbohydrate metabolism such as McArdle’s disease, 6-phosphofructokinase deficiency, and Pompe’s disease (adult acid maltase deficiency); disorders of lipid metabolism such as carnitine deficiency and carnitine palmitoyltransferase 2 (CPT2) deficiency; and disorders of purine metabolism, such as myoadenylate deaminase deficiency.
A 27-year-old patient who complained of weakness with activity was referred for possible myositis and was found to have a CK of 3,650 IU/L that never normalized. Physical examination showed intact strength and no muscle atrophy or fasciculations, and an enzyme stain for myophosphorylase showed a normal staining pattern and complete absence of the enzyme on quadricep biopsy. A 22-year-old man with similar symptoms plus recent onset of brown/black urine after physical activity had CK of 110,000 IU/L when symptomatic, and also underwent biopsy after being referred for possible myopathy. Both patients were ultimately diagnosed with CPT2 deficiency, which is associated with risk of rhabdomyolysis triggered by prolonged exercise, diets low in carbohydrates and high in fat, or by fasting.
Myalgias are common, and CK levels are normal or only mildly elevated between episodes in CPT2 deficiency, Dr. Christopher-Stine noted.
Toxic myopathies
Drug-induced myopathies are among the most common etiologies of myopathy and can range from mild myalgia to massive rhabdomyolysis. They can cause mild to severe weakness and may be chronic. The mechanism of toxic injury is direct via myotoxins such as ethyl alcohol, glucocorticoids, lipid-lowering drugs, cocaine, antimalarial drugs, antipsychotic drugs, colchicine, and Ipecac syrup.
One case described by Dr. Christopher-Stine involved “statin myopathy.”
A 55-year-old man on atorvastatin complained of myalgias and brown urine, but had no definitive weakness. He had intact strength and diffuse myalgias that weren’t reproducible. His CK was 45,000 IU/L.
Statin myopathy, as seen in this patient, is usually self-limited and is not associated with autoimmunity or with anti-HMGCR autoantibody positivity.
The mechanism is unknown, but statin myopathy has an incidence of 1.2 per 10,000 patient-years. Myalgias, myositis, rhabdomyolysis, and asymptomatic hyperCKemia are commonly seen. This is in contrast to the immune-mediated necrotizing myelitis that can be secondary to statins and is responsive to immunosuppression, she noted.
Other myositis mimics
In addition to these common myositis mimics, certain other neurologic diseases (such as ALS and cervical myelopathy), endocrinopathies (such as hypothyroidism), and infections (like toxoplasmosis) can also be mistaken for myositis, Dr. Christopher-Stine said, noting that cases illustrating these mimics underscore the need for careful consideration of possible alternate diagnoses.
“While most noninflammatory myopathies are self-limited or have no therapies available, knowing the diagnosis can be helpful for genetic counseling of the patient and family, for mitigating risk factors, and for precluding the use of unwarranted immunosuppressive agents,” she said.
Dr. Christopher-Stine reported having intellectual property interest in a novel Inova Diagnostics autoantibody assay detection for anti-HMGCR. She was also the safety officer for the JBT-101 Trial sponsored by Corbus and funded by the National Institutes of Health.
A number of conditions can mimic myositis, but clues that can point to the correct diagnosis are often present in cases involving the mimics, according to Lisa Christopher-Stine, MD.
For example, elevated levels of certain muscle enzymes are an important source of diagnostic information, Dr. Christopher-Stine, director of the Johns Hopkins Myositis Center, Baltimore, said at the Winter Rheumatology Symposium sponsored by the American College of Rheumatology.
Isolated elevations in aldolase can be seen in connective tissue–associated interstitial lung disease or in patients with fascial edema, and aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase (LDH), and creatine kinase (CK) levels can also be helpful, she explained.
The latter can also be elevated in the absence of muscle disease, for example, in healthy individuals following exercise. CK peaks at 24 hours after exercise before returning to baseline by 72 hours. In an experimental setting, a threefold increase in CK levels has been seen at 8-24 hours after exercise, Dr. Christopher-Stine said.
“HyperCKemia”
Trauma from causes such as intramuscular injection, electromyography (EMG), major surgery, or biopsy can also lead to increased CK levels. Motor neuron disease can also cause such increases. In one study, 75% of patients with amyotrophic lateral sclerosis had a mean twofold increase in CK levels, she said.
Asymptomatic CK elevations may also represent presymptomatic myopathies, type 1 or 2 macro-CK, manual labor occupations, or they may be idiopathic.
Race can play a role in CK levels as well. Black people tend to have higher CK levels than white people, she said, noting that one study of more than 10,000 adults showed that black race was strongly associated with CK, and that body composition largely explained differences in CK by age, but not by race/ethnicity (Medicine. Aug 2016;95[33]:e4344).
“So elevated CK may not herald any discernible illness,” she said.
Dr. Christopher-Stine described a case involving an otherwise healthy 30-year-old man with a CK level of 695 IU/L that was found incidentally. He had a desk job, no recent travel, and denied weakness, myalgias, joint pain, dysphagia, shortness of breath, and fevers. In this case, the elevated CK was felt to be secondary to his African American race given that other causes were ruled out.
Another case involved a 72-year-old man with left-arm pain. A cardiac event was ruled out, and CK was found to be about 4,500 IU/L. He reported “flare-ups” of diffuse swelling of the hands and feet. X-rays showed concerning signs of erosions. His transaminases and electromyogram were normal; he reported no weakness or myalgia; and an MRI showed no muscle edema. He was diagnosed with macro-CK, which refers to CK with an increased molecular weight. A clue to this diagnosis is a normal liver function test. In some cases, muscle/brain CK levels (CK-MB) are elevated and higher than total CK, she noted.
She presented an algorithm for the diagnostic work-up of patients presenting with elevated CK of unclear significance. Her recommended approach involves repeat CK assessment and a closer look at family history, medication, drug/toxin history, examination for weakness and neurologic abnormalities, and additional lab assessments in those whose levels remain elevated. In those in whom a diagnosis is not identified, the algorithm calls for observation every 3 months – including physical examination and labs – in asymptomatic patients with levels at less than five times the upper limit of normal, and further evaluation, including EMG with nerve-conduction velocity testing, muscle biopsy, and MRI in those with (or who later develop) marked elevation greater than five times the upper limit of normal and/or symptoms.
Patient assessment
The physical examination should involve localization and quantification of weakness, and assessment for fever, rash, atrophy/wasting/scooping of forearms, fasciculations, cranial nerve involvement, Raynaud’s phenomenon, nailfold capillary changes, arthritis, calcinosis, “mechanic’s hands,” signs of other autoimmune diseases, and lung crackles. Initial laboratory testing should include HIV and hepatitis B and C testing; measurement of CK, AST, ALT, aldolase, thyroid-stimulating hormone, and magnesium levels; a comprehensive metabolic panel and complete blood count; and measurement of erythrocyte sedimentation rate and C-reactive protein.
“Weakness may be secondary to a neuropathy, myopathy, or a problem at the neuropathic junction. Many causes of weakness can be readily identified by careful history taking, focused physical examination, and directed laboratory evaluation,” she said.
Features pointing toward a diagnosis of myositis include characteristic rashes, gradual symptom onset, proximal limb and truncal weakness, other connective tissue disease features such as Raynaud’s and arthritis, and the presence of lung disease, including interstitial lung disease or unexplained infiltrates, she said.
Features pointing away from a diagnosis of myositis include a family history of a similar illness, weakness that is associated with eating or fasting, neurologic signs, cranial nerve involvement, fasciculations, severe muscle cramping, early atrophy, and creatine phosphokinase levels that are either less than 2 times or more than 100 times the upper limit of normal.
Among the conditions to consider in the presence of the features that point away from a myositis diagnosis are muscular dystrophies, metabolic myopathies, and toxic (drug-induced) myopathies, to name a few, Dr. Christopher-Stine said.
She described a number of other cases to illustrate the need for – and to help develop – a differential diagnosis in patients presenting with apparent myositis.
Muscular dystrophies
A 38-year-old woman with limited scleroderma and anti-PM/Scl autoantibodies developed proximal weakness over 9 months and was eventually unable to walk up a flight of stairs. She had heliotrope rash and Gottron’s sign, her serum CK was 723 IU/L, and EMG showed an irritable myopathy.
Muscle biopsy showed inflammation, and she was treated with prednisone, but this led to worsening weakness. She complained of prominent fatigue and double vision at the end of the day, and these symptoms did not improve with steroids.
Anti-AChR and anti-MuSK antibodies were negative, but she had a decrement on repetitive nerve stimulation testing.
She was treated with pyridostigmine and experienced near-complete resolution of her proximal weakness and double vision. A chest CT scan showed thymic hyperplasia; thymectomy was recommended.
In another case, a 19-year-old woman who complained of leg pain after exercise was found to have intact strength but asymmetric calf hypertrophy. Her CK level was 5,000 IU/L, and she was referred to rule out acute myositis.
A quadriceps biopsy was performed and showed abnormal dystrophin immunostaining but no inflammation. A molecular genetic analysis showed deletions in Xp21 and she was diagnosed as a manifesting carrier of Duchenne muscular dystrophy. It was recommended that she be evaluated for cardiomyopathy and receive genetic counseling.
A number of other cases presented by Dr. Christopher-Stine highlighted other muscular dystrophies that can mimic myositis, such as:
- Myotonic dystrophies. These are more often type 2 than type 1. Myotonia may be subtle, cataracts are seen early in all patients, and cardiac arrhythmias are common.
- Limb girdle muscular dystrophy type 2 B (dysferlinopathy). In the legs, this often affects the gastrocnemius muscle, and this will be visible on MRI. In the arms, it most often affects the biceps, sparing the deltoids. CKs are typically very high.
- Facioscapulohumeral muscular dystrophy (FSHD). This involves facial weakness, especially obicularis oris, in 95% of cases, as well as scapular weakness and winging, inflammation on muscle biopsy in 75% of cases, and typically is endomysial or perivascular.
Metabolic myopathies
Among metabolic myopathies that can mimic myositis are disorders of carbohydrate metabolism such as McArdle’s disease, 6-phosphofructokinase deficiency, and Pompe’s disease (adult acid maltase deficiency); disorders of lipid metabolism such as carnitine deficiency and carnitine palmitoyltransferase 2 (CPT2) deficiency; and disorders of purine metabolism, such as myoadenylate deaminase deficiency.
A 27-year-old patient who complained of weakness with activity was referred for possible myositis and was found to have a CK of 3,650 IU/L that never normalized. Physical examination showed intact strength and no muscle atrophy or fasciculations, and an enzyme stain for myophosphorylase showed a normal staining pattern and complete absence of the enzyme on quadricep biopsy. A 22-year-old man with similar symptoms plus recent onset of brown/black urine after physical activity had CK of 110,000 IU/L when symptomatic, and also underwent biopsy after being referred for possible myopathy. Both patients were ultimately diagnosed with CPT2 deficiency, which is associated with risk of rhabdomyolysis triggered by prolonged exercise, diets low in carbohydrates and high in fat, or by fasting.
Myalgias are common, and CK levels are normal or only mildly elevated between episodes in CPT2 deficiency, Dr. Christopher-Stine noted.
Toxic myopathies
Drug-induced myopathies are among the most common etiologies of myopathy and can range from mild myalgia to massive rhabdomyolysis. They can cause mild to severe weakness and may be chronic. The mechanism of toxic injury is direct via myotoxins such as ethyl alcohol, glucocorticoids, lipid-lowering drugs, cocaine, antimalarial drugs, antipsychotic drugs, colchicine, and Ipecac syrup.
One case described by Dr. Christopher-Stine involved “statin myopathy.”
A 55-year-old man on atorvastatin complained of myalgias and brown urine, but had no definitive weakness. He had intact strength and diffuse myalgias that weren’t reproducible. His CK was 45,000 IU/L.
Statin myopathy, as seen in this patient, is usually self-limited and is not associated with autoimmunity or with anti-HMGCR autoantibody positivity.
The mechanism is unknown, but statin myopathy has an incidence of 1.2 per 10,000 patient-years. Myalgias, myositis, rhabdomyolysis, and asymptomatic hyperCKemia are commonly seen. This is in contrast to the immune-mediated necrotizing myelitis that can be secondary to statins and is responsive to immunosuppression, she noted.
Other myositis mimics
In addition to these common myositis mimics, certain other neurologic diseases (such as ALS and cervical myelopathy), endocrinopathies (such as hypothyroidism), and infections (like toxoplasmosis) can also be mistaken for myositis, Dr. Christopher-Stine said, noting that cases illustrating these mimics underscore the need for careful consideration of possible alternate diagnoses.
“While most noninflammatory myopathies are self-limited or have no therapies available, knowing the diagnosis can be helpful for genetic counseling of the patient and family, for mitigating risk factors, and for precluding the use of unwarranted immunosuppressive agents,” she said.
Dr. Christopher-Stine reported having intellectual property interest in a novel Inova Diagnostics autoantibody assay detection for anti-HMGCR. She was also the safety officer for the JBT-101 Trial sponsored by Corbus and funded by the National Institutes of Health.
A number of conditions can mimic myositis, but clues that can point to the correct diagnosis are often present in cases involving the mimics, according to Lisa Christopher-Stine, MD.
For example, elevated levels of certain muscle enzymes are an important source of diagnostic information, Dr. Christopher-Stine, director of the Johns Hopkins Myositis Center, Baltimore, said at the Winter Rheumatology Symposium sponsored by the American College of Rheumatology.
Isolated elevations in aldolase can be seen in connective tissue–associated interstitial lung disease or in patients with fascial edema, and aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase (LDH), and creatine kinase (CK) levels can also be helpful, she explained.
The latter can also be elevated in the absence of muscle disease, for example, in healthy individuals following exercise. CK peaks at 24 hours after exercise before returning to baseline by 72 hours. In an experimental setting, a threefold increase in CK levels has been seen at 8-24 hours after exercise, Dr. Christopher-Stine said.
“HyperCKemia”
Trauma from causes such as intramuscular injection, electromyography (EMG), major surgery, or biopsy can also lead to increased CK levels. Motor neuron disease can also cause such increases. In one study, 75% of patients with amyotrophic lateral sclerosis had a mean twofold increase in CK levels, she said.
Asymptomatic CK elevations may also represent presymptomatic myopathies, type 1 or 2 macro-CK, manual labor occupations, or they may be idiopathic.
Race can play a role in CK levels as well. Black people tend to have higher CK levels than white people, she said, noting that one study of more than 10,000 adults showed that black race was strongly associated with CK, and that body composition largely explained differences in CK by age, but not by race/ethnicity (Medicine. Aug 2016;95[33]:e4344).
“So elevated CK may not herald any discernible illness,” she said.
Dr. Christopher-Stine described a case involving an otherwise healthy 30-year-old man with a CK level of 695 IU/L that was found incidentally. He had a desk job, no recent travel, and denied weakness, myalgias, joint pain, dysphagia, shortness of breath, and fevers. In this case, the elevated CK was felt to be secondary to his African American race given that other causes were ruled out.
Another case involved a 72-year-old man with left-arm pain. A cardiac event was ruled out, and CK was found to be about 4,500 IU/L. He reported “flare-ups” of diffuse swelling of the hands and feet. X-rays showed concerning signs of erosions. His transaminases and electromyogram were normal; he reported no weakness or myalgia; and an MRI showed no muscle edema. He was diagnosed with macro-CK, which refers to CK with an increased molecular weight. A clue to this diagnosis is a normal liver function test. In some cases, muscle/brain CK levels (CK-MB) are elevated and higher than total CK, she noted.
She presented an algorithm for the diagnostic work-up of patients presenting with elevated CK of unclear significance. Her recommended approach involves repeat CK assessment and a closer look at family history, medication, drug/toxin history, examination for weakness and neurologic abnormalities, and additional lab assessments in those whose levels remain elevated. In those in whom a diagnosis is not identified, the algorithm calls for observation every 3 months – including physical examination and labs – in asymptomatic patients with levels at less than five times the upper limit of normal, and further evaluation, including EMG with nerve-conduction velocity testing, muscle biopsy, and MRI in those with (or who later develop) marked elevation greater than five times the upper limit of normal and/or symptoms.
Patient assessment
The physical examination should involve localization and quantification of weakness, and assessment for fever, rash, atrophy/wasting/scooping of forearms, fasciculations, cranial nerve involvement, Raynaud’s phenomenon, nailfold capillary changes, arthritis, calcinosis, “mechanic’s hands,” signs of other autoimmune diseases, and lung crackles. Initial laboratory testing should include HIV and hepatitis B and C testing; measurement of CK, AST, ALT, aldolase, thyroid-stimulating hormone, and magnesium levels; a comprehensive metabolic panel and complete blood count; and measurement of erythrocyte sedimentation rate and C-reactive protein.
“Weakness may be secondary to a neuropathy, myopathy, or a problem at the neuropathic junction. Many causes of weakness can be readily identified by careful history taking, focused physical examination, and directed laboratory evaluation,” she said.
Features pointing toward a diagnosis of myositis include characteristic rashes, gradual symptom onset, proximal limb and truncal weakness, other connective tissue disease features such as Raynaud’s and arthritis, and the presence of lung disease, including interstitial lung disease or unexplained infiltrates, she said.
Features pointing away from a diagnosis of myositis include a family history of a similar illness, weakness that is associated with eating or fasting, neurologic signs, cranial nerve involvement, fasciculations, severe muscle cramping, early atrophy, and creatine phosphokinase levels that are either less than 2 times or more than 100 times the upper limit of normal.
Among the conditions to consider in the presence of the features that point away from a myositis diagnosis are muscular dystrophies, metabolic myopathies, and toxic (drug-induced) myopathies, to name a few, Dr. Christopher-Stine said.
She described a number of other cases to illustrate the need for – and to help develop – a differential diagnosis in patients presenting with apparent myositis.
Muscular dystrophies
A 38-year-old woman with limited scleroderma and anti-PM/Scl autoantibodies developed proximal weakness over 9 months and was eventually unable to walk up a flight of stairs. She had heliotrope rash and Gottron’s sign, her serum CK was 723 IU/L, and EMG showed an irritable myopathy.
Muscle biopsy showed inflammation, and she was treated with prednisone, but this led to worsening weakness. She complained of prominent fatigue and double vision at the end of the day, and these symptoms did not improve with steroids.
Anti-AChR and anti-MuSK antibodies were negative, but she had a decrement on repetitive nerve stimulation testing.
She was treated with pyridostigmine and experienced near-complete resolution of her proximal weakness and double vision. A chest CT scan showed thymic hyperplasia; thymectomy was recommended.
In another case, a 19-year-old woman who complained of leg pain after exercise was found to have intact strength but asymmetric calf hypertrophy. Her CK level was 5,000 IU/L, and she was referred to rule out acute myositis.
A quadriceps biopsy was performed and showed abnormal dystrophin immunostaining but no inflammation. A molecular genetic analysis showed deletions in Xp21 and she was diagnosed as a manifesting carrier of Duchenne muscular dystrophy. It was recommended that she be evaluated for cardiomyopathy and receive genetic counseling.
A number of other cases presented by Dr. Christopher-Stine highlighted other muscular dystrophies that can mimic myositis, such as:
- Myotonic dystrophies. These are more often type 2 than type 1. Myotonia may be subtle, cataracts are seen early in all patients, and cardiac arrhythmias are common.
- Limb girdle muscular dystrophy type 2 B (dysferlinopathy). In the legs, this often affects the gastrocnemius muscle, and this will be visible on MRI. In the arms, it most often affects the biceps, sparing the deltoids. CKs are typically very high.
- Facioscapulohumeral muscular dystrophy (FSHD). This involves facial weakness, especially obicularis oris, in 95% of cases, as well as scapular weakness and winging, inflammation on muscle biopsy in 75% of cases, and typically is endomysial or perivascular.
Metabolic myopathies
Among metabolic myopathies that can mimic myositis are disorders of carbohydrate metabolism such as McArdle’s disease, 6-phosphofructokinase deficiency, and Pompe’s disease (adult acid maltase deficiency); disorders of lipid metabolism such as carnitine deficiency and carnitine palmitoyltransferase 2 (CPT2) deficiency; and disorders of purine metabolism, such as myoadenylate deaminase deficiency.
A 27-year-old patient who complained of weakness with activity was referred for possible myositis and was found to have a CK of 3,650 IU/L that never normalized. Physical examination showed intact strength and no muscle atrophy or fasciculations, and an enzyme stain for myophosphorylase showed a normal staining pattern and complete absence of the enzyme on quadricep biopsy. A 22-year-old man with similar symptoms plus recent onset of brown/black urine after physical activity had CK of 110,000 IU/L when symptomatic, and also underwent biopsy after being referred for possible myopathy. Both patients were ultimately diagnosed with CPT2 deficiency, which is associated with risk of rhabdomyolysis triggered by prolonged exercise, diets low in carbohydrates and high in fat, or by fasting.
Myalgias are common, and CK levels are normal or only mildly elevated between episodes in CPT2 deficiency, Dr. Christopher-Stine noted.
Toxic myopathies
Drug-induced myopathies are among the most common etiologies of myopathy and can range from mild myalgia to massive rhabdomyolysis. They can cause mild to severe weakness and may be chronic. The mechanism of toxic injury is direct via myotoxins such as ethyl alcohol, glucocorticoids, lipid-lowering drugs, cocaine, antimalarial drugs, antipsychotic drugs, colchicine, and Ipecac syrup.
One case described by Dr. Christopher-Stine involved “statin myopathy.”
A 55-year-old man on atorvastatin complained of myalgias and brown urine, but had no definitive weakness. He had intact strength and diffuse myalgias that weren’t reproducible. His CK was 45,000 IU/L.
Statin myopathy, as seen in this patient, is usually self-limited and is not associated with autoimmunity or with anti-HMGCR autoantibody positivity.
The mechanism is unknown, but statin myopathy has an incidence of 1.2 per 10,000 patient-years. Myalgias, myositis, rhabdomyolysis, and asymptomatic hyperCKemia are commonly seen. This is in contrast to the immune-mediated necrotizing myelitis that can be secondary to statins and is responsive to immunosuppression, she noted.
Other myositis mimics
In addition to these common myositis mimics, certain other neurologic diseases (such as ALS and cervical myelopathy), endocrinopathies (such as hypothyroidism), and infections (like toxoplasmosis) can also be mistaken for myositis, Dr. Christopher-Stine said, noting that cases illustrating these mimics underscore the need for careful consideration of possible alternate diagnoses.
“While most noninflammatory myopathies are self-limited or have no therapies available, knowing the diagnosis can be helpful for genetic counseling of the patient and family, for mitigating risk factors, and for precluding the use of unwarranted immunosuppressive agents,” she said.
Dr. Christopher-Stine reported having intellectual property interest in a novel Inova Diagnostics autoantibody assay detection for anti-HMGCR. She was also the safety officer for the JBT-101 Trial sponsored by Corbus and funded by the National Institutes of Health.
EXPERT ANALYSIS FROM THE WINTER RHEUMATOLOGY SYMPOSIUM
Amyloid PET may help facilitate diagnosis of inclusion body myositis
Amyloid PET imaging may help to accurately identify inclusion body myositis and distinguish it from polymyositis, which could potentially avoid misdiagnosis and unnecessary immunosuppressive medication, according to findings from a small prospective cohort study.
The study, which found significantly greater uptake of the imaging agent [18F]florbetapir (Amyvid) in muscle from patients with inclusion body myositis (IBM) than in those with polymyositis (PM), builds on previous research showing that the intramuscular beta-amyloid seen in histopathologic analysis of IBM can help distinguish it from PM, but this approach has a low sensitivity along with high diagnostic specificity. The latest diagnostic criteria for IBM have also shifted away from strict histopathologic analysis toward identifying its characteristic clinical pattern of muscle weakness, first author James B. Lilleker, PhD, of the Centre for Musculoskeletal Research at the University of Manchester (England) and his colleagues wrote in Annals of the Rheumatic Diseases.
“While this has improved sensitivity, clinically detectable weakness implies that significant and irreversible muscle damage has occurred, reducing the likelihood that novel treatments will be effective,” the researchers wrote.
Thomas E. Lloyd II, MD, PhD, codirector of the myositis center at Johns Hopkins University, Baltimore, said in an interview that IBM is difficult to diagnose because of a lack of awareness of the early clinical signs and symptoms of the disease among primary care physicians, neurologists, and rheumatologists.
“Typically, a myositis specialist can make the diagnosis based on a combination of history and exam [slowly progressive weakness affecting distal finger flexors and knee extensors] and muscle biopsy features [endomysial inflammation with rimmed vacuoles and protein aggregates],” said Dr. Lloyd, who was not involved in the current study. “However, early in the course of disease, some patients may be misdiagnosed with polymyositis due to having atypical clinical or pathological features, especially if the muscle biopsy lacks rimmed vacuoles or the patient lacks obvious finger flexor weakness.”
But amyloid PET is promising and needs further analysis comparing it with expert diagnosis, Dr. Lloyd said. “I think this imaging method has greatest potential utility to be helpful diagnostically early in the course of disease, when diagnosis of IBM can be most challenging. This approach may also have potential to identify presymptomatic patients, especially if amyloid imaging becomes used for screening for Alzheimer’s disease in the future.”
Dr. Lilleker and colleagues set out to determine whether amyloid PET with [18F]florbetapir could distinguish between IBM and PM. They identified 10 patients with IBM and 6 patients with PM and scanned each patient from shoulders to ankles with CT and PET, followed by a same-day, whole-body MRI scan. Overall, regions of interest included the left arm, right and left forearms, right and left thighs, and right and left calves. The researchers calculated the [18F]florbetapir standard uptake values (SUVs) for each region of interest while SUV ratios (SUVRs) were calculated using the lumbar fat pad reference region.
The IBM patients (9 men, 1 woman) had a mean age of 68.3 years at the time of the scan and a mean disease duration of 4 years, and they were not currently taking immunosuppressive treatments; however, patients had previously taken prednisolone (3 of 10 patients), azathioprine (1 of 10 patients), and mycophenolate (1 of 10 patients). In the PM group (4 men, 2 women), patients’ mean age was 59.7 years, with a mean disease duration of 1.5 years.
The researchers found significantly increased overall [18F]florbetapir SUVRs among all regions of interest for IBM patients (median total SUVR, 1.45; interquartile range, 1.28-2.05), compared with PM patients (total SUVR, 1.01; IQR, 0.80-1.22; P = .005). In addition, when total [18F]florbetapir SUVR was 1.28 or greater, the diagnostic sensitivity for IBM was 80% and specificity was 100%, with an area under the curve of 0.93. There were also no significant associations between total [18F]florbetapir SUVR and age at the time of the scan, disease duration, or clinical outcome measurements such as manual muscle testing of 26 muscles (MMT26), Health Assessment Questionnaire disability index, and IBM Functional Rating Scale.
Dr. Lilleker and his colleagues noted the small study size as a potential limitation, but said other factors such as age and disease severity, which differed between groups, were unlikely to affect the [18F]florbetapir SUVR.
The rarity of PM may make it difficult to determine amyloid PET imaging’s effectiveness in diagnosing IBM when compared with more traditional methods, Dr. Lloyd noted.
“Whether PET imaging is more sensitive than expert diagnosis using traditional methods [careful physical exam of individual distal interphalangeal finger flexor muscles, MRI imaging of thighs, detailed pathological analysis of muscle biopsy including immunostaining for p62/SQSTM1, detailed serum autoantibody testing, etc.] remains to be determined,” he said.
This study was supported by grants from the National Institute for Health Research Manchester Musculoskeletal Biomedical Research Centre, the Medical Research Council, and an award from the Centre for Imaging Sciences at the University of Manchester. The authors reported no conflicts of interest. Dr. Lloyd reported being a consultant for Acceleron and principal investigator for IBM clinical trials sponsored by Orphazyme and Regeneron.
SOURCE: Lilleker JB et al. Ann Rheum Dis. 2019 Feb 13. doi: 10.1136/annrheumdis-2018-214644.
Amyloid PET imaging may help to accurately identify inclusion body myositis and distinguish it from polymyositis, which could potentially avoid misdiagnosis and unnecessary immunosuppressive medication, according to findings from a small prospective cohort study.
The study, which found significantly greater uptake of the imaging agent [18F]florbetapir (Amyvid) in muscle from patients with inclusion body myositis (IBM) than in those with polymyositis (PM), builds on previous research showing that the intramuscular beta-amyloid seen in histopathologic analysis of IBM can help distinguish it from PM, but this approach has a low sensitivity along with high diagnostic specificity. The latest diagnostic criteria for IBM have also shifted away from strict histopathologic analysis toward identifying its characteristic clinical pattern of muscle weakness, first author James B. Lilleker, PhD, of the Centre for Musculoskeletal Research at the University of Manchester (England) and his colleagues wrote in Annals of the Rheumatic Diseases.
“While this has improved sensitivity, clinically detectable weakness implies that significant and irreversible muscle damage has occurred, reducing the likelihood that novel treatments will be effective,” the researchers wrote.
Thomas E. Lloyd II, MD, PhD, codirector of the myositis center at Johns Hopkins University, Baltimore, said in an interview that IBM is difficult to diagnose because of a lack of awareness of the early clinical signs and symptoms of the disease among primary care physicians, neurologists, and rheumatologists.
“Typically, a myositis specialist can make the diagnosis based on a combination of history and exam [slowly progressive weakness affecting distal finger flexors and knee extensors] and muscle biopsy features [endomysial inflammation with rimmed vacuoles and protein aggregates],” said Dr. Lloyd, who was not involved in the current study. “However, early in the course of disease, some patients may be misdiagnosed with polymyositis due to having atypical clinical or pathological features, especially if the muscle biopsy lacks rimmed vacuoles or the patient lacks obvious finger flexor weakness.”
But amyloid PET is promising and needs further analysis comparing it with expert diagnosis, Dr. Lloyd said. “I think this imaging method has greatest potential utility to be helpful diagnostically early in the course of disease, when diagnosis of IBM can be most challenging. This approach may also have potential to identify presymptomatic patients, especially if amyloid imaging becomes used for screening for Alzheimer’s disease in the future.”
Dr. Lilleker and colleagues set out to determine whether amyloid PET with [18F]florbetapir could distinguish between IBM and PM. They identified 10 patients with IBM and 6 patients with PM and scanned each patient from shoulders to ankles with CT and PET, followed by a same-day, whole-body MRI scan. Overall, regions of interest included the left arm, right and left forearms, right and left thighs, and right and left calves. The researchers calculated the [18F]florbetapir standard uptake values (SUVs) for each region of interest while SUV ratios (SUVRs) were calculated using the lumbar fat pad reference region.
The IBM patients (9 men, 1 woman) had a mean age of 68.3 years at the time of the scan and a mean disease duration of 4 years, and they were not currently taking immunosuppressive treatments; however, patients had previously taken prednisolone (3 of 10 patients), azathioprine (1 of 10 patients), and mycophenolate (1 of 10 patients). In the PM group (4 men, 2 women), patients’ mean age was 59.7 years, with a mean disease duration of 1.5 years.
The researchers found significantly increased overall [18F]florbetapir SUVRs among all regions of interest for IBM patients (median total SUVR, 1.45; interquartile range, 1.28-2.05), compared with PM patients (total SUVR, 1.01; IQR, 0.80-1.22; P = .005). In addition, when total [18F]florbetapir SUVR was 1.28 or greater, the diagnostic sensitivity for IBM was 80% and specificity was 100%, with an area under the curve of 0.93. There were also no significant associations between total [18F]florbetapir SUVR and age at the time of the scan, disease duration, or clinical outcome measurements such as manual muscle testing of 26 muscles (MMT26), Health Assessment Questionnaire disability index, and IBM Functional Rating Scale.
Dr. Lilleker and his colleagues noted the small study size as a potential limitation, but said other factors such as age and disease severity, which differed between groups, were unlikely to affect the [18F]florbetapir SUVR.
The rarity of PM may make it difficult to determine amyloid PET imaging’s effectiveness in diagnosing IBM when compared with more traditional methods, Dr. Lloyd noted.
“Whether PET imaging is more sensitive than expert diagnosis using traditional methods [careful physical exam of individual distal interphalangeal finger flexor muscles, MRI imaging of thighs, detailed pathological analysis of muscle biopsy including immunostaining for p62/SQSTM1, detailed serum autoantibody testing, etc.] remains to be determined,” he said.
This study was supported by grants from the National Institute for Health Research Manchester Musculoskeletal Biomedical Research Centre, the Medical Research Council, and an award from the Centre for Imaging Sciences at the University of Manchester. The authors reported no conflicts of interest. Dr. Lloyd reported being a consultant for Acceleron and principal investigator for IBM clinical trials sponsored by Orphazyme and Regeneron.
SOURCE: Lilleker JB et al. Ann Rheum Dis. 2019 Feb 13. doi: 10.1136/annrheumdis-2018-214644.
Amyloid PET imaging may help to accurately identify inclusion body myositis and distinguish it from polymyositis, which could potentially avoid misdiagnosis and unnecessary immunosuppressive medication, according to findings from a small prospective cohort study.
The study, which found significantly greater uptake of the imaging agent [18F]florbetapir (Amyvid) in muscle from patients with inclusion body myositis (IBM) than in those with polymyositis (PM), builds on previous research showing that the intramuscular beta-amyloid seen in histopathologic analysis of IBM can help distinguish it from PM, but this approach has a low sensitivity along with high diagnostic specificity. The latest diagnostic criteria for IBM have also shifted away from strict histopathologic analysis toward identifying its characteristic clinical pattern of muscle weakness, first author James B. Lilleker, PhD, of the Centre for Musculoskeletal Research at the University of Manchester (England) and his colleagues wrote in Annals of the Rheumatic Diseases.
“While this has improved sensitivity, clinically detectable weakness implies that significant and irreversible muscle damage has occurred, reducing the likelihood that novel treatments will be effective,” the researchers wrote.
Thomas E. Lloyd II, MD, PhD, codirector of the myositis center at Johns Hopkins University, Baltimore, said in an interview that IBM is difficult to diagnose because of a lack of awareness of the early clinical signs and symptoms of the disease among primary care physicians, neurologists, and rheumatologists.
“Typically, a myositis specialist can make the diagnosis based on a combination of history and exam [slowly progressive weakness affecting distal finger flexors and knee extensors] and muscle biopsy features [endomysial inflammation with rimmed vacuoles and protein aggregates],” said Dr. Lloyd, who was not involved in the current study. “However, early in the course of disease, some patients may be misdiagnosed with polymyositis due to having atypical clinical or pathological features, especially if the muscle biopsy lacks rimmed vacuoles or the patient lacks obvious finger flexor weakness.”
But amyloid PET is promising and needs further analysis comparing it with expert diagnosis, Dr. Lloyd said. “I think this imaging method has greatest potential utility to be helpful diagnostically early in the course of disease, when diagnosis of IBM can be most challenging. This approach may also have potential to identify presymptomatic patients, especially if amyloid imaging becomes used for screening for Alzheimer’s disease in the future.”
Dr. Lilleker and colleagues set out to determine whether amyloid PET with [18F]florbetapir could distinguish between IBM and PM. They identified 10 patients with IBM and 6 patients with PM and scanned each patient from shoulders to ankles with CT and PET, followed by a same-day, whole-body MRI scan. Overall, regions of interest included the left arm, right and left forearms, right and left thighs, and right and left calves. The researchers calculated the [18F]florbetapir standard uptake values (SUVs) for each region of interest while SUV ratios (SUVRs) were calculated using the lumbar fat pad reference region.
The IBM patients (9 men, 1 woman) had a mean age of 68.3 years at the time of the scan and a mean disease duration of 4 years, and they were not currently taking immunosuppressive treatments; however, patients had previously taken prednisolone (3 of 10 patients), azathioprine (1 of 10 patients), and mycophenolate (1 of 10 patients). In the PM group (4 men, 2 women), patients’ mean age was 59.7 years, with a mean disease duration of 1.5 years.
The researchers found significantly increased overall [18F]florbetapir SUVRs among all regions of interest for IBM patients (median total SUVR, 1.45; interquartile range, 1.28-2.05), compared with PM patients (total SUVR, 1.01; IQR, 0.80-1.22; P = .005). In addition, when total [18F]florbetapir SUVR was 1.28 or greater, the diagnostic sensitivity for IBM was 80% and specificity was 100%, with an area under the curve of 0.93. There were also no significant associations between total [18F]florbetapir SUVR and age at the time of the scan, disease duration, or clinical outcome measurements such as manual muscle testing of 26 muscles (MMT26), Health Assessment Questionnaire disability index, and IBM Functional Rating Scale.
Dr. Lilleker and his colleagues noted the small study size as a potential limitation, but said other factors such as age and disease severity, which differed between groups, were unlikely to affect the [18F]florbetapir SUVR.
The rarity of PM may make it difficult to determine amyloid PET imaging’s effectiveness in diagnosing IBM when compared with more traditional methods, Dr. Lloyd noted.
“Whether PET imaging is more sensitive than expert diagnosis using traditional methods [careful physical exam of individual distal interphalangeal finger flexor muscles, MRI imaging of thighs, detailed pathological analysis of muscle biopsy including immunostaining for p62/SQSTM1, detailed serum autoantibody testing, etc.] remains to be determined,” he said.
This study was supported by grants from the National Institute for Health Research Manchester Musculoskeletal Biomedical Research Centre, the Medical Research Council, and an award from the Centre for Imaging Sciences at the University of Manchester. The authors reported no conflicts of interest. Dr. Lloyd reported being a consultant for Acceleron and principal investigator for IBM clinical trials sponsored by Orphazyme and Regeneron.
SOURCE: Lilleker JB et al. Ann Rheum Dis. 2019 Feb 13. doi: 10.1136/annrheumdis-2018-214644.
FROM ANNALS OF THE RHEUMATIC DISEASES