Item selection for the development and validation of a revised classification criteria for adult and juvenile idiopathic inflammatory myopathies: MyoROC project.

Objective: A revision of the 2017 EULAR-ACR myositis classification criteria, namely EULAR-ACR funded Myositis Revision of Classification (MyoROC) project, is currently underway involving a large international group of experts. In the first phase of this project, we identified additional items to be tested in the criteria.

Methods: We distributed an electronic survey to International Myositis Assessment and Clinical Studies (IMACS) members to identify new items.

Effectiveness and Safety of IVIG for the Treatment of HMGCR Immune-Mediated Necrotizing Myopathy.

Introduction/aims: Immune-mediated necrotizing myopathy (IMNM) is an autoimmune myopathy. We aimed to compare clinical outcomes in patients with antibodies against 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) treated on immunotherapy regimens with and without maintenance intravenous immunoglobulin (IVIG). The secondary aim was to assess outcomes in a subset that received IVIG monotherapy.

Investigating phenotypic variability patterns in myotonic dystrophy type 2 in a neuromuscular referral center retrospective cohort.

We aimed at investigating the presence of patterns that account for the phenotypic variability in a myotonic dystrophy type 2 (DM2) retrospective cohort at the Mass General Brigham Neuromuscular Centers. We collected the presence or absence of 23 clinical variables at symptom onset and diagnosis (n = 67 patients) and follow-up (n = 37 patients). We first identified set/s of variables (factors or cluster/s) representative of the large research data pool at onset by performing factor analyses, then assigned each patient to the cluster for which they had the highest computed total factor score.

Mutations in Facial-Onset Sensory and Motor Neuronopathy.

Objectives: Facial-onset sensory and motor neuronopathy (FOSMN) is a rare neuromuscular disorder characterized by progressive facial sensory impairment followed by motor dysfunction in a rostro-caudal distribution. FOSMN is clinically and pathologically associated with amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). In contrast to ALS/FTD, the genetic profile of patients with FOSMN and the role of genetic testing are poorly defined.

Management of immune-mediated necrotizing myopathy.

The immune-mediated necrotizing myopathies (IMNM) are autoimmune myositides clinically characterized by proximal predominant weakness and elevated creatine kinase (CK). They may be associated with autoantibodies (anti-HMGCR, anti-SRP), triggered by statin use (e.g.

Neuromuscular pathology.

In this chapter, we discuss the indications for muscle, nerve, and skin biopsies, the techniques and normal processing of biopsy specimens, normal histological appearance, and the commonest histopathological abnormalities of different myopathies and neuropathies.

Parent-of-Origin Effect on the Age at Symptom Onset in Myotonic Dystrophy Type 2.

Background And Objectives: The existence of clinical anticipation, congenital form, and parent-of-origin effect in myotonic dystrophy type 2 (DM2) remains uncertain. Here, we aimed at investigating whether there is a parent-of-origin effect on the age at the first DM2-related clinical manifestation.

Methods: We identified patients with genetically confirmed DM2 with known parental inheritance from (1) the electronic medical records of our institutions and (2) a systematic review of the literature following the PRISMA 2020 guidelines and recorded their age at and type of first disease-related symptom.

Retinal Vasculitis in a Patient With Isaacs Syndrome and Inclusion Body Myositis.

Purpose: To report a case of bilateral occlusive retinal vasculitis in a patient with autoimmunity.

Methods: A case was analyzed and a literature review performed.

Results: A 55-year-old woman with autoimmune diagnoses of Isaacs syndrome and inclusion body myositis (IBM) reported decreased vision for 3 months.

Performance of the 2016 ACR-EULAR Myositis Response Criteria in adult dermatomyositis/polymyositis therapeutic trials and consensus profiles.

Objective: The ACR-EULAR Myositis Response Criteria (MRC) were developed as a composite measure using absolute percentage change in six core set measures (CSMs). We aimed to further validate the MRC by assessing the contribution of each CSM, frequency of strength vs extramuscular activity improvement, representation of patient-reported outcome measures (PROM), and frequency of CSM worsening.

Methods: Data from adult dermatomyositis/polymyositis patients in the rituximab (n = 147), etanercept (n = 14), and abatacept (n = 19) trials, and consensus patient profiles (n = 232) were evaluated.

Frequency and type of cancers in myotonic dystrophy: A retrospective cross-sectional study.

Introduction/aims: Myotonic dystrophies (DMs) are autosomal dominant diseases in which expression of a mutant expanded repeat mRNA leads to abnormal splicing of downstream effector genes thought to be responsible for their multisystem involvement. Cancer risk and cancer-related deaths are increased in DM patients relative to the general population. We aimed at determining the frequency and type of cancers in both DM1 and DM2 vs a non-DM muscular dystrophy cohort.

Safety and outcomes of eculizumab for acetylcholine receptor-positive generalized myasthenia gravis in clinical practice.

Introduction/aims: Safety and outcomes data on eculizumab for generalized myasthenia gravis (gMG) in clinical practice remain limited. Outcomes and concomitant medication use may differ in practice compared with clinical trials. We analyzed the clinical and safety outcomes of patients who received eculizumab at our institutions.

Randomized phase 2 study of ACE-083, a muscle-promoting agent, in facioscapulohumeral muscular dystrophy.

Introduction/aims: Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive muscular dystrophy without approved therapies. In this study we evaluated whether locally acting ACE-083 could safely increase muscle volume and improve functional outcomes in adults with FSHD.

Methods: Participants were at least 18 years old and had FSHD1/FSHD2.

Phase 2 Trial of Rituximab in Acetylcholine Receptor Antibody-Positive Generalized Myasthenia Gravis: The BeatMG Study.

Objective: To determine whether rituximab is safe and potentially beneficial, warranting further investigation in an efficacy trial for acetylcholine receptor antibody-positive generalized MG (AChR-Ab+ gMG).

Methods: The B-Cell Targeted Treatment in MG (BeatMG) study was a randomized, double-blind, placebo-controlled, multicenter phase-2 trial that utilized a futility design. Individuals 21-90 years of age, with AChR-Ab+ gMG (MG Foundation of America Class II-IV) and receiving prednisone ≥15 mg/day were eligible.

Retrospective analysis of safety and outcomes of rituximab for myasthenia gravis in patients ≥65 years old.

Introduction/aims: Optimal management of myasthenia gravis (MG) in individuals ≥65 y old is unknown and patient factors may limit therapeutic choices. Safety and efficacy of rituximab in older patients with MG has not been well-studied.

Methods: This retrospective study examined 40 patients (14 patients ≥65 y old) treated with rituximab for MG.

Consensus disease definitions for neurologic immune-related adverse events of immune checkpoint inhibitors.

Expanding the US Food and Drug Administration-approved indications for immune checkpoint inhibitors in patients with cancer has resulted in therapeutic success and immune-related adverse events (irAEs). Neurologic irAEs (irAE-Ns) have an incidence of 1%-12% and a high fatality rate relative to other irAEs. Lack of standardized disease definitions and accurate phenotyping leads to syndrome misclassification and impedes development of evidence-based treatments and translational research.

Neuromuscular complications of coronavirus disease-19.

Purpose Of Review: Since its outbreak in Wuhan, China in late 2019, coronavirus disease-19 (COVID-19) has become a global pandemic. The number of affected cases and deaths continues to rise. Primarily a respiratory illness, COVID-19 is now known to affect various organ systems including peripheral nerve and skeletal muscle.

Skeletal Muscle and Peripheral Nerve Histopathology in COVID-19.

Objective: To explore the spectrum of skeletal muscle and nerve pathology of patients who died after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to assess for direct viral invasion of these tissues.

Methods: Psoas muscle and femoral nerve sampled from 35 consecutive autopsies of patients who died after SARS-CoV-2 infection and 10 SARS-CoV-2-negative controls were examined under light microscopy. Clinical and laboratory data were obtained by chart review.

Mitochondrial DNA Analysis from Exome Sequencing Data Improves Diagnostic Yield in Neurological Diseases.

A rapidly expanding catalog of neurogenetic disorders has encouraged a diagnostic shift towards early clinical whole exome sequencing (WES). Adult primary mitochondrial diseases (PMDs) frequently exhibit neurological manifestations that overlap with other nervous system disorders. However, mitochondrial DNA (mtDNA) is not routinely analyzed in standard clinical WES bioinformatic pipelines.