P322 Inclusion body myositis with early onset – a population-based study
Inclusion body myositis (IBM), is an inflammatory myopathy with progressive muscle weakness and atrophy, typically affecting the quadriceps muscles and finger flexors. No efficient treatment is available. Swallowing difficulties are common. Symptoms usually presents in individuals over 50 years of age and younger patients are sparsely studied. In a population-based study during a 33-year period, 142 patients with IBM were identified in western Sweden. Six patients fell outside the inclusion criteria due to young age at symptom onset and had a first muscle biopsy (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: U. Lindgren, C. Hedberg-Oldfors, R. Pullerits, C. Lindberg, A. Oldfors Source Type: research
P323 Differences in clinicopathology and therapeutic response of idiopathic inflammatory myopathy with anti-SRP, HMGCR, and mitochondrial M2 antibodies
Anti-SRP and anti-HMGCR antibodies are pathologically often associated with immune-mediated necrotizing myopathy (IMNM). In addition, myositis with anti-mitochondrial M2 antibody has been also classified as IMNM. The purpose of this study is to characterize the clinical course, muscle pathology and treatment response of them. We selected the patients with idiopathic inflammatory myopathy with anti-SRP (SRP), HMGCR (HMGCR), and AMA-M2 (AMA) antibodies who underwent muscle biopsy at our department between 2011 and 2020, and analyzed clinical findings, muscle pathology, and treatment course. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: A. Yamanaka, N. Eura, Y. Nihimori, T. Shiota, H. Nanaura, T. Kiriyama, T. Izumi, H. Kataoka, K. Sugie Source Type: research
P324 A case of paediatric anti-HMGCR myopathy mimicking LGMD
8-year-old girl referred for hyperckaemia and early onset scoliosis. No family history of neuromuscular disorders, uneventful pregnancy, normal motor development, and no previous concerns. When seen at the age of 8 years, the family reported difficulties in climbing stairs in the previous 12 months. On clinical assessment, there was proximal muscle weakness in the lower and upper limbs (hamstring, iliopsoas, glutei, deltoid 4/5) and axial weakness (neck flexors 3/5, paraspinal, abdominal muscles 4/5) with no facial involvement. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: A. Frongia, L. Daniela, G. Tasca, F. Andreetta, L. Antonaci, E. Mercuri, M. Pane Source Type: research
P325 A comparative single nuclei transcriptomics approach to evaluating the terminally differentiated lymphocytes in autoimmune myositis
The utilization of genome-based studies has allowed the expansion of our understanding to encompass the role of transcriptomics in providing a more comprehensive picture of the diseases. However, the existing studies appear to be limited by the relative paucity of categorizing the gene signatures in relation to the spectrum of the cell types from which the signatures emerge from under the specific disease categories. Particularly for the inflammatory cells, single nuclei (sNuc) transcriptomics (RNA-seq) can characterize the gene expression in terminally differentiated lymphocytes and predict the myogenic and non-myogenic c...
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: F. De Los Reyes, S. Hayashi, S. Noguchi, I. Nishino Source Type: research
P326 Immune myopathy with perimysial pathology in a patient with an unusual clinical phenotype and Anti-Mi-2 antibody
We present a case of a 71-year-old woman with a six-month history of progressive muscle weakness. Her father had Paget's disease of the bone and dementia in his 70s. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: X. Pham, P. Siriratnam, E. Rodrigues, C. McLean Source Type: research
P327 Responsiveness of rituximab in refractory cases of inflammatory myopathies
Idiopathic inflammatory myopathies (IIM) are the disease with progressive weakness and evidence of muscle necrosis and inflammation. Most patients respond well to high dose steroid and subsequent immunosuppressants, but some are refractory to traditional regimens for immunosuppression. Rituximab (RTX), a chimeric monoclonal antibody targeting CD20 B cells, can be an option for refractory cases of IIM. We are to report our result of RTX treatment in those cases. Ten patients were enrolled, who were treated with RTX because they did not fully respond to prior medications. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: J. No, Y. Park Source Type: research
P328 Investigations of the specific interferon-signature in anti-synthetase syndrome-associated myositis
Myositis affects skeletal muscles, but may also feature multi-systemic organ involvement, which might be life threatening. Patients are classified based on clinical and morphological factors due to international criteria. Additionally, in recent years two major achievements have emerged: First, autoantibodies (Ab) have become a key pillar in diagnostics, used to classify subtypes of myositis. E.g., Dermatomyositis (DM) patients show a strong cancer-association when harboring TIF1g-Ab, while MDA5+ DM do not, but the often show ILD. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: C. Preusse, L. Gallay, I. Pinal-Fernandez, A. Mammen, O. Benveniste, H. Goebel, N. Streichenberger, A. Roos, T. Ruck, W. Stenzel Source Type: research
P329 The role of autoantibodies in diagnosis of Idiopathic inflammatory myopathies
Idiopathic inflammatory myopathies (IIM) are heterogenous disease group with common characteristics such as muscle weakness, muscle fatigue, and inflammation of muscle tissue. In recent years, four main types of IIM are widely recognized: Polymyositis (PM), Dermatomyositis (DM), Inclusion body myositis (IBM) and immune-mediated necrotizing myopathy (IMNM). We investigated clinical, pathological and serological features in subgroups of IIM patients who have visited Gangnam Severance hospital. We retrospectively reviewed the medical records of the myopathy database from August 2002 to March 2023. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: S. Kim, S. Lee, H. Park, Y. Choi Source Type: research
P330 Profile of adult idiopathic inflammatory myopathy in Dr Cipto Mangunkusumo Hospital Indonesia as tertiary health care
Idiopathic inflammatory myopathy (IIM) is a heterogeneous group of autoimmune disorders, frequently underdiagnosed, and characterized by clinical, autoantibody (Ab), and pathology findings, encompassing dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), antisynthetase syndrome (ASS), overlap myositis (OM), polymyositis (PM), and inclusion body myositis. The study aims to characterize the organ manifestations and Ab profile of IIM in Cipto Mangunkusumo Hospital. This is the first reported IIM profile in Indonesia. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: L. Indrawati, S. Wibowo, A. Widhani, E. Novianto, C. Nagpal, D. Paveta, E. Susanto, Y. Bilianti, N. Fadli, A. Budikayanti, A. Safri, W. Wiratman, F. Octaviana, M. Hakim Source Type: research
P331 The selection of biopsy sites in lower extremities for the diagnosis of vasculitis
To diagnose vasculitis, we usually examine various organs including kidney, lung, peripheral nerve, or skeletal muscle. Myalgia is frequently observed in patients with vasculitis, especially in their lower extremities. However, previous studies showed the usefulness of sural nerve biopsies but did not establish sensible approaches to pathological diagnosis of vasculitis involving skeletal muscle. Then we investigate muscles selected for biopsy in lower extremities. We collected clinical and radiological records of 20 patients with vasculitis in their lower extremities. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: M. Sato, T. Kurashige, T. Murao, T. Tokunaga, H. Suma, S. Hirata, T. Ohshita Source Type: research
P332 Mitochondrial pathology associated with refractory dermatomyositis after COVID-19 vaccination
We report on clinical, immunological, radiological and myopathological characterization of a case of refractory anti-Mi-2 DM which began after SARS-CoV-2 vaccine administration. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: A. Lauletta, G. Merlonghi, L. Fionda, M. Garibaldi Source Type: research
P333 Clinical, pathological heterogeneity and mitochondrial dysfunction in patients with anti-mitochondrial antibodies related myositis
Inflammatory myopathies are a heterogeneous group of rare, acquired autoimmune diseases involving skeletal muscle and other organs and/or tissue. Myositis specific or associated antibodies are commonly correlated with distinct clinical phenotypes of inflammatory myopathies and have helped to refine the classification. Anti-mitochondrial antibodies (AMAs), the hallmark of primary biliary cirrhosis, have been reported in patients with inflammatory myopathies. We aimed to reveal the clinical and histopathological characteristics and explore the mitochondrial dysfunction in patients with AMAs related myopathies. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: W. Zhang, Y. Wang, Y. Zhao, Y. Yuan Source Type: research
VP334 Clinicopathological features of anti-mitochondrial M2 antibody-positive myositis based on a cohort of 201 patients from Japan
This study utilized muscle biopsy samples from serologically AM2A-positive patients, which were sent to the National Center of Neurology and Psychiatry for diagnostic purposes from January 2008 to December 2020. We reviewed muscle biopsies and clinical information of 201 patients. (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: Y. Nishimori, J. Tanboon, M. Oyama, H. Motegi, Y. Tomo, M. Oba, K. Sugie, S. Suzuki, S. Hayashi, S. Noguchi, I. Nishino Source Type: research
P335 Inhibition of KDM5A reverses pathological features in sporadic Inclusion Body Myositis-like cell models
Sporadic Inclusion Body Myositis (sIBM) is the most common acquired myopathy in adults over the age of 50 and characterised by inflammatory and degenerative processes leading to progressive muscle weakness and physical disability. In an in-house proteomics study, KDM5A, a histone demethylase, was found as key upstream regulator in sIBM patients whole muscle lysates, interconnecting with hallmark processes in sIBM, and hypothesised as disease master regulator. KDM5A overactivity and inhibition was studied in sIBM-like cell models, incubating human myoblasts with inflammatory cytokines (IL-1 β and TNFα) or through APP over...
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: G. De Vries, W. de Ridder, J. Baets Source Type: research
P336 Refining the clinical and therapeutic spectrum of granulomatous myositis from a large cohort of patients
Granulomatous myositis (GM) is a rare condition whose precise clinical features and therapeutic outcome have not yet been well defined. We aimed to investigate the clinicopathological features and treatment response of a large cohort of patients with GM in order to better understand its clinical and therapeutic spectrum. We retrospectively examined clinical, histopathological and treatment data of all patients who referred to the Groupe Hospitalier Piti é-Salpêtrière (France) with myositis and non-caseating granuloma on muscle biopsy (Granulomatous myositis). (Source: Neuromuscular Disorders)
Source: Neuromuscular Disorders - October 1, 2023 Category: Neurology Authors: A. Lauletta, L. De le Hoye, S. L éonard-Louis, M. Garibaldi, Y. Allenbach, O. Benveniste Source Type: research
