INTRODUCTION Paraneoplastic autoantibody screening of 150,000 patient sera by tissue-based immunofluorescence incidentally revealed 170 with unsuspected signal recognition particle (SRP) immunoglobulin G (IgG), which is a recognized biomarker of autoimmune myopathy. Of the 77 patients with available information, 54 had myopathy. We describe the clinical/laboratory associations. METHODS Distin...

BACKGROUND Dermatomyositis (DM) is inflammatory myopathy or myositis characterized by muscle weakness and skin manifestations. In the differential diagnosis of DM the evaluation of the muscle biopsy is of importance among other parameters. Perifascicular atrophy in the muscle biopsy is considered a hallmark of DM. However, perifascicular atrophy is not observed in all patients with DM and, conv...

Inflammatory myopathies are a group of autoimmune diseases that affect muscles. In humans, the most common inflammatory myopathies are polymyositis, dermatomyositis, and inclusion body myositis. Autoantibodies may be found in humans with inflammatory myopathies, and these play an important role in diagnosis and disease classification. However, these Abs are typically not muscle specific. Sponta...

OBJECTIVE Antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) have recently been associated with immune-mediated necrotizing myopathy, especially in patients with statin exposure. As the data are very limited concerning phenotypes and treatment in paediatric patients, we aimed to identify the paediatric patients positive for anti-HMGCR antibodies and clarify their feature...

Statins have a variety of myotoxic effects and can trigger the development of inflammatory myopathies or myasthenia gravis (MG) mediated by immunomodulatory properties. Autoantibodies to 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) have been identified in patients with statin-associated myopathy. The purpose of the present study is to develop an enzyme-linked immunosorbent assay (ELI...

BACKGROUND Mutations of the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine-kinase (GNE)-gene are causally related to GNE myopathy. Yet, underlying pathomechanisms of muscle fibre damage have remained elusive. In sporadic inclusion body myositis (sIBM), the pro-inflammatory cell-stress mediators αB-crystallin and inducible nitric oxide synthase (iNOS) are crucial markers of the disease ...

The patient, a 47-year-old woman, presented with a 1month history of hoarseness, mild dysphagia, proximal muscular weakness and a heliotropic rash. Localized face and neck edema was evident (Picture A). The level of creatinine phosphokinase was elevated at 4,193 U/L (normal range: 45-163 U/L). The clinical, laboratory and biopsy findings were suggestive of dermatomyositis. Fat-suppressed, T2wei...

Sporadic inclusion body myositis (sIBM) is considered to be the most common acquired muscle disease associated with aging. It is a disabling disorder still without effective treatment. sIBM causes weakness and atrophy of the distal and proximal muscles. Involvement of quadriceps and deep finger flexors are clues to early diagnosis. Dysphagia in the course of the disease is common. Muscle biopsy...

Immune mediated necrotizing myopathy (IMNM) is a unique form of myositis that is characterized by distinct muscle biopsy features including abundant myofiber necrosis, degeneration, and regeneration with only minimal, if any, inflammation on muscle biopsy. IMNM is clinically similar to idiopathic inflammatory myopathy (IIM); hence, muscle biopsy is essential to diagnose IMNM. Herein we describe...