title: Immune-Mediated Necrotizing Myopathy: Update on Diagnosis and Management.
abstract: The idiopathic inflammatory myopathies (IIMs) comprise a group of autoimmune disorders that target skeletal muscle. They are characterized by typical laboratory and clinical features including muscle weakness, elevated muscle enzymes, characteristic histopathology of muscle biopsies, as well as electromyography abnormalities. The IIMs are divided into polymyositis, dermatomyositis, inclusion body myositis, nonspecific myositis, and immune-mediated necrotizing myopathy (IMNM). IMNM is distinguished by the absence of primary inflammation on muscle biopsy. IMNM may be associated with myositis-specific autoantibodies (i.e., anti-SRP and anti-HMGCR) and malignancy, in association with viral infections (HIV or hepatitis C), or in relation to other connective tissue diseases (i.e., scleroderma). Typical clinical findings such as severe muscle weakness, highly elevated creatine kinase (CK) levels, as well as resistance to conventional immunosuppressive therapy are associated with this subtype of IIM. This review provides an overview of this disease entity and focuses on its diagnosis and treatment.
authors.affiliation: Division of Rheumatology, Department of Medicine, The University of Western Ontario, 268 Grosvenor Street, London, ON, Canada, N6A 4V2. Pari.Basharat@sjhc.london.on.ca.
authors.forename: Pari
authors.initials: P
authors.lastname: Basharat
authors.affiliation: Johns Hopkins Myositis Center, The Johns Hopkins University School of Medicine, 5200 Eastern Avenue, Mason F. Lord Center Tower; Suite 4500, Baltimore, MD, 21224, USA. lchrist4@jhmi.edu.
authors.forename: Lisa
authors.initials: L
authors.lastname: Christopher-Stine
mesh_terms: D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D001706:Biopsy; D003346:Corticotropin-Releasing Hormone / Q000276:immunology; D003680:Deglutition Disorders / Q000209:etiology; D004576:Electromyography / Q000379:methods; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000276:immunology; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D018908:Muscle Weakness / Q000209:etiology; D018482:Muscle, Skeletal / Q000473:pathology; D009220:Myositis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D054832:Urocortins / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007166:Immunosuppressive Agents; C426705:UCN2 protein, human; D054832:Urocortins; D003346:Corticotropin-Releasing Hormone; C553220:HMGCR protein, human; D006903:Hydroxymethylglutaryl CoA Reductases
keywords: Immune-mediated necrotizing myopathy; Myositis; Statin-induced myopathy; anti-HMGCR; anti-SRP