title: Necrotizing autoimmune myopathy.
abstract: OBJECTIVE
  Necrotizing autoimmune myopathy (NAM) is a relatively newly recognized subgroup of idiopathic inflammatory myopathies, which despite diverse causes, have the common histopathological features of myocyte necrosis without significant inflammation. Patients present with a subacute severe symmetrical proximal myopathy, associated with a markedly elevated creatine kinase level. These are most likely immune-mediated, as they respond to immunotherapy. The review aims to define this heterogeneous entity and summarize the salient clinical, laboratory, and muscle biopsy findings, in order to facilitate the diagnosis and treatment of this condition.
  
  
  RESULTS
  Statin-associated NAM has been linked with an antibody against the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) protein, which is up-regulated in regenerating fibres. This finding suggests that NAM is an antibody-mediated disease, and may explain the continuing progression of disease despite cessation of the statin. In addition it may provide a useful diagnostic test in the future, to help differentiate immune from nonimmune statin myopathies.
  
  
  CONCLUSIONS
  It is important to recognize and distinguish NAM from other causes of myocyte necrosis, because it has the potential of being amenable to treatment.
authors: Department of Neurology, Royal North Shore Hospital, St Leonards, New South Wales, Australia.
authors: Christina
authors: C
authors: Liang
authors: Merrilee
authors: M
authors: Needham
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology / Q000473:pathology; D003240:Connective Tissue Diseases / Q000209:etiology / Q000276:immunology / Q000473:pathology; D018450:Disease Progression; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000276:immunology; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D009220:Myositis / Q000209:etiology / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D009336:Necrosis; D010257:Paraneoplastic Syndromes / Q000209:etiology / Q000276:immunology / Q000473:pathology; D018271:Signal Recognition Particle / Q000276:immunology; D014777:Virus Diseases / Q000150:complications
chemical_list: D000911:Antibodies, Monoclonal; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007166:Immunosuppressive Agents; D018271:Signal Recognition Particle; D006903:Hydroxymethylglutaryl CoA Reductases