Statins and Immune-Mediated Necrotizing Myopathy

• Main Author: Mauro Turrin
• Format: Article
• Language: English
• Published: SEEd 2018-10-01
• Series: Clinical Management Issues
• Subjects: Hydroxymethylglutaryl-CoA Reductase Inhibitors; Dermatomyositis; Polymyositis; Immune-mediated necrotizing myopathy; Anti-HMGCR antibodies
• Online Access: https://journals.seedmedicalpublishers.com/index.php/cmi/article/view/1367

Statins are a well-recognized cause of a variety of skeletal myopathic effects, which generally resolve when discontinuing the treatment. Among autoimmune manifestations associated with statins, there is immune-mediated necrotizing myopathy (IMNM). The present article summarizes the main features of statin-related IMNM, describing diagnosis, classification, epidemiology, treatment, and the main autoantibodies detected. Statins are a well-recognized cause of a variety of skeletal myopathic effects, which generally resolve when discontinuing the treatment. Among autoimmune manifestations associated with statins, there is immune-mediated necrotizing myopathy (IMNM). The present article summarizes the main features of statin-related IMNM, describing diagnosis, classification, epidemiology, treatment, and the main autoantibodies detected. Although it is impossible to define the precise number, it evident that more than 550 statin-related IMNM cases have been described in the literature. Among IMNM, two forms must be distinguished: with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) and with anti-signal recognition particle (SRP) antibodies. The differential diagnosis should be made between the IMNM and self-limited statin-related myopathy, drug-induced rhabdomyolysis, and nonautoimmune myopathies. Patients who have failed to normalize high creatine phosphokinase (CPK) after statin withdrawal should be tested for anti-HMGCR antibodies and, if these are positive, undergo muscle biopsy to confirm the diagnosis of IMNM. Pharmacological therapy of IMNM, not yet based on evidence, involves the use of high-dose corticosteroids, immunosuppressant drugs used alone or in combination, intravenous immunoglobulins (IVIg) or plasmapheresis.