Statins as a possible cause of inflammatory and necrotizing myopathies.

BACKGROUND: Hydroxy-methyl-glutaryl Co-A reductase (HMGCR) inhibitors or statins are a well recognized cause of a variety of skeletal myopathic effects which generally resolve on stopping the medication. Recent reports, however, suggest that statins are associated with a unique autoimmune myopathy wherein symptoms persist or even progress after statin discontinuation and require immunosuppressive therapy. We performed a systematic review to examine the association of statins with inflammatory (dermatomyositis/polymyositis) and necrotizing myopathies.

METHODS: We searched PubMed, Ovid and Scopus for English language articles addressing statin associated inflammatory and necrotizing myopathies. Given the paucity of cases, we extended the search to include articles in all languages.

RESULTS: The search yielded 14 articles reporting a possible association of statins with inflammatory myopathies describing 10 cases of polymyositis and 14 cases of dermatomyositis, and 4 articles reporting a possible association of statins with necrotizing myopathies describing 63 cases. One study identified a unique antibody directed against HMGCR in patients with necrotizing myopathy. Systemic immunosuppressive therapy was required in majority of these cases for resolution of symptoms.

CONCLUSION: Statins have recently been associated with a variety of inflammatory myopathies including polymyositis, dermatomyositis, and a necrotizing myopathy. The association of statins with necrotizing myopathy is strengthened by the discovery that the serum of some of these patients contains an anti-HMGCR antibody. This suggests that statins can cause or unmask an immune mediated myopathy.