Statin-Induced Necrotizing Autoimmune Myopathy: An Uncommon yet Challenging Complication of Statin Use.

Statin-induced necrotizing autoimmune myopathy (SINAM) is a rare, disabling, and potentially life-threatening complication of statin use. Although not fully understood, a prevailing hypothesis proposes that statins induce molecular changes in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), leading to the formation of anti-HMGCR antibodies. The subsequent myofibre necrosis is expressed as progressive and persistent proximal muscle weakness and elevated creatine kinase (CK) levels. The authors describe the case of a 49-year-old Caucasian male with the diagnosis of SINAM after two years of statin therapy. He presented with progressive proximal muscle weakness, particularly at the shoulder and pelvic girdle, and significant elevated CK levels. Besides statin suspension, treatment with three immunosuppressants was necessary with clinical and analytical remission after two years.