Remission of Statin-associated Autoimmune Necrotizing Myopathy With Sequential Immunotherapy: A Well-studied Patient

Statins are a group of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors aimed at reducing cholesterol synthesis. Since their discovery in 1970, their use has exponentially increased, becoming a regular preventive treatment for cardiovascular diseases. Among their most common adverse effects are myopathies, with the most severe being autoimmune necrotizing myopathy. We present a case of a woman in her 70s, with high cardiovascular-risk comorbid conditions, including autoimmune hypothyroidism, type 2 diabetes, arterial hypertension, and dyslipidemia. After 5 years on atorvastatin, she developed proximal limb weakness and elevated creatine kinase and creatine kinase-MB levels. A muscle biopsy showed autoimmune necrotizing myopathy and blood work confirmed positive 3-hydroxy-3-methylglutaryl coenzyme A reductase antibodies. Based on these findings, a diagnosis of statin-associated autoimmune necrotizing myopathy was made. In this case, treatment with intravenous immunoglobulin and rituximab resulted in complete remission.