Autoimmune anti-HMGCR myopathy: a rare but disabling complication of statin therapy

<p><strong>Presentation </strong></p> <p>An 85-year-old farmer developed disabling progressive proximal limb weakness and dysphagia after 10 years of statin therapy. </p> <p><strong>Diagnosis </strong></p> <p>Creatine kinase was elevated, and electromyography demonstrated myopathic abnormalities. A muscle biopsy confirmed a necrotising myopathy. Serum 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) antibodies were positive. These investigations confirmed a diagnosis of autoimmune anti-HMGCR myopathy. </p> <p><strong>Treatment </strong></p> <p>The statin was stopped and treatment with steroids, intravenous immunoglobulins and rituximab yielded minimal clinical improvement over 1 year. </p> <p><strong>Conclusion </strong></p> <p>Autoimmune anti-HMGCR myopathy is a rare complication of statin therapy. In severe cases earlier treatment with multiple immunotherapies may be necessary.</p>