Subcutaneous immunoglobulin therapy in statin-induced necrotizing autoimmune myopathy

We report a case of statin-associated necrotising autoimmune myopathy successfully treated with subcutaneous immunoglobulin therapy (SCIG) monotherapy without corticosteroids. This is a 51-year old female with seronegative rheumatoid arthritis, who had been on statins for several years, who developed proximal muscle weakness and elevated creatine kinase after resuming her statin post sleeve gastrectomy for weight loss. Our patient had a history of severe side effects to prednisone. She did not respond to mycophenolate, cyclophosphamide, and rituximab treatment. She had responded to partial treatment with intravenous immunoglobulin (IVIG) but had a severe headache after IVIG infusion. IVIG treatment was discontinued. We tried SCIG treatment, and she was able to tolerate the SCIG treatment with intermittent headaches that were less intense. After treatment with SCIG, creatine kinase levels decreased significantly, with an improvement of muscle strength. She continues to do well on SCIG treatment. To our knowledge, no other cases of statin-associated necrotising autoimmune myopathy treated with SCIG have been reported in the literature. More studies and reports are needed to confirm the utility and efficacy of SCIG in statin-associated necrotising autoimmune myopathy, as well as to provide information about dosing, tolerability, and durability of SCIG in the treatment of statin-associated necrotising autoimmune myopathy.