Statin-induced anti-HMGCR antibody-related immune-mediated necrotising myositis achieving complete remission with rituximab

BMJ Case Rep. 2019 Dec 1;12(11):e232406. doi: 10.1136/bcr-2019-232406.


Statin-induced immune-mediated necrotising myopathy (IMNM) is a rare but increasingly recognised myositis. Many cases have positive antibodies to 3-hydroxy-3-methylglutaryl coenzyme A reductase (anti-HMGCR). The current treatment is ceasing the statin, but often immunosuppressive therapy is required as the antibodies persist, causing muscle necrosis. Despite the use of immunosuppressive medications, most commonly prednisolone, methotrexate, plasma exchange and/or intravenous immunoglobulin, some patients do not respond. We report the successful treatment with rituximab therapy for three patients with IMNM with positive anti-HMGCR antibodies. All three patients with statin-induced IMNM were elderly, with a disease history of 7-9 years, and had failed several immunosuppressive agents. They responded well to rituximab (induction and maintenance) therapy. They remain in remission with no symptoms and normal creatine kinase. One patient had normalisation of anti-HMGCR antibody level, and one patient's antibody level reduced significantly. Rituximab is an effective immunosuppressive treatment for patients with refractory IMNM.

Keywords: muscle disease; neurology (drugs and medicines); neuromuscular disease.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Autoantibodies / blood
  • Female
  • Humans
  • Hydroxymethylglutaryl CoA Reductases / immunology
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / adverse effects*
  • Immunologic Factors / therapeutic use*
  • Induction Chemotherapy
  • Male
  • Middle Aged
  • Myositis / chemically induced
  • Myositis / drug therapy*
  • Myositis / immunology
  • Necrosis / chemically induced
  • Necrosis / drug therapy*
  • Necrosis / immunology
  • Rituximab / therapeutic use*


  • Autoantibodies
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Immunologic Factors
  • Rituximab
  • HMGCR protein, human
  • Hydroxymethylglutaryl CoA Reductases