Opinion statement
Purpose of Review Necrotizing autoimmune myopathies (NAM), or immune-mediated necrotizing myopathies (IMNM), are considered as a unique category of autoimmune myopathy given their distinctive histologic, serologic, and clinical features. The goals of this article are to review the subtypes of IMNM and to discuss treatment options that apply to these conditions.
Recent findings Two thirds of cases of IMNM are associated with either autoantibodies recognizing the signal recognition particle (SRP) or with autoantibodies recognizing 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Corticosteroids remain first-line therapy in combination with other immunosuppressive treatments, including methotrexate, azathioprine, mycophenolate mofetil, cyclosporine, intravenous immunoglobulins, rituximab, cyclophosphamide, and plasmapheresis.
Summary Though a great deal has been learned about IMNM, there are no standardized treatment protocols yet developed for these conditions and future advances in the field will benefit from randomized clinical trials in which the efficacies of selected therapies are tested in a rigorous manner.