Inclusion Body Myositis.

Inclusion body myositis (IBM) is usually refractory to immunosuppressive therapy; however, a few reports suggest that a minority of patients with IBM may have a partial, transient response or that therapy may slow progression. Therefore, although we generally discourage the use of immunosuppressive therapy for IBM, if the patient is willing to accept the potential side effects of therapy, a 3- to 6-month trial of oral prednisone can be attempted: 100 mg/d for 2 to 4 weeks, then 100 mg every other day for 2 to 3 months. If prednisone alone produces no improvement after 3 months, oral methotrexate can be added: 10 to 15 mg/wk for 6 to 12 months. If there is no objective clinical improvement in strength after a trial of prednisone alone or prednisone plus methotrexate over the course of 6 to 12 months, we discontinue pharmacologic therapy. Because of the great expense, relative lack of availability, and minimal evidence of benefit of intravenous immunoglobulin (IVIG), we do not recommend this form of immunomodulating therapy for IBM.