Reversal of Chronic Polymyositis Following Intravenous Immune Serum Globulin Therapy

Abstract

POLYMYOSITIS is an inflammatory disease of striated muscle, which has been attributed to a vasculopathy. Although the pathogenesis is unknown, studies suggest that an immune mechanism may contribute to this disorder. The evidence consists of the presence of tissue-bound immunoglobulins and complement within blood vessels of involved muscle¹ and the in vitro cytotoxic effect of patients' lymphocytes on muscle cells grown in culture.^2,3 The mainstay of therapy in polymyositis is corticosteroids. This treatment results in improvement of prognosis and life-style in most patients with this disorder.^4-10 However, some individuals are refractory to steroid therapy or demonstrate only a partial response.^11,12 In other patients, short- or long-term toxic reactions to corticosteroids force discontinuation of the drug. Such patients who are resistant to or intolerant of corticosteroids have been treated with immunosuppressive agents, including methotrexate sodium,^13-17 azathioprine sodium,^18-20 cyclophosphamide,^17,21,22 and cyclosporine.²³ Although patients may