Intravenous immunoglobulin in polymyositis and dermatomyositis.

Purpose. - Polymyositis (PM) and dermatomyositis (DM) are inflammatory idio pathic myopathies of dysimmune origin. Studies have shown two different pat hogenic mechanisms: a primitive vascular mechanism mediated mainly by a hum oral mechanism responsible for a muscular ischemia in juvenile DM; and a pr imitive injury of muscle cells mediated by a cytotoxic cellular mechanism, directed against the myofibrillae, in PM. Current knowledge and key points. - Oral corticosteroids are treatment of f irst choice in patients with PM/DM. This therapy has transformed the progno sis of these diseases. The efficacy of polyvalent human intravenous immunog lobulin (IVIG) was first described in an open study with severe refractory PM and DM, and confirmed by a controlled study in DM. Future prospects and projects. - We present our experience about the intere st of intravenous immunoglobulin (IVIG) in refractory PM and DM and discuss the different mechanisms of action of this new immunotherapy. (C) 1999 Els evier, Paris.