[Plasma exchange in dermatomyositis. A retrospective study of 21 cases].

We have reviewed the results obtained in 21 dermatomyositis patients who were treated with plasma exchanges (PE) in 8 french centres between 1980 and 1986. Patients and methods. Seven of the 21 patients studied were male and 14 were female; 16 were children under 15 years of age. The disease was initially acute in 17 cases, subacute in 3 cases and chronic in 1 case. Plasma exchanges were performed as first-line therapy in 13 patients and after failure of the usual treatments in 18 patients. The decision to use PE therapy was prompted by an increase in muscle weakness in 14 of these 18 patients and by a lack of improvement despite treatment in the remaining 4 patients. PE therapy was started 17 months on average after the beginning of treatment. At the time 10 patients were under systemic corticosteroid therapy (prednisone or prednisolone greater than 1 mg/kg/day in 7 cases); 7 patients were receiving immunosuppressants jointly with corticosteroids (prednisone or prednisolone greater than 1 mg/kg/day in 5 cases); and 1 patient had systemic corticosteroids (3 mg/kg/day), methotrexate and antilymphocyte serum. In 3 patients, 2 of whom had severe muscle weakness. PE's were performed from the start. Our 21 patients underwent a total of 234 plasma exchanges. Each patient had a mean series of 11 +/- 6 PE's spread over 11 +/- 3 weeks. In addition to PE therapy, 12 patients received corticosteroids (greater than 1 mg/kd/day in 7 cases) and 8 had corticosteroids (greater than 1 mg/kd/day in 5 cases) together with immunosuppressants. One patient who was put on TE therapy from the start received no other treatment. It must be noted that in 12 patients the introduction of PE was accompanied by another therapeutic change.(ABSTRACT TRUNCATED AT 250 WORDS)