Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy.

Eleven consecutive patients with progressive chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) underwent plasma exchange. Eight patients were previously unresponsive to prednisone, two were started on prednisone with plasma exchange, and one did not receive corticosteroids. Electrodiagnostic studies revealed evidence of an acquired demyelinating polyradiculoneuropathy with varying degrees of axonal degeneration. Neurologic impairment was monitored using conventional functional status index. Five patients demonstrated substantial clinical improvement, beginning 2 days to 3 weeks after initiating plasma exchange. Two additional patients improved following a second course of plasma exchange, and four patients demonstrated minimal or no change. Comparison of responding and nonresponding patients showed no differences related to the presence or absence of antecedent illness, duration of disease, duration of maximum weakness, or severity of impairment prior to plasma exchange. Responders had significantly prolonged F-response and motor distal latencies compared to nonresponders. Results in this unselected, consecutive patient trial suggest a temporal relationship between plasma exchange and clinical improvement in some patients with progressive CIDP.