Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy; different beneficial effects and their correlation to the clinical features.

We report 7 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) who showed significant clinical improvement by plasma exchange (PE). Their clinical features were extensively varied but fulfilled the diagnostic criteria for CIDP. The patients could be divided into 2 subgroups based on the mode of effectiveness of PE; one group consisted of those who once achieved complete remission, but required highly frequent PEs for long-term maintenance of remission and the others were those who showed persistent and complete remission with several sessions of PE alone. These findings raise issues about the long-term therapeutic goals to be achieved by PE for CIDP patients, particularly on supportive therapy other than PE, as well as the optimization of frequency and duration of PE.