[Double filtration plasmapheresis (DFPP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)].

We studied the therapeutic characteristics of double filtration plasmapheresis (DFPP) in 14 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The patients were classified into 2 subgroups of the responders (7 patients) and the non-responders (7 patients) to DFPP. The responders to DFPP were designated as those showing the improvement 2 or more grades in measures the activity of daily living by the modified Rankin scale (MRS). All these patients underwent neurological assessment, CSF study, electrophysiological studies at the beginning and end of treatment. Sural nerve biopsy study was performed in 10 cases. Neurological function was assessed serially using a quantitative neurological disability score (NDS). At the beginning of treatment, there were no significant differences in various measurements between the responders and the non-responders except for the frequency of demyelination. In responders, significant improvement was found in mean changes in MRS, NDS, motor nerve conduction velocity, compound muscle action potential, distal motor latency, while in non-responders, all measures remained unchanged or worsened. Muscle wasting was seen in 3/7 responders and 4/7 non-responders, and denervation potentials in needle EMG were seen in 1/7 responders and 3/7 non-responders. Four patients of the responders were classified as chronic relapsing course, and 6 patients of the non-responders as chronic progressive course. We conclude that DFPP was useful for the subgroups of CIDP patients, but the underlying immuno-pathological background that determine the efficacy of plasmapheresis should be elucidated.