Plasma exchange in chronic inflammatory demyelinating polyneuropathies

Chronic Inflammatory Demyelinating Polyneuropathies (CIDP) are characterized by demyelination of peripheral nerves with mononuclear cell infiltrates, electrical conduction slowing or block and elevated cerebrospinal fluid protein with no cells. An immune mediated pathogenesis has been suggested. Immune suppressive therapy, as well as plasmapheresis and intravenous immunoglobulins have been used with variable success. Our objective was to review our results of plasma exchange in this disease in 20 patients with very different underlying diseases, none of them eligible for the Canadian CIDP plasmapheresis study, and define certain guidelines of predictability for the effectiveness of plasma exchange. Five patients had monoclonal gammopathies of unknown significance, two had lung cancer, one breast cancer, one hairy cell leukemia and later carcinoma of the pancreas; two had hepato-splenomegaly and hemolytic anemia; nine were idiopathic (two with autoimmune markers). Plasmapheresis varied from 4 to 31 plasma volumes and procedures with a median of 12, always with 5% albumin. Two excellent responses, one very good, two moderate transient and 12 had no change in clinical or conduction status. Best response occurred in paraproteinemias. Thus immune modulation with plasma exchange may be useful in CIDPs with paraproteinemias and autoimmune manifestations.