Plasma-exchange in mixed cryoglobulinemia. Effects on renal, liver and neurologic involvement.

Prolonged plasma-exchange without addition of cytotoxic agents was employed in 16 patients with mixed cryoglobulinemia and kidney, liver or neurologic involvement. Patients with rapidly progressive renal failure or active and reversible lesions generally improved after plasma-exchange, as well as those with a recently occurring sensory-motor peripheral neuropathy. In 4 out of 6 patients with mixed cryoglobulinemia and chronic active hepatitis, plasma-exchange was followed by either normalization or significant reduction of liver enzymes and bromosulfophthalein retention. In all cases responding to plasma-exchange the beneficial effects were evident after the first 2-3 weeks of treatment, while symptoms did not generally recur when the procedures were either slowly tapered or discontinued. Although the pathogenetic mechanism(s) of action of plasma-exchange remains largely unknown, preliminary data indicate that these procedures induce quantitative as well as qualitative changes in the immune system.