Plasmapheresis and cytotoxic drugs for mixed cryoglobulinemia.

Fifteen patients with symptomatic cryoglobulinaemia were subjected to apheretic treatment when acute renal insufficiency, glomerulonephritis, severe generalized vasculitis and polyneuropathy unresponsive to conventional therapy or complications due to steroids, such as vertebral collapse, peptic ulcer and steroid diabetes, had appeared. Treatment was performed by discontinuous flow centrifugation or cascade filtration: when discontinuous flow centrifugation was employed, a mixture of saline, gelatin and fresh frozen plasma was used for replacement. Cytotoxic drugs were administered to patients with lymphoma (4 patients) or chronic active hepatitis (5 patients) and also to patients suffering from essential mixed cryoglobulinaemia. Exchanges were organized into courses of 3 to 5 sessions over 5 to 10 days and employed as a supportive measure. No patient underwent long-term treatment. A complete resolution of kidney damage, skin involvement and neurologic signs was observed when treatment was started early in the course of the disease, whereas unequivocal but moderate improvement was obtained in the case of long-lasting symptoms such as polyneuropathy. Relapses were seen in most patients when cytotoxic drugs had been discontinued abruptly. In 8 patients the solubility of cryoglobulins was studied by a recently developed turbidimetric assay. Following treatment the solubility increased; when solubility decreased, 2 patients of this group had a relapse. On the basis of these preliminary observations it appears that the possibility of predicting relapsing disease or the need of continuing therapy can eventually be achieved.