DEFECTIVE LEUKOCYTE FUNCTION-RELATED CRYOPRECIPITABLE PROTEIN IN CRYOGLOBULINEMIA

Cryoprecipitable proteins (CPP), purified from plasmas removed during plasmapheresis treatment of patients with type II and type III cryoglo bulinemia (CG), were evaluated in vitro for their effect on normal leu kocyte function. CPP reduced normal mononuclear cell blastogenesis and polymorphonuclear cell phagocytosis responses in a dose-dependent fas hion. At the maximum concentration studied, 5,000 mug/ml, CPP were sho wn to suppress normal blastogenesis and phagocytosis 30-60% and 50-80% below the albumin control, respectively. A 50% suppression of normal blastogenesis and phagocytosis was observed at 500 mug/ml for type III CPP. Leukocyte functions in CG patients were evaluated and compared t o those of healthy controls. Blastogenesis and phagocytosis were signi ficantly inhibited in CG patients. These studies suggest that CG patie nts have defective leukocyte function and that CPP have suppressive ef fects on normal leukocyte function. Our studies suggest that removal o f CPP in CG patients may prove beneficial not only in reducing typical symptoms of CG but also in reducing the potencial inhibitory effects of CPP on leukocyte function. (C) 1994 Wiley-Liss, Inc.