LARGE MOLECULE FRACTION OF PLASMA SEPARATED WITH POLYETHYLENE-GLYCOL IN TREATMENT OF CHRONIC RELAPSING THROMBOTIC THROMBOCYTOPENIC PURPURA

Plasma exchange and plasma infusion are effective in the treatment of patients with thrombotic thrombocytopenic purpura (TTP). It has been p roposed that some component in normal plasma may be deficient in TTP p atients. In this experiment normal plasma was fractionated and an effe ctive fraction for the treatment of TTP was sought, Plasma was fractio nated with 5% polyethylene glycol and a large molecule fraction was ob tained which was composed mainly of proteins and lipoproteins with mol ecules larger than that of IgG. The fraction was dissolved in physiolo gical saline and infused in two patients with chronic relapsing TTP wh o had been successfully treated periodically with plasma infusion, Per ipheral platelet counts and serum LDH levels were measured, and the ef ficacy of the treatment was assessed, Infusion of the large molecule f raction elevated platelet counts and lowered the LDH level, However, t he efficacy of the large molecule fraction was 25 to 50% that of plasm a. Components in the fraction may have been inactivated partially duri ng preparation, We propose that the large molecule fraction contains f actors which are effective in some patients with TTP. (C) 1995 Wiley-L iss, Inc.