Protein A tangential flow affinity membrane cartridge for extracorporeal immunoadsorption therapy

Tangential flow affinity membrane cartridge (TFAMC) fs a new model of immun oadsorption therapy for hemoperfusion. Recombinant Protein A was immobilize d on the membrane cartridge through Schiff base formation for extracorporea l IgG and immune complex removal from blood. Flow characteristics, immunoad sorption capacity and biocompatibility of protein A TFAMC were studied. The results showed that the pressure drop increased with the increasing flow r ate of water, plasma and blood, demonstrating reliable strength of membrane at high now rare. The adsorption capacities of protein A TFAMC for IgG fro m human plasma and blood were measured. The cartridge with 139 mg protein A immobilized on the matrix (6 mg protein A/g dry matrix) adsorbed 553 mg Ig G (23.8 mg IgG/g dry matrix) from human plasma and 499.4 mg IgG (21.5 mg Ig G/g dry matrix) from human blood, respectively. The circulation time had a major influence on IgG adsorption capacity, but the flow rate had little in fluence. Experiments in vitro and in vivo confirmed that protein A TFAMC ma inly adsorbed Ige and Little of other plasma proteins, and that blood cell damage was negligible. The extracorporeal circulation system is safe and re liable. Copyright (C) 1999 John Wiley & Sons, Ltd.