Specific removal of anti-A and anti-B antibodies by using modified dialysis filters

Removal of anti-A and anti-B blood group antibodies from human blood has be en shown to facilitate cross-matched kidney transplantation by preventing h yperacute rejection. Patients in these studies had anti-A and anti-B antibo dies removed by using plasmapheresis, followed by immunoadsorption onto pac ked bead columns. We conducted a study to assess the feasibility of selecti vely removing anti-A and anti-B antibodies directly from blood by using mod ified dialysis filters. An anti-A and anti-B specific antigen was covalentl y attached to the lumenal surfaces of hollow fibers within selected commerc ial dialysis modules. The filters were able to reduce the anti-A and anti-B titers of 300 ml of blood to 2 or below low molecular weight fraction of o ur antigen system was found to have no antibody binding capacity. The stand ard antigen was purified by removal of the low molecular weight fraction an d a dialysis filter was modified by using the purified:antigen. This filter displayed a six-fold higher capacity than a dialysis filter modified with the same mass of standard antigen. We conclude that selective blood group a ntibody removal by antigen modified dialysis filters is feasible and may be a simpler system than plasmapheresis followed by immunoadsorption.