CIRCULATING IMMUNE-COMPLEXES CONTAINING ANTI-VIII ANTIBODIES IN MULTI-TRANSFUSED PATIENTS WITH HEMOPHILIA-A

Abstract

Evidence for the presence of circulating immune complexes was found in 34 of 55 samples from 47 patients with hemophilia A. In 11 patients the complexes, precipitated from the blood with polyethylene glycol [PEG], were digested with pepsin. The F(ab'')2 antibody was tested, and had neutralizing activity coagulant factor VIII in 2 patients. In 1 of these, no free antibody had ever been found in the plasma, while in the other the antibody was concentrated 10-fold in the complex. In 2 other samples free without complexed antibody was found. In comparison, Ig[immunoglobulin]G-containing complexes were found in 9 of 19 patients with von Willebrand''s disease and no complexes were found in the sera from 12 multi-transfused thalassemics. PEG precipitation is a useful technique for the preparation of concentrated immune complexes for further study such as antigen identification.