Humoral responses in human organ transplantation.

The plasmas of fifteen patients undergoing organ transplantation were serially tested for a variety of humoral antibodies. The antibodies studied were those which usually reflect covert immunologic events, i.e. the antiglobulins (rheumatoid factors and serum agglutinators), heterophile antibodies and typical and atypical isoantibodies. Although the isoantibodies and the heterophile antibodies were not significantly stimulated by organ transplantation, the administration of ALG (horse antilymphocyte globulin) invariably led to the presence of antihorse globulin antibodies. Three patients were Rh negative and received organs from Rh-positive donors. However, only one of the patients responded with anti-Rh antibodies, but these antibodies exceeded in titre the anti-Rh antibodies usually observed following intentional immunization of normal volunteers. The most startling observation was the significant increase in titres of the serum agglutinators in eight of the patients. These observations suggest that the antigen–antibody complexes associated with chronic rejection may stimulate the production of the serum agglutinators.