Identification of the antibody to vascular endothelial cells in patients undergoing cardiac transplantation.

Acute cardiac dysfunction occurred in four cardiac allograft recipients with negative donor-specific lymphocyte crossmatches. In two recipients the transplanted heart was removed and the patients were maintained on bypass for several hours until a second cardiac allograft was available. In these patients the second transplanted heart also underwent acute dysfunction. The lymphocyte crossmatch was again negative in both second transplants. Two of the four recipients had no detectable antibody to a panel of lymphocytes. Examination of the hearts demonstrated histologic findings consistent with hyperacute rejection. Direct immunofluorescence performed on the transplanted hearts revealed the presence of immunoglobulin and complement deposited on the vascular endothelium. Pathology data was available on 3 of the 4 patients who experienced acute cardiac dysfunction. Pretransplant sera from these four recipients were screened for the presence of antivascular endothelial cell (VEC) antibody. The sera from all four recipients were found to contain antibody against an endothelial cell panel. In addition, donor-specific aorta and vena cava were available from one of the heart donors. The recipient was found to have donor-specific antibody to VEC. Thus, antibody directed against VEC specific antigens appears to be related to hyperacute rejection of heart allografts.