THE CLINICAL-SIGNIFICANCE OF ALLOSPECIFIC ANTIBODIES AGAINST ENDOTHELIAL-CELLS DETECTED WITH AN ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY ASSAY FOR VASCULAR REJECTION AND GRAFT LOSS AFTER RENAL-TRANSPLANTATION

Serum samples of 64 consecutive patients who underwent renal transplan tation in our institution were examined for the presence of antibody-d ependent cellular cytotoxicity (ADCC) activity against endothelial cel ls (EC). From each patient serum samples were obtained immediately bef ore transplantation and 1 week, 1 month and 1 year thereafter. The res ults were evaluated in the context of tests to measure donor-specific humoral immunity against lymphocytes and monocytes, and related to par ameters of presensitization, graft survival, and histology. Sera from 10 patients were positive for ADCC on a panel of HLA-typed endothelial cells. In 8 patients sera were already positive before transplantatio n and remained positive thereafter. In 4 patients a positive crossmatc h with donor T and B cells and monocytes could be observed after trans plantation. In only one patient were these crossmatches positive befor e transplantation. A significant correlation was found between ADCC po sitivity and vascular rejection (P=0.015); in addition graft survival was significantly better in the ADCC negative group vs. the positive g roup (P=0.0004). These data demonstrate the significance of allospecif ic anti EC antibodies for the occurrence of vascular rejection and gra ft loss after renal transplantation.