Assessment of the cellular immune response to HL-A antigens in human renal allograft recipients.

The cellular response to HL-A antigens has been studied in thirty-one patients who had received a renal allograft from either a cadaveric or living donor, utilizing the leucocyte migration technique. The results indicate that inhibition of migration develops prior to or during the onset of a clinical rejection episode. This inhibition of migration reverts to non-inhibition in autologous serum when the rejection crisis is reversed. Inhibition of migration is still noted in allogeneic serum following this clinical reversal, but after varying time intervals the inhibition reaction also decreases in this serum. The abrogation of inhibition in autologous serum is specific to the HL-A antigens of the donor. These observations suggest that survival of human renal allografts depends on a blocking substance in the serum initially; subsequently, the loss of inhibition of migration with HL-A antigens in both autologous and allogeneic serum suggests an inactivation of specific antigen sensitive cells to the histocompatibility antigens of the donor.