SECONDARY ORGAN ALLOGRAFTING AFTER A PRIMARY BRIDGING XENOTRANSPLANT

It remains uncertain whether xenotransplantation can sensitize the rec ipient to alloantigens, rendering subsequent allotransplantation unsuc cessful. This is of considerable importance if a xenograft is to be us ed as a ''bridge'' to support the patient until a suitable allograft b ecomes available. When sera from 9 baboons that had received pig or Af rican green monkey heart or liver xenografts were tested against a pan el of lymphocytes from 5 or 6 potential donor baboons, positivity was seen in only 1 baboon (and then to only 2 of the potential 5 donors). In 4 baboons that had undergone previous xenotransplants (1 from this series of 9 baboons and 3 others), subsequent organ allografting was n ot followed by hyperacute, antibody-mediated, or accelerated cellular rejection. We conclude that organ xenotransplantation using discordant or concordant donor species does not prohibit subsequent allotranspla ntation.