Mobile blood-derived components in rat renal allograft contain significant immunogenic potential

Using a modified 'primed rejection assay' (PRA), we have investigated the immunogenic potential of different rat renal allograft components. Temporary transplantation of an extensively perfused DA kidney to a WF recipient can sensitize the WF recipient in less than 10 min; consequently, the survival of a subsequent DA heart allograft is significantly reduced. Irradiation of the renal allograft donor significantly reduces the immunogenic potential of the first allograft, but does not deplete it entirely. When the first allograft was made chimeric with regard to the (capillary) blood compartment, it was found that in vivo perfusion of an irradiated DA kidney with WF blood did not alter the immunogenic potential in WF recipients, whereas perfusion of irradiated DA kidneys with DA blood increased the immunogenicity. On the other hand, short in vivo perfusion of irradiated WF kidneys with DA blood make the first WF kidney allograft strongly immunogenic in the WF recipient, whereas perfusion of the kidney with WF blood has no effect. The rapid rate of sensitization observed, coupled with the induction and alteration of the allograft immunogenic potential by manipulation of blood-derived capillary compartment, suggests that mobile blood-derived components, which are outside the reach of extensive perfusion, contain significant immunogenic potential.