In vitro alteration of canine renal allograft immunogenicity

Significant prolongation of renal allograft survival was demonstrated in a controlled canine model with the host suboptimally immunosuppressed when grafts were perfused for 24 hr with cryoprecipitated plasma (CPP) that had been obtained from plasma of dogs“pretreated” with i.v. cyclophosphamide (80 mg/kg for 51/2 hr) and i.v. methylprednisolone (60 mg/kg for 21/2 hr). The active metabolites of these drugs within the pretreated plasma may have modified the graft immunogenicity in vitro. However, the use of pretreated kidneys in combination with 24 hr of perfusion with CPP did not result in prolonged graft survival. Furthermore, 24-hr perfusion of pretreated kidneys with their own pretreated CPP did not improve graft survival. This suggests that the pretreated canine kidney does not tolerate pulsatile preservation with CPP; this is in contrast to the human experience and may be attributable to a species difference.