THE FREQUENCY OF REJECTION EPISODES AFTER COMBINED KIDNEY-PANCREAS TRANSPLANT - THE IMPACT ON GRAFT-SURVIVAL

The recipients of combined kidney-pancreas transplants (SPK) are uniqu e because they routinely receive two allografts from the same donor. I n a previous study, we found that the long-term graft survival of the two allografts was different, with better graft survival seen in the p ancreas allograft. In an attempt to understand the reason for the diff erent graft survival in the recipients of organs from the same donor, we have reviewed the incidence and timing of rejection episodes in 160 consecutive technically successful whole-organ bladder-drained SPK pe rformed at a single institution using a uniform immunosuppressive regi men. Rejection episodes were common. A total of 53% of the recipients had at least one episode of rejection in one of the organs. Multiple r ejection episodes requiring hospitalization occurred in 23% of the rec ipients. The kidney allograft had more frequent rejection episodes tha n the pancreas allograft: 78 patients had 130 renal rejection episodes while only 50 patients had 65 episodes of pancreas rejection. No reje ction episodes occurred in 111 pancreas and 82 kidney grafts (P=0.0014 ). Multiple rejection episodes were three times as common in the kidne y grafts (20%) than in the pancreas grafts (6%; P=0.0001). The timing of the first rejection episode was also different. The median time to the first kidney rejection episode was 29 days compared with 39 days t o the first pancreas rejection episode (P=0.0191). Graft survival in t he organs was equal when stratified by the number of rejection episode s (none, one, > one) per organ (P=0.9378). These data suggest that the worse long-term kidney graft survival seen in SPE( recipients is due to the greater risk of rejection (relative risk: 2.04; [95% conf. inte rval: 1.29-3.23]) and a greater frequency of rejection episodes of rej ection episodes in the kidney (0.81/ patient) compared with the pancre as (0.41/patient). The implications for patient management and the pos sible reasons for the different rates of rejection are discussed.