Fig. 7.13. The changing use of calcineurin inhibitors for new SPK transplants (Source, 2002 OPTN/SRTR Annual Report).

initial presentation of acute rejection. Graft pancreatitis and urinary leak of a bladder-drained pancreas can present in a similar manner. Often, patients will require bladder catheterization to differentiate graft rejection from reflux pancreatitis.

The gold standard for confirming the diagnosis of pancreas graft rejection is pancreas graft biopsy. The biopsy may be performed by several methods including the percutaneous approach, transcystoscopic biopsy in a bladder-drained pancreas, or open surgical biopsy. The usefulness of pancreas graft biopsy to confirm the clinical suspicion of rejection is so important that the surgical procedure of pancreas transplantation should include consideration of the intra-abdominal location of the pancreas to make it accessible for percutaneous biopsy. This is especially important in pancreas transplant alone and pancreas-after-kidney transplant procedures. Figure 7.14 shows the histologic features of acute pancreas graft rejection.

In the situation of a simultaneous pancreas-kidney transplant, it is the kidney allograft that is the best indicator of a rejection reaction. Rejection of the kidney allograft will manifest as a rise in serum creatinine. This will prompt ultrasound and biopsy of the kidney allograft. If rejection is present, anti-rejection therapy is instituted. If there is a concurrent pancreas graft rejection process, the anti-rejection therapy will reverse the process in both organs. It is extremely uncommon for isolated pancreas allograft rejection to occur in a setting of a simultaneous kidney-pancreas transplant. However, this may occur in 1-2% of cases and the diagnosis is made by kidney and pancreas transplant biopsies. Treatment of the pancreas alone rejection is guided by its severity and requires pulse steroids or anti-lymphocyte immunotherapy. The success rates for reversing pancreas allograft rejection are very high, in excess of 90%, if diagnosed promptly. There was a time when incidence of pancreas transplant rejection was greater than in kidney transplant-alone recipients. With the application of new immunosuppressive agents, however, the incidence of pancreas rejection has been reduced from approximately 80% to less than 30%.

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