Increasing Rejection Rates of Pancreas Transplants in the Long Term Follow Up after SPK

Abstract

Introduction: In simultaneous pancreas and kidney transplantation (SPK) most authors suppose that the majority of rejection episodes of the pancreas transplant (PTX) and kidney transplant (KTX) occur simultaneously. However exact numbers are not available because in contrast to KTX biopsies PTX biopsies are not routinely performed in the majority of centres. At our institution KTX and/or PTX biopsies are done in about 85% of patients with graft dysfunction. We therefore were able to estimate the distribution of rejected grafts in our SPK patients. Method: In this retrospective analysis we investigated 90 consecutively transplanted SPK patients for the number and the graft distribution of their rejection episodes. SPK was performed between 1995-2000, the follow-up period ended 2008, median follow-up time was 9.4 years. Rejection episodes of the KTX were detected by biopsy, rejection episodes of the PTX were either detected by biopsy or by clinical signs (doubling of serum lipase, impairment of HbA1c and/or fasting plasma glucose and/or OGTT which was not related to pancreatitis, drug toxicity or other diabetes inducing events). Simultaneous rejection episodes of KTX and PTX were diagnosed, when the biopsy of both grafts showed rejections or when one graft biopsy showed rejection and the other graft showed clinical signs of rejection. Results: Survival of patients/PTX/KTX was 87/75/79% after 9.4 years (not censored for death). Overall, we observed 145 rejection episodes in 71 of 90 patients. The distribution of the rejection episodes within the first year and after the first year post-SPK was:KTX only and simultaneous rejection of PTX and NTX were more common during the first year. Afterwards an increasing proportion of PTX only rejections could be detected:Conclusion: Despite high numbers of rejection episodes -which may be related to a very narrow follow- up and very aggressive diagnostic strategies concerning KTX and/or PTX biopsies- it is possible to achieve very good long-term results in SPK. KTX only rejection is the most frequent diagnosed type of rejection. Single PTX rejections are more frequent than suspected, especially in the long-term course of SPK. Most of these PTX rejections can be treated successfully, when detected early.