Abstract Background Simultaneous pancreas–kidney (SPK) transplantation offers the best long-term survival for selected patients with insulin-dependent diabetes and end-stage renal disease. However, determinants of pancreas graft survival remain incompletely defined, particularly the role of HLA mismatch and induction therapy. Methods We analysed all SPK transplants in the UK between April 2007–March 2019 using data extracted from the UK Transplant Registry. Multivariable Cox proportional hazards models assessed the impact of locus-specific HLA mismatch and induction therapy (Alemtuzumab versus Basiliximab) on pancreas, kidney, and patient survival, adjusted for donor, recipient, and transplant factors. Results Among 1705 SPK recipients, pancreas graft survival was 88.6, 81.3, and 72.7% at 1, 5, and 10 years, respectively. Kidney graft and patient survival at 10 years were 76.7 and 75.3%. Independent predictors of pancreas graft loss included donor age, cold ischaemic time, and HLA-DQ mismatch. Unexpectedly, recipients with a DQ mismatch had improved long-term pancreas graft survival compared with those with no mismatch (HR 0.75, 95% c.i. 0.59–0.94, P = 0.033). This protective effect was not observed for kidney or patient outcomes. Induction therapy type did not significantly influence survival on adjusted analyses. Conclusions In this first national analysis of HLA and induction in SPK transplantation, DQ mismatch was associated with superior long-term pancreas graft survival. This novel finding warrants mechanistic investigation and may inform future allocation and immunogenetic strategies in pancreas transplantation.
Malik et al. (Sun,) studied this question.