O236: The Impact of HLA Matching on Pancreas and Simultaneous Pancreas-Kidney (SPK) Transplantation Outcomes

Abstract

Abstract Background This study evaluates the controversial impact of human leukocyte antigen (HLA) matching on pancreas graft survival and acute rejection. Methods Utilizing a large-scale multi-center database (UNOS/OPTN), we identified 8,005 pancreas and 7,850 simultaneous pancreas-kidney (SPK) transplant patients. Patients were classified into HLA matched (0-3 mismatches) and mismatched (4-6 mismatches) groups. Subsequently, utilizing multivariate Cox analysis, we evaluated risk-adjusted outcomes, represented through Kaplan-Meier survival curves. We also examined differences in graft survival and acute rejection based on transplant type (SPK or pancreas alone) within the same HLA mismatch group. Findings There were no significant differences in pancreas graft survival or acute rejection observed between HLA matched and mismatched groups for both pancreas and SPK transplant recipients (P > 0.05). However, among HLA mismatched patients, pancreas patients exhibited a 629-day lower pancreas graft survival than SPK patients (3774 vs. 4403 days, P < 0.001) and had a higher likelihood of experiencing acute rejection post-transplant (P < 0.001). Similarly, within the HLA matched groups, pancreas patients showed lower graft survival compared to SPK patients (3774 vs. 4403 days, P < 0.001); however, their acute rejection rates did not significantly differ (P > 0.05). Interpretation Although HLA matching was not associated with improved pancreas graft survival or a reduction in acute rejection, the results suggest a potential protective effect of the kidney in SPK transplants against the consequences of HLA mismatching. This underscores the clinical significance of considering the kidney component in donor-recipient matching for pancreas transplantation.