Impact of HLA matching on the outcome of simultaneous pancreas-kidney transplantation

Background. Simultaneous pancreas-kidney (SPK) transplantation has become the therapy of choice for type 1 diabetic patients with end-stage renal disease. The current analysis examined the impact of human leukocyte antigen (HLA) matching on graft outcome following SPK transplantation. The study population was obtained from patients enrolled in the Euro-SPK 001 study. Methods. The effect of HLA matching on graft function and survival was assessed in 180 SPK recipients in whom complete donor recipient HLA data were available. A group of 45 patients with 0-3 HLA mismatches (MM) was compared with a group of 135 patients with 4-6 MM. Results. There were no differences in 3-year kidney, pancreas or patient survival between the 0-3 and 4-6 MM groups. Biological parameters of kidney and pancreas graft function were similar in both groups. Significantly more patients with 0-3 MM (66%) were rejection-free at 3 years than was the case among those with 4-6 MM (41%; P = 0.003). The relative risk of acute rejection was 2.6 times higher among patients with 4-6 MM than among those with 0-3 MM. Conclusions. There was no evidence that HLA matching was associated with improved kidney or pancreas survival. However, a higher rate of acute rejection was observed with poor HLA match, which may impact long-term survival.