Even in more recent periods, HLA mismatches show a linear association with the outcomes of kidney allograft survival, concludes a study in Transplantation.
The analysis included more than 189,000 first adult, deceased-donor, kidney-only transplants performed in the US from 1987 through 2013. Number of HLA mismatches was evaluated for associated-with-kidney-allograft survival, with adjustment for recipient and donor characteristics.
In nearly 995,000 years of follow-up, HLA mismatch was significantly related to allograft survival. In the fully adjusted model, hazard ratio for allograft failure increased in linear fashion with each additional HLA mismatch: from 1.13 with 1 mismatch to 1.98 with 6 mismatches (compared to zero mismatches).
The effect of HLA mismatch remained significant after considering the increasing success of kidney transplantation in recent years. Nearly all mismatch categories showed equal effect on the risk of transplant failure, independent of locus.
There are conflicting reports as to the importance of HLA matching as a determinant of kidney allograft survival. The new analysis shows a significant linear relationship of hazard ratios for allograft failure with the number of HLA mismatches—even at a time of better transplant success rates. The investigators conclude that their results “reinforce the importance of optimizing HLA matching to further improve survival in renal allografts in the future” [Williams RC, et al. The risk of transplant failure with HLA mismatch in first adult kidney allografts from deceased donors. Transplantation 2016; 100:1094–1102].
