The interesting study by Vu et al1 describes the impact of HLA-DR mismatching on rejection, graft survival, and sensitization in pediatric kidney transplantation. They considered that HLA-DRB1 mismatches were a significant risk factor for rejection but not for graft failure or sensitization. However, history of rejection was an independent predictor of graft failure and sensitization. Their study was performed for a population of pediatric patients with a pretransplantation panel reactive antibody level of 0% to show the effect of HLA-DR mismatches on sensitization. Based on a previous observation,2 it would be interesting to study an immunized population with pretransplantation panel reactive antibody levels of greater than 0% in order to evaluate the effect of HLA-DR mismatches on the posttransplantation levels of panel reactive antibody, on rejection, and on graft survival. Moreover, the HLA-DR mismatch may influence long-term graft survival,3 so it would be interesting to evaluate the effects of HLA-DR mismatching not only at 5 years but also at 10 years. Although there is some controversy over the importance of HLA matching in the allocation of the kidney, it could be useful to analyze simultaneously the effect of HLA-ABC mismatches on rejection, graft survival, and sensitization in the same population as that in the study by Vu et al.1 The high degree of HLA mismatching during the first transplant could have an effect on young patients with a longer life expectancy who may need a second transplant during their lifetime. Indeed, several studies4 have suggested that there is a correlation between the degree of mismatches and posttransplantation sensitization.
Grimaldi V, Napoli C. The Effect of HLA-DR Matching on Pediatric Kidney Transplantation. Arch Surg. 2012;147(1):97. doi:10.1001/archsurg.147.1.97-a