HLA-DQ Mismatching and Kidney Transplant Outcomes

Abstract

HLA-DQ mismatching is associated with lower graft survival independent of HLA-ABDR in living donor kidney transplants and deceased donor kidney transplants with cold ischemia time ≤17 hours, and a higher 1-year risk of acute rejection in living and deceased donor kidney transplants.

Substituting imputation of HLA antigens for high-resolution HLA typing: Evaluation of a multiethnic population and implications for clinical decision making in transplantation

“…Historically, only HLA‐A, ‐B, and ‐DR have been considered when assessing the degree of mismatch between donor and recipient. Recent evidence has shown that HLA‐DQ mismatch is associated with graft loss, 26 and anti‐DQ antibodies are the most common type of donor specific antibody to develop after a kidney transplant 27 . Despite this evidence, it is still common practice to rely on linkage disequilibrium between HLA‐DR and HLA‐DQ, assuming that matching at ‐DR “automatically” means a match at DQ 28 .…”

Does HLA matching matter in the modern era of renal transplantation?

“…Therefore, both allograft quality and HLA matching are important for determining survival outcomes though there is a larger effect of donor quality in the earlier post-transplant years (5-10 years) registry studies, Lim et al recently showed that HLA-DQ MM increased the likelihood of acute rejection and ABMR (all patients in ANZDATA) [27]. HLA-DQ MM alone was not a risk factor for allograft loss but the combination of HLA-DR and DQ MM had the worst outcome [27,28]. Incorporating HLA-DQ MM information in future registry studies will further elucidate the importance of HLA class II versus class I matching.…”

Is There a Need for Additional DQ Matching?

“…In this issue of the Clinical Journal of the American Society of Nephrology, Leeaphorn et al (5) report evidence that, in addition to HLA-A, -B, and -DR matching, matching for HLA-DQ antigens could also be beneficial in recipients of deceased as well as living donor kidneys regarding clinical outcome; .90,000 patients transplanted between 2005 and 2014 in the United States were analyzed. This high number was necessary, because the most important part of this analysis had to be performed in the subgroup of patients who received a zero DR and one DQ mismatched deceased donor organ; the number of such patients is, due to the strong linkage disequilibrium between HLA-DQ and HLA-DR and exclusion of recipients with cold ischemic time .17 hours, small.…”

“…However, a donor HLA-DR7 antigen can be associated with either the HLA-DQ2 or the HLA-DQ9 antigen and represent a mismatch if the donor has the DR7/DQ2 and the recipient has the DR7/DQ9 constellation. By analyzing patients with zero DR/one DQ mismatches, Leeaphorn et al (5) found that these patients had a higher rate of acute rejection episodes during the first year after transplantation and a higher rate of overall graft loss at 10 years than the patients with zero DR/zero DQ mismatches.…”