Session Name: Poster Session A: Histocompatibility and Immunogenetics
Date: Saturday, May 30, 2020
Session Time: 3:15pm-4:00pm
Presentation Time: 3:30pm-4:00pm
*Purpose: The development of de novo donor-specific anti-HLA antibodies (dnDSA) remains a major risk factor for poor long-term kidney allograft outcomes. In particular, anti-HLA-DQ dnDSAs, which are resistant to treatment, have the highest association with poor allograft outcomes. The purpose of this study is to evaluate whether HLA-DQ epitope matching from serological HLA-DQ typing may identify HLA-DQ mismatches (MMs) with a lower risk for anti-HLA-DQ dnDSA development in a large multi-center cohort.
*Methods: We retrospectively studied 1703 HLA-DQ mismatched kidney recipients, without preformed DSA, that were transplanted between 2007 and 2016 at four U.S. centers without preformed DSA. HLA-DQ serological epitope mismatch load (DQEpiL) was assessed using Table 1, where only antibody-verified HLA-DQB1 epitopes present on any HLA-DQB1 molecule of a same HLA-DQ serology are considered.
*Results: Among the 1703 recipients, we observed a total of 2389 HLA-DQ MMs, of which 163 induced a dnDSA. There was no significant difference in the prevalence of dnDSA between DQ MMs with DQEpiL from 0 to 8 (p=0.065). However, the prevalence of dnDSA was significantly higher for HLA-DQ MMs with DQEpiL>0 compared to HLA-DQ MMs with DQEpiL=0 (7.2% vs. 3.8%, respectively) (p=0.037), but there was no significant difference in the prevalence of dnDSA among DQ MMs with DQEpiL>0 (p=0.19) (Figure 1). Last, stratifying recipients based on total DQEpiL=0 identified 144 (8.5%) recipients, which had a significantly lower prevalence of anti-HLA-DQ dnDSA compared to recipients with a total DQEpiL>0 (3.5% vs. 8.7%, respectively) (p=0.030) (Figure 2).
*Conclusions: This study shows that, in contrast to the level of DQEpiL, HLA-DQ MMs with DQEpiL=0 induce dnDSA significantly less often than HLA-DQ MMs with DQEpiL>0. Moreover, the stratification of recipients based on total DQEpiL=0 significantly lowers the prevalence of anti-HLA-DQ dnDSA. Serological HLA-DQ epitope matching may be a strategy to reduce the development of dnDSA, although further studies are warranted.
To cite this abstract in AMA style:Jucaud V, Stegall M, Schinstock C, Heilman R, Rebellato L, Samaniego-Picota M, Leeser D, Gandhi M, Beaumont J, Everly M. Is the Epitope Mismatch Load Enough to Identify HLA-DQ Mismatches with a Low Risk for De Novo DSA Development? [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/is-the-epitope-mismatch-load-enough-to-identify-hla-dq-mismatches-with-a-low-risk-for-de-novo-dsa-development/. Accessed August 1, 2021.
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