Korean J Transplant.  2022 Nov;36(Supple 1):S47. 10.4285/ATW2022.F-1621.

Impact of low-level donor-specific anti-HLA antibody on posttransplant clinical outcomes of kidney transplant recipients: analysis from Korean Organ Transplantation Registry data

• Lee H
• Park JH
• Park JW
• Ban TH
• Yang J
• Kim MS
• Yang CW
• Chung BH
• Korean Organ Transplantation Registry

• KMID: 2535251
• DOI: http://doi.org/10.4285/ATW2022.F-1621

Abstract

Background
The clinical relevance of donor-specific anti-human leukocyte antigen antibody (HLA-DSA), detected only by solid phase assay (SPA) remains controversial. This study aimed to investigate the impact of low-level donor-specific anti-HLA anti-body (low-DSA) on posttransplant clinical outcomes of living donor kidney transplantation (LDKT) recipients using the Korean Organ Transplantation Registry (KOTRY) database, the nationwide cohort.
Methods
We analyzed KOTRY data, which included 5,047 cases of LDKT performed between 2014 and 2020. Patients whose HLA-DSA was positive in SPA but negative in crossmatch test were defined as the low-DSA group. Patients without HLA-DSA using both SPA and crossmatch test were defined as the no-DSA group. 2,612 were excluded because of the positive or unknown crossmatch test result or the unknown SPA result. Thus, 2,435 patients were eligible for analysis. Because we observed obvious differences in baseline characteristics between low-DSA and no-DSA groups, propensity score matching was conducted. Two groups were matched in a 1:1 ratio. We compared the incidence of clinical rejection and biopsy proven acute rejection (BPAR), allograft and patient survival rates, changes in allograft function, and infection free survival rate.
Results
The incidence of total rejection including clinical rejection, overall BPAR, or biopsy-proven acute T-cell mediated re-jection did not differ between two groups. However, biopsy-proven acute antibody-mediated rejection (ABMR) developed more frequently in low-DSA group than in no-DSA group (5.8%, 17/295 vs. 1.7%, 5/295; P=0.009) (Fig. 1). In multivariable analysis, low-DSA was an independent risk factor for the development of ABMR (odds ratio, 3.060; 95% confidence interval, 1.090–8.592; P=0.034). There was no significant difference in allograft survival rate, patient survival rate, changes in allograft function, or in-fection free survival rate.
Conclusions
In conclusion, pretransplant low-DSA was a significant risk factor for the development of acute ABMR. However, this impact did not lead to differences in long-term allograft outcomes.