Results of kidney transplants in patients who are HLA incompatible (HLAi) are inconsistent, particularly when lower levels of donor-specific antibodies (DSA) are involved.

HLAi kidney transplant recipients were matched 1:2 with HLA-compatible (HLAc) kidney transplant recipients in a multi-center nationwide cohort study. HLAi was described as DSA found by Luminex. Kaplan-Meier plots were used to analyze antibody-mediated rejection (AMR) and transplant-survival data. To assess recipient and transplant survival between groups, Propensity Score (PS) matching was employed to assess recipient and transplant survival between groups.

With a mean age of 46 years and 60% female recipients, researchers included 61 HLAi and 122 HLAc patients. 23 (38%) of the 3,327 (IQR 1,352-6,458) MFIT0 samples had positive Flow Cytometry Crossmatch results (FC-XMPOS). In comparison to DSAPOS/FC-XMNEG (27%) and HLAc (0%), DSAPOS/FC-XMPOS transplantation was associated a higher risk of AMR at 1 year (52%) than those two combinations. At three years, unadjusted death-filtered graft loss was 13% (HLAi) and 8%. (HLAc). Patient survival at three years was 95% in HLAc recipients, 84% in DSAPOS/FC-XMNEG recipients, and 69% in DSAPOS/FC-XMPOS recipients; 58% of HLAi fatalities were caused by infections. In the PS-matched group, HLA incompatibility was linked to a worse 3-year survival rate.

DSA, and positive FC-XM in kidney transplantation enhances the risk of AMR. Even with less favorable transplant and survival results than HLAc transplantation, it was still a viable alternative for very sensitive individuals who must endure long waiting periods and decreased survival on dialysis.