IMPACT OF HLA SENSITIZATION ON PATIENT AND GRAFT OUTCOMES IN ABO-INCOMPATIBLE LIVING DONOR KIDNEY TRANSPLANTATIONS

Introduction:

Kidney transplants (KT) across the HLA barrier and Anti-ABO antibodies with desensitization treatment are believed to improve the patient survival rate rather than remaining on hemodialysis. Sensitization poses a challenge in ABO-incompatible (ABO-i) KTs, as it may increase the risk of antibody-mediated rejection (AMR), affecting graft and patient outcomes. Despite advances in desensitization and monitoring, the impact of HLA sensitization on outcomes in ABO-i KT remains underexplored.

Methods:

We conducted a retrospective observational study including 184 ABO-i kidney transplant recipients from Jan 2013 to Dec 2023. The cohort was divided into HLA-sensitized (n=74) and non-sensitized (n=110) groups. Baseline characteristics, immunological profiles, and clinical outcomes were analyzed, including graft survival, patient mortality, and biopsy-proven acute rejection (BPAR), Kaplan-Meier survival analysis was employed to assess patient and graft survival, while Cox proportional hazards models were used to identify predictors of mortality and graft loss.

Results:

Out of 184 patients with ABO-i KT, 74 (40.2%) were HLA-sensitized, among these, 50 patients (67.6%) were sensitized to class II antigens, 13 patients (17.6%) to class I antigens, and 11 patients (14.9%) were sensitized to both class I and class II HLA antigens.The incidence of BPAR within 30 days post-transplant was comparable between the sensitized and non-sensitized groups (21.6% vs. 22.7%, p=0.491). Between 30 days and 1 year, BPAR rates were lower in the HLA-sensitized group (4.4% vs. 10.1%, p=0.136). Late rejection rates (>1 year) were similar between groups (15.15% vs. 12.8%, p=0.421) Graft survival was comparable between the sensitized and non-sensitized groups (p=0.161), with mean survival times of 105.78 months and 106.17 months, respectively. Patient mortality was also similar between the groups (p=0.426), with mean survival times of 99.19 months for sensitized patients and 102.57 months for non-sensitized patients. On follow-up, overall patient survival at 1, 3, 5, and 10 years were 91.6%,84.9%,81.8%, and 70.4% for HLA-sensitized and 91.8%,91.8%,87.5%, and 81.4% for non-sensitized patients, respectively (p=0.426). Death-censored graft survival at 1-, 3-, 5-, and 10-years were 98.2%,93.2%,88.1%, and 66.6% for HLA-sensitized and 98.6%,96.9%,94.7%, and 85.3% for non-sensitized patients (p=0.161), respectively. Poor graft outcome was identified as a significant predictor of mortality (HR=4.80, p=0.002). Serious infections requiring hospitalization (SIRH) within the first year occurred in 31.5% of sensitized patients and 44.4% of non-sensitized patients (p=0.080), while post-1-year infections occurred in 27.1% of sensitized patients and 36.9% of non-sensitized patients (p=0.181).

Conclusions:

HLA sensitization in ABO-i KT does not significantly impact graft survival or overall mortality compared to non-sensitized patients. However, early infectious complications were similar. This study underscores the feasibility and safety of ABO-i KT in sensitized patients, expanding the donor pool and improving access to transplantation for high-risk groups, and provides insights for optimizing transplant protocols in similar settings.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.