Abstract
RATIONALE & OBJECTIVE: The option for A2/A2B deceased donor kidney transplantation was integrated into the kidney allocation system in 2014 to improve access for B blood group waitlist candidates. Despite excellent reported outcomes, center uptake has remained low across the United States. Here, we examined the effect of implementing an A2/A2B protocol using a cutoff titer of ≤1:8 for IgG and ≤1:16 for IgM on blood group B kidney transplant recipients at a single center. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Blood group B recipients of deceased donor kidney transplants at a single center from January 1, 2019, to December 2022. EXPOSURE: Recipients of deceased donor kidney transplants were analyzed based on donor blood type with comparisons of A2/A2B versus blood group compatible. OUTCOMES: One-year patient survival, death-censored allograft function, primary nonfunction, delayed graft function, allograft function as measured using serum creatinine levels and estimated glomerular filtration rate at 1 year, biopsy-proven rejection, and need for plasmapheresis. ANALYTICAL APPROACH: Comparison between the A2/A2B and compatible groups were performed using the Fisher test or the χ(2) test for categorical variables and the nonparametric Wilcoxon rank-sum test for continuous variables. RESULTS: A total of 104 blood type B patients received a deceased donor kidney transplant at our center during the study period, 49 (47.1%) of whom received an A2/A2B transplant. Waiting time was lower in A2/A2B recipients compared with blood group compatible recipients (57.9 months vs 74.7 months, P = 0.01). A2/A2B recipients were more likely to receive a donor after cardiac death (24.5% vs 1.8%, P < 0.05) and experience delayed graft function (65.3% vs 41.8%). There were no observed differences in the average serum creatinine level or estimated glomerular filtration rate at 1 month, 3 months, and 1 year post kidney transplantation, acute rejection, or primary nonfunction. LIMITATIONS: Single-center study. Small cohort size limiting outcome analysis. CONCLUSIONS: Implementation of an A2/A2B protocol increased transplant volumes of blood group B waitlisted patients by 83.6% and decreased the waiting time for transplantation by 22.5% with similar transplant outcomes.