Impact of ABO-Incompatible Living Donor Kidney Transplantation on Patient Survival

ABSTRACT Rationale and Objective Compared to recipients of ABO-compatible (ABOc) living donor kidney transplants (LDKT), recipients of ABO-incompatible (ABOi) LDKT have a higher risk of graft loss, particularly in the first few weeks after transplantation. However, the decision to proceed with ABOi LDKT should be based on a comparison of the alternative: waiting for future ABOc LDKT (e.g, through kidney paired exchange) or for a deceased donor kidney transplant (DDKT). We sought to evaluate the patient survival difference between ABOi LDKT and waiting for an ABOc LDKT or an ABOc DDKT. Study Design Retrospective cohort study of adults in the Scientific Registry of Transplant Recipients (SRTR) Setting and Participants 808 ABOi LDKT recipients and 2423 matched controls from among 245,158 adult, first-time kidney-only waitlist registrants who did not receive an ABOi LDKT and who remained on the waitlist or received either an ABOc LDKT or an ABOc DDKT, 2002-2017 Exposure Receipt of ABOi LDKT Outcome Death Analytical approach We compared mortality among ABOi LDKT recipients versus a weighted matched comparison population using Cox proportional hazards regression as well as Cox models that accommodated for changing hazards ratios over time. Results Compared to matched controls, ABOi LDKT was associated with lower survival risk in the first 30 days post-transplant (99.0% vs 99.6%, respectively), but higher survival risk beyond 180 days post-transplant. Patients who received ABOi LDKT had higher survival at 5 and 10 years (90.0% and 75.4% respectively) than similar patients who remained on the waitlist or received ABOc LDKT or ABOc DDKT (81.9% and 68.4% respectively). Limitations No measurement of ABO antibody titers in recipients; eligibility of participants for kidney paired donation is unknown. Conclusions Transplant candidates who receive an ABOi LDKT and survive more than 180 days post-transplant experience a long-term survival benefit compared to remaining on the waitlist to potentially receive an ABO compatible kidney transplant.