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

Abstract

Rationale & objective: Compared with recipients of blood group ABO-compatible (ABOc) living donor kidney transplants (LDKTs), recipients of ABO-incompatible (ABOi) LDKTs have higher risk for 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 LDKTs (eg, through kidney paired exchange) or for a deceased donor kidney transplant (DDKT). We sought to evaluate the patient survival difference between ABOi LDKTs and waiting for an ABOc LDKT or an ABOc DDKT.

Study design: Retrospective cohort study of adults in the Scientific Registry of Transplant Recipients.

Setting & participants: 808 ABOi LDKT recipients and 2,423 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 to 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 and Cox models that accommodated for changing hazard ratios over time.

Results: Compared with matched controls, ABOi LDKT was associated with greater mortality risk in the first 30 days posttransplantation (cumulative survival of 99.0% vs 99.6%) but lower mortality risk beyond 180 days posttransplantation. Patients who received an ABOi LDKT had higher cumulative survival at 5 and 10 years (90.0% and 75.4%, respectively) than similar patients who remained on the waitlist or received an 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 posttransplantation experience a long-term survival benefit compared to remaining on the waitlist to potentially receive an ABOc kidney transplant.

Keywords: ABO incompatible; deceased donor kidney transplantation; end-stage renal disease (ESRD); kidney transplant recipient; living donor kidney transplantation; mortality; survival benefit.