Outcomes of ABO-Incompatible Versus ABO-Compatible Liver Transplantation in Pediatric Recipients: An Updated Systematic Review and Meta-Analysis.

BACKGROUND AND

OBJECTIVE

ABO-incompatible (ABO-i) liver transplantation (LT) in children is increasingly used to address organ scarcity, but concerns about immunological, vascular, and biliary complications remain. With evolving desensitization strategies and emerging pediatric data, an updated meta-analysis comparing ABO-i and ABO-compatible (ABO-c) LT is warranted.

METHODS

PubMed, Embase, and Scopus were searched from inception to June 2026 to include studies evaluating ABO-i versus ABO-c LT in recipients ≤ 18 years of age. Primary outcomes were comparison of 1-, 3-, and 5-year patient and graft survival between the two groups. Secondary outcomes included comparisons of vascular and biliary complications, rejection, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections, and post-transplant lymphoproliferative disease (PTLD).

RESULTS

Seventeen studies were included. Patient survival was comparable between the two groups at 1 year (risk ratio [RR]: 0.97, 95% confidence interval [CI]: 0.94-1.0, p = 0.07), 3 years (RR: 0.98, 95% CI: 0.94-1.01, p = 0.22) and 5 years (RR: 0.97, 95% CI: 0.88-1.07, p = 0.50). Likewise, graft survival showed no significant differences. Incidence of vascular and biliary complications, acute rejection, CMV and EBV infection, and PTLD also did not differ significantly between groups. Antibody-mediated rejection (AMR) was significantly higher in ABO-i recipients (RR: 20.04, 95% CI: 3.25-123.56, p = 0.001), although this finding was based on only four studies. Overall, heterogeneity was low. Certainty of evidence was rated as very low, primarily due to the observational design of included studies and risk of bias.

CONCLUSIONS

ABO-i LT in pediatric recipients demonstrates survival and complication outcomes comparable to those of ABO-c LT. However, very low certainty of evidence highlights the need for future well-designed prospective studies.