# Impact of Baseline Anti-ABO Antibody Titer on Biliary Complications in ABO-Incompatible Living-Donor Liver Transplantation

## TL;DR

Higher baseline anti-ABO antibody levels in liver transplant patients increase the risk of biliary complications.

## Contribution

Identifies high baseline anti-ABO antibody titer as a novel independent risk factor for biliary complications in ABO-incompatible liver transplants.

## Key findings

- Biliary complications occurred more frequently in patients with high anti-ABO antibody titers (≥1:128).
- High titer is an independent risk factor for biliary complications (hazard ratio 3.943).
- Diffuse intrahepatic biliary strictures were more common in the high titer group.

## Abstract

Background: Although advancements in desensitization protocols have led to increased ABO-incompatible (ABOi) living-donor liver transplantation (LDLT), a higher biliary complication rate remains a problem. This study evaluated the effect of baseline anti-ABO antibody titers before desensitization on biliary complications after ABOi LDLT. Methods: The study cohort comprised 116 patients in the ABO-compatible group (ABOc), 29 in the ABOi with the low titer (<1:128) group (ABOi-L), and 14 in the high titer (≥1:128) group (ABOi-H). Results: Biliary complications occurred more frequently in the ABOi-H group than in the ABOi-L and ABOc groups (7 [50.0%] vs. 8 [27.6%] and 24 [20.7%], respectively, p = 0.041). Biliary complication-free survival was significantly worse in the ABOi-H group than in the other groups (p = 0.043). Diffuse intrahepatic biliary strictures occurred more frequently in the ABOi-H group than in the other groups (p = 0.005). Multivariable analysis revealed that the high anti-ABO antibody titer (≥1:128) is an independent risk factor for biliary complications (hazard ratio 3.943 [1.635–9.506]; p = 0.002). Conclusions: A high baseline anti-ABO antibody titer (≥1:128), female sex, and hepatic artery complications are significant risk factors for biliary complications.