# Midterm Outcome of AB0 Incompatible Kidney Transplantation in Children and Adolescents—A Single Center Experience

## TL;DR

This study shows that AB0 incompatible kidney transplants in children have similar safety and outcomes to compatible transplants over the midterm.

## Contribution

Demonstrates the safety and comparable midterm outcomes of AB0 incompatible kidney transplants in pediatric patients.

## Key findings

- AB0 incompatible kidney transplants in children had a 90% 3-year graft survival rate.
- Infections were more frequent in the AB0 compatible group compared to the AB0 incompatible group.
- No significant difference in graft or patient survival was found between AB0 incompatible and compatible groups.

## Abstract

In order to reduce the waiting time, new strategies have been developed to safely transplant donor and recipient pairs with mismatched blood groups. The present study examined the safety of the preparatory treatments and the midterm outcome of AB0 incompatible (AB0i) kidney transplantation in children.

We retrospectively analyzed 10 children who received a kidney transplant from an AB0i donor from 2012 to 2024 and 30 patients matched by sex, height, and weight who received an AB0 compatible (AB0c) living kidney transplant in the same period.

In the AB0i group, preparatory treatment before KTx was well tolerated. The number of rejection episodes was comparable in the AB0i group and in the AB0c group (three episodes in three patients vs. seven episodes in six patients) during the observation period of 36 months, with rejections occurring earlier in the AB0c group. Infections were more frequent in the AB0c group than in the AB0i group (30 episodes in 23 patients [76%] vs. eight episodes in six patients [60%]). In the AB0i group, the 3‐year graft survival rate was 90%; the 3‐year patient survival was 100%. In the AB0c group, the 3‐year graft survival was 86.8%, and the 3‐year patient survival was 93.3%. There was no difference in graft survival (p = 0.08) and patient survival (p = 0.24) between the AB0i and AB0c groups.

AB0 incompatible kidney transplants can be safely performed in children with equivalent midterm graft and patient survival.

AB0‐incompatible kidney transplantation in children can be performed with excellent results. Midterm outcome of AB0 incompatible KTx was not inferior to that of AB0 compatible KTx. Graft survival and graft function were comparably good in both groups. There was no increase in infectious complications or malignancies with AB0i KTx.