Introduction: Neonates between 0 and 6 months exhibit minimal anti-AB0 antibody production due to the immaturity of their immune system. During this period, they rely solely on maternally transferred antibodies via the placenta. Antibodies develop gradually and reach adult levels between 2 and 4 years of age. This physiological immaturity facilitates AB0-incompatible (AB0-I) liver transplantation (LT) in children under 2 years of age.
Methods: We conducted a retrospective review of all consecutive patients aged between 0 and 2 years who underwent LT at ISMETT Hospital between February 2017 and November 2024. Data were collected on demographics data, clinical indications, age at transplant, donor type and post-transplant outcomes. Patients were divided into two groups: Group 1 (AB0-compatible (AB0-C) transplants) and Group 2 (AB0-I transplants). Isoagglutinin dosage was performed in all patients during work up study, and no desensitization protocols were applied prior to transplantation to any patient. Graft and patient survival rate was considered as most important element in the outcome.
Results: A total of 39 patients, aged between 0 and 2 years, were recruited (12 males and 27 females). 26 patients (67%) corresponded to group 1 and 13 patients (33) to group 2. 34 patients (87%) underwent a living donor (LD) LT. For 33 patients (85%) biliary atresia was the indication to LT. In group 1 the mean age at transplant was 0,98 years and in group 2 was 0,75 years. The mean follow up in group 1 was 3,1 years and in group 2 was 3,2 years. The graft survival rate in group 1 was 100% and the patient survival rate was 96%. In group 2 graft and patient survival rates were 100%. Only one patient died for measles.
Conclusion: In our series there are no differences in graft and patient survival rate of ABO-I transplanted patients. Isoagglutinin production remains limited in children under 2 years of age, allowing for ABO-I LT without the need for desensitization protocols. Our study confirms the safety of ABO-I LT in living donors. This approach confirms the safety and the appropriate indication of LD LT in case of AB0-I and helps to reduce waiting times on the national transplant waiting list.