Autoimmune liver disease in pediatrics: its association with extrahepatic autoimmune diseases.

ntroduction. Autoimmune liver disease is a chronic and progressive inflammatory pathology; it often requires organ transplantation. In pediatrics, although the incidence is low, a significant percentage of patients also present with associated extrahepatic autoimmune diseases. Diagnosis is based on elevated transaminases and immunoglobulins, the presence of autoantibodies, and specific histological findings, with the absence of other known liver pathologies. Objective. To determine the prevalence of extrahepatic autoimmune diseases in pediatric patients with autoimmune liver disease, to describe the relationship between these entities, and to evaluate possible clinical and laboratory differences at diagnosis between patients with and without associated extrahepatic autoimmune diseases. Population and methods. Retrospective study that analyzed pediatric patients diagnosed with autoimmune liver disease between 2000 and 2022 in a tertiary-level hospital. Results. A total of 139 patients were included, with 62.6% being women. The median age at diagnosis was 7.3 years. The most frequent type of autoimmune hepatitis was type 1 (74.8%). An associated extrahepatic disease was present in 41.7% of patients; ulcerative colitis was the most common (39.7%), followed by celiac disease (20.7%) and hypothyroidism (12.1%). Ulcerative colitis was present in 73.3% of patients with autoimmune sclerosing cholangitis. Patients without associated autoimmune extrahepatic disease required liver transplantation more frequently (18.5%) than those with associated extrahepatic disease (5.2%). Conclusion. The study shows a high prevalence of extrahepatic autoimmune diseases in children with autoimmune liver disease. Ulcerative colitis is the most frequent, especially in cases of autoimmune sclerosing cholangitis.