Paediatric autoimmune liver disease in Europe, the prospective ERN R-Liver registry

BACKGROUND & AIMS: Most literature on paediatric autoimmune liver disease (p-AILD) comprises single-centre, retrospective studies. This study aims to describe robust, real-world data for p-AILD during the first year following diagnosis, utilising data from the prospective European Reference Network (ERN) R-LIVER Registry. METHODS: All patients younger than 18 years with autoimmune hepatitis (AIH) or autoimmune sclerosing cholangitis (ASC) enrolled in the ERN R-LIVER Registry from January 2017 to October 2023 and with >12 months of follow-up were included. Each participating centre recorded data from three time points: diagnosis, six and twelve months. RESULTS: A total of 116 p-AILD patients were enrolled. 71 patients had AIH1, 8 had AIH2, and 37 had ASC. At diagnosis, 27% had cirrhosis. Large duct disease was diagnosed in 45% of ASC. Inflammatory bowel disease was present in 14% at diagnosis. No differences were found in presentation and outcome between AIH1 and 2. Most patients (94%) began treatment with standard therapy (prednisolone with/without thiopurines), and 80% were kept on it during the first year. Complete biochemical remission was achieved by 44 (42%) at six months and by 45 (42%) at 1 year, while normal ALT (<45) and IgG (age dependent) levels were observed in 81 (72%) and 53 (51%), respectively, at 12 months. All patients were alive at the end of follow-up, and two required liver transplantation. CONCLUSIONS: Short-term survival in p-AILD is excellent. However, less than half of p-AILD patients achieved complete biochemical remission at one year, with ASC and cirrhosis as main predictors of failure. These findings emphasise the need for improved therapeutic strategies.