The epidemiology of pediatric autoimmune hepatitis in Scotland: a national cohort study

Objectives: Autoimmune hepatitis (AIH) is a rare, but potentially severe, cause of liver disease in children. We aimed to summarise how children with AIH in Scotland presented, were investigated and managed in addition to producing novel epidemiological data and outcomes.
Methods: All prevalent paediatric patients with AIH cared for in paediatric services between January 2013 and September 2018 were included. Individual patient data was obtained from electronic patient records in the three-main academic paediatric centres in Scotland covering the entire population.
Results: 38 patients were included (25 female) with median follow-up of 33 months (range 2 -145 months) and 136 total patient years. The incidence between 2014-2017 was 0.49/100,000/yr (95%CI 0.29-0.78) and point prevalence between 2013-2018 was 1.75/100,000 (95%CI 1.42-2.13). 35 (92%) patients were autoantibody positive, most commonly anti-nuclear antibody (63%) and anti-smooth muscle antibody (42%). 37 (97%) patients had induction therapy with oral corticosteroids, 30 (79%) required maintenance treatment with azathioprine, and 23 (61%) received ursodeoxycholic acid. There were 1.4 disease flares per 10 patient years and 3 patients required liver transplantation with an overall 5-year survival rate without the need for transplantation of 95%.
Conclusion: We calculated a novel incidence and prevalence rate for paediatric AIH in Scotland. Nearly all were invariably treated initially with corticosteroids with most placed-on azathioprine as maintenance therapy. Outcomes were generally favourable with low rates of disease flares and the need for transplantation being rare.