Incidence, Prevalence, Medication Use, and Transplant Rates in Paediatric Autoimmune Hepatitis-A Nationwide Cohort Study.

BACKGROUND AND AIMS: Despite the aggressive nature of paediatric autoimmune hepatitis (P-AIH), population-based epidemiology is poorly described. We aimed to validate an algorithm to identify patients with P-AIH in the Danish National Patient Registry (DNPR) and report incidence rates, prevalence, and describe medication exposure and liver transplantation rates.

METHODS

This was a nationwide, register-based study. We used a smaller population-based P-AIH cohort as true positives for validation. The best-performing algorithm was then used to identify all patients in Denmark with P-AIH (1978-2022). Incidence rates and prevalence for the period 1996-2022 are presented. We used the National Prescription Register and DNPR to report on the use of prednisolone, thiopurine, and tacrolimus as well as liver transplantation.

RESULTS

Based on the best-performing algorithm (sensitivity 0.94, specificity 1.0), we identified 222 incident patients. The incidence rate rose from 0.7/100000 person-years in 1999-2001 to the highest observed incidence rate in 2014-2016 (4.5/100000 person-years). The prevalence rose from 2.2/100.000 persons in 1999-2001 to the highest observed in the 2017-2019 period (8.8/100.000 persons). During the first year, 212 (95%) were treated with prednisolone, 159 (72%) with thiopurines, and 23 (10%) with tacrolimus. After five years, 219 (99%) had been treated with prednisolone, 178 (80%) with thiopurines, and 44 (20%) with tacrolimus. Native liver survival was 97% and 93% at 5 and 10 years after diagnosis.

CONCLUSION

The incidence and prevalence of paediatric autoimmune hepatitis in Denmark have increased over the past two decades. Most patients receive corticosteroids and thiopurines, and native liver survival remains high.