Characteristics and Outcomes of Autoimmune Hepatitis from a Tertiary Paediatric Centre, Cape Town, South Africa

Efficiency of azathioprine monotherapy for maintenance treatment of autoimmune hepatitis in children

INTRODUCTION

Autoimmune hepatitis (AIH) is a common pediatric liver disease and long-term remission is usually maintained with low dose prednisolone and azathioprine (AZA). The aim of this study is to evaluate the efficiency of AZA monotherapy for maintenance treatment of children with AIH.

MATERIALS AND METHODS

This study was a retrospective analysis of the 55 children with AIH. Patients were divided into two groups: combination therapy (CT) and AZA group based on maintenance therapy. Results of these two different maintenance treatments were compared in children with AIH.

RESULTS

The mean age of the children was 10.67 ± 4.30 years (61.8% females) with a mean follow-up period of 46.8 ± 33.6 months. For maintenance treatment, 39 (70.9%) patients received AZA and 16 (29.1%) patients received CT. Relapse was observed in nine (19.6%) cases in the follow-up period; two were in the CT group (2/16; 12.5%) and seven (7/39; 17.9%) were in the AZA group (P = 0.620). In AZA group, the duration of remission was 22.2 ± 6.1 months and that was longer than CT group (P = 0.025).

CONCLUSION

Our study suggests that AZA monotherapy is an effective and safe therapy for maintaining remission in children with AIH. AZA monotherapy may be used for maintenance treatment of children with AIH, except in cases of overlap syndrome and also to avoid side effects of long-term used steroids and to improve treatment compliance in proper cases.

Pathogenesis of Autoimmune Hepatitis-Cellular and Molecular Mechanisms

Pediatric autoimmune liver disorders include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is an idiopathic disease characterized by immune-mediated hepatocyte injury associated with the destruction of liver cells, causing inflammation, liver failure, and fibrosis, typically associated with autoantibodies. The etiology of AIH is not entirely unraveled, but evidence supports an intricate interaction among genetic variants, environmental factors, and epigenetic modifications. The pathogenesis of AIH comprises the interaction between specific genetic traits and molecular mimicry for disease development, impaired immunoregulatory mechanisms, including CD4+ T cell population and Treg cells, alongside other contributory roles played by CD8+ cytotoxicity and autoantibody production by B cells. These findings delineate an intricate pathway that includes gene to gene and gene to environment interactions with various drugs, viral infections, and the complex microbiome. Epigenetics emphasizes gene expression through hereditary and reversible modifications of the chromatin architecture without interfering with the DNA sequence. These alterations comprise DNA methylation, histone transformations, and non-coding small (miRNA) and long (lncRNA) RNA transcriptions. The current first-line therapy comprises prednisolone plus azathioprine to induce clinical and biochemical remission. Further understanding of the cellular and molecular mechanisms encountered in AIH may depict their impact on clinical aspects, detect biomarkers, and guide toward novel, effective, and better-targeted therapies with fewer side effects.