The relationship between 6-thioguanine levels and remission outcomes in children with autoimmune hepatitis. Single center experience

AIM OF THE STUDY: The treatment of autoimmune hepatitis (AIH) is based on steroids and azathioprine (AZA). AZA is a pro-drug which is converted among others into 6-thioguanine (6-TG) and 6-methylmercaptopurine (6-MMP). The aim of the study was to determine the relationship between the AZA active metabolite 6-TG and both the biochemical and histological remission outcomes. MATERIAL AND METHODS: The authors conducted a retrospective analysis of a single chart review. The sample size consisted of 44 pediatric patients with AIH. Biochemical remission was defined as an alanine aminotransferase (ALT) level below 40 U/l and histological remission was defined as a situation when the control biopsy revealed inflammation grade G1 (or lower) in the Batts-Ludwig score. Statistical analysis was applied to assess the difference in remission outcomes in patients with different levels of 6-TG. RESULTS: In the benchmark variant of our statistical analysis, we found that the correlation between 6-TG and ALT in the sample was not statistically significant. Moreover, the difference between the mean levels of ALT in the populations in and without remission was not statistically significant (the p-value of the t-test was 0.16). CONCLUSIONS: Our results tend to support the claim that there is no statistically significant relationship between 6-TG concentration and remission (both biochemical and histological) in pediatric patients with AIH.