Thiopurine S- methyltransferase genotype mutation in pediatric patients with inflammatory bowel disease on azathioprine: A pilot study

Abstract

nflammatory Bowel Disease (IBD) is a serious disease as well as the drugs used to treat it.Polymorphism of thioprone S-methyl transferase enzyme (TPMT) gene has been reported to cause fatal complications in patients treated with azathioprine (AZA). The FDA recommends TPMT genotyping or phenotyping before starting treatment with azathioprine. This allows patients who are at increased risk for toxicity to be identified and for the starting dose of azathioprine to be reduced, or for an alternative therapy to be used. We hypothesized that we have a different mutation because of our oligo ethnicity in comparison with the worldwide most common alleles mutation and we aimed to detect the frequency and mutation of TPMT variants and to monitor the clinical response of AZA and correlate the presence of side effects to the TPMT testing. The study included 19 patients with IBD who were planned to start azathioprine during our research duration (2017-2019) at the Pediatric Gastroenterology Unit, Ain shams University Children’s Hospital. IBD was diagnosed based on clinical, endoscopic, radiological and histological criteria.11 patients with crohns’ disease (Group A) and 8 patients with ulcerative colitis (Group B) 47.4%(n=9) males and 52.6% (n=10) females.