Monotherapy with thiopurines in stricturing Crohn's disease: A real-life experience from low- and middle-income countries

Background Stricturing Crohn's disease (CD) is difficult to manage medically with limited treatment options, anti-tumor necrosis factor (TNF) therapy being the first-line therapy. Although thiopurines are also recommended first-line treatment option for maintenance of remission in steroid-dependent CD, evidence on their use in stricturing CD is lacking. We evaluated the efficacy of azathioprine (AZA) in patients with stricturing CD. Methods In this retrospective cohort study (January 2005 to July 2020), patients with stricturing CD who were managed with AZA as a primary therapy for at least 6 months, and had a follow-up of at least 6 months after AZA initiation were included. Disease characteristics, complications, long-term response, and adverse events were noted. Results One hundred and fifteen patients were included (mean age 33.8 +/- 14 years, 67.8% males, median disease duration 98 months [IQR: 60-158], median follow-up duration 60 months [IQR: 50-96]). 46.1% (n=53) patients had significant anemia at presentation, and 73% (n=84) had isolated small bowel involvement. Median dose of AZA was 100 mg (equivalent to 1.5 mg/kg). Median therapy and follow-up duration (after AZA initiation) was 17 (IQR: 9-42) and 33 months (IQR 18-60), respectively. The cumulative probability of maintaining response without treatment failure at 1, 2, and 5 years was 73.1%, 40.7%, and 18.5%, respectively. Among patients with AZA failure, 15.6% received methotrexate, 13% received anti-TNFs, and 9.5% underwent surgery. Significant anemia (<10 g/dL) at presentation and steroid dependence predicted AZA failure. 31.3% patients experienced adverse events, commonest being leukopenia (n=29, 25.2%). Conclusion Azathioprine demonstrated good short-term and modest long-term response rates in patients with stricturing CD.