Azathioprine is effective in corticosteroid-dependent Asian inflammatory bowel disease patients

Azathioprine (AZA) is widely used to treat corticosteroid (CS)-dependent IBD patients but evidence supporting its use in Asian IBD patients is limited. We evaluated the efficacy of AZA in a single-center cohort of CS-dependent Asian IBD patients.

Patients treated with AZA were identified from our registry and the medical records were reviewed. Inclusion criterion was: first course of AZA and treatment duration ≥ 6 months. Clinical response was assessed at 6 months and classified as complete response, partial response, and nonresponse. Factors associated with response (age, gender, ulcerative colitis [UC] extent, Crohn's disease [CD] behavior, ethnicity, concomitant 5-aminosalicylates/sulfasalazine, baseline activity, disease duration, leukocyte count, mean corpuscular volume, and AZA dose) were analyzed using the chi-square or Mann-Whitney U-test. Probability of sustained remission was estimated using the Kaplan-Meier method. Differences in survival curves between factors were tested with log-rank tests.

Sixty-four patients were included. At baseline the median age was 37.5 (range, 15-76) years, 50% male, 59.4% Chinese, 50% CD, 50% UC, and mean CS dose 20.2 (SD 10.9) mg. At month 6, complete response was 48.4% (95% confidence interval [CI], 36.7-61.3), partial response 45.1% (95% CI, 32.8-58.3), and nonresponse 7.8% (95% CI, 2.6-17.3). Partial responders had mean CS dose reductions of 11.7 mg (95% CI, 7.2-16.4, P < 0.001). The proportion of patients with sustained remission was 0.87 (95% CI, 0.73-1.0) at 2 years, 0.76 (95% CI, 0.57-0.95) at 3 years, and 0.61 (95% CI, 0.30-0.91) at 5 years of AZA treatment. Female gender was positively associated with sustained remission.

Our study demonstrates the short- and long-term effectiveness of AZA therapy among CS-dependent Asian IBD patients.