Background: The benefits of immunosuppressants for sustaining remission and preventing flares of IBD are well known. However, optimal timing for withdrawal has not been determined.
Aims: The objective of this study was to calculate the risk of relapse and predictors after withdrawal of azathioprine (AZA) monotherapy in patients who sustain deep remission.
Methods: This was a multicenter observational study of patients with IBD in remission whose immunosuppressant had been withdrawn. We recorded demographic variables, disease data, laboratory values, and the results of imaging tests performed at withdrawal and, in patients who relapsed, time to relapse and the efficacy of reintroducing the drug.
Results: Ninety-five patients were included (35 UC and 60 CD). The mean duration of AZA treatment was 87 and 77 months for UC and CD, respectively. Endoscopic remission was evaluated in 23 patients with UC and 35 with CD. After AZA withdrawal, 91% patients with UC and 67% with CD received high doses of salicylates. A total of 26 patients relapsed. The cumulative relapse rate at 5 years was 46% for CD and UC. AZA was reintroduced in 19 patients, of whom 14 responded. Predictors of relapse were corticosteroid dependence, early introduction of AZA (CD), and late introduction of AZA (UC).
Conclusions: Almost half of the patients in whom AZA was withdrawn were in remission at 5 years. The candidates for withdrawal could be better identified based on corticosteroid dependence, previous surgery, timing of initiation, and indication for AZA.
Keywords: Azathioprine; Inflammatory bowel disease; Remission; Withdrawal.