Crohn's disease outcome in patients under azathioprine: a tertiary referral center experience

Azathioprine is of major importance in the treatment of Crohn's disease; its efficacy has been showed in several works, but real-life data regarding its use is scarce. Our aim was to address the outcome of patients with Crohn's disease under azathioprine in the real-life setting.

Crohn's disease patients followed at an Inflammatory Bowel Disease Outpatient Clinic under azathioprine were consecutively enrolled, being allocated in one of four groups. Two groups included patients on treatment with this drug, regarding its two major indications - prevention of post-operative recurrence and steroid-dependent disease; a third group included patients who needed infliximab in addition to azathioprine and a fourth group comprised patients who did not tolerate azathioprine.

A total of 221 patients were enrolled, 180 on azathioprine due to steroid-dependency (64 needing additional treatment with infliximab) and 41 for prevention of post-operative recurrence. Steroid-free remission was obtained in 48%. Immunosuppression decreased the number of hospitalized patients (64% vs 36%; p<0.001), but not the surgery rates per person per year. Azathioprine as a post-operative drug was effective in decreasing hospitalizations. The addition of infliximab decreased the number of patients hospitalized (p=0.009) and hospitalization rates per person per year (p<0.001), but had no effect in the surgery rates per person per year. Sixty patients (23%) experienced adverse effects with AZA, 39 requiring discontinuation of the drug.

In this real-life study, azathioprine had a long-term steroid sparing effect and reduced hospitalizations. Combination with infliximab reduced hospitalizations but did not decrease the surgery rate.