Background: The long-term effectiveness of azathioprine, in Crohn's disease (CD) patients remains a matter of debate. This study aims at assessing the effectiveness and safety of azathioprine in patients treated continuously for less or more than 4 years.
Methods: Patients with steroid-dependent Crohn's disease in remission on azathioprine (2-2.5 mg/kg) for between 2 and 8 years were assigned into two groups. Patients in Group A were being treated continuously for 2 to 4 years whereas patients in Group B for 4 to 8 years. Patients were followed every month for 1 year with physical examination and laboratory tests. Compliance with treatment was also assessed every month. Every 3 months the Crohn's Disease Activity Index (CDAI) was calculated and the quality of life (QOL) Inflammatory Bowel Disease Questionnaire (IBDQ) was completed. Colonoscopy with calculation of the Crohn's Disease Endoscopic Index of Severity (CDEIS) was performed at baseline and at the end of the study. The primary end point was relapse after 1 year. Secondary end points were safety of treatment, QOL, and endoscopic healing.
Results: Fifty-eight patients were included in Group A and 42 in Group B. The relapse rates per protocol were 19.6% and 11.9%, respectively (p: not significant). There were no significant differences overall and at each time point of the study between the two treatment groups regarding compliance with and safety of treatment, CDAI, IBDQ, and CDEIS scores. Multifactorial analysis did not identify any factor influencing the remission of disease in any patient group.
Conclusions: Long-term treatment with azathioprine of steroid-dependent Crohn's disease is efficacious and safe.