P301 Relapse rates after withdrawal of thiopurines in patients with Inflammatory Bowel Disease.
Ranjan, M.K.(1);Vuyyuru, S.K.(1);Kante, B.(1);Kumar, P.(1);Mundhra, S.K.(1);Golla, R.(1);Sharma, R.(2);Sahni, P.(3);Das, P.(4);Makharia, G.(1);Kedia, S.(1);Ahuja, V.(1);
(1)All India Institute of Medical Sciences, Department of Gastroenterology and Human Nutrition, New Delhi, India;(2)All India Institute of Medical Sciences, Department of Radio Diagnosis, New Delhi, India;(3)All India Institute of Medical Sciences, Department of Gastrointestinal Surgery, New Delhi, India;(4)All India Institute of Medical Sciences, Department of Pathology, New Delhi, India;
Background
Withdrawal of thiopurines after remission has been shown to be associated with an increased risk of relapse in patients with inflammatory bowel disease. However, long-term data on thiopurine withdrawal is limited especially from developing countries.
Methods
We retrospectively analyzed data of patients with IBD on thiopurine monotherapy who had stopped and were not on any other immunomodulator or biologics at the time of stopping thiopurines. All these were in clinical remission at the time of withdrawal.
Results
Among 1264 patients of IBD who were treated with thiopurines, a total of 461 patients had to stop thiopurine because of various reasons. Among these, 218 (UC=179; CD=39) patients were eligible for further study (Table-1). Overall, 36.7% (n=80) had relapsed after a median duration of months of 20 months (IQR: 9-49). There was no difference in relapse rate between UC and CD (39.6% vs 23%; P: 0.055). The overall cumulative probabilities of relapse were 17%, 34%, and 44% at the end of 1, 3, and 5 years respectively (Figure-1). The cumulative probabilities of relapse at 1, 3, and 5 years after thiopurine withdrawal were significantly lower in patients who had received azathioprine for at least 48 months (14%, 20%, and 31%) in comparison to those who had received for less than 48 months (28%, 45%, and 54%) respectively (P=0.007) (Figure-2). On multivariate Cox regression analysis, male sex [(HR: 1.7 (1.1-2.7), P=0.014] and short duration of therapy with thiopurines [HR: 0.98 (0.98-0.99), P=0.003] before withdrawal were associated with increased risk of relapse (Table-2).
Conclusion
Approximately 50% of patients with IBD will relapse within 5 years of thiopurine withdrawal. Male sex and shorter treatment duration (< 4 years) predict relapse after thiopurine withdrawal. Treatment should be continued even beyond 4 years in patients who tolerate and maintain remission on thiopurines.