The long-term prognosis of Japanese patients with Crohn's disease (CD) treated by switching anti-tumor necrosis factor-α (anti-TNFα) antibodies remains unclear.
This study aimed to clarify the long-term prognosis and clinical factors that affect the long-term prognosis and outcomes of such patients.
This retrospective, observational, single-center cohort study analyzed Japanese patients with CD treated by switching between infliximab and adalimumab in the Tohoku University Hospital between March 2003 and December 2017. Cumulative relapse-free survival and cumulative surgery-free survival rates were analyzed using the Kaplan-Meier method. Clinical factors that affected the long-term outcomes were identified using both a log-rank test and the Cox proportional hazards model.
The cumulative relapse-free survival rates were 68.6, 33.7, and 22.9% at 1, 3, and 5 years, respectively. The surgery-free survival rates were 91.7, 75.7, and 57.4% at 1, 3, and 5 years, respectively. The cumulative relapse-free survival rate was significantly higher in the group with ileal lesions (HR = 0.12; 95% CI 0.0066-0.64, 
We should clarify the reason for switching anti-TNFα antibodies and investigate bowel complications before switching. Surgical reset of bowel complications including stricture and fistula could reduce the risk of recurrence after switching anti-TNFα antibodies. Concomitant thiopurine administration might reduce the risk of bowel surgery after switching anti-TNFα antibodies.