Objective In patients with ulcerative colitis (UC), the relationship between the initial endoscopic findings and the response to anti-tumor necrosis factor (TNF)-α antibodies remains unclear. We herein evaluated the potential of endoscopic assessment using the ulcerative colitis endoscopic index of severity (UCEIS) to predict the response to anti-TNF-α antibodies. Methods We enrolled 64 patients with UC undergoing anti-TNF-α maintenance therapy with infliximab (IFX) or adalimumab (ADA) between April 2010 and March 2015. Anti-TNF-α trough levels were determined by ELISA. Endoscopic disease activity was assessed using the UCEIS. Results The clinical response rate at 8 weeks was 77.4% for IFX and 66.7% for ADA. Serum albumin levels were significantly higher and the UCEIS bleeding descriptor before treatment was significantly lower in the responders than in the non-responders (p < 0.05 each). The CRP levels at 2 weeks were significantly lower in the responders (p < 0.001). The serum albumin levels before treatment were significantly higher and the UCEIS erosions and ulcers descriptor was significantly lower in the mucosal healing group than in the non-mucosal healing group (p < 0.05 each). A significant and negative correlation between the trough levels of anti-TNF-α antibodies and the UCEIS descriptors was observed. The trough levels of anti-TNF-α antibodies to achieve mucosal healing were 2.7 μg/mL for IFX and 10.3 μg/mL for ADA. Conclusions The UCEIS score, as well as some clinical markers (serum albumin and CRP levels), is useful for the prediction of the treatment outcome of UC patients in response to anti-TNF-α antibodies.
Keywords: Adalimumab; infliximab; trough levels; ulcerative colitis endoscopic index of severity.