Serum interleukin-6 level predicts short-term clinical response of anti-tumor necrosis factor therapy in patients with ulcerative colitis

AIM: Insufficient responses to anti-tumor necrotic factor (TNF) therapy drugs such as infliximab and adalimumab are sometimes observed in patients with ulcerative colitis (UC). The aim of this study was to evaluate potential biomarkers for response to anti-TNF therapy in patients with UC. METHODS: Patients with moderate-to-severe active UC who were administered anti-TNF agents in our hospital between June 2010 and August 2016 were retrospectively investigated in this study. The pretreatment partial Mayo score, serum TNF-a, interleukin-6 (IL-6), and soluble human mucosal vascular addressin cell adhesion molecule-1 (sMAdCAM; as a potential biomarker for biologics to target a4b7 integrin) concentrations were measured. The primary endpoint was the association between these biomarkers at baseline and the clinical response to anti-TNF agents at week 14. A clinical response was defined as a partial Mayo score reduction of three or more points, accompanied by a decrease of one or more point in the rectal bleeding subscore or an absolute rectal bleeding subscore of 0 or 1 without secondary alternative drug use (for example, tacrolimus or corticosteroids). RESULTS: After excluding inappropriate cases, forty-one patients were included in this study (38 were administered infliximab and 3 adalimumab). After induction therapy, 27 patients (65.9%) obtained a clinical response at week 14. According to the results of a univariate analysis among all variables studied, there was a significant difference between responders and non-responders based on serum IL-6 levels at baseline (p = 0.048). In contrast, there were no significant differences based on serum TNF-a levels (p = 0.196) or sMAdCAM levels (p = 0.441) at baseline. Multivariate analysis revealed that the serum IL-6 level at baseline was a predictive factor for clinical response to infliximab (odds ratio = 1.22, 95% confidence interval: 1.00 - 1.48, p = 0.049). CONCLUSIONS: The serum IL-6 level at baseline before anti-TNF therapy can predict the short-term efficacy of this therapy in patients with UC. Measuring serum IL-6 levels might assist physicians to choose between the administration of anti-TNF agents or anti-adhesion molecule agents.