Utility of the Serum-Based Endoscopic Healing Index in Monitoring Therapeutic Response in Ulcerative Colitis.

Abstract

Convenient and objective non-invasive tools to monitor therapy response in patients with ulcerative colitis (UC) are needed. This study aimed to evaluate the performance of the Endoscopic Healing Index [EHI], a serum test originally developed to monitor mucosal inflammation in Crohn's disease, in patients with UC. Serum samples paired with endoscopic data from consecutive adult UC patients initiating advanced therapy for active disease (Mayo Endoscopic Subscore (MES) > 1) were analyzed. EHI values were compared between groups showing endoscopic improvement, remission and non-response, defined respectively as MES of ≤1, 0 and >1. We also assessed the association of EHI with longitudinal changes of MES, and compared its performance with that of faecal calprotectin (FC) and C-reactive protein (CRP). A total of 127 patients provided 303 samples. Median EHI increased significantly with increasing MES score (p < 0.001). Median EHI was significantly lower in patients with endoscopic remission or improvement compared to patients with no response (p < 0.001, p < 0.001, respectively). A 10-points decrease in EHI was associated with 89% higher odds of 1-point decrease in MES (p < 0.001). EHI detected MES 0-1 with an area under the receiver operating curve of 77.8%, which was comparable to that of FC and CRP (85.0% [p = 0.076] and 70.6% [p = 0.055], respectively). EHI values are significantly responsive to changes in mucosal inflammation, also in UC patients, and can confirm and/or rule out mucosal inflammation with an almost similar accuracy to that of faecal calprotectin.