Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2016; 22(48): 10617-10624
Published online Dec 28, 2016. doi: 10.3748/wjg.v22.i48.10617
Assessment of disease activity by fecal immunochemical test in ulcerative colitis
Dae Gon Ryu, Hyung Wook Kim, Su Bum Park, Dae Hwan Kang, Cheol Woong Choi, Su Jin Kim, Hyeong Seok Nam
Dae Gon Ryu, Hyung Wook Kim, Su Bum Park, Dae Hwan Kang, Cheol Woong Choi, Su Jin Kim, Hyeong Seok Nam, Department of Internal Medicine, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 626-770, South Korea
Author contributions: Ryu DG wrote the manuscript; Kim HW organized the manuscript; Park SB, Kang DH, Choi CW, Kim SJ and Nam HS contributed to the design, organization, and draft of the manuscript; all authors read and approved the final manuscript.
Supported by a 2-Year Research Grant of Pusan National University.
Conflict-of-interest statement: No potential conflict of interest relevant to this article was reported.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hyung Wook Kim, PhD, MD, Department of Internal Medicine, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, 20, Geumo-ro, Mulgeum-eup, Yangsan 626-770, Gyeongsangnam-do, South Korea. mdkhwook@gamil.com
Telephone: +82-55-3601535 Fax: +82-55-3601536
Received: July 18, 2016
Peer-review started: July 21, 2016
First decision: October 11, 2016
Revised: October 15, 2016
Accepted: November 15, 2016
Article in press: November 16, 2016
Published online: December 28, 2016
Processing time: 161 Days and 15.3 Hours
Abstract
AIM

To evaluate the efficacy of quantitative fecal immunochemical test (FIT) as biomarker of disease activity in ulcerative colitis (UC).

METHODS

Between February 2013 and November 2014, a total of 82 FIT results, obtained in conjunction with colonoscopies, were retrospectivelyevaluated for 63 patients with UC. The efficacy of FIT for evaluation of disease activity was compared to colonoscopic findings. Quantitative fecal blood with automated equipment examined from collected feces. Endoscopic disease severity were assessed using the Mayo endoscopic subscore (MES) classification. The extent of disease were classified by proctitis (E1), left sided colitis (E2), and extensive colitis (E3). Clinical activity were subgrouped by remission or active.

RESULTS

All of 21 patients with MES 0 had negative FIT (< 7 ng/mL), but 22 patients with MES 2 or 3 had a mean FIT of > 134.89 ng/mL. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of negative FIT about mucosal healing were 73.33%, 81.82%, 91.49%, 51.43% and 73.17%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of predictive value of positive FIT (cutoff value > 100 ng/mL) about active disease status were 45.45%, 93.33%, 71.43%, 82.35% and 26.83%, respectively. Among patients with clinical remission, FIT was negative in 31 (81.6%) of 38 cases, with a mean fecal hemoglobin concentration of 6.12 ng/mL (range, negative to 80.9 ng/mL) for this group of patients. Among patients with clinical active disease, FIT was negative in 16 (36.4%) out of 44 cases, with a mean fecal hemoglobin concentration > 167.4 ng/mL for this group of patients. FIT was positively correlated with endoscopic activity (r = 0.626, P < 0.01) and clinical activity (r = 0.496, P < 0.01). But, FIT did not correlate with the extent of disease (r = -0.047, P = 0.676)

CONCLUSION

Quantitative FIT can be a non-invasive and effective biomarker for evaluation of clinical and endoscopic activity in UC, but not predict the extent of disease.

Keywords: Ulcerative colitis; Fecal immunochemical test; Mayo endoscopic subscore; Biomarker; Disease activity

Core tip: Until now, colonoscopy has been regarded as the gold standard to assess mucosal status and disease activity in patients with ulcerative colitis (UC). Recently, non-invasive markers of mucosal healing have been studied in UC. Fecal immunochemical test (FIT) is one of them suggested association with mucosa healing in some studies. Our results have identified that FIT correlated positively with endoscopic activity and clinical remission, but not with extent of disease. In particular a negative FIT could be regarded as an indication of endoscopic and clinical remission. FIT can be a non-invasive and economic biomarker in patients with UC.