Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 14, 2018; 24(38): 4384-4392
Published online Oct 14, 2018. doi: 10.3748/wjg.v24.i38.4384
Practical fecal calprotectin cut-off value for Japanese patients with ulcerative colitis
Jun Urushikubo, Shunichi Yanai, Shotaro Nakamura, Keisuke Kawasaki, Risaburo Akasaka, Kunihiko Sato, Yosuke Toya, Kensuke Asakura, Takahiro Gonai, Tamotsu Sugai, Takayuki Matsumoto
Jun Urushikubo, Shunichi Yanai, Shotaro Nakamura, Keisuke Kawasaki, Risaburo Akasaka, Kunihiko Sato, Yosuke Toya, Kensuke Asakura, Takahiro Gonai, Takayuki Matsumoto, Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Iwate Medical University, Morioka 020-8505, Japan
Tamotsu Sugai, Division of Molecular Diagnostic Pathology, Department of Pathology, School of Medicine, Iwate Medical University, Morioka 020-8505, Japan
Author contributions: All authors helped to perform the research; Urushikubo J manuscript writing, performing procedures and data analysis; Yanai S manuscript writing, drafting conception and design, performing experiments, and data analysis; Nakamura S contribution to writing the manuscript, drafting conception and design; Kawasaki K, Akasaka R, Sato K, Toya Y, Asakura K and Gonai T contribution to writing the manuscript; Sugai T reviewed the histological specimens and was responsible for the pathological diagnosis; Matsumoto T critically reviewed and revised the manuscript; all authors have read and approved the final version of the manuscripts.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Iwate Medical University Hospital.
Informed consent statement: Patients were not required to give informed consent as this is a retrospective study.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
Data sharing statement: No additional data are available.
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: Jun Urushikubo, MD, Doctor, Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka 020-8505, Japan. urujun50@gmail.com
Telephone: +81-19-6515111 Fax: +81-19-6526664
Received: July 10, 2018
Peer-review started: July 10, 2018
First decision: August 27, 2018
Revised: September 10, 2018
Accepted: October 5, 2018
Article in press: October 5, 2018
Published online: October 14, 2018
Abstract
AIM

To determine appropriate fecal calprotectin cut-off values for the prediction of endoscopic and histologic remission in Japanese patients with ulcerative colitis (UC).

METHODS

We performed a cross-sectional observational study of 131 Japanese patients with UC and measured fecal calprotectin levels by fluorescence enzyme immunoassay. The clinical activity of UC was assessed with the partial Mayo score (PMS). Relapse was defined as increase of PMS by 2 points or more in stool frequency or rectal bleeding subscore. The endoscopic and histologic activities of UC were evaluated in 50 patients within a 2-mo period from fecal sampling. Endoscopic activity was determined by Mayo endoscopic subscore, Rachmilewitz endoscopic index, and ulcerative colitis endoscopic index of severity. The histologic grade of inflammation was evaluated with biopsy specimens obtained from the endoscopically most severely inflamed site, according to the scheme by Matts grade and Riley’s score.

RESULTS

Fecal calprotectin levels varied from 1-20783 μg/g. There was a significant correlation between the partial Mayo score and fecal calprotectin levels (r = 0.548, P < 0.001). In 50 patients who underwent colonoscopy with biopsy, levels were significantly correlated with the Mayo endoscopic subscore (r = 0.574, P < 0.001), Rachmilewitz endoscopic index (r = 0.628, P < 0.001), ulcerative colitis endoscopic index of severity (r = 0.613, P < 0.001), Riley’s histologic score (r = 0.400, P = 0.006), and Matts grade (r = 0.586, P < 0.001). Receiver-operating characteristic analyses identified the best cut-off value for the prediction of endoscopic remission as 288 μg/g, with an area under the curve of 0.777 or 0.823, while that for histologic remission was 123 or 125 μg/g, with an AUC of 0.881 or 0918, respectively. Of the 131 study patients, 88 patients in clinical remission were followed up 6 mo. During the follow-up period, 19 patients relapsed. The best fecal calprotectin cut-off value for predicting relapse was 175 μg/g.

CONCLUSION

Fecal calprotectin is a predictive biomarker for endoscopic and histologic remission in Japanese patients with UC.

Keywords: Ulcerative colitis, Remission, Mucosal healing, Colonoscopy, Histology, Biomarker, Feces, Calprotectin

Core tip: In recent years, fecal calprotectin (FC) has been reported as a reliable surrogate marker for clinical, endoscopic and histologic activity in ulcerative colitis (UC). The aim of the present study was to determine appropriate FC cut-off values measured by fluorescence enzyme immunoassay (FEI) for predicting endoscopic and histologic remission in Japanese patients with UC. The best FC cut-off values predictive of histologic remission were 125 μg/g for Riley histologic score and 123 μg/g for Matts histologic grade. FC measured by FEI is a useful biomarker for predicting histologic remission in UC.