Observational Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2016; 22(14): 3845-3851
Published online Apr 14, 2016. doi: 10.3748/wjg.v22.i14.3845
Autofluorescence imaging endoscopy can distinguish non-erosive reflux disease from functional heartburn: A pilot study
Xi Luo, Xiao-Xu Guo, Wei-Feng Wang, Li-Hua Peng, Yun-Sheng Yang, Noriya Uedo
Xi Luo, Xiao-Xu Guo, Wei-Feng Wang, Li-Hua Peng, Yun-Sheng Yang, Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing 100853, China
Noriya Uedo, Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka 537-8511, Japan
Author contributions: Luo X and Guo XX contributed equally to this work. Luo X, Guo XX, Wang WF and Peng LH performed the research; Luo X and Guo XX analyzed the data and wrote the paper; Wang WF designed the research; Yang YY and Uedo N critically reviewed the article.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of Chinese PLA General Hospital Institutional Review Board.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Clinical trial registration statement: This study is registered at https://clinicaltrials.gov/ct2/results?term=NCT01504971&Search=Search. The registration identification number is NCT01504971.
Conflict-of-interest statement: The authors disclose no conflicts of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at wangwf301@hotmail.com.
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: Wei-Feng Wang, MD, Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China. wangwf301@hotmail.com
Telephone: +86-13911952018 Fax: +86-10-68154653
Received: December 18, 2015
Peer-review started: December 22, 2015
First decision: January 13, 2016
Revised: February 9, 2016
Accepted: March 1, 2016
Article in press: March 2, 2016
Published online: April 14, 2016
Abstract

AIM: To investigate whether autofluorescence imaging (AFI) endoscopy can distinguish non-erosive reflux disease (NERD) from functional heartburn (FH).

METHODS: In this prospective observational trial, 127 patients presenting with typical reflux symptoms for > 6 mo were screened. All the participants underwent endoscopy, during which white light imaging (WLI) was followed by AFI. Finally 84 patients with normal esophageal appearance on WLI were enrolled. It was defined as being suggestive of NERD if one or more longitudinal purple lines longer than one centimeter were visualized in the distal part of the esophagus during AFI endoscopy. Ambulatory 24-h multichannel intraluminal impedance and pH monitoring was also performed. After standard proton-pump inhibitor (PPI) tests, subjects were divided into an NERD group and an FH group and the diagnostic performance of AFI endoscopy to differentiate NERD from FH was evaluated.

RESULTS: Of 84 endoscopy-negative patients, 36 (42.9%) had a normal pH/impedance test. Of these, 26 patients with favorable responses to PPI tests were classified as having NERD. Finally 10 patients were diagnosed with FH and the others with NERD. Altogether, 68 (81.0%) of the 84 patients were positive on AFI endoscopy. In the NERD group, there were 67 (90.5%) patients with abnormal esophageal findings on AFI endoscopy while only 1 (10%) patient was positive on AFI endoscopy in the FH group. The sensitivity and specificity of AFI in differentiating NERD from FH were 90.5% (95%CI: 81.5%-96.1%) and 90.0% (95%CI: 55.5%-99.7%), respectively. Meanwhile, the accuracy, positive predictive value and negative predictive value of AFI in differentiating between NERD and FH were 90.5% (95%CI: 84.2%-96.8%), 98.5% (95%CI: 92.1%-99.9%) and 56.3% (95%CI: 30.0%-80.2%), respectively.

CONCLUSION: Autofluorescence imaging may serve as a complementary method in evaluating patients with NERD and FH.

Keywords: Gastroesophageal reflux disease, White light imaging, Non-erosive reflux disease, Functional heartburn, Autofluorescence imaging, Ambulatory 24-h pH/impedance monitoring, Endoscopy, Esophagitis

Core tip: To date, few efforts have been put on the application of autofluorescence imaging (AFI) endoscopy in patients with non-malignant conditions such as gastrointestinal reflux disease (GERD). Our data showed that endoscopic features on AFI can distinguish non-erosive reflux disease (NERD) from functional heartburn (FH). Its real-time characteristics and simple endoscopic criteria may enhance the use of AFI as a complementary tool in the differentiation of NERD and FH. We believe that these findings have important implications for future research on the application of AFI endoscopy in patients with GERD.