Asian minimal-change esophagitis in the era of high-definition endoscopy

I read the article by Kim et al., ”Is minimal change esophagitis really part of the spectrum of endoscopic findings of gastroesophageal reflux disease? A prospective, multicenter study” with interest [1]. My initial thought is in line with that of the authors on the absence of a definition for minimal erosive reflux disease (MERD) based on endoscopy. However, I disagree with their conclusion that ”endoscopic findings of MERD are not associated with GERD.” There are many points in their study that need further evaluation and clarification.

As mentioned by the authors, the interobserver agreement among the endoscopists from the 30 centers involved was not determined, and this is very important to demonstrate standardization of their reading skills. In addition, I would like to emphasize the need to revalidate the six endoscopic criteria for defining MERD. The authors claim that these criteria were reported as having acceptable-to-good agreement between endoscopists. However, the pilot studies on which this agreement was based were done in the era of conventional endoscopy, and one of the references used pictures obtained using fiberoptic scopes [2] [3]. I suspect that the high-definition endoscopes used by the authors (GIF-H260 or GIF-Q260) may have a higher sensitivity for detecting subtle abnormalities related to reflux disease. However, without validation of the picture criteria from new scopes, the high level of specificity and interobserver agreement from previous studies [2] [3] may have been lost.

Digital chromoendoscopy (narrow-band imaging, Fuji Intelligent Color Enhancement, and the i-Scan) with or without magnification provides good sensitivity, specificity, and interobserver agreement to detect GERD, including minimal changes [4] [5] [6]. In the study by Kim et al., no magnification or digital chromoendoscopic technique was used. In experience at my institute, we observed that positive endoscopic findings from the latter modality correlated well with a MERD diagnosis [5].

Lastly, the details of patient recruitment in the study need more clarification. Patients with a positive endoscopic finding but no reflux symptoms should not be called ”completely non-GERD.” It is possible that some of them actually have reflux disease but no complaint – they may have a high threshold for reflux pain [7] [8]. The hot and spicy Korean diet containing capsaicin may play an important role in this phenomenon, since capsaicin and acid both stimulate a painful, burning sensation in the gastrointestinal tract via the same transient receptor potential vanilloid-1 (TRPV1) [7]. In addition, most Asian languages lack any word that precisely translates ”heartburn,” so reflux symptoms are often overlooked or misinterpreted [9]. For this reason the GerdQ questionnaire needs validation in the native language of every Asian country. Needless to say, the authors’ ”non-GERD” patients may be GERD patients with very low-grade symptoms.

References

• 1 Kim J H, Park H, Lee Y C. et al . Is minimal change esophagitis really part of the spectrum of endoscopic findings of gastroesophageal reflux disease? A prospective, multicenter study.  Endoscopy. 2011;  43 190-195
• 2 Armstrong D, Bennett J R, Blum A L et al. The endoscopic assessment of esophagitis: a progress report on observer agreement.  Gastroenterology. 1996;  111 85-92
• 3 Hongo M. Minimal changes in reflux esophagitis: red ones and white ones.  J Gastrolenterol. 2006;  41 95-99
• 4 Sharma P, Wani S, Bansal A et al. A feasibility trial of narrow band imaging endoscopy in patients with gastroesophageal reflux disease.  Gastroenterology. 2007;  133 454-464
• 5 Chaiteerakij R, Geratikornsupuk N, Tangmankongworakoon  et al. Efficacy of intelligent chromo endoscopy for detection of minimal mucosal breaks in patients with typical reflux symptoms of gastroesophageal reflux disease.  Gastrointest Endosc. 2008;  67 AB86
• 6 Hoffman A, Basting N, Goetz M et al. High definition endoscopy with i-Scan and Lugol’s solution for more precise detection of mucosal breaks in patients with reflux symptoms.  Endoscopy. 2009;  41 107-112
• 7 Gonlachanvit S. Are rice and spicy diet good for functional gastrointestinal disorders?.  J Neurogastroenterol Motil. 2010;  16 131-138
• 8 Jutaghokiat S, Imraporn B, Gonlachanvit S. Chili improves gastroesophageal reflux symptoms in patients with non erosive gastroesophageal reflux disease (NERD) [abstract].  Gastroenterology. 2009;  136 (Suppl. 1) A92
• 9 Wu J C. Gastroesophageal reflux disease: an Asian perspective.  J Gastroenterol Hepatol. 2008;  23 1785-1793