Background/aim: It has been reported that the Z-line appearance (the ZAP grade) wascorrelated with the prevalence of intestinal metaplasia. Therefore, we prospectively investigated the clinical usefulness of ZAP classification based on the histology in making a diagnosis of non-erosive reflux disease (NERD).
Methodology: We studied 80 consecutive young male patients with heartburn and acid regurgitation. The symptom characteristics were collected by interviewing with a structured questionnaire. Upper GI endoscopy with biopsy was performed to identify the distal esophagitis.
Results: Correlation was significant between the ZAP score and the LA classification (Spearman cor relation factor: 0.463). There were no significant differences in symptom according to the ZAP score. There were no significant differences in microscopic esophagitis between the patients with NERD (ZAP 0) and those with ERD (Erosive Reflux Disease, ZAP I, II, III). No statistical significance was observed between the ZAP score and the histology. In the diagnosis of NERD, ZAP classificationwas more accurate than LA classification in the basis of histology at distal esophagus (p < 0.05).
Conclusions: The ZAP classification could be applied to diagnosis of GERD, especially NERD. Biopsy taken at distal esophagus can be a limited but useful diagnostic tool, particularly in patients with NERD.