Background and Aim: Z-line appearance grading (ZAP) is a validated system that correlates with prevalence of intestinal metaplasia (IM) in gastroesophageal reflux disease (GERD). The aim was to determine the significance of ZAP grading in GERD patients.

Materials and Methods: In this prospective cross-sectional hospital based case-control study, 109 consecutive GERD patients diagnosed by GERD questionnaire and 102 controls were included. On endoscopy GERD was classified as erosive reflux disease (ERD) (n=42) and non-erosive reflux disease (NERD) (n=67). Los Angeles (LA) grading and ZAP grading were done. Biopsies were taken from lower esophagus, Z-line, gastric cardia, gastric corpus and antrum incases. Findings were correlated with ZAP grading.

Results: Controls had significantly more ZAP grade ‘0’ (79.41% vs 21.11%) and less ZAP grade I, II and III (20.58% vs 78.89%) as compared to cases (P=0.0001). Microscopic esophagitis was seen in all ZAP III GERD patients and was significantly more in ZAP II as compared to ZAP I (97.67% vs 71.055, p=0.0023). ZAP grading correlated significantly with LA grading (Spearman correlation factor=0.478, p<0.01). The likelihood ratio of ZAP grade to diagnose NERD was 3.26 in cases. At the lower esophagus, IM was significantly more with higher grades (III vs II) of ZAP.

Conclusion: ZAP grading is useful in diagnosing GERD, especially NERD in subjects with positive GERD symptom score.Microscopic esophagitis and IM is more with a higher ZAP grade. ZAP grading is a simple, uniform, objective, validated, cost-effective grading system and should be incorporated in endoscopic reporting of GERD patients.