Anti-Endomysial Antibody May Predict a Second Endoscopy in Coeliac-Suspected Patients with False Negative Index Duodenal Biopsies

Background/aims: A subset of coeliac-suspected patients requires 2 Oesophagogastroduodenoscopies (OGDs) to achieve histological confirmation. Their index OGD would fail to reach diagnosis despite 4 duodenal biopsies suggested by guidelines. We compared this subgroup of patients with other coeliac patients requiring 1 endoscopy and recognize any predictors to identify the former group. Methods: Coeliac-suspected patients at our department underwent an OGD. Clinical, serological and histological data were retrieved from medical notes. Group 1 comprised patients who achieved diagnosis with 1 OGD. Group 2 required 2 OGDs. Results: 178 patients underwent an OGD (mean age 47 years; 73.6% females). 12 patients (6.7%) required 2 OGDs. Both groups had the same mean number of duodenal biopsies at their index endoscopy (4.6 vs 4.5, P=0.76). In Group 2, the number of biopsies was higher at the second endoscopy (6.4 vs 4.5, P=0.028). Group 2 showed a negative or lower positivity for anti-EMA (P=0.039) and a lower anti-tTG IgA level (P=0.06) than Group 1. Conclusion: Anti-EMA seronegativity or low positivity in coeliac-suspected patients indicates the need for more duodenal biopsies to achieve diagnosis and avoiding subsequent OGDs. This finding makes anti-EMA testing crucial in coeliac diagnostics.