Introduction Serology testing with IgA tissue transglutaminase (TTG) is relatively cheap and non-invasive which NICE guidelines for coeliac disease (CD) advocate as a first choice test for patients with unexpected weight loss or anaemia.¹ Referral for duodenal biopsy is indicated if serology is positive or if negative but there is still a clinical suspicion of CD. The sensitivity, specificity and negative predictive value for IgA TTG have been found to be 90.9%, 90.9% and 99.6% respectively thus demonstrating IgA TTG to be a sensitive marker for CD.² Our aim was to evaluate the diagnostic yield of duodenal biopsies relative to clinical indications and serology findings.

Methods This is a retrospective review of 2109 adult patients from the Heart of England Trust, between January 2009 and December 2010. Coeliac serology (IgA TTG), immunoglobulin levels and D2 biopsy results were recorded for patients referred for upper gastrointestinal endoscopy for anaemia (n=1550) or weight loss (n=559).

Results In the anaemia group, 7/27 (25.9%) with positive serology had a negative biopsy, 19/27 (70.4%) with positive serology had a positive biopsy and 1/27 (3.7%) with positive serology had no biopsy taken. 6/27 (22.2%) with positive biopsy had negative serology. In the weight loss group, 4/12 (33.3%) with positive serology had a negative biopsy, 5/12 (41.7%) with positive serology had a positive biopsy and 3/12 (25.0%) with positive serology had no biopsy taken. 7/14 (50.0%) with positive biopsy had negative serology.

Conclusion Our review demonstrates that anaemia or weight loss are good indicators to attempt to diagnose CD by duodenal biopsy. If we corrected for the diagnosis of upper GI cancer, in our cohort, an additional 14 cases of CD would have been diagnosed if all patients had a duodenal biopsy. Furthermore, a significant proportion of patients in our study with a biopsy positive for CD had negative serology, strengthening the argument that all such patients should have a duodenal biopsy. Rates of serology testing were poor. However, we suggest regardless of serology patients referred with anaemia or weight loss should have a duodenal biopsy to look for evidence of coeliac disease.

Competing interests None declared.

References 1. NICE Guidelines. Coeliac Disease: Recognition and Assessment of Coeliac Disease. 2009.

2. Hopper AD, Hadjivassiliou M, Hurlstone DP, et al. What is the role of serologic testing in celiac disease? A prospective, biopsy-confirmed study with economic analysis. Clin Gastroenterol Hepatol 2008;6:314–20.