Abstract

Objective: To determine the relative incidence and characteristics of endomysial antibody (EMA)-negative coeliac disease in adults. Design: Retrospective analysis of prospectively collected data on adults with newly diagnosed coeliac disease, with determination of EMA status before gluten withdrawal. Setting: District general hospital (secondary care institution). Participants: Sixty consecutive incident cases. Main outcome measures: (i) Proportion of cases who were EMA-negative; (ii) comparison of clinical and laboratory variables at diagnosis for EMA-positive and EMA-negative subjects. Results: Fifteen subjects (25%, 95% CI 15-38%) were EMA negative, of whom only two were IgA deficient. There was clinical evidence in all 15 patients and histological evidence in 13 patients of a response to gluten withdrawal. No significant differences were found between EMA-positive and EMA-negative subjects with respect to histological features, age, gender, clinical manifestations, concurrent autoimmune disorders, family history of coeliac disease, or haemoglobin and albumin concentrations at diagnosis. However, EMA-negative status at diagnosis was associated strongly with current or recent cigarette smoking (OR 7.0, 95% CI 1.7-31.5, P = 0.003). Conclusions: A substantial minority of patients with otherwise typical coeliac disease are EMA negative, and most of these are IgA replete. The value of EMA as a screening tool is therefore limited. EMA status in untreated coeliac disease correlates strongly with cigarette smoking history: this may be of pathogenic significance, given the previously demonstrated association between smoking and the risk of coeliac disease.