Flow cytometry of duodenal intraepithelial lymphocytes improves diagnosis of celiac disease in difficult cases

Background: Diagnosis of celiac disease is difficult when the combined results of serology and histology are inconclusive. Studies using flow cytometry of intraepithelial lymphocytes (IELs) have found that celiac patients have increased numbers of IELs, along with a decrease in CD3-CD103+IELs. Objective: The objective of this article is to assess the role of flow cytometric analysis of IELs in the diagnosis of celiac disease in difficult cases. Methods: A total of 312 patients with suspicion of celiac disease were included in the study. Duodenal biopsy samples were used for histological assessment and for flow cytometric analysis of IELs. Results: In 46 out of 312 cases (14.7%) the combination of serology and histology did not allow the confirmation or exclusion of celiac disease. HLA typing had been performed in 42 of these difficult cases. Taking into account HLA typing and the response to a gluten-free diet, celiac disease was excluded in 30 of these cases and confirmed in the remaining 12. Flow cytometric analysis of IELs allowed a correct diagnosis in 39 out of 42 difficult cases (92.8%) and had a sensitivity of 91.7% (95% CI: 61.5% to 99.8%) and a specificity of 93.3% (95% CI: 77.9% to 99.2%) for the diagnosis of celiac disease in this setting. Conclusion: Flow cytometric analysis of IELs is useful for the diagnosis of celiac disease in difficult cases.