Activated gut-homing CD8+ T cells for coeliac disease diagnosis on a gluten-free diet
Fernando Fernández‐Bañares, Natalia López‐Palacios, María Corzo, Beatriz Arau, Mercedes Rubio, Marta Fernández-Prieto, Eva Tristán, Mar Pujals, Sergio Farráis, Saúl Horta, Juana María Jiménez Hernández, Marta Gomez‐Perosanz, Pedro A. Reche, María Esteve, Concepción Núñez
Abstract
Abstract Background The diagnosis of coeliac disease (CD) in individuals that have started a gluten-free diet (GFD) without an adequate previous diagnostic work-out is a challenge. Several immunological assays such as IFN-γ ELISPOT have been developed to avoid the need of prolonged gluten challenge to induce the intestinal damage. We aimed to evaluate the diagnostic accuracy of activated gut-homing CD8 + and TCRγδ + T cells in blood after a 3-day gluten challenge and to compare it with the performance of IFN-γ ELISPOT in a HLA-DQ2.5 subsample. Methods A total of 22 CD patients and 48 non-CD subjects, all of them following a GFD, underwent a 3-day 10-g gluten challenge. The percentage of two T cell subsets (CD8 + CD103 + β7 hi CD38 + /total CD8 + and TCRγδ + CD103 + β7 hi CD38 + /total TCRγδ + ) in fresh peripheral blood drawn baseline and 6 days after the challenge was determined by flow cytometry. IFN-γ ELISPOT assays were also performed in HLA-DQ2.5 participants. ROC curve analysis was used to assess the diagnostic performance of the CD8 + T cell response and IFN-γ ELISPOT. Results Significant differences between the percentage of the two studied subsets of CD8 + and TCRγδ + cells at days 0 and 6 were found only when considering CD patients ( p < 10 −3 vs. non-CD subjects). Measuring activated CD8 + T cells provided accurate CD diagnosis with 95% specificity and 97% sensitivity, offering similar results than IFN-γ ELISPOT. Conclusions The results provide a highly accurate blood test for CD diagnosis in patients on a GFD of easy implementation in daily clinical practice.