Ex-vivo whole blood secretion of interferon (IFN)-[gamma] and IFN-[gamma]-inducible protein-10 measured by enzyme-linked immunosorbent assay are as sensitive as IFN-[gamma] enzyme-linked immunospot for the detection of gluten-reactive T cells in human leucocyte antigen (HLA)-DQ2·5+-associated coeliac disease

• Published in: Clinical and experimental immunology Vol. 175; no. 2; p. 305
• Main Authors: Ontiveros, N, Tye-Din, J A, Hardy, M Y, Anderson, R P
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-02-2014
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/cei.12232

Summary T cell cytokine release assays are used to diagnose infectious diseases, but not autoimmune or allergic disease. Coeliac disease (CD) is a common T cell-mediated disease diagnosed by the presence of gluten-dependent intestinal inflammation and serology. Many patients cannot be diagnosed with CD because they reduce dietary gluten before medical workup. Oral gluten challenge in CD patients treated with gluten-free diet (GFD) mobilizes gluten-reactive T cells measurable by interferon (IFN)-[gamma] enzyme-linked immunospot (ELISPOT) or major histocompatibility complex (MHC) class II tetramers. Immunodominant peptides are quite consistent in the 90% of patients who possess HLA-DQ2·5. We aimed to develop whole blood assays to detect gluten-specific T cells. Blood was collected before and after gluten challenge from GFD donors confirmed to have CD (n=27, all HLA-DQ2·5+), GFD donors confirmed not to have CD (n=6 HLA-DQ2·5+, 11 HLA-DQ2·5-) and donors with CD not following GFD (n=4, all HLA-DQ2·5+). Plasma IFN-[gamma] and IFN-[gamma] inducible protein-10 (IP-10) were measured by enzyme-linked immunosorbent assay (ELISA) after whole blood incubation with peptides or gliadin, and correlated with IFN-[gamma] ELISPOT. No T cell assay could distinguish between CD patients and controls prior to gluten challenge, but after gluten challenge the whole blood IFN-[gamma] ELISA and the ELISPOT were both 85% sensitive and 100% specific for HLA-DQ2·5+ CD patients; the whole blood IP-10 ELISA was 94% sensitive and 100% specific. We conclude that whole blood cytokine release assays are sensitive and specific for detection of gluten-reactive T cells in CD; further clinical studies addressing the utility of these tests in patients with an uncertain diagnosis of CD is warranted. [PUBLICATION ABSTRACT]