Detection of Autoreactive T Cells in Type 1 Diabetes Using Coded Autoantigens and an Immunoglobulin-Free Cytokine ELISPOT Assay: Report from the Fourth Immunology of Diabetes Society T Cell Workshop

: The “gold standard” for evaluation of immunoassays is blinded testing, using coded samples and antigens. Although assays for autoreactive T cells are no exception to this rule, it is nonetheless rarely applied in this context. To facilitate such investigations, we coded a panel of 10 peptides representing T cell epitopes reported to be of relevance to islet autoimmunity. These were deployed in a novel cytokine ELISPOT assay, in which the use of immunoglobulin‐free medium reduces background reactivity and thus potentially enhances the specificity and sensitivity of detection of autoreactive T cells. Significant IFN‐γ production against GAD65 (554‐575), insulin (B9‐23), and IA‐2 (709‐736) peptides were observed in type 1 diabetic patients, whereas no significant changes from background were detected in healthy controls. These results confirm the utility of the blinded performance of T cell assays as the most robust platform for assessing technologies to T cell autoreactivity.