Validity and Reproducibility of Measurement of Islet Autoreactivity by T-cell Assays in Subjects with Early Type 1 diabetes
- Kevan C. Herold, MD (Kevan.herold{at}yale.edu),
- Barbara Brooks-Worrell, PhD,
- Jerry Palmer, MD,
- H. Michael Dosch, MD,
- Mark Peakman, MD,
- Peter Gottlieb, MD,
- Helena Reijonen, PhD,
- Sefina Arif, PhD,
- Lisa M Spain, PhD,
- Clinton Thompson, M.S.,
- John M. Lachin, ScD and
- The Type 1 Diabetes TrialNet Research Group
- The Biostatistics Center, The George Washington University (J.M. Lachin, C Thompson), Rockville, MD; Yale University (K. Herold), University of Washington (J Palmer and B Brooks-Worrell), University of Toronto (HM Dosch), Dept of Immunobiology and NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and Kings College, London, UK (S Arif and M Peakman), University of Colorado (P. Gottlieb), Benaroya Research Institute (H Reijonen), and NIDDK
Abstract
Objective: Type 1 diabetes results from an immune mediated destruction of β cells, most likely to be mediated by T lymphocytes, but the sensitivity, specificity, and other measures of validity of existing assays for islet autoreactive T cells are not well established. Such assays are vital for monitoring responses to interventions that may modulate disease progression.
Research Design and Methods: We studied the ability of cellular assays to discriminate responses in patients with Type 1 diabetes and normal control subjects in a randomized blinded study in the US and UK. We evaluated the reproducibility of these measurements overall and to individual analytes from repeat collections.
Results: Responses in the cellular immunoblot (CI), UK-ELISPOT, and T cell proliferation (TCP) assays could differentiate patients from control subjects with odds ratios of 21.7, 3.44, and 3.36, respectively, with sensitivity and specificity as high as 74% and 88%. The Class II tetramer and US ELISPOT assays performed less well. Despite the significant association of the responses with Type 1 diabetes, the reproducibility of the measured responses, both overall and individual analytes, was relatively low. Positive samples from normal control subjects (i.e. false positives) were generally isolated to single assays
Conclusions: The CI, UK-ELISPOT, and TCP assays can distinguish responses from patients with Type 1 diabetes and healthy control subjects. The limited reproducibility of the measurements overall and of responses to individual analytes may reflect the difficulty in detection of low frequency of antigen specific T cells or variability in their appearance in peripheral blood.
Footnotes
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- Received February 19, 2009.
- Accepted July 16, 2009.
- Copyright © American Diabetes Association
