title: The temporal association between gamma delta T cells and the natural history of insulin-dependent diabetes.
abstract: We previously reported a significant increase in percentages of peripheral blood gamma delta+ T cells in islet cell antibody (ICA) positive relatives of patients with insulin-dependent diabetes (IDD). In the present study, we further characterized this T cell abnormality in a larger group of ICA+ subjects and report that (1) Percentages of gamma delta+ T lymphocytes were significantly increased only in subjects with high ICA titers (> or = 20 JDF units) (P = 0.005) and resulted from an increase in absolute numbers of gamma delta+ T lymphocytes. (2) In these subjects, the increase in gamma delta+ T lymphocytes was associated with an increase in the V gamma 9 V delta 2 subpopulation (r = 0.99). (3) In these same subjects, high percentages of gamma delta+ T lymphocytes were associated with normal beta cell function while low percentages were associated with diminished insulin response. Using 65 microU/ml as the threshold of abnormal intravenous glucose tolerance test (IVGTT) response, percentages of gamma delta+ T lymphocytes could significantly predict IVGTT status in these subjects (P < 0.01). A longitudinal follow-up further suggested that the development of an abnormal IVGTT response and progression to diabetes was associated with a decrease in percentages of gamma delta+ T lymphocytes while patients whose gamma delta+ T cell percentages remained high retained normal beta cell function. Our data therefore suggest that gamma delta+ T lymphocytes and more specifically V gamma 9 V delta 2 T cells are implicated in the autoimmune process leading to diabetes and may have a regulatory role. The monitoring of their percentages in the blood of patients at risk for diabetes may be useful as an additional predictor of diabetes development.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Florida College of Medicine, Gainesville.
authors.forename: F P
authors.initials: FP
authors.lastname: Lang
authors.forename: B H
authors.initials: BH
authors.lastname: Pollock
authors.forename: W J
authors.initials: WJ
authors.lastname: Riley
authors.forename: N K
authors.initials: NK
authors.lastname: Maclaren
authors.forename: D J
authors.initials: DJ
authors.lastname: Barrett
mesh_terms: D000293:Adolescent; D000328:Adult; D001327:Autoimmune Diseases / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005951:Glucose Tolerance Test; D006801:Humans; D007111:Immunity, Cellular; D007515:Islets of Langerhans / Q000276:immunology / Q000503:physiopathology; D008875:Middle Aged; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology; D013997:Time Factors
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta