gamma delta T-cells alterations in the peripheral blood of high risk diabetes type 1 subjects with subclinical pancreatic B-cells impairment

There is increasing evidence that CD3+ cells bearing gamma delta T-cell rec eptor (represent the minor subpopulation of the T-cells in the peripheral b lood in humans) are involved in autoimmunity development, gamma delta T-cel l receptor (TCR)+/CD8+ T-cells have been recently found to play a critical role in the pathogenesis and prevention of autoimmune diabetes in the anima l model. The aim of the present study was the estimation the gamma delta T- cell subpopulation levels in the peripheral blood of subjects with preclini cal and overt type 1 diabetes and their possible associations with the humo ral immunity, metabolic parameters and pancreatic B-cells function. The stu dy was carried out in three groups of subjects: 26 first degree relatives o f type 1 diabetes patients (prediabetics) with the combinations of autoanti bodies against pancreatic B-cells (ICA, GADA, IA-2A, IAA), 22 patients with a recent onset of type 1 diabetes and age and sex-matched 24 healthy volun teers (control group). A decrease was observed in the absolute numbers and percentages of gamma delta+/CD8+ and gamma delta+/CD8- T-cell subpopulation s in peripheral blood in the prediabetics with the impaired first phase of insulin secretion in comparison to relatives with autoantibodies but still with normal B-cells function, patients with clinical diabetes and healthy c ontrols. In conclusion, the study suggests that the gamma delta T-cells pla y an important role in the development of insulin-dependent diabetes mellit us (IDDM). It is possible that their levels in the peripheral blood could b e an additional marker of preclinical detection of the disease, but further prospective studies in high risk of IDDM subjects are needed. (C) 1999 Els evier Science B.V. All rights reserved.