Persistent activation of CD8+ T-cells characterizes prediabetic twins

Area of Science:

• Immunology
• Endocrinology
• Genetics

Background:

• Type I diabetes diagnosis shows elevated activated CD3+ T-cells, with CD8+ T-cells prominent in pancreatic islets.
• Understanding early immune changes in individuals at high risk for type I diabetes is crucial for prevention strategies.

Purpose of the Study:

• To investigate the presence of activated CD8+ T-cells in the peripheral blood of prediabetic and non-diabetic identical twins of type I diabetes patients.
• To analyze the association between activated CD8+ T-cells and the development of type I diabetes.

Main Methods:

• A 10-year prospective study analyzed T-cell subsets (CD3+, CD4+, CD8+) for activation markers (HLA-DR, CD25) in identical twins of type I diabetes patients.
• Comparison groups included prediabetic twins (n=8), non-diabetic low-risk twins (n=10), and healthy controls (n=15).

Main Results:

• Prediabetic twins showed persistently elevated HLA-DR+ CD8+ T-cells compared to controls and low-risk twins.
• Elevated HLA-DR+ CD8+ T-cells in twins predicted a 50% risk of progression to type I diabetes with 100% specificity.
• Activated CD3+ and CD4+ T-cells were also elevated in prediabetic and low-risk twins, but CD8+ T-cells were more specific for disease progression.

Conclusions:

• Persistent elevation of HLA-DR+ CD8+ T-cells characterizes prediabetes.
• These circulating activated CD8+ T-cells share a cytotoxic phenotype with those found in pancreatic islets at type I diabetes diagnosis.
• The findings suggest a potential role for these activated CD8+ T-cells in the pathogenesis of islet damage in type I diabetes.