Expression of CD4+ CD28null T lymphocytes in children and adolescents with type 1 diabetes mellitus: Relation to microvascular complications, aortic elastic properties, and carotid intima media thickness.

Abstract

Cardiovascular risk in type 1 diabetes mellitus (T1DM) is associated with endothelial dysfunction, inflammation, and altered immunity. CD4+ CD28null T-cells are a subset of long-lived cytotoxic CD4+ T-lymphocytes with proatherogenic and plaque-destabilizing properties. We hypothesized that the frequency of CD4+ CD28null T-cells may be altered in T1DM and related to vascular complications. To assess the percentage of CD4+ CD28null T-lymphocytes in children and adolescents with T1DM and their relation to vascular structure and glycemic control. Totally 100 patients with T1DM were divided into 2 groups according to the presence of microvascular complications and compared with 50 healthy controls. CD4+ CD28null T-lymphocytes were analyzed using flow cytometry. Aortic elastic properties and carotid intima media thickness (CIMT) were assessed. Aortic stiffness index and CIMT were significantly higher among patients compared with healthy controls while aortic strain and distensibility were decreased. The percentage of CD4+ CD28null T-cells was significantly higher in patients with and without microvascular complications compared with controls. High frequency of CD4+ CD28null T-cells was found among patients with microalbuminuria or peripheral neuropathy. Patients with CD4+ CD28null T-cells ≥10% had higher HbA1c, urinary albumin creatinine ratio, aortic stiffness, and CIMT. CD4+ CD28null T-cells were positively correlated to HbA1c, aortic stiffness index, and CIMT. Changes in aortic elastic properties and increased CIMT among young patients with T1DM may enable the recognition of preclinical cardiac impairment. The correlation between CD4+ CD28null T-cells and assessed parameters of vascular structure highlights the role of altered immune response in the occurrence of diabetic vascular complications.