Frequency and function of circulating invariant NKT cells in autoimmune diabetes mellitus and thyroid diseases in Colombian patients

The frequency and functionality of peripheral blood invariant (iNKT) cells and their subsets, as well as other regulatory T-cell subsets, were evaluated in patients with type 1A diabetes mellitus (DM1), Hashimoto's disease, and Graves' disease. In addition to healthy individuals (HC), patients with type 2 diabetes mellitus (DM2) were included as controls because this disease has a different physiopathology. A similar frequency of total iNKT cells, as well as their subsets, existed among HC and the different study groups. Similar results were reported when we compared the frequency of CD4+/CD25high T cells, CD8+/CD28negative T cells, and γ-δ T cells among HC and study groups, whereas patients with DM2 exhibited a higher frequency of CD8+/CD28negative T cells compared with HC and DM1. Also, patients with DM2 exhibited a lower frequency of CD4negative and CD4+ iNKT cells expressing tumor necrosis factor-α (TNF-α) than HC. We did not observe significant differences in the frequency of iNKT cells expressing interleukin-4 or interferon-γ among study groups and controls. Our findings support a normal frequency and function of peripheral blood iNKT cells in different endocrine autoimmune diseases, but an abnormal expression of TNF-α by circulating iNKT cells from patients with DM2.