Micro-inflammation Characterized by Disturbed Treg/Teff Balance with Increasing sIL-2R in Patients with Type 2 Diabetes

Objectives: Type 2 diabetes mellitus (T2DM) has been gradually considered as a micro-inflammatory disease. To explore the significance of peripheral CD4(+) regulatory T cells and CD4(+) effector T cells in T2DM, we analyzed inflammation, humoral and cellular immune state in patients with T2DM. Patients and Methods: 118 patients with T2DM without complications and 116 healthy volunteers were included. Serum C-reactive protein (CRP), Complement 3 (C3), Complement 4 (C4), IgG, IgA, IgM, plasma sIL-2 R and peripheral T lymphocyte subsets (including CD4(+)CD25(high) regulatory T cells (Treg) and CD4(+)CD25(low+median) effector T cells (Teff)) were analyzed by rate nephelometry immunoassay, chemiluminescence immunoassay and flow cytometry, respectively. Results: (1) micro-inflammation state in T2DM: Serum CRP, C3, IgA and plasma sIL-2R were all significantly higher in T2DM than those in healthy control (HC) (all P < 0.05). (2) Disturbance of cellular immune in T2DM: Compared with HC, the percentage of peripheral CD3(+)CD4(+)T cells and ratio of CD3(+)CD4(+)T cells to CD3(+)CD8(+)T cells in T2DM were both significantly increased (P < 0.05); and the percentage of peripheral CD4(+)CD25(+)T cells, Teff cells increased (P > 0.05), Treg cells strikingly decreased in T2DM (P < 0.05). A positive correlation between sIL-2R levels and peripheral CD4(+)CD25(+)T cells or Teff cell percentages, as well as a negative correlation between plasma sIL-2 R levels and serum HDL, LDL or CHOL levels in T2DM were shown (all P < 0.05). Conclusions: Micro-inflammation state in T2DM was characterized by increased sIL-2 R, elevated CD3(+)CD4(+)T cells and the imbalance of Treg cells and Teff cells, which as one of the pathogeneses took part in inflammation reaction in T2DM.