Impact of Low Interferon-γ and IL-10 Levels on TNF-α and IL-6 Production by PHA-Induced PBMCs in Type 2 Diabetes Mellitus.

PURPOSE

In this study, we analyzed the production of interferon γ (IFN-γ) and interleukin 10 (IL-10) by peripheral blood mononuclear cells (PBMCs) in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the capacity of monocytes to produce tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) following IFN-γ stimulation and the associated role of IL-10 in TNF-α and IL-6 production.

PATIENTS AND METHODS

In vitro experiments were conducted on PBMCs obtained from 19 patients with T2DM and 17 healthy participants. PBMCs were isolated from venous blood by density gradient centrifugation, followed by 3-day phytohemagglutinin induction. In vitro production of TNF-α, IL-6, IFN-γ, and IL-10 was measured using the multiplex immunoassay. Statistical analysis was performed using IBM SPSS 23 version.

RESULTS

IFN-γ concentration in the T2DM group was significantly lower than that in control group (T2DM 7,700.86 ± 3,037.77 vs control 10,672.69 ± 5,625.50 pg/mL; = 0.048). However, TNF-α, IL-6, and IL-10 levels showed no significant difference between the two groups. The TNF-α/IFN-γ and IL-6/IFN-γ ratios were significantly higher in T2DM than in the control group ( = 0.026 and = 0.048, respectively). In T2DM, the high TNF-α/IFN-γ ratio was consistent, with the low baseline IL-10 level ( = 0.022).

CONCLUSION

In T2DM, T-cell response is impaired with significantly reduced IFN-γ production, and simultaneously, circulatory monocytes show enhanced cellular responsiveness to inflammatory stimuli. The low baseline IL-10 level likely contributes to such an immune response.