Interleukin-6 and Interleukin-15 as Possible Biomarkers of the Risk of Autoimmune Diabetes Development

Abstract EN

Aim.

The aim of our study was to assay circulating interleukin-15 (IL-15) and interleukin-6 (IL-6) levels and insulin resistance measured by two different methods in newly diagnosed autoimmune diabetes (AD) patients, their I° relatives, and healthy controls.

Material and Methods.

The group studied consisted of 54 patients with AD (28 with Latent Autoimmune Diabetes in Adults (LADA) and 26 with type 1 diabetes (T1D)), 70 first-degree relatives, and 60 controls.

IL-6, IL-15, and anti-islet antibodies concentrations were measured by ELISA method.

Homeostatic model assessment-insulin resistance (HOMAIR) and estimated glucose disposal rate (eGDR) were calculated.

Results.

The patients with AD had significantly higher IL-15, IL-6, and HOMAIR and lower eGDR than the controls (p<0.001, respectively) and first-degree relatives (p<0.001, respectively).

Significantly higher IL-15 and IL-6 were shown in the relatives with positive Ab as compared to the relatives without antibodies (p<0.001, respectively) and the controls (p<0.001, respectively).

IL-15 negatively correlated with eGDR (r=−0.436, p=0.021) in LADA and positively with HOMAIR in LADA and T1D (r=0.507, p<0.001; r=0.4209, p<0.001).

Conclusions.

Significantly higher IL-15 and IL-6 concentrations, HOMAIR, and markedly lower eGDR in newly diagnosed AD patients and first-degree relatives with positive anti-islet antibodies might suggest the role of these pro-inflammatory cytokines and insulin resistance in the pathogenesis of autoimmune diabetes.

IL-15 and IL-6 might be used as biomarkers of the risk of autoimmune diabetes development, in particular IL-15 for LADA.

Both methods of IR measurement appear equally useful for calculating insulin resistance in autoimmune diabetes.