Endocrine Abstracts

Background: Interleukin-15 and -6 play a role in an inflammation, autoimmune, infectious and cancerous processes. Their increased concentrations were observed in psoriasis, asthma, multiple sclerosis and type 2 diabetes. However, the role of IL-15 and IL-6 in autoimmune diabetes (AD) pathogenesis is still unknown.

Aim: The aim of our study was to assay circulating IL-15 and IL-6 levels in newly diagnosed AD patients, their I° relatives and healthy controls in comparison to the presence of anti-islet antibodies and insulin resistance.

Material and methods: The group studied consisted of 54 patients with AD (28 with LADA and 26 with T1D), 70 I° relatives and 60 controls. IL-6, IL-15 and anti-islet antibodies concentrations were measured by ELISA method. HOMAIR and 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) and I° relatives (P<0.001). 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) and the controls (P<0.001). IL-15 negatively correlated with eGDR (r=−0.436, P=0.02) in LADA and positively with HOMAIR in LADA and T1D (r=0.5072, P<0.001; r=0.4209, P<0.001).

Conclusions: Significantly higher IL-15, IL-6 concentrations, HOMAIR and markedly lower eGDR in newly diagnosed AD patients and I° relatives with positive anti-islet antibodies might suggest the role of these proinflammatory cytokines and insulin resistance in the pathogenesis of AD. IL-15 and IL-6 might be used as biomarkers of the risk of AD development, in particular IL-15 for LADA. Both type of method of IR measurement seem to be equally useful for calculate insulin resistance in AD.