Influence of IL-17 on visceral adiposity in HIV-infected patients.

Background: General and visceral adiposity are metabolic conditions associated with a state of chronic inflammation. In HIV1+ patients, visceral adiposity (VO) is a serious complication that predisposes to an increased risk of cardiovascular diseases. IL-17 has been associated with induction of tissue inflammation by up-regulation of IL-23. The aim of this study was to evaluate the role of IL-17 in visceral tissue in HIV1+ patients. Methods: eighty-two HIV1+ patients (41 with VO, Group-A; 41 without VO, Group-B) and 32 HIV1- controls (22 with VO, Group-C; 10 without VO, Group-D) receiving Highly-Active-Antiretroviral-Therapy (HAART) for more 12 months, were enrolled. Sonographically measured Perirenal Fat Diameter/Body Mass INdex was used to assess thickness of visceral adipose tissue using 3.75MHz convex probe. A value >0.22 was considered an index of central obesity. Metabolic parameters as well as IL-17 and IL-23 levels were measured. The association of IL-17 with PRFD/BMI and IL-23 was analyzed. Results: IL-17 serum levels in HIV1+ patients were significantly greater than those in control (837.86±260.06 pg/mL vs 377.36±144.76 pg/mL, p<0.001). IL-17 serum levels in Group A and C were lower than those in Groups B and D (756.98±282.98 and 344.44±138.94 vs 918.74±208.47 and 449.77±136.62 respectively; p<0.001) (Figure 1). For all subjects a statically significant positive correlation between IL-17 and IL-23 was found (r=0.7504; p< 0.0001). Conclusions: Our preliminary data could confirm a pro-inflammatory role of IL-17 in immune and adaptive response to host defense. The findings suggest a potential implication for IL-17 in obesity and describe emerging data regarding the role of IL-17 in adipogenesis.