The aim of the study was to evaluate the percentage of regulatory T cells (Tregs) and cells producing cytokines (IL-17, IFN-gamma and TNF-alpha) in children with primary hypertension (PH).Design and method:
The peripheral whole blood samples were obtained from PH patients and normotensive, healthy children. T-cell subtypes were defined by the combinations of cell surface markers and antibodies against intracellular cytokines they secrete (IL-17, IFN-gamma, TNF-alpha). For enumeration of Tregs (CD4+/CD25+/CD127-) and cytokines-producing cells conjugated monoclonal antibodies were used in direct method. Leukocyte adiponectin receptor expression (AdipoR1) was determined using direct and indirect three-color flow cytometry.Design and method:
After having compared immunological parameters between children with PH and normotensive ones, patients were divided into two groups, based on the AdipoR1 expression: patients exhibiting high expression [AdipoR1(+)] and children with a low expression [AdipoR1(−)] of the test marker on leukocytes.Results:
Children with PH had greater percentage of Tregs (8.33 ± 1.84 vs. 7.45 ± 1.77) and cells producing proinflammatory cytokines (IL-17+:3.51 ± 1.75 vs. 1.57 ± 0.75; IFN-gamma+:3.68 ± 1.72 vs. 2.23 ± 0.84; TNF-alpha+:3.38 ± 1.66 vs. 2.28 ± 1.16; p < 0.05). AdipoR1(−) PH patients showed greater percentage of Tregs (9.45 ± 1.81) than AdipoR1(+) PH patients (7.35 ± 1.22) and normotensive ones (7.45 ± 1.77) (p < 0.001). The percentage of Tregs did not differ between the AdipoR1(+) group and the control group (p = 0.8). The highest proportion of proinflammatory cells was found in AdipoR1(−) group (IL-17+: 4.76 ± 1.77, IFN-gamma+: 4.25 ± 2.06) versus AdipoR1(+) group (IL-17+: 2.47 ± 0.81, IFN-gamma+: 3.20 ± 1.24) of PH patients (in all cases p < 0.001). The percentage of cells producing TNF-alpha was significantly higher in both groups of patients (3.07 ± 0.94 and 3.78 ± 2.28) compared to the control (2.29 ± 1.16; p < 0.05).Conclusions:
Our results indicate that children with PH have greater percentage of Tregs and cells producing cytokines than normotensive ones.Conclusions:
We also observed that decreased AdipoR1 expression may limit leukocyte responsiveness to adiponectin. This in turn may increase synthesis of proinflammatory cytokines IL-17 and IFN-gamma. These observations are an argument for the significance of adipose tissue and adipokines in the regulation of inflammatory responses in hypertensive children. T-regulatory cells can limit inflammatory response and therefore prevent tissue damage (in this case – arteriolar walls, which leads to hypertension) as was previously described.