Elevated Th17 and IL-23 in Hypertensive Patients with Acutly Increased Blood Pressure

Problem statement: Many severe cardiovascular complications such as stroke and heart attack can result from acutely increased blood pressure in patients with hypertension. The underlying mechanisms remain unclear despite of extensive study. To characterize the inflammatory mechanisms in hypertensive patients with acute blood pressure increase, we tested circulating Th17 levels, IL-23R expression and plasma levels of IL-17 and IL-23 in hypertensive patients with acute blood pressure increase. Approach: 50 patients (24 males and 26 females) and 20 healthy volunteers between the ages of 18 and 78 were enrolled in this study. 30 of them were hypertensive patients with acute blood pressure increase (group A). The other 20 patients were hypertensive patients with steady blood pressure (group B). 20 healthy volunteers that were sex- and age-matched to group B were recruited as normal controls (group C). IL-23R expression and Th17 ratio in CD4⁺ T cells were examined by Flow Cytometry (FCM). The levels of IL-17 and IL-23 in plasma were measured using ELISA. Results: Increased Th17 and IL-23R⁺CD4⁺ T cells were detected in the patients of group A (1.4±0.6 and 8.6±3.3 respectively, p<0.05). No difference between group B and C was observed (p>0.05). The levels of IL-17 and IL-23 in group A were significantly higher than group B and C (11.9±5.1 v.s. 7.8±3.8 v.s. 6.0±1.1 for IL-17, 3017±950 v.s. 2143±927 v.s. 1916±935 for IL-23, P<0.05). No significant difference between group B and C was detected. Furthermore, there were a positive correlation between Th17/CD4⁺T ratio and IL-17 level (r = 0.514, p<0.05) and a positive correlation between IL-17 and IL-23 level (r = 0.837, p<0.05) in all subjects. Conclusion: Our results suggested that IL-23 and Th17 cells may be involved in the pathogenesis of acute blood pressure increase in the patients with hypertension. Understanding its inflammatory characterization might be of fundamental importance for the prevention and treatment of acute blood pressure increase in hypertensive patients.