Th17/Treg imbalance in patients with primary hyperaldosteronism and resistant hypertension

INTRODUCTION Inflammation plays a pivotal role in blood pressure regulation. Data on experimental models of hypertension and hypertensive patients reflect the imbalance between T regulatory (Treg) and Th17 effector cells (Th17). OBJECTIVE The aim of this study was to quantify peripheral blood Treg lymphocytes and Th17 subsets in individuals with primary hyperaldosteronism (PHA) and resistant hypertension (RHT) presenting with elevated blood pressure levels and augmented cardiovascular risk when compared with normotensive controls (CTRL). PATIENTS AND METHODS Twenty CTRL participants, 21 patients with PHA, and 20 patients with RHT were enrolled. Plasma renin and angiotensin II, serum aldosterone concentration, ambulatory blood pressure monitoring (ABPM), echocardiography, clinical data, and phenotype of peripheral blood cells were assessed. RESULTS There were no statistically significant differences in terms of age and sex between the groups. Similar systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels in ABPM were observed in individuals with PHA and RHT. PHA patients had lower angiotensin II and 4-fold higher aldosterone concentrations than CTRL patients. Both, PHA and RHT were associated with cardiac hypertrophy and coronary artery disease. RHT patients presented a significantly higher CD4(+)IL-17A(+) T cell number when compared with PHA and CTRL ones. The number of CD4(+)CD25(+)OXP3(+) T cells did not differ between patients with secondary hypertension and normotensive controls. Finally, positive correlations between the data on 24 h SBP and the content of CD4(+)IL-17A(+) and CD4(+)CD25(+)FOXP3(+) in the PHA were found. CONCLUSION Elevated 24 h SBP in PHA was associated with the increased numbers of CD4(+)IL-17 and CD4(+)CD25(+)FOXP3(+) T cells.