Abstract 665: Hypertension Is Associated With Phenotypic Changes Of Peripheral Blood Monocytes.

While immunopathogenesis of atherosclerosis is well defined, immunological mechanisms of hypertension (HTN) and its link to atherosclerosis remain unclear. We hypothesized, that primary HTN is associated with a pro-inflammatory and pro-atherogenic phenotype of circulating monocytes, characterized by co-expression of the Fc-gamma receptor (CD16+) and LPS receptor (CD14+high). Methods: 132 subjects (74M and 58F) with typical clinical risk factors of atherosclerosis were studied. HTN (85%) was diagnosed based on blood pressure monitoring and use of anti-HTN drugs. Monocyte characteristics in the peripheral blood were determined by flow cytometry and plasma cytokine levels by ELISA. Results: CD16+CD14+ cells were more prevalent in subjects with HTN and were highest in subjects whose blood pressure was poorly controlled (Figure ). A significant correlation between blood pressure levels at the time of study (JNC7) and prevalence of CD14+CD16+ monocytes was found (Figure ). These relationships remained significant in multi-variate analysis (p = 0.01; type 3 sum of squares ANOVA) taking into account other major risk factors for atherosclerosis or treatments. Further analysis of subpopulations showed that levels of CD16 +CD14+ (high) monocytes, rather than CD16 + CD14(dim) revealed a strong relationship to hypertension. These monocytes showed significantly higher expression of activation markers HLA-DR and CD45RA and TNF-α production(p<0.05). These results provide a novel marker of inflammation in hypertension and may provide a link between hypertension and the development of atherosclerosis, which has been clinically well defined, but mechanistically unclear.