Individual monocyte subsets have been associated with atherosclerotic disease, but their distribution has not been evaluated in aortic valve stenosis (AS) so far. In the present study, we have asked whether levels of the circulating intermediate monocyte subset are increased in AS. Classical (CD14++CD16-), intermediate (CD14++CD16+), and non-classical (CD14+CD16++) CD86-positive monocytes and monocyte activation (intensity of CD11b expression) were determined by flow cytometry in peripheral blood of patients with severe AS (n = 100) and matched AS-free controls (n = 75). AS patients exhibited significantly higher levels of circulating intermediate monocytes, while levels of circulating classical and non-classical monocytes or monocyte activation did not differ compared to controls. The difference in levels of intermediate monocytes between groups was independent of age, gender, BMI, LDL-C, NT-proBNP, NYHA functional class, or creatinine levels. The present pilot study provides evidence of an association of severe AS with increased levels of circulating intermediate monocytes. Further studies need to clarify whether this finding is related to the inflammatory status and hemodynamic disturbances associated with severe AS.
Keywords: Aortic valve stenosis; Inflammation; Monocyte subsets.