PROBLEM: The clinical significance of the differential expression of estrogen receptor (ER) in human monocytes was evaluated.
METHOD: Two color flow cytometry analysis was used on peripheral blood samples of young and postmenopausal females and postmenopausal females treated with estrogen replacement therapy. In addition, the monocyte and lymphocyte counts and the blood estrogen levels of each patient were determined.
RESULTS: During menopause there is a significant decrease in the percentage of ER positive monocytes, and an increase in blood monocyte number, which declines following estrogen replacement therapy to values of the young.
CONCLUSIONS: These findings suggest that estrogen modulates the monocyte numbers and its effects may be mediated through the ER in the monocytes.