E₂ administration increases the frequency of pDC producing IFN-α and TNF-α after TLR-7 stimulation. (A) The first 2 blood samples (S1 and S2) from early postmenopausal women volunteers were collected before E₂ treatment by oral or transdermal route with standard substitutive posology. The last blood sample (S3) was collected after 30 ± 3 days of treatment. (B,D) Representative flow cytometry plots showing IFN-α (B) and TNF-α (D) production by BDCA-2⁺ pDCs derived from postmenopausal women before (left) or after E₂ treatment (right), after 5 hours of in vitro stimulation with TLR-7/TLR-8 ligand R-848. (C,E) Percentage of pDCs from postmenopausal women before (S2) and after E₂ treatment (S3), producing IFN-α (C, n = 17) or TNF-α (E, n = 21) on in vitro culture in the presence of R848. Horizontal bars indicate mean values, and P values were determined using the Wilcoxon signed rank test. (C,E) Dot plot panels show the correspondence between the values for each patient between mean S1-S2 versus S3.