Pregnancy favors the expansion of circulating functional follicular helper T Cells.

Pregnancy favors antibody production, and some evidence has suggested a direct effect of estrogen on B cells. The impact of pregnancy on circulating follicular helper T (T) cells, typically identified by the expression of CD45RO and CXCR5, has not been previously investigated. Here, the percentage of T cells, co-expressing or not PD-1, ICOS, or CXCR3 markers was significantly higher in pregnant women (PW) as compared with non-pregnant ones (nPW).