The distribution of CD56(dim) CD16+ and CD56(bright) CD16- cells are associated with prolactin levels during pregnancy and menstrual cycle in healthy women

The pregnancy and menstrual cycle (MC) are the main physiologic events linked to the human reproduction. An adequate neuroendocrine axis is mandatory for the homeostasis in both events. To analyze the distribution of NK, T, Treg cells, expression of their receptors and to associate with hormone levels in pregnant and MC in healthy women. We studied two groups of healthy women: 13 pregnant women followed up at 1st, 2nd and 3rd trimesters and 11 women in the 5th and 21st day of the MC. The distribution of NK, T, Treg cells population, expression of their receptors and hormone levels were quantified. In pregnant women, we found an association of NK cells CD56(dim) CD16(+) with prolactin levels. This finding was also was observed for CD56(brigthCD16-) being statistical significant during 1st trimester for both subpopulations. During MC, correlation of CD56(dim) CD16(+) , CD56(bright) CD16(-) cells with prolactin in follicular and luteal phase was found. This is the first report where these cell subpopulations have been analyzed prospectively. Even we can argue the random effect for the small number of women is interesting that prolactin showed the more consistent correlation with CD56(dim) CD16(+) , CD56(brigth) CD16(-) cells during both events studied.