title: Leukocyte changes across menstruation, ovulation, and mid-luteal phase and association with sex hormone variation.
abstract: Total leukocyte count (white blood cells-WBC) and the count of each subpopulation vary across the menstrual cycle, but results of studies examining the time and direction of these changes are inconsistent and methodologically flawed. Besides, no previous study focused on leukocyte count on the day of ovulation.
  
  
  
  Blood samples were obtained from 37 healthy and regularly cycling women aged 19.8-36.1 years. Samples were taken three times: during menstruation (M), ovulation (O), and in the mid-luteal phase (ML). WBC, neutrophils, lymphocytes, mixed cells, progesterone (P,) and estradiol (E) were measured in each of the three target phases of the cycle.
  
  
  
  Compared to menstruation, WBC (P = 0.002) and neutrophils (P < 0.001) increased around ovulation and remained stable in the mid-luteal phase, whereas lymphocyte and mixed cell counts did not change throughout the menstrual cycle. There were some correlations of sex hormone variation with leukocyte changes between M and O (positive for E and WBC, negative for P and WBC and for P and neutrophil count; P < 0.05), but not between O and ML.
  
  
  
  Peripheral leukocyte changes taking place in the second half of the cycle are already observable on the day of ovulation and they are associated with sex hormone variation. We speculate that these changes may lead to increased immune protection against pathogens at a time when fertilization and implantation typically occur. Am. J. Hum. Biol. 28:721-728, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Human Biology, University of Wroclaw, 50-138, Wroclaw, Poland.
authors.forename: Judyta
authors.initials: J
authors.lastname: Nowak
authors.affiliation: Department of Human Biology, University of Wroclaw, 50-138, Wroclaw, Poland. barbara.borkowska@antropo.uni.wroc.pl.
authors.forename: Barbara
authors.initials: B
authors.lastname: Borkowska
authors.affiliation: Department of Human Biology, University of Wroclaw, 50-138, Wroclaw, Poland.
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Pawlowski
mesh_terms: D000328:Adult; D004958:Estradiol / Q000097:blood*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008183:Luteal Phase; D008598:Menstruation; D010060:Ovulation; D011374:Progesterone / Q000097:blood*; D055815:Young Adult
chemical_list: D011374:Progesterone; D004958:Estradiol