title: Comparative analysis of peripheral natural killer cells in the two phases of the ovarian cycle.
abstract: OBJECTIVE
  Changes in endometrial Natural Killer (NK) cells during the luteal phase of the ovarian cycle are important in initiating/maintaining a subsequent pregnancy. In the present study it was investigated whether during the menstrual cycle changes occur also in peripheral blood (PB) NKs.
  
  
  METHODS
  Blood samples during the follicular and the luteal phase were collected from 30 women without fertility problems. Samples were analyzed by flow-cytometry for: (1) NK cells (CD3(-)CD16+CD56+) and (2) intracellular production of interferon-gamma (IFN-gamma) by NK cells. For the comparison and correlation of the two populations between the two phases, Wilcoxon signed-rank test and Spearman's Coefficient were used.
  
  
  RESULTS
  The differences in percentages of CD3(-)CD16+CD56+ cells and that of CD3(-)CD16+CD56+/IFN-gamma+ cells between the follicular and the luteal phase were not statistically significant (10.61 +/- 5.11 versus 9.76 +/- 4.57 and 6.48 +/- 7.90 versus 7.30 +/- 6.77, respectively, P > 0.05). The correlation between the two variables (NK% and NK/IFN-gamma%) was weakly positive (P = 0.07) only in the follicular phase.
  
  
  CONCLUSIONS
  The study did not reveal menstrual cycle-depended changes in PB NK cells. Thus, a suggestion to measure these cells in a specific phase of the cycle in order to predict the outcome of a subsequent pregnancy in women with fertility problems is objected.
authors.affiliation: Department of Biology, Section of Cell Biology and Biophysics, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Ageliki
authors.initials: A
authors.lastname: Pantazi
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Tzonis
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Perros
authors.forename: Olga
authors.initials: O
authors.lastname: Graphou
authors.forename: Theodora
authors.initials: T
authors.lastname: Keramitsoglou
authors.forename: Stavros
authors.initials: S
authors.lastname: Koussoulakos
authors.forename: Loukas
authors.initials: L
authors.lastname: Margaritis
authors.forename: Marighoula
authors.initials: M
authors.lastname: Varla-Leftherioti
mesh_terms: D000328:Adult; D005260:Female; D005434:Flow Cytometry; D005498:Follicular Phase / Q000097:blood; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D008183:Luteal Phase / Q000097:blood; D008875:Middle Aged; D012015:Reference Standards; D055815:Young Adult