title: Stability of serum interleukin-10 levels during the menstrual cycle.
abstract: OBJECTIVE
  Menstrual cycle-associated variability in the circulating levels of several cytokines can be a confounding factor in measurements of in vivo cytokine levels in clinical studies. Since pregnancy-associated increases in interleukin-10 (IL-10) levels are well documented, we have investigated the variability in serum levels of IL-10 in healthy women at different stages of the menstrual cycle to ascertain whether this is a problem in comparative studies of circulating IL-10 levels.
  
  
  METHODS
  We obtained fifty-four successive serum samples at points in the menstrual cycles of 12 healthy fertile women, precisely timed by measurement of the luteinizing hormone surge, and measured the interleukin-10 levels.
  
  
  RESULTS
  Levels of IL-10 in successive serum samples from each woman taken on days LH - 7 (that is seven days prior to LH surge), LH - 4, LH + 1, LH + 7, and LH + 10 showed that IL-10 does not vary in a systematic way during the menstrual cycle.
  
  
  CONCLUSIONS
  These results validate the sampling of women in studies of IL-10 levels in various clinical situations and establish that these levels are not dependent on menstrual cycle dates. They also suggest that menstrual cycle-related changes in IL-1 are not mediated by IL-10. The rise in progesterone in the luteal phase of the menstrual cycle is not mirrored by a rise in the circulating IL-10 level, which implies either that the pregnancy-associated rise is not related to progesterone or that it is only observed at the higher progesterone levels in pregnancy.
authors.affiliation: Division of Biomedical Sciences, Sheffield Hallam University, United Kingdom.
authors.forename: J K
authors.initials: JK
authors.lastname: Maskill
authors.forename: S M
authors.initials: SM
authors.lastname: Laird
authors.forename: M
authors.initials: M
authors.lastname: Okon
authors.forename: T C
authors.initials: TC
authors.lastname: Li
authors.forename: A I
authors.initials: AI
authors.lastname: Blakemore
mesh_terms: D000328:Adult; D005260:Female; D005498:Follicular Phase / Q000097:blood / Q000276:immunology; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D016753:Interleukin-10 / Q000097:blood*; D008183:Luteal Phase / Q000097:blood / Q000276:immunology; D008597:Menstrual Cycle / Q000097:blood* / Q000276:immunology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D013997:Time Factors
chemical_list: D007375:Interleukin-1; D016753:Interleukin-10; D011374:Progesterone