title: Impact of gender and menstrual cycle phase on plasma cytokine concentrations.
abstract: OBJECTIVE
  The lifetime prevalence of major depression is twice as high in females as in males. Depression is known to increase at periods where there are changes in gonadal hormones. We examined pro- and anti-inflammatory cytokine levels during the normal menstrual cycle of healthy females compared to similar time points in healthy males.
  
  
  METHODS
  Plasma concentrations of interleukin (IL)-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-alpha) and soluble IL-6 receptor (sIL-6R) were measured with enzyme-linked immunosorbent assays in healthy females during the normal ovulatory menstrual cycle and also in males at similar time points.
  
  
  RESULTS
  The luteal phase of the menstrual cycle is associated with increased production of sIL-6R, IL-4 and TNF-alpha compared to the early follicular phase. No change was observed in IL-6, IL-8 and IL-10 concentration throughout the menstrual cycle. We found IL-4 positively correlated with oestrogen while TNF-alpha positively correlated with progesterone. Females were found to have significantly higher concentrations of TNF-alpha and sIL-6R across all phases of the menstrual cycle, compared to males across similar time points.
  
  
  CONCLUSIONS
  The normal menstrual cycle is associated with increased production of sIL-6R, IL-4 and TNF-alpha in the luteal phase compared to the early follicular phase. Females have significantly higher concentrations of sIL-6R and TNF-alpha at all time points across the menstrual cycle than males.
authors: Alimentary Pharmabiotic Centre, Department of Psychiatry, Cork University Hospital, Cork, Ireland. sinead.obrien2@gmail.com
authors: Sinead M
authors: SM
authors: O'Brien
authors: Peter
authors: P
authors: Fitzgerald
authors: Paul
authors: P
authors: Scully
authors: Anne
authors: A
authors: Landers
authors: Lucinda V
authors: LV
authors: Scott
authors: Timothy G
authors: TG
authors: Dinan
mesh_terms: D000328:Adult; D016207:Cytokines / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000097:blood* / Q000276:immunology*; D012737:Sex Factors
chemical_list: D016207:Cytokines