title: Maternal serum levels of interferon-gamma and interleukin-2 soluble receptor-alpha predict the outcome of early IVF pregnancies.
abstract: BACKGROUND
  Elevated maternal serum levels of interleukin-2 soluble receptor-alpha (IL-2 sRalpha), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) have been associated with pregnancy loss. The aim of our study was to evaluate the predictive value of these cytokines in the outcome of early IVF pregnancies.
  
  
  METHODS
  One hundred and fifty-nine consecutive IVF patients who were subsequently diagnosed to have a biochemical pregnancy (n = 23), a first-trimester miscarriage (n = 19) or a normal term delivery (n = 117) were included in this study. Serum was collected from the initial pregnancy test, 11 days after a day 3 embryo transfer, and all samples were analysed for IL-2 sRalpha, TNF-alpha and IFN-gamma by commercially available enzyme-linked immunosorbent assay (ELISA) kits.
  
  
  RESULTS
  IL-2 sRalpha levels were significantly higher in patients with an early pregnancy loss compared with patients with a normal term delivery (849.5 +/- 69.6 versus 693.5 +/- 31.2 pg/ml, P = 0.02), and a cut-off point of IL-2 sRalpha >1000 pg/ml predicted a poor pregnancy outcome (44.4 versus 22.7% pregnancy loss, IL-2 sRalpha >or=1000 versus IL-2 sRalpha <1000 pg/ml; P = 0.02). IFN-gamma-positive patients had twice the risk for poor IVF pregnancy outcome compared with IFN-gamma-negative subjects (40.8 versus 20.0%, respectively; P < 0.02), including a significantly lower implantation rate (37.6 +/- 0.05 versus 50.0 +/- 0.03%, respectively; P = 0.02). There was no difference in pregnancy outcome based upon serum levels, or the ability to detect the presence of TNF-alpha. No differences in levels of these cytokines were found based on the aetiology of the patients' infertility.
  
  
  CONCLUSIONS
  Elevated maternal serum levels of IL-2 sRalpha and IFN-gamma as early as 11 days after embryo transfer are associated with poor IVF pregnancy outcome.
authors.affiliation: Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University, New York, NY 10021, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Fasouliotis
authors.forename: S D
authors.initials: SD
authors.lastname: Spandorfer
authors.forename: S S
authors.initials: SS
authors.lastname: Witkin
authors.forename: G
authors.initials: G
authors.lastname: Schattman
authors.forename: H C
authors.initials: HC
authors.lastname: Liu
authors.forename: J E
authors.initials: JE
authors.lastname: Roberts
authors.forename: Z
authors.initials: Z
authors.lastname: Rosenwaks
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D053645:Interleukin-2 Receptor alpha Subunit; D009994:Osmolar Concentration; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011379:Prognosis; D011446:Prospective Studies; D018123:Receptors, Interleukin / Q000097:blood / Q000737:chemistry; D012995:Solubility; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D018123:Receptors, Interleukin; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma