title: The identification of elevated urinary kisspeptin-immunoreactivity during pregnancy.
abstract: BACKGROUND
  Kisspeptin is an arginine-phenylalanine amide peptide hormone critical for reproductive function. Kisspeptin is also abundantly expressed in the placenta, where it has an important physiological role in regulating placental invasion. Accordingly, plasma kisspeptin concentrations rise dramatically during normal pregnancy. However, lower plasma concentrations of kisspeptin are associated with obstetric complications such as pre-eclampsia. It is not currently known whether kisspeptin-immunoreactivity (IR) can be detected in bodily fluids not requiring invasive collection such as saliva or urine.
  
  
  OBJECTIVE
  To determine the clinical utility of urinary and salivary kisspeptin measurement in healthy pregnant women.
  
  
  METHODS
  Forty-nine healthy third trimester pregnant women (gestational age 34 ± 0.6 w) from a single maternity unit and 50 healthy non-pregnant women were recruited. Urine, saliva and blood were simultaneously collected from all volunteers. Kisspeptin concentrations were determined by in-house manual radioimmunoassay.
  
  
  RESULTS
  Mean concentrations of plasma kisspeptin-IR were over 200-fold greater in third trimester pregnant women compared with non-pregnant women (13,783 ± 864 pmol/L, pregnant; 65 ± 13 pmol/L, non-pregnant; p < 0.0001). The urine kisspeptin:creatinine ratio was greater in pregnant women when compared with non-pregnant women (urine kisspeptin:creatinine: 37 ± 6 pmol/µmol, pregnant; 7 ± 1 pmol/µmol, non-pregnant; p < 0.0001). Mean concentrations of salivary kisspeptin-IR were not statistically different between pregnant and non-pregnant women (123 ± 34 pmol/L, pregnant; 83 ± 33 pmol/L, non-pregnant; p = 0.2).
  
  
  CONCLUSIONS
  We demonstrate for the first time that kisspeptin-IR is elevated in urine during pregnancy. Urinary measurement of kisspeptin-IR may, therefore, offer a non-invasive and simple method of screening for pregnancy and obstetric complications.
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Channa N
authors.initials: CN
authors.lastname: Jayasena
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Comninos
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Shakunthala
authors.initials: S
authors.lastname: Narayanaswamy
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Ali
authors.initials: A
authors.lastname: Abbara
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Gurjinder M K
authors.initials: GM
authors.lastname: Nijher
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Mansimran
authors.initials: M
authors.lastname: Cheema
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Malik
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Ghatei
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Bloom
authors.affiliation: Department of Investigative Medicine, Imperial College London, Hammersmith Hospital, London, UK w.dhillo@imperial.ac.uk.
authors.forename: Waljit S
authors.initials: WS
authors.lastname: Dhillo
mesh_terms: D015415:Biomarkers / Q000652:urine; D005260:Female; D006801:Humans; D059648:Kisspeptins / Q000652:urine*; D010865:Pilot Projects; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000652:urine*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D015415:Biomarkers; D059648:Kisspeptins
keywords: Pregnancy; peptide hormones; radioimmunoassay