title: Maternal serum serpin B7 is associated with early spontaneous preterm birth.
abstract: OBJECTIVE
  We sought to identify serum biomarkers of early spontaneous preterm birth (SPTB) using semiquantitative proteomic analyses.
  
  
  METHODS
  This was a nested case-control study of pregnant women with previous SPTB. Maternal serum was collected at 19-24 and 28-32 weeks' gestation, and analyzed by liquid chromatography-multiple reaction monitoring/mass spectrometry. Targeted and shotgun proteomics identified 31 candidate proteins that were differentially expressed in pooled serum samples from spontaneous preterm (cases [<34 weeks]) and term (controls) deliveries. Candidate protein expression was compared in individual serum samples between cases and controls matched by age and race groups, and clinical site. Protein expression was verified by Western blot in the placenta and fetal membranes from cases and controls.
  
  
  RESULTS
  Serum samples were available for 35 cases and 35 controls at 19-24 weeks, and 16 cases and 16 controls at 28-32 weeks. One protein, serpin B7, yielded serum concentrations that differed between cases and controls. The mean concentration of serpin B7 at 28-32 weeks was 1.5-fold higher in women with subsequent preterm deliveries compared to controls; there was no difference at 19-24 weeks. Higher levels of serpin B7 at both gestational age windows were associated with a shorter interval to delivery, and higher levels of serpin B7 in samples from 28-32 weeks were associated with a lower gestational age at delivery. Western blotting identified serpin B7 protein in placenta, amnion, and chorion from cases and controls.
  
  
  CONCLUSIONS
  Targeted and shotgun serum proteomics analyses associated 1 protein, serpin B7, with early SPTB. Our results require validation in other cohorts and analysis of the possible mechanistic role of serpin B7 in parturition.
authors: Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, PA. Electronic address: parry@mail.med.upenn.edu.
authors: Samuel
authors: S
authors: Parry
authors: Collaborative Center for Statistics in Science, Yale University School of Public Health, New Haven, CT.
authors: Heping
authors: H
authors: Zhang
authors: Department of Obstetrics and Gynecology, University of Alabama, Birmingham, School of Medicine, Birmingham, AL.
authors: Joseph
authors: J
authors: Biggio
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX.
authors: Radek
authors: R
authors: Bukowski
authors: Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, UT.
authors: Michael
authors: M
authors: Varner
authors: Collaborative Center for Statistics in Science, Yale University School of Public Health, New Haven, CT.
authors: Yaji
authors: Y
authors: Xu
authors: Department of Obstetrics and Gynecology, University of Alabama, Birmingham, School of Medicine, Birmingham, AL.
authors: William W
authors: WW
authors: Andrews
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX.
authors: George R
authors: GR
authors: Saade
authors: Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City, UT.
authors: M Sean
authors: MS
authors: Esplin
authors: Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, PA.
authors: Rita
authors: R
authors: Leite
authors: Pregnancy and Perinatology Branch, Center for Developmental Biology and Perinatal Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD.
authors: John
authors: J
authors: Ilekis
authors: Pregnancy and Perinatology Branch, Center for Developmental Biology and Perinatal Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD.
authors: Uma M
authors: UM
authors: Reddy
authors: Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA.
authors: Yoel
authors: Y
authors: Sadovsky
authors: Center for Cancer Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA.
authors: Ian A
authors: IA
authors: Blair
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008137:Longitudinal Studies; D007752:Obstetric Labor, Premature / Q000097:blood*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000097:blood; D011263:Pregnancy Trimester, Third / Q000097:blood; D047928:Premature Birth / Q000097:blood*; D011446:Prospective Studies; D020543:Proteome; D040901:Proteomics; D015843:Serpins / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D020543:Proteome; C114170:SERPINB7 protein, human; D015843:Serpins
keywords: preterm birth; proteomics; serine proteinase inhibitors