title: Excess syncytiotrophoblast microparticle shedding is a feature of early-onset pre-eclampsia, but not normotensive intrauterine growth restriction.
abstract: BACKGROUND
  Syncytiotrophoblast microparticles (STBM) are shed into the maternal circulation in higher amounts in pre-eclampsia compared to normal pregnancy and are believed to be the stimulus for the systemic inflammatory response and endothelial cell damage which characterises the maternal syndrome. The excess shedding of STBM may be caused by hypoxia as a result of poor placentation, which is often a feature of pre-eclampsia. Similar placental pathology occurs in some cases of normotensive intrauterine growth restriction (nIUGR), but in the absence of maternal disease.
  
  
  OBJECTIVE
  To examine whether the shedding of STBM in nIUGR occurs to the same extent as in pre-eclampsia.
  
  
  METHODS
  A prospective case-control study in a tertiary referral centre of: 1) women with early-onset pre-eclampsia (EOPET < 34 week), 2) women with late-onset pre-eclampsia (LOPET > or = 34 week), 3) women with nIUGR), 4) matched normal pregnant women (NPC), and 5) non-pregnant women. An ELISA using the antitrophoblast antibody NDOG2 was used to measure STBM levels in peripheral venous plasma. Non-parametric analyses were conducted with statistical significance set at p < 0.05.
  
  
  RESULTS
  STBM levels rise during normal pregnancy. EOPET was associated with increased STBM levels (EOPET (median): 41 ng/ml, n = 15) compared with matched normal pregnancy (16 ng/ml, n = 15; Wilcoxon p = 0.005). LOPET (50 ng/ml, n = 10) and nIUGR (18 ng/ml, n = 8) STBM levels did not differ from matched normal pregnancy (36 ng/ml, n = 15, and 36 ng/ml, n = 8, respectively). Background levels in non-pregnant plasma were 0.49 ng/ml, n = 10.
  
  
  CONCLUSIONS
  Increased STBM levels were found in EOPET but not in nIUGR providing further evidence for their role in the pathogenesis of the maternal syndrome.
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, 4500 Oak Street, Vancouver BC V6H 3N1, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Goswami
authors.forename: D S
authors.initials: DS
authors.lastname: Tannetta
authors.forename: L A
authors.initials: LA
authors.lastname: Magee
authors.forename: A
authors.initials: A
authors.lastname: Fuchisawa
authors.forename: C W G
authors.initials: CW
authors.lastname: Redman
authors.forename: I L
authors.initials: IL
authors.lastname: Sargent
authors.forename: P
authors.initials: P
authors.lastname: von Dadelszen
mesh_terms: D000293:Adolescent; D000328:Adult; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D006801:Humans; D011225:Pre-Eclampsia / Q000473:pathology* / Q000503:physiopathology*; D011247:Pregnancy; D013997:Time Factors; D014327:Trophoblasts / Q000473:pathology*