title: Systemic changes in haemostatic balance are not associated with increased levels of circulating microparticles in women with recurrent spontaneous abortion.
abstract: OBJECTIVE
  Placental fibrin deposits in patients wih recurrent spontaneous abortion (RSA) indicate an exaggerated haemostatic response. This 'hypercoagulability' may involve pro-coagulant factors such as circulating microparticles (MPs). We investigated the relationship between circulating pro-coagulant MPs and systemic coagulation in RSA patients.
  
  
  METHODS
  Platelet- and endothelial cell-derived microparticles (PMPs, EMPs) were evaluated by flow cytometry in RSA patients (n = 51) and compared to controls (n = 24) using annexin V (total numbers of MP), and antibodies against CD61, CD63 and CD62P (PMP), as well as CD144 and CD62E (EMP). Prothrombin fragment 1 + 2 (F(1+2)) and thrombin generation were determined to assess the pro-coagulant potential of MP.
  
  
  RESULTS
  Numbers of annexin V-binding MP were nearly similar in RSA patients and controls. However, a subgroup of ten RSA patients (10/51; 20%) presented with MP concentrations >10,000 x 10(6)/L, compared to only one women out of the control group (1/24; 4%; P = 0.038). Neither PMP and EMP nor F(1+2) and thrombin generation differed significantly within the study population.
  
  
  CONCLUSIONS
  The present study shows that circulating MPs are not directly associated with the extent of systemic coagulation activation in RSA patients. We hypothesize that increased numbers of circulating MPs either are only indirectly associated with coagulation during pregnancy of RSA patients, or affect abortion via mechanisms independently from hypercoagulation.
authors.affiliation: Department of Obstetrics and Gynecology-Grosshadern, Ludwig-Maximilians-University, Munich, Germany. bettina.toth@med.uni-muenchen.de
authors.forename: Bettina
authors.initials: B
authors.lastname: Toth
authors.forename: Rienk
authors.initials: R
authors.lastname: Nieuwland
authors.forename: Meike
authors.initials: M
authors.lastname: Kern
authors.forename: Nina
authors.initials: N
authors.lastname: Rogenhofer
authors.forename: René
authors.initials: R
authors.lastname: Berkmans
authors.forename: Andreas
authors.initials: A
authors.lastname: Rank
authors.forename: Peter
authors.initials: P
authors.lastname: Lohse
authors.forename: Klaus
authors.initials: K
authors.lastname: Friese
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Thaler
mesh_terms: D000026:Abortion, Habitual / Q000097:blood*; D000328:Adult; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000378:metabolism*; D001792:Blood Platelets / Q000502:physiology; D016022:Case-Control Studies; D042783:Endothelial Cells / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D006487:Hemostasis; D006801:Humans; D010446:Peptide Fragments / Q000097:blood; D011446:Prospective Studies; D011516:Prothrombin; D018709:Statistics, Nonparametric; D013917:Thrombin / Q000378:metabolism
chemical_list: D001779:Blood Coagulation Factors; D010446:Peptide Fragments; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D013917:Thrombin