Systemic changes in haemostatic balance are not associated with increased levels of circulating microparticles in women with recurrent spontaneous abortion.
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.
Toth
Bettina
B
Department of Obstetrics and Gynecology-Grosshadern, Ludwig-Maximilians-University, Munich, Germany. bettina.toth@med.uni-muenchen.de
Nieuwland
Rienk
R
Kern
Meike
M
Rogenhofer
Nina
N
Berkmans
René
R
Rank
Andreas
A
Lohse
Peter
P
Friese
Klaus
K
Thaler
Christian J
CJ
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
D001779:Blood Coagulation Factors; D010446:Peptide Fragments; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D013917:Thrombin