Antiphospholipid antibodies may impair factor XIIa-dependent activation of fibrinolysis in pregnancy: in vitro evidence with human endothelial cells in culture and monoclonal anticardiolipin antibodies.
OBJECTIVE
The purpose of this study was to analyze the in vitro activation of the contact complex with the use of human umbilical vein endothelial cells (HUVEC) in culture and monoclonal anticardiolipin antibodies (MaCL).


METHODS
Cultured HUVECs were incubated with pooled plasma from third-trimester pregnant women with the addition (20 mg/mL) of MaCL with anti-beta-2 glycoprotein I activity that was obtained from patients with antiphospholipid syndrome (APS), MaCL from an individual without APS, or from a control patient with immunoglobulin M without aCL activity. Supernatants were evaluated. Activated factors XII and VII, prothrombin-fragment 1 + 2, urokinase-type plasminogen activator (UPA), and differentiating 2 chain UPA were determined.


RESULTS
In the cultured HUVEC supernatants, the addition of MaCL increased activated factor VII and prothrombin-fragment 1 + 2, did not modify UPA, and decreased activated factor XII and differentiating 2 chain UPA, in comparison with samples with control immunoglobulin M added. The MaCL without APS activity did not change any parameter that was evaluated.


CONCLUSIONS
MaCL with anti-beta-2 activity that was obtained from patients with APS may interfere in the activation of the contact complex during pregnancy.
Lázaro
Isabel
I
Faculty of Medicine, Institut Clínic of Ginecology, Obstetrics and Neonatology, University of Barcelona, Barcelona, Spain.
Carmona
Francisco
F
Reverter
Juan Carlos
JC
Cervera
Ricard
R
Tassies
Dolors
D
Balasch
Juan
J
D000328:Adult; D000368:Aged; D017152:Antibodies, Antiphospholipid / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000276:immunology; D002478:Cells, Cultured; D004730:Endothelium, Vascular; D015956:Factor XIIa / Q000276:immunology*; D005260:Female; D005342:Fibrinolysis / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010446:Peptide Fragments / Q000097:blood / Q000276:immunology; D011247:Pregnancy / Q000276:immunology* / Q000502:physiology; D011248:Pregnancy Complications / Q000503:physiopathology; D011263:Pregnancy Trimester, Third; D011516:Prothrombin / Q000276:immunology; D013927:Thrombosis / Q000503:physiopathology; D014471:Umbilical Veins / Q000166:cytology
D017152:Antibodies, Antiphospholipid; D010446:Peptide Fragments; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D015956:Factor XIIa