A comparative study of the protein C system in mother's blood, cord blood and amniotic fluid

Activated protein C (APC) is an important anticoagulant which plays a role in pathophysiology of pregnancy, e.g. in maintenance of the uteroplacental circulation and development of the fetus as well as in pathogenesis of preeclampsia. The study objective was to compare the levels of the respective components of the protein C system (protein C, PC; protein S, PS; thrombomodulin, TM) as well as thrombin activatable fibrinolysis inhibitor - TAFI in mother's blood, cord blood and amniotic fluid. The study group consisted of 136 healthy parturients at term, divided into subgroups of 30-35. The immunoenzymatic method (ELISA) was used to measure the antigens of the components studied. The concentrations of PC and PS antigens were the highest in the mother's blood plasma (135.11+/-1.05% and 92.0+/-13.24%, respectively), lower in cord blood plasma (57.60+/-10.32% and 33.19+/-4.96%, respectively) and the lowest in amniotic fluid (6.75+/-3.50% and 2.40+/-1.64%, respectively); the differences between the levels of that of mother, fetus and amniotic fluid were statistically significant (p< or =0.0001). The TM and TAFI antigen concentrations were the highest in cord blood plasma (11.35+/-3.71 ng/ml and 91.50 (median; range: 71.76-160.77) ng/ml, respectively) and lower in maternal plasma (4.51+/-0.71 ng/ml and 55.46 - median; range: 39.77-68.54 ng/ml, respectively); the differences between the levels of that of cord blood plasma and maternal plasma were statistically significant (p< or =0.0001). Of the three protein C system components, PC and PS occur in relatively high concentrations in maternal blood, being lower in fetal blood and the lowest in amniotic fluid. On the other hand, as an exception, the concentrations of TM and TAFI are the highest in fetus blood.