Alterations of profibrinolytic receptor annexin A2 in pre-eclampsia: a possible role in placental thrombin formation.

INTRODUCTION

Deficient fibrinolytic activity due to alterations of profibrinolytic receptor annexin A2 has been shown to be related to increased thrombosis. We compared the expression of annexin A2 in pre-eclampsia with that in normal pregnancies and investigated its relationship to placental thrombin formation.

MATERIALS AND METHODS

Sixty patients with pre-eclampsia and 30 matched normal pregnant controls were included in the study. Expression of annexin A2 mRNA in placental tissues was analyzed using quantitative RT-PCR. Annexin A2 protein in placentas as well as blood was determined by western blot analysis and immunohistochemistry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the presence of anti- annexin A2 antibodies in peripheral maternal blood.

RESULTS

The expression of annexin A2 mRNA in placentas was significantly decreased in pre-eclampsia compared to normal pregnancies. Levels of annexin A2 protein in placentas as well as in peripheral maternal blood were also significantly reduced in patients with pre-eclampsia compared with healthy pregnant women. High titers of anti- annexin A2 antibodies were more frequently detected in pre-eclampsia group. Decreased levels of annexin A2 expression and the presence of anti-annexin A2 antibodies were associated with increased placental thrombosis.

CONCLUSION

The down regulation of annexin A2 expression and the presence of anti-annexin A2 antibodies were correlated to PE and may increase placental thrombin formation.