Association between genotype and plasma levels of thrombin-activated fibrinolysis inhibitor (TAFI) in the development of preeclampsia

Genetic Variants in Preeclampsia: Lessons From Studies in Latin-American Populations

Placental vascularization is a tightly regulated physiological process in which the maternal immune system plays a fundamental role. Vascularization of the maternal-placental interface involves a wide range of mechanisms primarily orchestrated by the fetal extravillous trophoblast and maternal immune cells. In a healthy pregnancy, an immune cross-talk between the mother and fetal cells results in the secretion of immunomodulatory mediators, apoptosis of specific cells, cellular differentiation/proliferation, angiogenesis, and vasculogenesis, altogether favoring a suitable microenvironment for the developing embryo. In the context of vasculopathy underlying common pregnancy disorders, it is believed that inefficient invasion of extravillous trophoblast cells in the endometrium leads to a poor placental blood supply, which, in turn, leads to decreased secretion of angiogenic factors, hypoxia, and inflammation commonly associated with preterm delivery, intrauterine growth restriction, and preeclampsia. In this review, we will focus on studies published by Latin American research groups, providing an extensive review of the role of genetic variants from candidate genes involved in a broad spectrum of biological processes underlying the pathophysiology of preeclampsia. In addition, we will discuss how these studies contribute to fill gaps in the current understanding of preeclampsia. Finally, we discuss some trending topics from important fields associated with pregnancy vascular disorders (e.g., epigenetics, transplantation biology, and non-coding RNAs) and underscore their possible implications in the pathophysiology of preeclampsia. As a result, these efforts are expected to give an overview of the extent of scientific research produced in Latin America and encourage multicentric collaborations by highlighted regional research groups involved in preeclampsia investigation.

Antibodies directed against annexin A2 and obstetric morbidity

Acquired and inherited thrombophilia have both been reported to be associated with an increased risk of obstetric complications in early or later stages of pregnancy. Annexin A2 (ANXA2) is strongly expressed in vascular and placental tissues and plays a crucial role in fibrinolysis. The aim of the present study was to evaluate the prevalence of antibodies directed against ANXA2 in patients with recurrent miscarriage or obstetric complications. Anti-ANXA2 antibodies (aANXA2) were detected by ELISA in the sera from 46 women with obstetric morbidity, mainly recurrent miscarriage. The cut-off value for positivity was defined as 3 standard deviations above the mean optical density (OD) obtained in the sera from 42 female blood donors. The prevalence of aANXA2 in patients and healthy individuals was 15.2% and 2.3%, respectively. A statistically significant difference was observed between the 2 groups in terms of aANXA2 IgG titers (p=0.01). The highest aANXA2 levels were observed in sera from 2 patients with recurrent miscarriage and one patient with preeclampsia. aANXA2 could play a role in thrombotic mechanisms leading to recurrent pregnancy loss and placental vascular disease. Further studies are needed to determine whether ANXA2 is critical for maintenance of placental integrity.

Effect of single nucleotide polymorphism in thrombin-activatable fibrinolysis inhibitor on the risk of diabetic macrovascular disease

Hypofibrinolysis is commonly found in patients with diabetes mellitus and is associated with the increased risk for many diabetic complications. An important inhibitor of fibrinolysis, thrombin-activatable fibrinolysis inhibitor (TAFI), participates in hypofibrinolysis in diabetes mellitus and may be involved in diabetic macrovascular disease. The present study was designed to determine whether TAFI polymorphisms (505G/A and 1040C/T) and TAFI levels are correlated with the development of type 2 diabetes mellitus (T2DM) and macrovascular diseases (MVDs). A total of 249 clinical samples were collected, including 102 healthy individuals (H group), 44 T2DM patients without MVD (T group) and 103 T2DM patients with MVD (M group). The 505G/A polymorphism was equally represented in the three groups. In contrast, analysis of the 1040C/T polymorphism revealed a statistically lower percentage of the T allele in the M group than in the H group (P = 0.014). This difference was due to decreased T/T homozygotes in the M groups compared with the H group (P = 0.029). The antigen TAFI level was 31.72 ± 13.64% in the H group, 62.56 ± 18.77% in the T group (P < 0.05, compared with the H group) and 63.70 ± 15.76% in the M group (P < 0.05, compared with the H group). As high plasma TAFI level is associated with the increasing risk of T2DM, it may thus serve as a potential marker for the diagnosis of T2DM.