The PAI-1 4G/5G polymorphism is not associated with an increased risk of adverse pregnancy outcome in asymptomatic nulliparous women

Impact of Thrombophilic Polymorphisms in Antenatal Women on Perinatal Health: A Single-Center Prospective Study

BACKGROUND

Despite pregnancy's hypercoagulable state, the correlation between inherited thrombophilia and thrombotic adverse pregnancy outcomes remains uncertain. The objective of this study was to determine the prevalence of inherited thrombophilic polymorphisms among asymptomatic pregnant individuals and to examine their potential correlation with adverse perinatal outcomes.

METHODS

in this single-center prospective study, 105 healthy pregnant women were included. Genotyping was conducted for factor V Leiden (FVL), prothrombin gene mutation, methylenetetrahydrofolate reductase enzyme (MTHFR) C677T, MTHFR A1298C, and plasminogen activator inhibitor-1 (PAI-1), alongside the assessment of protein C (PC), protein S (PS), and antithrombin (AT) levels. The study analyzed the association between inherited thrombophilic polymorphisms and pregnancy complications linked to placental insufficiency, such as gestational hypertension (GH), preeclampsia (PE), intrauterine death (IUD), fetal growth restriction (FGR), and placental abruption.

RESULTS

The prevalence of identifiable thrombophilic polymorphism mutations was 61.9% (95% confidence interval-CI 52.4-70.8%), with the most common single mutation being PAI-1 4G/5G (12/105, 11.4%, 95% CI 6.4-18.5). The most frequent combined mutation was heterozygosity for MTHFR C677T and PAI-1 (12/105, 11.4%, 95% CI 6.4-18.5). Notably, no FVL homozygous carriers or single homozygous and heterozygous carriers for prothrombin polymorphisms were found. Additionally, no deficiencies in PC and AT were detected among participants. Except for homozygosity for PAI-1, none of the studied polymorphisms demonstrated a significant association with pregnancy complications linked to placental insufficiency.

CONCLUSIONS

The asymptomatic carriers of inherited thrombophilic polymorphisms do not have an increased risk of adverse perinatal outcomes.

The Role of Plasminogen Activator Inhibitor Type 1 (PAI-1) in Placenta-Mediated Pregnancy Complications: A Systematic Review

Plasminogen activator inhibitor type 1 (PAI-1) is a main inhibitor of fibrinolysis. The PAI-1 gene (SERPINE1) harbors genetic variants with the potential of modifying plasma levels of PAI-1. A delicate balance exists between the coagulation and fibrinolytic system, and changes in PAI-1 have been suggested to compromise establishment of a successful pregnancy. Therefore, this systematic review investigated the association between genetic variants and/or plasma levels of PAI-1 and placenta-mediated pregnancy complications. An extensive literature search was conducted in PubMed, Embase, and Web of Science on the 29^th of April 2021. All studies underwent quality rating according to The Study Quality Assessment Tools checklist provided by National Heart, Lung and Blood Institute. A total of 71 studies were included, among which 60 studies investigated PAI-1 genotypes and 11 studies measured PAI-1 plasma levels. In 32 out of 59 studies, no association was found between the PAI-1 4G/5G polymorphism (rs1799768) and placenta-mediated pregnancy complications, which was stated as no significant difference in the genotype distribution comparing women with and without placenta-mediated pregnancy complications or no significantly increased odds of placenta-mediated pregnancy complications carrying the 4G/4G or 4G/5G genotype. Eight out of 11 studies reported significantly higher PAI-1 plasma levels in preeclamptic women than in women without preeclampsia. In conclusion, no clear evidence indicates that PAI-1 polymorphisms are associated with placenta-mediated pregnancy complications, and the possible association between high PAI-1 plasma levels and preeclampsia needs further investigations. Thus, investigation of PAI-1 genotypes and PAI-1 plasma levels does not currently seem to have a place in daily clinical practice managing placenta-mediated pregnancy complications.

Galectin-1-Related Modulation of Trophoblast Endothelial Interactions by Integrins α1 and β1

During normal trophoblast invasion, integrins α6β4 are downregulated, and α1β1 are upregulated in invasive cytotrophoblast cells. In preeclampsia both interstitial and endovascular invasion are shallow and cytotrophoblasts fail to upregulate α1β1 and downregulate α6β4. This study aims to investigate the role of integrins α1β1 and α6β4 on cellular pathways influencing trophoblast integration into endothelial cellular networks in vitro. Red fluorescent-labeled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel to form endothelial networks. Green fluorescent-labeled trophoblastic HTR-8/SVneo cells pre-incubated with 20 μg/ml of neutralizing antibodies (anti-α1, β1, α6, β4, α1 + β1, or α6 + β4) for 1 h were then co-cultured with endothelial networks with the neutralizing antibodies for 24 h. Fluorescent images were captured, and quantified utilizing Image J. Cells were retrieved to analyze mRNA expression of galectin-1, TIMP-1, and PAI-1 by quantitative PCR. MMP-2, MMP-9, free sFlt-1, and PlGF from conditioned media were measured by ELISA. The integration of trophoblast cells into endothelial cellular networks was inhibited by anti-β1(- 28 ± 3%, p < 0.0001), and increased by anti-α6(+ 19 ± 5%, p < 0.01). Galectin-1 mRNA expression was decreased by anti-α1(- 35 ± 7%, p < 0.001), anti-β1(- 23 ± 5%, p < 0.05), and anti-α1+β1(- 35 ± 5%, p < 0.001). The mRNA expression of TIMP-1 was inhibited by anti-α1(- 59 ± 9%, p < 0.01) and anti-β1(- 63 ± 7%, p < 0.001) while PAI-1 mRNA expression was increased by anti-α1 + β1(+ 285 ± 70%, p < 0.0001). In the conditioned medium, anti-α1 reduced MMP-2(-28 ± 1%, p < 0.001), MMP-9(-27 ± 8%, p < 0.01), and sFlt-1(-27 ± 5%, p < 0.001) production. Anti-β1 reduced MMP-2(- 15 ± 2%, p < 0.05) production. There were no changes in PlGF. Appropriate integrins α1β1 modulate trophoblast cell integration into endothelial cellular networks in vitro through invasive pathways including galectin-1, TIMP-1, PAI-1, MMP-2, and MMP-9 production.

Role of Plasminogen Activator Inhibitor Type 1 in Pathologies of Female Reproductive Diseases

Normal pregnancy is a state of hypercoagulability with diminishing fibrinolytic activity, which is mainly caused by an increase of plasminogen activator inhibitor type 1 (PAI-1). PAI-1 is the main inhibitor of plasminogen activators, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In human placentas, PAI-1 is expressed in extravillous interstitial trophoblasts and vascular trophoblasts. During implantation and placentation, PAI-1 is responsible for inhibiting extra cellular matrix (ECM) degradation, thereby causing an inhibition of trophoblasts invasion. In the present study, we have reviewed the literature of various reproductive diseases where PAI-1 plays a role. PAI-1 levels are increased in patients with recurrent pregnancy losses (RPL), preeclampsia, intrauterine growth restriction (IUGR), gestational diabetes mellitus (GDM) in the previous pregnancy, endometriosis and polycystic ovary syndrome (PCOS). In general, an increased expression of PAI-1 in the blood is associated with an increased risk for infertility and a worse pregnancy outcome. GDM and PCOS are related to the genetic role of the 4G/5G polymorphism of PAI-1. This review provides an overview of the current knowledge of the role of PAI-1 in reproductive diseases. PAI-1 represents a promising monitoring biomarker for reproductive diseases and may be a treatment target in the near future.

Associations between Maternal and Fetal Inherited Thrombophilias, Placental Characteristics Associated with Vascular Malperfusion, and Fetal Growth

Pregnancy results in alterations in coagulation processes, which may increase the risk of thrombosis. Inherited thrombophilia mutations may further increase this risk, possibly through alterations in the placenta, which may result in pregnancy complications such as poor fetal growth. The purpose of our study is to evaluate the association of fetal growth, approximated by birth weight for gestational age percentile, with genetic markers of thrombophilia and placental characteristics related to vascular malperfusion. We analyzed data from the Stillbirth Collaborative Research Network's population-based case–control study conducted in 2006–2008. Study recruitment occurred in five states: Rhode Island and counties in Massachusetts, Georgia, Texas, and Utah. The analysis was restricted to singleton, nonanomalous live births ≤42 weeks' gestation with a complete placental examination and successful testing for ≥1 thrombophilia marker (858 mothers, 902 infants). Data were weighted to account for oversampling, differential consent, and availability of placental examination. We evaluated five thrombophilia markers: factor V Leiden, factor II prothrombin, methylenetetrahydrofolate reductase A1298C and C677T, and plasminogen activator inhibitor type 1 in both maternal blood and placenta/cord blood. We modeled maternal and fetal thrombophilia markers separately using linear regression. Maternal factor V Leiden mutation was associated with a 13.16-point decrease in adjusted birth weight percentile (95% confidence interval: −25.50, −0.82). Adjustment for placental abnormalities related to vascular malperfusion did not affect the observed association. No other maternal or fetal thrombophilia markers were significantly associated with birth weight percentile. Maternal factor V Leiden may be associated with fetal growth independent of placental characteristics.

Factor V Leiden, prothrombin G20210A, and methylene tetrahydrofolate reductase mutations and stillbirth: the Stillbirth Collaborative Research Network

BACKGROUND

An evaluation for heritable thrombophilias is recommended in the evaluation of stillbirth. However, the association between thrombophilias and stillbirth remains uncertain.

OBJECTIVE

We sought to assess the association between maternal and fetal/placental heritable thrombophilias and stillbirth in a population-based, case-control study in a geographically, racially, and ethnically diverse population.

STUDY DESIGN

We conducted secondary analysis of data from the Stillbirth Collaborative Research Network, a population-based case-control study of stillbirth. Testing for factor V Leiden, prothrombin G20210A, methylene tetrahydrofolate reductase C677T and A1298C, and plasminogen activating inhibitor (PAI)-1 4G/5G mutations was done on maternal and fetal (or placental) DNA from singleton pregnancies. Data analyses were weighted for oversampling and other aspects of the design. Odds ratios (OR) were generated from univariate models regressing stillbirth/live birth status on each thrombophilia marker.

RESULTS

Results were available for ≥1 marker in 488 stillbirths and 1342 live birth mothers and 405 stillbirths and 990 live birth fetuses. There was an increased odds of stillbirth for maternal homozygous factor V Leiden mutation (2/488; 0.4% vs 1/1380; 0.0046%; OR, 87.44; 95% confidence interval, 7.88-970.92). However, there were no significant differences in the odds of stillbirth for any other maternal thrombophilia, even after stratified analyses. Fetal 4G/4G PAI-1 (OR, 0.63; 95% confidence interval, 0.43-0.91) was associated with decreased odds of stillbirth. Other fetal thrombophilias were similar among groups.

CONCLUSION

Most maternal and fetal thrombophilias were not associated with stillbirth. Maternal factor V Leiden was weakly associated with stillbirth, and the fetal PAI-1 4G/4G polymorphism was associated with live birth. Our data do not support routine testing for heritable thrombophilias as part of an evaluation for possible causes of stillbirth.

The Impact of Inherited Thrombophilia Types and Low Molecular Weight Heparin Treatment on Pregnancy Complications in Women with Previous Adverse Outcome

PURPOSE

To assess the distribution of births and spontaneous abortions, first-trimester abortion (FTA) and mid-trimester abortion (MTA), in untreated (n=128) and low molecular weight heparin (LMWH) treated pregnancies (n=50) of the same women with inherited thrombophilias and adverse pregnancy outcome (APO) in previous pregnancies. We particularly investigated the impact of LMWH on reducing the pregnancy complications in two thrombophilia types, "Conventional" and "Novel".

MATERIALS AND METHODS

50 women with inherited thrombophilia (26 Conventional and 24 Novel) and APO in previous pregnancies were included in the study. Conventional group included factor V Leiden (FVL), prothrombin G20210A (PT) mutations and antithrombin (AT), protein S (PS), and protein C (PC) deficiency, while the Novel group included methylentetrahydrofolate-reductase (MTHFR), plasminogen activator inhibitor-1 (PAI-1), and angiotensin converting enzyme (ACE) polymorphism. APO was defined as one of the following: preterm birth (PTB), fetal growth restriction (FGR), preeclampsia (PE), intrauterine fetal death (IUFD), placental abruption (PA) and deep venous thrombosis (DVT).

RESULTS

There was no difference in distribution of births and spontaneous abortions between Conventional and Novel thrombophilia in untreated pregnancies (χ²=2.7; p=0.100) and LMWH treated pregnancies (χ²=0.442; p=0.506). In untreaed pregnancies thrombophilia type did not have any impact on the frequency of FTA and MTA (χ²=0.14; p=0.711). In birth-ended pregnancies LMWH treatement reduced the incidence of IUFD (p=0.011) in Conventional and FGR, IUFD, and PTB in Novel thrombophilia group.

CONCLUSION

The equal impact of two thrombophilia types on the pregnancy outcomes and a more favorable effect of LMWH therapy on pregnancy complications in Novel thrombophilia group point the need for Novel thrombophilias screening and the future studies on this issue should be recommended.

Decidual GM-CSF is a critical common intermediate necessary for thrombin and TNF induced in-vitro fetal membrane weakening

INTRODUCTION

Inflammation/infection and decidual bleeding/abruption are highly associated with pPROM. As no animal model for pPROM exists, we have developed an in-vitro model system for the study of human fetal membrane (FM) weakening/rupture. Using it we have demonstrated that both TNF/IL-1 (modeling inflammation) and thrombin (modeling bleeding) weaken full thickness FM in a dose dependent manner concomitant with inducing biochemical changes similar to those seen in the FM physiological weak zone.

METHODS

As the physiological site of infection and bleeding is the choriodecidua (CD), we modified our model system with full thickness FM tissue mounted on modified Transwell culture inserts to permit directional TNF/thrombin exposure on the decidua only (rather than both sides of the FM). After incubation, medium was sampled separately from the CD facing (maternal side) or from the amnion facing (fetal side) compartments and probed for cytokine release and confirmed with western blots. The FM was strength tested within the insert.

RESULTS

Full-thickness FM fragments exposed to TNF or thrombin on CD side only showed dose dependent weakening and biochemical changes consistent with previous reports. Concomitantly, GM-CSF increased markedly on the CD but not the amnion side. Numerous proteases including MMP1 and MMP3 also increased on the CD side. Pre-incubation with GM-CSF antibody blocked both thrombin and TNF induced weakening. Finally, GM-CSF weakened FM in a dose dependent manner.

DISCUSSION

GM-CSF is a critical common intermediate in the thrombin and TNF FM weakening pathways.

Low molecular weight heparin treatment and impact of inherited thrombophilia type in pregnancies with previous adverse outcome

OBJECTIVE

To assess the impact of low molecular weight heparin (LMWH) treatment in 50 pregnancies of women with inherited thrombophilia and adverse pregnancy outcome (APO) in previous untreated pregnancies. The impact of "Conventional" (FVL, PT, AT, PC, PS) and "Novel" (MTHFR, PAI-1, ACE) thrombophilias on APO was investigated.

METHODS

The primary outcomes (PO) were: early and late pregnancy loss (EPL, LPL), preterm birth (PTB) or term birth (TB) compared to the last untreated pregnancies of the same women. Secondary outcomes (SO) were APO in LMWH treated and last untreated pregnancies ended with birth. PO and SO were compared in relation to the thrombophilia type.

RESULTS

LMWH decreased EPL and LPL rate and improved TB rate compared with last untreated pregnancies (p < 0.001). There were less PTB (p = 0.019) and no cases of intrauterine fetal death (IUFD) (p = 0.0019) in LWMH-treated pregnancies. The division to Conventional and Novel thrombophilias showed: (a) difference between pregnancy losses and birth rate (p = 0.0069) and (b) no difference in the prevalence of APO in untreated pregnancies ended with birth.

CONCLUSIONS

LMWH treatment improves pregnancy outcome in women with inherited thrombophilia and APO in previous pregnancies. Novel thrombophilias have the equal impact on the pregnancy outcome compared to the Conventional thrombophilias.

Thrombophilic Mutations and Polymorphisms, Alone or in Combination, and Recurrent Spontaneous Abortion

Generally, recurrent spontaneous abortions (RSAs) have no identifiable cause; yet, vascular alterations during pregnancy may be associated with pregnancy loss. Therefore, we evaluated the association between thrombophilic mutations and RSAs. This case–control study was conducted in 112 patients who had RSAs and 98 health control women. Genomic DNA was extracted from whole blood, and polymorphism genotyping was conducted using polymerase chain reaction. The following 6 genetic variants were analyzed: factor V Leiden, prothrombin mutation, methylenetetrahydrofolate reductase C677T and A1298C, plasminogen activator inhibitor type 1 (4G>5G), and factor XIII G103T (V34L). No correlations were found in any of the investigated polymorphisms. Moreover, 35.0% of cases and 25.5% of controls had at least 2 mutations in combination, and 4.8% of cases and 5.1% of controls had 3, but these combinations were not associated with additional risk. In conclusion, we found no association between the polymorphisms studied and the occurrence of RSAs.

Association of plasminogen activator inhibitor-type 1 (-675 4G/5G) polymorphism with pre-eclampsia: systematic review

BACKGROUND AND AIMS

Excessive generation of plasminogen activator inhibitor-type 1 (PAI-1) is implicated in the pathogenesis of pre-eclampsia and related conditions. The PAI-1 (-675 4G/5G) promoter polymorphism (rs1799889) affects transcriptional activity and is a putative genetic risk factor for pre-eclampsia. The aim of this study was identify, appraise and synthesise the available evidence for the association of the PAI-1 (-675 4G/5G) polymorphism with pre-eclampsia.

METHODS

Systematic review and random effects meta-analysis of genetic association studies.

RESULTS

We found 12 eligible genetic association studies in which a total of 1511 women with pre-eclampsia, eclampsia or HELLP syndrome and 3492 controls participated. The studies were generally small (median number of cases 102, range 24 to 403) and underpowered to detect plausible association sizes. Meta-analysis of all of the studies detected statistically significant gene-disease associations in the recessive [pooled odds ratio 1.28 (95% confidence interval 1.09, 1.50); population attributable risk 7.7%] and dominant [pooled odds ratio 1.21 (95% confidence interval 1.01, 1.44); population attributable risk 13.7%] models. We did not find evidence of statistical heterogeneity, funnel plot asymmetry or small study bias.

CONCLUSIONS

These data suggest that the fibrinolytic pathway regulated by the PAI-1 gene may contribute to the pathogenesis of pre-eclampsia and related conditions. This association, if confirmed in larger genetic association studies, may inform research efforts to develop novel interventions or help to prioritise therapeutic targets that merit evaluation in randomised clinical trials.