Increased global fibrinolytic capacity as a clue for activated fibrinolysis in pre-eclampsia

Quantitative Proteomics of Maternal Blood Plasma in Isolated Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) remains a significant concern in modern obstetrics, linked to high neonatal health problems and even death, as well as childhood disability, affecting adult quality of life. The role of maternal and fetus adaptation during adverse pregnancy is still not completely understood. This study aimed to investigate the disturbance in biological processes associated with isolated IUGR via blood plasma proteomics. The levels of 125 maternal plasma proteins were quantified by liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM MS) with corresponding stable isotope-labeled peptide standards (SIS). Thirteen potential markers of IUGR (Gelsolin, Alpha-2-macroglobulin, Apolipoprotein A-IV, Apolipoprotein B-100, Apolipoprotein(a), Adiponectin, Complement C5, Apolipoprotein D, Alpha-1B-glycoprotein, Serum albumin, Fibronectin, Glutathione peroxidase 3, Lipopolysaccharide-binding protein) were found to be inter-connected in a protein-protein network. These proteins are involved in plasma lipoprotein assembly, remodeling, and clearance; lipid metabolism, especially cholesterol and phospholipids; hemostasis, including platelet degranulation; and immune system regulation. Additionally, 18 proteins were specific to a particular type of IUGR (early or late). Distinct patterns in the coagulation and fibrinolysis systems were observed between isolated early- and late-onset IUGR. Our findings highlight the complex interplay of immune and coagulation factors in IUGR and the differences between early- and late-onset IUGR and other placenta-related conditions like PE. Understanding these mechanisms is crucial for developing targeted interventions and improving outcomes for pregnancies affected by IUGR.

Fibrinolytic Changes in Women with Preeclampsia

Objectives

Preeclampsia (PE) is a serious complication of pregnancy. The fibrinolytic system play crucial roles regarding placentation and evolution of PE.

Aim

To study comprehensively components of the fibrinolytic system and fibrin lysability in women with PE.

Design and Methods

117 women with PE and matched controls were included. Tissue type plasminogen activator (t-PA), plasminogen, PAI-1, plasmin inhibitor (PI), D-dimer, the fibrinolytic potential of dextran sulphate euglobulin fraction (DEF), PAI-2, polymere PAI-2, fibrin clot lysability, thrombin activatable fibrinolysis inhibitor (TAFI) and fibrinogen were assessed.

Results

Women with PE had significantly increased concentrations of t-PA and PAI-1, whereas the plasma concentration of PAI-2 was significantly lower compared to controls, p < 0.0001. Polymere PAI-2 was detected in both groups. DEF, TAFI and fibrinogen were not different between the groups. D-dimer was significantly increased and plasminogen/PI together with fibrin clot lysability time decreased in the PE-group, p  =  0.0004 p  =  0.04, p  =  0.03, p < 0.0001 respectively.

Conclusion

This study demonstrates that PE is associated with an affected t-PA/PAI-1 system, decreased PAI-2 and increased fibrin lysability. Furthermore, PAI-2 has the potential to polymerize during pregnancy.

Differences and similarities in endothelial and angiogenic profiles of preeclampsia and COVID-19 in pregnancy

Background

COVID-19 presents a spectrum of signs and symptoms in pregnant women that might resemble preeclampsia. Differentiation between severe COVID-19 and preeclampsia is difficult in some cases.

Objective

To study biomarkers of endothelial damage, coagulation, innate immune response, and angiogenesis in preeclampsia and COVID-19 in pregnancy in addition to in vitro alterations in endothelial cells exposed to sera from pregnant women with preeclampsia and COVID-19.

Study Design

Plasma and sera samples were obtained from pregnant women with COVID-19 infection classified into mild (n=10) or severe (n=9) and from women with normotensive pregnancies as controls (n=10) and patients with preeclampsia (n=13). A panel of plasmatic biomarkers was assessed, including vascular cell adhesion molecule-1, soluble tumor necrosis factor-receptor I, heparan sulfate, von Willebrand factor antigen (activity and multimeric pattern), α2-antiplasmin, C5b9, neutrophil extracellular traps, placental growth factor, soluble fms-like tyrosine kinase-1, and angiopoietin 2. In addition, microvascular endothelial cells were exposed to patients’ sera, and changes in the cell expression of intercellular adhesion molecule 1 on cell membranes and von Willebrand factor release to the extracellular matrix were evaluated through immunofluorescence. Changes in inflammation cell signaling pathways were also assessed by of p38 mitogen-activated protein kinase phosphorylation. Statistical analysis included univariate and multivariate methods.

Results

Biomarker profiles of patients with mild COVID-19 were similar to those of controls. Both preeclampsia and severe COVID-19 showed significant alterations in most circulating biomarkers with distinctive profiles. Whereas severe COVID-19 exhibited higher concentrations of vascular cell adhesion molecule-1, soluble tumor necrosis factor-α receptor I, heparan sulfate, von Willebrand factor antigen, and neutrophil extracellular traps, with a significant reduction of placental growth factor compared with controls, preeclampsia presented a marked increase in vascular cell adhesion molecule-1 and soluble tumor necrosis factor-α receptor I (significantly increased compared with controls and patients with severe COVID-19), with a striking reduction in von Willebrand factor antigen, von Willebrand factor activity, and α2-antiplasmin. As expected, reduced placental growth factor, increased soluble fms-like tyrosine kinase-1 and angiopoietin 2, and a very high soluble fms-like tyrosine kinase-1 to placental growth factor ratio were also observed in preeclampsia. In addition, a significant increase in C5b9 and neutrophil extracellular traps was also detected in preeclampsia compared with controls. Principal component analysis demonstrated a clear separation between patients with preeclampsia and the other groups (first and second components explained 42.2% and 13.5% of the variance), mainly differentiated by variables related to von Willebrand factor, soluble tumor necrosis factor-receptor I, heparan sulfate, and soluble fms-like tyrosine kinase-1. Von Willebrand factor multimeric analysis revealed the absence of von Willebrand factor high-molecular-weight multimers in preeclampsia (similar profile to von Willebrand disease type 2A), whereas in healthy pregnancies and COVID-19 patients, von Willebrand factor multimeric pattern was normal.

Sera from both preeclampsia and severe COVID-19 patients induced an overexpression of intercellular adhesion molecule 1 and von Willebrand factor in endothelial cells in culture compared with controls. However, the effect of preeclampsia was less pronounced than the that of severe COVID-19. Immunoblots of lysates from endothelial cells exposed to mild and severe COVID-19 and preeclampsia sera showed an increase in p38 mitogen-activated protein kinase phosphorylation. Patients with severe COVID-19 and preeclampsia were statistically different from controls, suggesting that both severe COVID-19 and preeclampsia sera can activate inflammatory signaling pathways.

Conclusion

Although similar in in vitro endothelial dysfunction, preeclampsia and severe COVID-19 exhibit distinctive profiles of circulating biomarkers related to endothelial damage, coagulopathy, and angiogenic imbalance that could aid in the differential diagnosis of these entities.

Decreased expression of annexin A2 and loss of its association with vascular endothelial growth factor leads to the deficient trophoblastic invasion in preeclampsia

OBJECTIVES

Preeclampsia (PE) remains the major cause for maternal and foetal mortality and morbidity. Invasion of endovascular trophoblast and remodelling of spiral artery are crucial actions of normal placental development. Non-fulfilment of these processes plays a leading role in the development of preeclampsia. Vascular endothelial growth factor (VEGF) is produced by extravillous trophoblastic tissue and decidual cell population is a well-known angiogenic growth which plays a fundamental role in placental pathogenesis of PE. Annexin A2 (ANXA2) is a profibrinolytic protein receptor required for plasminolysis, which is an important step in the formation of new blood vessel along with VEGF. Role of ANXA2 is poorly studied in context with human reproductive disease like preeclampsia. The purpose of the present study is to examine the expression and association of VEGF and ANXA2 in the term placentas of pregnancies with and without PE.

METHODS

The study group comprised of placental tissues procured from gestations with PE (n=30) and without (n=20) PE. The expression of VEGF and ANXA2 in the placental villous tissue was evaluated quantitatively by means of IHC, western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Our IHC, western blotting and RT-PCR analysis illustrated the significant decrease in the expression of VEGF and ANXA2 in PE group compared with the normotensive control group (p<0.005). We observed statistically significant positive correlation among the expression of ANXA2 and VEGF in placentas of normotensive control group (p<0.0001).

CONCLUSIONS

The diminished expression of VEGF and ANXA2 in placenta may be associated with the defective angiogenesis and which may possibly play a vital role in PE pathogenesis.

miRNAs and Their Gene Targets-A Clue to Differentiate Pregnancies with Small for Gestational Age Newborns, Intrauterine Growth Restriction, and Preeclampsia

Despite the differences in the clinical manifestations of major obstetric syndromes, such as preeclampsia (PE) and intrauterine growth restriction (IUGR), their pathogenesis is based on the dysregulation of proliferation, differentiation, and invasion of cytotrophoblast cells that occur in the developing placenta, decidual endometrium, and myometrial parts of the spiral arteries. To understand the similarities and differences in the molecular mechanisms of PE and IUGR, samples of the placental bed and placental tissue were analyzed using protein mass spectrometry and the deep sequencing of small RNAs, followed by validation of the data obtained by quantitative RT-PCR in real time. A comparison of the transcriptome and proteomic profiles in the samples made it possible to conclude that the main changes in the molecular profile in IUGR occur in the placental bed, in contrast to PE, in which the majority of molecular changes occurs in the placenta. In placental bed samples, significant changes in the ratio of miRNA and its potential target gene expression levels were revealed, which were unique for IUGR (miR-30c-5p/VIM, miR-28-3p/VIM, miR-1-3p/ANXA2, miR-30c-5p/FBN1; miR-15b-5p/MYL6), unique for PE (miR-185-3p/FLNA), common for IUGR and PE (miR-30c-5p/YWHAZ and miR-654-3p/FGA), but all associated with abnormality in the hemostatic and vascular systems as well as with an inflammatory process at the fetal‒maternal interface.

Fibrinolytic proteins of normal pregnancy and pre-eclamptic patients in North West Nigeria

BACKGROUND

The hypercoagulability of pregnancy is exaggerated in pre-eclamptic state because of endothelial activation with resultant production of some endothelial derived proteins that are said to be inhibitors of fibrinolysis. This study compares these proteins like tPA, PAI-1 and D-dimers in normal pregnant women and the pre-eclamptic women.

METHODOLOGY

This was a comparative cross-sectional study. Eighty-five pre-eclamptic women were recruited as subjects and eighty five age, trimester and parity matched normotensive pregnant women as controls. Levels of PT, aPTT, tPA, PAI-1, D-dimer protein were determined in blood samples of subjects and controls. Urinalysis was performed with dipstick method on their urine samples. Data generated was analysed using the IBM®SPSS 20.0 (2011) soft ware packages and the level of significance was a p-value <0.05.

RESULTS

The mean age of the respondents was 29.9±5.2 years. The median(25th-75th percentile) values of D-dimer, tPA, and PAI-1 of subjects were 730 (305.000-1560.000ng/ml), 0.11 (0.065-0,300ng/ml) and 3.65 (2.970-4,400ng/ml) respectively which were significantly higher than the corresponding values in the controls of 520 (24.000-1030.000ng/ml), 0.05 (0.040-0.090ng/ml and 2.650 (2.125-3.400ng/ml) respectively, p<0.05 each.

CONCLUSION

The abnormal levels of PAI-1, D-dimer and tPA imply that they contribute to the exaggerated hypercoagulabilty state in pre-eclampsia thus, measuring their levels can help in the management of the condition.

Using antifibrinolytics in the peripartum period - concern for a hypercoagulable effect?

INTRODUCTION

Although antifibrinolytic agents are used to prevent and treat hemorrhage, there are concerns about a potential increased risk for peripartum venous thromboembolism. We sought to determine the impact of tranexamic acid and ɛ-aminocaproic acid on in vitro clotting properties in pregnancy.

METHODS

Blood samples were obtained from healthy pregnant, obese, and preeclamptic pregnant women (n = 10 in each group) prior to delivery as well as from healthy non-pregnant controls (n = 10). Maximum clot firmness (MCF) and clotting time (CT) were measured using rotation thromboelastometry in the presence of tranexamic acid (3, 30, or 300 μg/mL) or ɛ-aminocaproic acid (30, 300, or 3000 μg/mL). ANOVA and regression analyses were performed.

RESULTS

Mean whole blood MCF was significantly higher in healthy pregnant vs. non-pregnant women (66.5 vs. 57.5 mm, p < 0.001). Among healthy pregnant women, there was no significant difference between mean MCF (whole blood alone, and with increasing tranexamic acid doses = 66.5, 66.1, 66.4, 66.3 mm, respectively; p = 0.25) or mean CT (409, 412, 420, 424 sec; p = 0.30) after addition of tranexamic acid. Similar results were found using ɛ-aminocaproic acid. Preeclamptic women had a higher mean MCF after the addition of ɛ-aminocaproic acid and tranexamic acid (p = 0.05 and p = 0.04, respectively) compared to whole blood alone.

CONCLUSIONS

Pregnancy is a hypercoagulable state, as reflected by an increased MCF compared to non-pregnant women. Addition of antifibrinolytic therapy in vitro does not appear to increase MCF or CT for non-pregnant, pregnant, and obese women. Whether antifibrinolytics are safe in preeclampsia may require further study.

Changes in coagulation and hemodynamics during pregnancy: a prospective longitudinal study of 58 cases

PURPOSE

To investigate changes and establish reference values in coagulation, anticoagulation, fibrinolysis, anti-fibrinolysis and hemodynamics during normal pregnancy.

METHODS

A total of 58 women with singleton pregnancies were recruited. Blood and ultrasound examinations were performed in the 10th-14th, 20th-24th, and 30th-34th weeks of pregnancy. The same examinations were performed in 50 non-pregnant women who were selected as the control group.

RESULTS

Levels of fibrinogen, thrombin time, fibronectin, prothrombin activated fragments 1+2 and thrombomodulin were higher in early pregnancy than those in the control group (P < 0.05). Fibrinogen, prothrombin time, activated partial thromboplastin time, thrombin time, thromboxane B2, prothrombin activated fragments 1+2, thrombomodulin, D-dimer, and plasminogen activator inhibitor-2 were statistically different between the mid pregnancy and the control group (P < 0.05). Meanwhile, fibrinogen, prothrombin time, activated partial thromboplastin time, thrombin time, fibronectin, thromboxane B2, prothrombin activated fragments 1+2, thrombomodulin, and plasminogen activator inhibitor-2 were obviously elevated in late pregnancy as compared with the control group (P < 0.05). Moreover, fibrinogen, thromboxane B2, prothrombin activated fragment 1+2, D-dimer plasminogen, and activator inhibitor-2 gradually increased during pregnancy with some fluctuation. Prothrombin time, activated partial thromboplastin time, thrombin time, international normalized ratio, and thrombomodulin as well as systolic/diastolic ratio, pulsatility index, and resistance index in uterine arteries showed a tendency to decrease in pregnant women.

CONCLUSIONS

Coagulation, anti-coagulation, fibrinolytic and anti-fibrinolytic activities are enhanced and balanced at a higher level during pregnancy. In addition, uterine artery and umbilical artery hemodynamics become more baby friendly (i.e., high flow and low resistance).

Pregnancy outcome and fibrinolytic, endothelial and coagulation markers in women undergoing uterine artery Doppler screening at 23 weeks

BACKGROUND

Pre-eclampsia (PET) and/or fetal growth restriction (FGR) remain a major cause of maternal and fetal morbidity and mortality. In pregnancy, fibrinolysis is controlled by the maternal endothelium and placenta, both of which are central to the pathogenesis of PET/FGR. Clinically, uterine artery Doppler screening at 23 weeks is used to predict PET/FGR. An abnormal uterine artery Doppler finding is defined as early diastolic bilateral uterine artery notching (BN) in the waveform. However, about 50% of mothers with BN do not develop PET/FGR.

OBJECTIVES

We investigated fibrinolytic changes and uterine artery Doppler findings in the second trimester, and related them to pregnancy outcome; in particular assessing whether fibrinolytic markers could discriminate between normal and abnormal outcome in mothers with BN.

PATIENTS/METHODS

Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasminogen activator inhibitor-2 (PAI-2), plasmin-alpha(2) antiplasmin (PAP), D-dimers and markers of endothelial dysfunction were measured with Doppler ultrasound at 23 weeks.

RESULTS

Those with BN had decreased PAP and D-dimer levels, and raised PAI-1 and thrombomodulin levels. Mothers with BN and PET/FGR had significantly increased t-PA levels and reduced PAI-2 levels.

CONCLUSIONS

BN at 23 weeks of gestation is associated with increased PAI-1 levels. Within the BN group, mothers who developed PET/FGR had increased t-PA levels and decreased PAI-2 levels, although there was no net change in fibrinolysis as measured by D-dimer levels. No single fibrinolytic marker is helpful in determining pregnancy outcome in those with BN, but t-PA and PAI-2 are worthy of study in a multifactorial algorithm.

Determination of the global fibrinolytic state

Fibrinolysis consists of a plasmatic part and a cellular part. A rapid global assay for plasmatic fibrinolysis is the fibrinolysis parameters assay (FIPA). Cellular fibrinolysis is measured by testing the clot lysis capacity using the microtitre plate clot lysis assay with polymorphonuclear neutrophils (CLA-PMN). Individual citrated plasma or pooled normal plasma (50 microl) of 232 patients was recalcified, incubated for 90 min at 37 degrees C, oxidized with 0 or 1.5 mmol/l (final concentration) chloramine-T, and supplemented with 50 microl respective polymorphonuclear neutrophil plasma. The turbidity of the clots was measured at 405 nm after 12 h and 60 h (37 degrees C). Plasma (50 microl) was also incubated with 5 microl of 100 IU/ml urokinase, 6 mmol/l tranexamic acid, 6% human albumin for 10 min (37 degrees C). Then 100 microl of 0.5 mmol/l Val-Leu-Lys-pNA in 2.45 mol/l arginine, pH 8.6, was added and the increase in absorbance with time was measured. The different CLA-PMN assay versions correlated with each other with r = 0.543-0.782. Cellular fibrinolysis (34 +/- 30% lysis; normal: 25 +/- 10%) did not correlate with the FIPA (72 +/- 27%; normal: 100 +/- 15%), prothrombin time, activated partial thromboplastin time, fibrinogen, C-reactive protein, or the blood counts of thrombocytes, leukocytes, or polymorphonuclear neutrophils. Chloramine (1.5 mmol/l) oxidation of the microclots favours their fibrinolytic breakdown, especially if lysis-resistant microclots are oxidized. The FIPA and CLA-PMN are new economical tests for the fibrinolytic state in patient blood.