Platelet function in preeclampsia - a systematic review and meta-analysis

The relationship between platelet indices and hypertensive disorders of pregnancy

OBJECTIVE

To investigate the relationship between platelet indices (count, size and production/immaturity) and hypertensive disorders of pregnancy.

STUDY DESIGN

This was a secondary analysis of a prospective cohort of pregnant individuals followed from first trimester through delivery at an academic tertiary care institution. Routine platelet indices obtained prospectively during prenatal care and delivery were compared between those who developed a hypertensive disorder of pregnancy and those who did not. We assessed platelet count (by trimester), mean platelet volume, and immature platelet fraction measured as percent (%) and absolute count. Data were analyzed using Fisher's Exact test, chi-square test, and multivariable logistic regression. P < 0.05 was considered statistically significant.

RESULTS

Among 459 participants enrolled, 78 (17.0 %) developed a hypertensive disorder of pregnancy. Pregnant individuals who developed a hypertensive disorder of pregnancy had significantly higher mean platelet volume (11.7 fL [10.8,12.4] vs. 11.1 fL [10.5,12.0], Padj < 0.01), percent immature platelet fraction (7.3 % [4.9,10.7] vs. 5.9 % [4.2,9.2], Padj = 0.01) and absolute immature platelet fraction (16.4 × 109 [11.2,20.4] vs. 13.3 × 109 [9.3,17.4], Padj = 0.01) compared to those without a hypertensive disorder of pregnancy, after adjusting for age, race/ethnicity, obesity, nulliparity, and chronic hypertension. The prevalence and likelihood of a hypertensive disorder of pregnancy increased with increasing mean platelet volume, as well as with both the percent and absolute immature platelet fraction. There was no difference between groups in platelet count in the first trimester, second trimester, or at delivery.

CONCLUSIONS

An increase in platelet size and immaturity was observed in those with a hypertensive disorder of pregnancy. These data support further investigation of platelets in the mechanisms of the development of hypertensive disorders of pregnancy and the use of platelet indices to better identify high risk groups in pregnancy.

Platelet aggregation and thromboelastometry monitoring in women with preeclampsia: a prospective observational study

BACKGROUND

Thrombocytopenia affects 12-20% of women with preeclampsia and a low platelet count impairs coagulation. Women with preeclampsia have an increased risk of both cerebral hemorrhage, thromboembolism, and postpartum hemorrhage. Studies of platelet function and coagulation in women with preeclampsia show conflicting results. Therefore, we aimed to study platelet aggregation and coagulation in women with preeclampsia.

METHOD

Women with preeclampsia and women with normotensive pregnancies were included prior to delivery in a prospective observational study as a part of the Gothenburg Preeclampsia Adverse Event (GoPROVE) Biobank and Database. Sampling and analyses were performed shortly before delivery. Platelet count was analyzed and impedance aggregometry was used for examining platelet adhesion and aggregation. Thromboelastometry was used to assess coagulation.

RESULTS

Ninety-three women with preeclampsia and 45 normotensive pregnant control patients were included. There was no difference in platelet aggregation (adenosine diphosphate, ADP-test), (arachidonic acid, ASPI-test) or (thrombin receptor-activating peptide, TRAP-test) between women with preeclampsia and women with normotensive pregnancies. Women with preeclampsia had lower platelet counts, shorter clotting (EXTEM-CT and INTEM-CT) and clot formation (EXTEM-CFT and INTEM-CFT) times than women with normotensive pregnancies. Platelet aggregation and coagulation were hyperactivated in women with preeclampsia and normal platelet counts. In women with preeclampsia and thrombocytopenia, platelet aggregation and thromboelastic tests of coagulation were impaired compared with normotensive pregnancies.

CONCLUSION

Platelet aggregation and thromboelastic tests of coagulation are dependent on platelet counts in women with preeclampsia. At normal platelet counts, women with preeclampsia have hyperactivated tests of coagulation. In contrast, women with thrombocytopenia demonstrated lower coagulation test values.

Predictive value of platelet parameters for early-onset pre-eclampsia: A prospective cohort study in a teaching institution in Gujarat, India

Background

Early-onset pre-eclampsia is associated with severe maternal and perinatal complications. Identifying novel biomarkers for early prediction is crucial for timely intervention and improved outcomes. This study aimed to evaluate the predictive value of platelet parameters, namely mean platelet volume (MPV), platelet distribution width (PDW), and platelet count (PC), for early-onset pre-eclampsia.

Methods

A prospective cohort study was conducted at a tertiary care hospital in Gujarat, India. Pregnant women (n = 712) between 14 and 18 weeks of gestation were enrolled and followed up until delivery. MPV, PDW, and PC were measured at enrollment. The primary outcome was the development of early-onset pre-eclampsia (<34 weeks). Receiver operating characteristic (ROC) curves were used to evaluate the predictive value of platelet parameters.

Results

The prevalence of early-onset pre-eclampsia was 5.3%. Women who developed early-onset pre-eclampsia had significantly higher MPV and PDW and lower PC at 14-18 weeks compared to those who remained normotensive. The combination of MPV > 10.2 fL, PDW > 16.5 fL, and PC < 180 × 103/µL had the highest predictive value (AUC: 0.951, sensitivity: 71.1%, specificity: 99.1%). Individual platelet parameters also demonstrated good predictive ability.

Conclusion

Platelet parameters, particularly MPV, PDW, and PC, measured at 14-18 weeks of gestation, have good predictive value for early-onset pre-eclampsia. Incorporating these parameters into routine antenatal screening could improve the early identification of at-risk women. Further research is needed to validate these findings and evaluate the cost-effectiveness of implementation.

Evaluating mean platelet volume and platelet distribution width as predictors of early-onset pre-eclampsia: a prospective cohort study

BACKGROUND

Platelets are pivotal players in the pathophysiology of pre-eclampsia, with observed lower counts in affected individuals compared to normotensive counterparts. Despite advancements, the elusive cause of pre-eclampsia persists, motivating intense global efforts to identify reliable predictors. The currently recommended predictors of pre-eclampsia are not readily available in many resource-limited regions like Nigeria. This cohort study explores the potential of mean platelet volume (MPV) and platelet distribution width (PDW) as predictive markers of early-onset pre-eclampsia. Both platelet indices are components of the full blood count, a widely available routine test in pregnancy.

METHODS

In this prospective cohort study, 648 healthy pregnant women attending antenatal care at Lagos State University Teaching Hospital and General Hospital Ifako-Ijaiye, Lagos, were recruited between 14-18weeks gestational age. Platelet count (PC), MPV and PDW were measured from their venous blood at recruitment. Participants were monitored until 34weeks of gestation, focusing on the occurrence of early-onset preeclampsia as the outcome of interest. Individuals with chronic medical conditions were excluded from the study. Data analysis involved t-test, Chi-Square and Mann-Whitney U tests, with statistical significance set at a confidence level of 95% and p < 0.05. Sensitivity, specificity, and predictive values were determined using receiver operating characteristics (ROC) curves.

RESULTS

The incidence of early-onset pre-eclampsia in the study was 5.9%. Women who later developed pre-eclampsia had higher median MPV and PDW at 14-18weeks (10.8 fl. and 24.8 fl.) compared to normotensive women (8.1 fl. and 13.3 fl.)(p < 0.001). The median PC was lower in pre-eclamptics (190 × 103/µl) compared to normotensives(264 × 103/µl)(p < 0.001). Using Youden's test, cut-off values identified: PC < 211.5 × 103/µl, MPV > 9.4 fl., and PDW > 21.3 fl., predicted early-onset pre-eclampsia with 96.6% sensitivity and 65.6% specificity for PC; 79.3% sensitivity and 97.7% specificity for PDW; and 82.8% sensitivity and 96.1% specificity for MPV. Cut-offs of PC < 185 × 103/µl, MPV > 10.7 fl., and PDW > 28.3 fl., predicted severe early-onset pre-eclampsia with 100.0% sensitivity and 90.9% specificity for PC, 100.0% sensitivity and 99.4% specificity for MPV, and 100.0% sensitivity and 99.8% specificity for PDW, with corresponding area under the ROC curves of 0.983, 0.996, and 0.998, respectively.

CONCLUSION

The evaluation of MPV and PDW between 14 and 18 weeks of gestation appears to be a reliable predictor of severe early-onset pre-eclampsia.

The role of viscoelastic hemostatic assays for postpartum hemorrhage management and bedside intrapartum care

Viscoelastic hemostatic assays are point-of-care devices that assess coagulation and fibrinolysis in whole blood samples. These technologies provide numeric and visual information of clot initiation, clot strength, and clot lysis under low-shear conditions, and have been used in a variety of clinical settings and subpopulations, including trauma, cardiac surgery, and obstetrics. Emerging data indicate that these devices are useful for detecting important coagulation defects during major postpartum hemorrhage (especially low plasma fibrinogen concentration [hypofibrinogenemia]) and informing clinical decision-making for blood product use. Data from observational studies suggest that, compared with traditional formulaic approaches to transfusion management, targeted or goal-directed transfusion approaches using data from viscoelastic hemostatic assays are associated with reduced hemorrhage-related morbidity and lower blood product requirement. Viscoelastic hemostatic assays can also be used to identify and treat coagulation defects in patients with inherited or acquired coagulation disorders, such as factor XI deficiency or immune-mediated thrombocytopenia, and to assess hemostatic profiles of patients prescribed anticoagulant medications to mitigate the risk of epidural hematoma after neuraxial anesthesia and postpartum hemorrhage after delivery.

Classification of preeclampsia according to molecular clusters with the goal of achieving personalized prevention

The prevention of pre-eclampsia is difficult due to the syndromic nature and multiple underlying mechanisms of this severe complication of pregnancy. The current clinical distinction between early- and late-onset disease, although clinically useful, does not reflect the true nature and complexity of the pathologic processes leading to pre-eclampsia. The current gaps in knowledge on the heterogeneous molecular pathways of this syndrome and the lack of adequate, specific diagnostic methods are major obstacles to early screening and tailored preventive strategies. The development of novel diagnostic tools for detecting the activation of the identified disease pathways would enable early, accurate screening and personalized preventive therapies. We implemented a holistic approach that includes the utilization of different proteomic profiling methods of maternal plasma samples collected from various ethnic populations and the application of systems biology analysis to plasma proteomic, maternal demographic, clinical characteristic, and placental histopathologic data. This approach enabled the identification of four molecular subclasses of pre-eclampsia in which distinct and shared disease mechanisms are activated. The current review summarizes the results and conclusions from these studies and the research and clinical implications of our findings.

Unraveling the Mechanism of Platelet Aggregation Suppression by Thioterpenoids: Molecular Docking and In Vivo Antiaggregant Activity

Natural monoterpenes and their derivatives are widely considered the effective ingredients for the design and production of novel biologically active compounds. In this study, by using the molecular docking technique, we examined the effects of two series of "sulfide-sulfoxide-sulfone" thioterpenoids containing different (e.g., bornane and pinane) monoterpene skeletons on the platelet's aggregation. Our data revealed that all the synthesized compounds exhibit inhibitory activities on platelet aggregation. For example, compound 1 effectively inhibited platelet activation and demonstrated direct binding with CD61 integrin, a well-known platelet GPIIb-IIIa receptor on platelets. We further examined the antiaggregant activity of the most active compound, 1, in vivo and compared its activity with that of acetylsalicylic acid and an oral GPIIb-IIIa blocker, orbofiban. We found that compound 1 demonstrates antiaggregant activity in rats when administered per os and its activity was comparable with that of acetylsalicylic acid and orbofiban. Moreover, similarly, tirofiban, a well-known GPIIb-IIIa blocker, compound 1, effectively decreased the expression of P-selectin to the values similar to those of the intact platelets. Collectively, here, we show, for the first time, the potent antiaggregant activity of compound 1 both in vitro and in vivo due to its ability to bind with the GPIIb-IIIa receptor on platelets.

Clinical value of mean platelet volume in predicting and diagnosing pre-eclampsia: a systematic review and meta-analysis

Background

Pre-eclampsia (PE) is a severe pregnancy complication. Thrombocytopenia and platelet dysfunction are common hematology disorders in PE. Previous studies considered mean platelet volume (MPV), a functional marker of platelets, as a potentially useful predictor for the diagnosis of PE.

Methods

PubMed, China Biomedical Literature Database, Chinese National Knowledge Infrastructure, Embase, Wanfang, VIP, and Cochrane Library databases were searched to gather diagnostic trials evaluating the diagnosis of PE using MPV, from their inception to 13 March 2023. We also searched Google Scholar and Baidu.

Results

A total of 22 studies from 20 articles were found. The pooled diagnostic accuracy of the MPV for PE recognition was as follows: sensitivity (SEN) 0.676 [95% confidence interval (CI) (0.658-0.694)], specificity (SPE) 0.710 [95% CI (0.703-0.717)], and diagnostic odds ratio (DOR) 7.012 [95% CI (4.226-11.636)], and the SROC-AUC and Q* indices were 0.7889 and 0.7262, respectively. The pooled SEN, SPE, and DOR of the diagnostic accuracy of MPV for PE before 16 weeks of gestation were 0.707 [95% CI (0.670-0.743)], 0.639 [95% CI (0.611-0.667)], and 4.026 [95% CI (2.727-5.943)], and the SROC-AUC and Q* indices were 0.7278 and 0.6753, respectively. For the interval of truncation values between 9 and 10 fl, the SROC-AUC and Q* indices for MPV were 0.8856 and 0.8162, respectively.

Conclusions

Available evidence suggests that MPV has a moderate predictive and diagnostic value for PE, particularly in diagnosing after 20 weeks of gestation. The diagnostic accuracy is higher when the MPV cut-off falls between 9 and 10 fl. The sensitivity of MPV alone in diagnosing PE is not high, and the combination of other markers for predictive diagnosis may better differentiate PE.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023425154, identifier: CRD42023425154.

Examination of the haematological profile of pregnant Polish Holstein-Friesian black-and-white cattle in the early stage

Introduction

Cattle health and welfare are monitored via the analysis of the haematological profile, and it shows cattle's ability to adapt to changing environmental conditions, pregnancy and lactation; profile changes also indicate reproductive disorders. The literature lacks reports of the examination of the haematological profile in cows up to the 50th day of pregnancy (dop). Therefore, this research examined that in cows up to this pregnancy stage.

Material and Methods

A total of 101 Polish Holstein-Friesian black-and-white cows were divided into groups. The control groups consisted of non-pregnant heifers (group C00) and non-pregnant cows (group C0), and the experimental groups were pregnant heifers (group T1 at dop ≤ 28 and group T2 at dop ≥ 29-dop < 45) and pregnant cows (group T3 at dop ≥ 29-dop ≤ 50). In addition, the T3 group was divided into cows pregnant for up 45 dop and cows between 45 and 50 dop. Blood samples were collected in March and April 2021 from each animal and analysed. A transrectal ultrasound examination was performed to detect and confirm pregnancy.

Results

Statistically significant differences (P ≤ 0.01) between the group of cows at dop < 45 dop and those at dop ≥ 45-dop ≤ 50 dop were noted in granulocyte percentage (GRA%), white and red blood cell counts (WBC/RBC), platelets (PLT), platelet distribution width (PDW), haematocrit (HCT) and lymphocyte percentage (LYM%). No statistically significant differences were found in the mean corpuscular haemoglobin, monocytes (MON), monocyte percentage (MON%), mean platelet volume (MPV), thrombocrit or red blood cell distribution width (RDW). Similar statistically significant differences (P ≤ 0.01) emerged between the groups of heifers in PLT, GRA, RBC, lymphocytes, LYM% and HCT, and no significant differences were found between MPV, MON, MON% or RDW.

Conclusion

Examining the haematological profile in high-yielding cattle is vital in maintaining herd profitability and high reproduction, which depend on the quick diagnosis of disorders facilitated by haematology. This study analysed the haematology profile of dairy cattle at dop ≤ 50 for the first time, indicating changes in lymphocyte levels, which suggests that the animals experienced direct stress during the study.

Platelet count in preeclampsia: a systematic review and meta-analysis

OBJECTIVE

Many studies have reported the association between platelets and preeclampsia. However, sample sizes were small, and their findings were inconsistent. We conducted a systematic review and meta-analysis to evaluate the association in pooled samples and in detail.

DATA SOURCES

A systematic literature search was performed using Medline, Embase, ScienceDirect, Web of Science, Cochrane Library, NICHD-DASH, LILACS, and Scopus from inception to April 22, 2022.

STUDY ELIGIBILITY CRITERIA

Observational studies comparing platelet count between women with preeclampsia and normotensive pregnant women were included.

METHODS

The mean differences with 95% confidence interval in platelet count were calculated. Heterogeneity was assessed using I2 statistics. Sensitivity and subgroup analyses were conducted. Statistical analysis was performed using RevMan 5.3 and ProMeta 3 software.

RESULTS

A total of 56 studies comprising 4892 preeclamptic and 9947 normotensive pregnant women were included. Meta-analysis showed that platelet count was significantly lower in women with preeclampsia than in normotensive controls (overall: mean difference, -32.83; 95% confidence interval, -40.13 to -25.52; P<.00001; I2=92%; mild preeclampsia: mean difference, -18.65; 95% confidence interval, -27.17 to -10.14; P<.00001; I2=84%; severe preeclampsia: mean difference, -42.61; 95% confidence interval, -57.53 to -27.68; P<.00001; I2=94%). Significantly lower platelet count was also observed in the second trimester (mean difference, -28.84; 95% confidence interval, -44.59 to -13.08; P=.0003; I2=93%), third trimester (mean difference, -40.67; 95% confidence interval, -52.14 to -29.20; P<.00001; I2=92%), and before the diagnosis of preeclampsia (mean difference, -18.81; 95% confidence interval, -29.98 to -7.64; P=.009; I2=87%), but not in the first trimester (mean difference, -15.14; 95% confidence interval, -37.71 to 7.43; P=.19; I2=71%). Overall, the pooled sensitivity and specificity of platelet count were 0.71 and 0.77, respectively. The area under the curve was 0.80.

CONCLUSION

This meta-analysis confirmed that platelet count was significantly lower in preeclamptic women, irrespective of severity and presence or absence of associated complications, even before the onset of preeclampsia and in the second trimester of pregnancy. Our findings suggest that platelet count may be a potential marker to identify and predict preeclampsia.

Preeclampsia: Platelet procoagulant membrane dynamics and critical biomarkers

A state-of-the-art lecture titled "Preeclampsia and Platelet Procoagulant Membrane Dynamics" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2022. Platelet activation is involved in the pathophysiology of preeclampsia and contributes to the prothrombotic state of the disorder. Still, it remains unclear what mechanisms initiate and sustain platelet activation in preeclampsia and how platelets drive the thrombo-hemorrhagic abnormalities in preeclampsia. Here, we highlight our findings that platelets in preeclampsia are preactivated possibly by plasma procoagulant agonist(s) and overexpress facilitative glucose transporter-3 (GLUT3) in addition to GLUT1. Preeclampsia platelets are also partially degranulated, procoagulant, and proaggregatory and can circulate as microaggregates/microthrombi. However, in response to exposed subendothelial collagen, such as in injured vessels during cesarean sections, preeclampsia platelets are unable to mount a full procoagulant response, contributing to blood loss perioperatively. The overexpression of GLUT3 or GLUT1 may be monitored alone or in combination (GLUT1/GLUT3 ratio) as a biomarker for preeclampsia onset, phenotype, and progression. Studies to further understand the mediators of the platelet activation and procoagulant membrane dynamics in preeclampsia can reveal novel drug targets and suitable alternatives to aspirin for the management of prothrombotic tendencies in preeclampsia. Finally, we summarize relevant new data on this topic presented during the 2022 ISTH Congress.

Molecular subclasses of preeclampsia characterized by a longitudinal maternal proteomics study: distinct biomarkers, disease pathways and options for prevention

OBJECTIVES

The heterogeneous nature of preeclampsia is a major obstacle to early screening and prevention, and a molecular taxonomy of disease is needed. We have previously identified four subclasses of preeclampsia based on first-trimester plasma proteomic profiles. Herein, we expanded this approach by using a more comprehensive panel of proteins profiled in longitudinal samples.

METHODS

Proteomic data collected longitudinally from plasma samples of women who developed preeclampsia (n=109) and of controls (n=90) were available from our previous report on 1,125 proteins. Consensus clustering was performed to identify subgroups of patients with preeclampsia based on data from five gestational-age intervals by using select interval-specific features. Demographic, clinical, and proteomic differences among clusters were determined. Differentially abundant proteins were used to identify cluster-specific perturbed KEGG pathways.

RESULTS

Four molecular clusters with different clinical phenotypes were discovered by longitudinal proteomic profiling. Cluster 1 involves metabolic and prothrombotic changes with high rates of early-onset preeclampsia and small-for-gestational-age neonates; Cluster 2 includes maternal anti-fetal rejection mechanisms and recurrent preeclampsia cases; Cluster 3 is associated with extracellular matrix regulation and comprises cases of mostly mild, late-onset preeclampsia; and Cluster 4 is characterized by angiogenic imbalance and a high prevalence of early-onset disease.

CONCLUSIONS

This study is an independent validation and further refining of molecular subclasses of preeclampsia identified by a different proteomic platform and study population. The results lay the groundwork for novel diagnostic and personalized tools of prevention.

Fibrinogen beta chain may be a potential predict biomarker for pre-eclampsia: A preliminary study

OBJECTIVE

There are no approaches for the early detection of pre-eclampsia (PE). Using parallel reaction monitoring proteomics, we investigated 79 maternal serum protein changes before PE onset and its predictive capability.

METHODS

We conducted a nested case-control study with 60 PE patients and 60 normotensive pregnant women matched for age and gestational week. These differentially expressed proteins were quantified using the data-dependent acquisition (DDA) combined parallel response monitoring (PRM) approach, and a PE prediction model was developed using the least absolute shrinkage and selection operator (LASSO) regression. We further examined the link between these biomarkers and PE using bioinformatics. ELISA assay was used to investigate the expression and clinical significance of the critical variables.

RESULTS

Among the 79 analyzed proteins, we identified 11 serum proteins with significantly abnormal expression. Fibrinogen beta chain (FGB) was likely connected with the progression of PE due to the positive correlation between their levels and those of hypertension and proteinuria. In addition, an early prediction model for PE with an AUC of 92% was developed using LASSO regression.

CONCLUSION

Our research employs predictive algorithms and screens for relevant variables, which could result in a potential approach to enhancing PE prediction.

Prediction of HELLP Syndrome Severity Using Machine Learning Algorithms-Results from a Retrospective Study

(1) Background: HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome is a rare and life-threatening complication of preeclampsia. The aim of this study was to evaluate and compare the predictive performances of four machine learning-based models for the prediction of HELLP syndrome, and its subtypes according to the Mississippi classification; (2) Methods: This retrospective case-control study evaluated pregnancies that occurred in women who attended a tertiary maternity hospital in Romania between January 2007 and December 2021. The patients' clinical and paraclinical characteristics were included in four machine learning-based models: decision tree (DT), naïve Bayes (NB), k-nearest neighbors (KNN), and random forest (RF), and their predictive performance were assessed; (3) Results: Our results showed that HELLP syndrome was best predicted by RF (accuracy: 89.4%) and NB (accuracy: 86.9%) models, while DT (accuracy: 91%) and KNN (accuracy: 87.1%) models had the highest performance when used to predict class 1 HELLP syndrome. The predictive performance of these models was modest for class 2 and 3 of HELLP syndrome, with accuracies ranging from 65.2% and 83.8%; (4) Conclusions: The machine learning-based models could be useful tools for predicting HELLP syndrome, and its most severe form-class 1.

Platelet protease activated receptor 4 (PAR 4) receptor genotype is associated with an increased risk of preterm birth

BACKGROUND

Platelet protease activated receptor-4 (PAR4) Thr120 is a common genetic variant associated with increased platelet activity. Increased platelet activity is implicated in the pathogenesis of preeclampsia and preterm birth.

OBJECTIVE

Compare the rate of preeclampsia and preterm birth in pregnant individuals homozygous for PAR4 Thr120 variant vs not.

STUDY DESIGN

This is a prospective cohort study of patients who delivered November 2020-July 2021. Maternal blood collected on admission for PAR4 genotyping. The primary outcome was the rate of preeclampsia/gestational hypertension in those with Thr/Thr genotype compared with Ala/Thr or Ala/Ala. Secondary outcomes included rates of preterm birth and placental pathology.

RESULTS

Three hundred and twenty singletons were included and 52 (16.3%) were PAR4 Thr/Thr. Those PAR4 Thr/Thr were more likely to be Black (67.3% vs 29.5%, p < .001), younger (28 ± 6 vs 31 ± 6, p = .004), and have higher body mass index (35.2 ± 6.8 vs 33.1 ± 7.4, p = .047). There was no difference in preeclampsia/gestational hypertension (19.2% vs 22.8%, p = .705). Those Thr/Thr had a significantly higher rate of preterm birth (15.4% vs 3.7%, adjusted odds ratio [aOR] 4.04 [1.47-11.10], p = .007), indicated preterm birth because of fetal growth restriction or preeclampsia (5.8% vs 0.4%, aOR 10.03 [1.48-67.87], p = .02), spontaneous preterm birth (7.7% vs 2.2%, aOR 4.81 [1.27-18.27], p = .02), and placental intervillous thrombosis (18.5% vs 7.9%, aOR 4.12 [1.14-14.92], p = .03).

CONCLUSION

Platelet receptor PAR4 Thr120 is a common variant associated with an increased risk of placental vascular pathology and preterm birth in homozygous individuals. Although a cohort study cannot establish causation, this strong association warrants further exploration.

Platelet aggregation in normal pregnancy

It was recently shown that abnormal platelet aggregation (PA) had played a critical role in some adverse pregnancies. Till now reference range for PA in normal pregnancy has not been determined. Furthermore, few study has been conducted to explore the factors related to PA. Our study was performed to assess the reference range of PA in normal pregnancy (150 participants in the second trimester), and to determine whether it differs from that of the controls (38 nonpregnant participants). In addition, this study explored the factors related to PA. The results showed that PA was significantly higher in normal pregnancy than that in the controls (84.40% vs. 80.7%, respectively, P = 0.013). The reference interval for PA in normal pregnancy was 74.75%-94.77%. Hemoglobin (Hb), platelet counts (PLT) and albumin (Alb) were significant lower in normal pregnancy than those in the control group. Moreover, it was found that PA was positively correlated with PLT (r = 0.263, P < 0.001), and negatively correlated with platelet distribution width (PDW) (r = -0.342, P < 0.001) and mean platelet volume (r = -0.296, P < 0.001). Linear correlations between PA and Alb, PDW were proved by linear regression model (LRM). In conclusion, PA was enhanced in normal pregnancy, and Alb and PDW might be the possible contributing factors to PA.

Study of the effect of acetylsalicylic acid and a selective arginase II inhibitor KUD 975 on the correction of hemostatic disorders in experimental preeclampsia

Introduction: The disruption of the functional state of the vascular endothelium is among the main causes of preeclampsia, which is one of the most common causes of maternal and perinatal mortality. It can be enhanced by the humoral factors secreted by the activated platelets. The use of acetylsalicylic acid is an effective way to prevent preeclampsia. However, its ability to activate eNOS is a prerequisite for researching its ability to correct the disorders in developing preeclampsia, including by reducing the platelet activity. In this case its effect can be enhanced through increasing the bioavailability of L-arginine by using a selective arginase II inhibitor KUD 975. These facts were the prerequisite for conducting this study.

Materials and methods: The study was conducted on 180 female Wistar rats weighing 250–300 g. Acetylsalicylic acid was used at a dose of 7 mg/kg/day and 10 mg/kg/day, KUD 975 – at a dose of 1 mg/kg/day and 3 mg/kg/day. Adenosine diphosphate (ADP, 6.5 microns), arachidonic acid (ASPI, 0.5 mM), and collagen (3.2 mcg/ml) were used as aggregation inducers.

Results and discussion: ADMA-like preeclampsia simulation led to an increase in platelet aggregation ability when using all aggregation inducers. This is evidenced by an increase in a degree, rate of aggregation, and a shortened time of thrombus formation. The use of acetylsalicylic acid and a selective arginase II inhibitor KUD 975 led to a decrease in the aggregation ability of platelets and an increase in thrombosis time, while the combined administration of the studied agents showed a more pronounced effect.

Conclusion: The data obtained while performing a series of experiments strongly indicate a promising outlook for using acetylsalicylic acid and a selective arginase II inhibitor KUD 975 in order to correct emerging disorders in preeclampsia.

Development and Validation of Multi-Stage Prediction Models for Pre-eclampsia: A Retrospective Cohort Study on Chinese Women

Objective

The aim of this study is to develop multistage prediction models for pre-eclampsia (PE) covering almost the entire pregnancy period based on routine antenatal measurements and to propose a risk screening strategy.

Methods

This was a retrospective cohort study that included 20582 singleton pregnant women with the last menstruation between January 1, 2013 and December 31, 2019. Of the 20582 women, 717 (3.48%) developed pre-eclampsia, including 46 (0.22%) with early-onset pre-eclampsia and 119 (0.58%) preterm pre-eclampsia. We randomly divided the dataset into the training set (N = 15665), the testing set (N = 3917), and the validation set (N = 1000). Least Absolute Shrinkage And Selection Operator (LASSO) was used to do variable selection from demographic characteristics, blood pressure, blood routine examination and biochemical tests. Logistic regression was used to develop prediction models at eight periods: 5-10 weeks, 11-13 weeks, 14-18 weeks, 19-23 weeks, 24-27 weeks, 28-31 weeks, 32-35 weeks, and 36-39 weeks of gestation. We calculated the AUROC (Area Under the Receiver Operating Characteristic Curve) on the test set and validated the screening strategy on the validation set.

Results

We found that uric acid tested from 5-10 weeks of gestation, platelets tested at 18-23 and 24-31 weeks of gestation, and alkaline phosphatase tested at 28-31, 32-35 and 36-39 weeks of gestation can further improve the prediction performance of models. The AUROC of the optimal prediction models on the test set gradually increased from 0.71 at 5-10 weeks to 0.80 at 24-27 weeks, and then gradually increased to 0.95 at 36-39 weeks of gestation. At sensitivity level of 0.98, our screening strategy can identify about 94.8% of women who will develop pre-eclampsia and reduce about 40% of the healthy women to be screened by 28-31 weeks of pregnancy.

Conclusion

We developed multistage prediction models and a risk screening strategy, biomarkers of which were part of routine test items and did not need extra costs. The prediction window has been advanced to 5-10 weeks, which has allowed time for aspirin intervention and other means for PE high-risk groups.

A New Model for the Predicting the Risk of Preeclampsia in Twin Pregnancy

Objective

We aimed to develop an effective nomogram model for predicting the risk of preeclampsia in twin pregnancies.

Methods

The study was a retrospective cohort study of women pregnant with twins who attended antenatal care and labored between January 2015 and December 2020 at the Fujian Maternity and Child Health Hospital, China. We extracted maternal demographic data and clinical characteristics. Then we performed the least absolute shrinkage and selection operator regression combined with clinical significance to screen variables. Thereafter, multivariate logistic regression was used to construct a nomogram that predicted the risk of preeclampsia in twin pregnancies. Finally, the nomogram was validated using C-statistics (C-index) and calibration curves.

Results

A total of 2,469 women with twin pregnancies were included, of whom 325 (13.16%) had preeclampsia. Multivariate logistic regression models revealed that serum creatinine, uric acid, mean platelet volume, high-density lipoprotein, lactate dehydrogenase, fibrinogen, primiparity, pre-pregnancy body mass index, and regular prenatal were independently associated with preeclampsia in twin pregnancies. The constructed predictive model exhibited a good discrimination and predictive ability for preeclampsia in twin pregnancies (concordance index 0.821).

Conclusion

The model for the prediction of preeclampsia in twin pregnancies has high accuracy and specificity. It can be used to assess the risk of preeclampsia in twin pregnancies.

Proteomics and Metabolomics Profiling of Platelets and Plasma Mediators of Thrombo-Inflammation in Gestational Hypertension and Preeclampsia

Platelets may be pivotal mediators of the thrombotic and coagulopathic complications of preeclampsia (PE), linking inflammation and thrombosis with endothelial and vascular dysfunction. Both PE and gestational hypertension (GH) fall within the spectrum of hypertensive complications of pregnancy, with GH being a risk factor for preeclampsia. However, it is unclear what biomarkers distinguish PE from GH. Using a discovery size cohort, we aimed to characterize specific plasma and platelet thrombo-inflammatory drivers indicative of PE and differentiate PE from GH. We performed multiplex immunoassays, platelet and plasma quantitative proteomics and metabolomics of PE patients, comparing with non-pregnant (NP), healthy pregnant controls (PC) and GH participants. The expression pattern of plasma proteins and metabolites in PE/GH platelets was distinct from that of NP and PC. Whilst procoagulation in PC may be fibrinogen driven, inter-alpha-trypsin inhibitors ITIH2 and ITIH3 are likely mediators of thrombo-inflammation in GH and PE, and fibronectin and S100A8/9 may be major procoagulant agonists in PE only. Also enriched in PE were CCL1 and CCL27 plasma cytokines, and the platelet leucine-rich repeat-containing protein 27 and 42 (LRRC27/42), whose effects on platelets were explored using STRING analysis. Through protein-protein interactions analysis, we generated a new hypothesis for platelets’ contribution to the thrombo-inflammatory states of preeclampsia.

Triggering receptor expressed on myeloid cells (TREM) like transcript-1 (TLT-1) reveals platelet activation in preeclampsia

Triggering receptor expressed on myeloid cells (TREM) like transcript-1 (TLT-1) is a membrane protein receptor found in α-granules of megakaryocytes and platelets. Upon platelet activation TLT-1 is rapidly relocated to the surface of platelets. In plasma, a soluble form of TLT-1 (sTLT-1) is present. Plasma levels of sTLT-1 are significantly elevated in thrombotic diseases. In the present study, we investigated to whether TLT-1 reflects platelet activation in pregnant women with preeclampsia. We studied 30 preeclamptic patients who were matched with 30 normotensive pregnant women and 30 non-pregnant controls. Basal TLT-1, P-selectin, and CD63 expressions on platelets were analyzed with the use of flow-cytometry (FCM). Platelet reactivity was induced by thrombin receptor activation peptide and determined by FCM. Plasma concentrations of sTLT-1 and soluble P-selectin (sP-selectin) were measured by an enzyme-linked immunosorbent assay. Results show that basal platelet expression of TLT-1, P-selectin and CD63 were increased in women with preeclampsia (PE) compared with normotensive pregnant women (NP). Platelets from PE women and NP women were more responsive compared to from nonpregnant women controls (NC), and which was demonstrated by increased expression of TLT-1, P-selectin, and CD63 upon stimulation in vitro. Plasma concentration of sTLT-1 was greater in PE women compared to NP women and NC women. Plasma sP-selectin level was higher in pregnant women than in nonpregnant women, but there were no significant differences between PE and NP women. In summary, our results revealed that platelet activation is prominent in preeclampsia, TLT-1 reflects platelet activation and may be a useful indicator for preeclampsia.

Activated platelets and platelet-leukocyte aggregates in the equine systemic inflammatory response syndrome

In humans, activated platelets contribute to sepsis complications and to multiple organ failure. In our prospective analytical study of cases of the equine systemic inflammatory response syndrome (SIRS), we adapted a standard human protocol for the measurement of activated platelets and platelet-leukocyte aggregates (PLAs) in equine platelet-leukocyte-rich plasma (PLRP) by flow cytometry, and we investigated the hypothesis that activated platelets and PLAs are increased in clinical cases of SIRS. We included 17 adult horses and ponies fulfilling at least 2 SIRS criteria, and 10 healthy equids as controls. Activation of platelets was determined by increased expression of CD62P on platelets. Activated platelets and PLAs were measured before and after in vitro activation of platelets with collagen. Median expression of CD62P on platelets was significantly increased after activation in the control group: 1.45% (interquartile range [IQR]: 1.08-1.99%) initially versus 8.78% (IQR: 6.79-14.78%, p = 0.002) after activation. The equids with SIRS had significantly more activated platelets and PLAs in native PLRP than controls: CD62P 4.92% (median, IQR: 2.21-12.41%) versus 1.45% in controls (median, IQR: 1.08-1.99%, p = 0.0007), and PLAs 4.16% (median, IQR: 2.50-8.58%) versus 2.95% in controls (median, IQR: 1.57-3.22%, p = 0.048). To our knowledge, increased platelet activation and PLAs have not been demonstrated previously with flow cytometry in clinical cases of equine SIRS.

Taurine and Its Derivatives: Analysis of the Inhibitory Effect on Platelet Function and Their Antithrombotic Potential

Taurine is a semi-essential, the most abundant free amino acid in the human body, with a six times higher concentration in platelets than any other amino acid. It is highly beneficial for the organism, has many therapeutic actions, and is currently approved for heart failure treatment in Japan. Taurine has been repeatedly reported to elicit an inhibitory action on platelet activation and aggregation, sustained by in vivo, ex vivo, and in vitro animal and human studies. Taurine showed effectiveness in several pathologies involving thrombotic diathesis, such as diabetes, traumatic brain injury, acute ischemic stroke, and others. As human prospective studies on thrombosis outcome are very difficult to carry out, there is an obvious need to validate existing findings, and bring new compelling data about the mechanisms underlying taurine and derivatives antiplatelet action and their antithrombotic potential. Chloramine derivatives of taurine proved a higher stability and pronounced selectivity for platelet receptors, raising the assumption that they could represent future potential antithrombotic agents. Considering that taurine and its analogues display permissible side effects, along with the need of finding new, alternative antithrombotic drugs with minimal side effects and long-term action, the potential clinical relevance of this fascinating nutrient and its derivatives requires further consideration.

Unraveling the Mechanism of Platelet Aggregation Suppression by Monoterpenoids

Platelet aggregation causes various diseases and therefore challenges the development of novel antiaggregatory drugs. In this study, we report the possible mechanism of platelet aggregation suppression by newly synthesized myrtenol-derived monoterpenoids carrying different heteroatoms (sulphur, oxygen, or nitrogen). Despite all tested compounds suppressed the platelet aggregation in vitro, the most significant effect was observed for the S-containing compounds. The molecular docking confirmed the putative interaction of all tested compounds with the platelet’s P2Y₁₂ receptor suggesting that the anti-aggregation properties of monoterpenoids are implemented by blocking the P2Y₁₂ function. The calculated binding force depended on heteroatom in monoterpenoids and significantly decreased with the exchanging of the sulphur atom with oxygen or nitrogen. On the other hand, in NMR studies on dodecyl phosphocholine (DPC) as a membrane model, only S-containing compound was found to be bound with DPC micelles surface. Meanwhile, no stable complexes between DPC micelles with either O- or N-containing compounds were observed. The binding of S-containing compound with cellular membrane reinforces the mechanical properties of the latter, thereby preventing its destabilization and subsequent clot formation on the phospholipid surface. Taken together, our data demonstrate that S-containing myrtenol-derived monoterpenoid suppresses the platelet aggregation in vitro via both membrane stabilization and blocking the P2Y₁₂ receptor and, thus, appears as a promising agent for hemostasis control.

Case controlled study on diagnostic predictive value of inflammatory markers of complete blood count in pregnant women with acute appendicitis

The aim of this study is to evaluate and compare the diagnostic ability of platelet-related parameters and white cell-based parameters in pregnant women with appendicitis. This is a retrospective case-controlled study. Women aged between 18 and 50-years-old who had undergone appendectomy between January 2010 and January 2021 were enrolled in the study. Age, pathological diagnosis and relevant laboratory parameters were recorded for each patient. Gestational characteristics were recorded for pregnant patients. There were 58 pregnant and 1171 non-pregnant women enrolled. Pregnant women with acute appendicitis were significantly younger (p < .0001, d= -0.532), had significantly lower PLT (p = .002, d= -0.428) and ALC (p = .033, d= -.304) levels but had significantly higher MPV (p = .004, d = .415) levels than non-pregnant counterparts. In pregnant women, only MPV was the independent predictor of acute appendicitis (OR: 1,952). MPV cut-off value of 9,6 fL provided 63,5% sensitivity, 67,7% specificity, 94,2% PPV and 17,3% NPV whereas 10 fL provided 55,8% sensitivity, 100% specificity, 100% PPV and 21,4% NPV for acute appendicitis in pregnant women. Therefore, MPV might be useful for diagnosing acute appendicitis in pregnant women.Impact statementWhat is already known on this subject? In pregnant women, counts and percentages of white blood cells and neutrophils are known to be independent predictors of acute appendicitis. Meanwhile, physiologic leukocytosis of gestation is a challenge for interpretation of these parameters. Platelets and related markers are, as well, predictive for inflammatory processes in the human body.What do the results of this study add? The role of platelet-related markers in the diagnosis of acute appendicitis in pregnant women has not been studied previously. The results of the present study indicate that in pregnant women, changes in mean platelet volume might be an independent predictor of acute appendicitis.What are the implications of these findings for clinical practice and/or further research? Further similar large-scale case-controlled or cohort studies are required to validate the present results. In pregnant women with abdominal pain, the use of mean platelet volume as a biomarker could reduce negative laparotomy rates. A mean platelet volume is a useful tool for diagnosing acute appendicitis in pregnant women and provides helpful guidance for clinicians dealing with these patients in the emergency room.

Vascular Dysfunction in Preeclampsia

Preeclampsia is a life-threatening pregnancy-associated cardiovascular disorder characterized by hypertension and proteinuria at 20 weeks of gestation. Though its exact underlying cause is not precisely defined and likely heterogenous, a plethora of research indicates that in some women with preeclampsia, both maternal and placental vascular dysfunction plays a role in the pathogenesis and can persist into the postpartum period. Potential abnormalities include impaired placentation, incomplete spiral artery remodeling, and endothelial damage, which are further propagated by immune factors, mitochondrial stress, and an imbalance of pro- and antiangiogenic substances. While the field has progressed, current gaps in knowledge include detailed initial molecular mechanisms and effective treatment options. Newfound evidence indicates that vasopressin is an early mediator and biomarker of the disorder, and promising future therapeutic avenues include mitigating mitochondrial dysfunction, excess oxidative stress, and the resulting inflammatory state. In this review, we provide a detailed overview of vascular defects present during preeclampsia and connect well-established notions to newer discoveries at the molecular, cellular, and whole-organism levels.

Peripartum Investigation of Red Blood Cell Properties in Women Diagnosed with Early-Onset Preeclampsia

We investigated peripartum maternal red blood cell (RBC) properties in early-onset preeclampsia (PE). Repeated blood samples were taken prospectively for hemorheological measurements at PE diagnosis (n = 13) or during 26-34 weeks of gestation in healthy pregnancies (n = 24), then at delivery, and 72 h postpartum. RBC aggregation was characterized by M index (infrared light transmission between the aggregated RBCs in stasis) and aggregation index (AI-laser backscattering from the RBC aggregates). We observed significantly elevated RBC aggregation (M index = 9.8 vs. 8.5; AI = 72.9% vs. 67.5%; p < 0.001) and reduced RBC deformability in PE (p < 0.05). A positive linear relationship was observed between AI and gestational age at birth in PE by regression analysis (R² = 0.554; p = 0.006). ROC analysis of AI showed an AUC of 0.84 (0.68-0.99) (p = 0.001) for PE and indicated a cutoff of 69.4% (sensitivity = 83.3%; specificity = 62.5%), while M values showed an AUC of 0.75 (0.58-0.92) (p = 0.019) and indicated a cutoff of 8.39 (sensitivity = 90.9% and specificity = 50%). The predicted probabilities from the combination of AI and M variables showed increased AUC = 0.90 (0.79-1.00) (p < 0.001). Our results established impaired microcirculation in early-onset PE manifesting as deteriorated maternal RBC properties. The longer the pathologic pregnancy persists, the more pronounced the maternal erythrocyte aggregation. AI and M index could help in the prognostication of early-onset PE, but further investigations are warranted to confirm the prognostic role before the onset of symptoms.

Platelet-derived extracellular vesicles may contribute to the hypercoagulable state in preeclampsia

It has previously been shown that preeclampsia is associated with disturbed hemostasis and that extracellular vesicles (EVs) play important role in the regulation of hemostatic homeostasis. Thus, we hypothesized that the altered procoagulant characteristics of circulating platelet-derived EVs may contribute to the disturbed hemostasis in preeclampsia. Using multicolor flow cytometry, we have analyzed both tissue factor expressing procoagulant EVs and platelet-derived EV subpopulations derived from resting and activated thrombocytes by examining them in plasma samples of preeclamptic patients and pregnancy-matched healthy individuals. Compared to pregnancy-matched healthy individuals in preeclamptic patients a significantly (p < 0.05) higher ratio of Annexin-V positive activated platelets and a higher number of CD142⁺ tissue factor bearing procoagulant EVs were found, whereas the absolute amount of circulating CD41a⁺ platelet-derived EVs and CD62P⁺/CD41a⁺ EVs produced by activated thrombocytes was significantly lower in the plasma of preeclamptic women. In the plasma samples, there was no significant difference in the amount of CD63⁺ platelet-derived EVs. We propose that increased platelet activation and tissue factor expression of platelet derived extracellular vesicles may contribute to the hypercoagulable state observed in preeclampsia.

Prothrombotic state associated with preeclampsia

PURPOSE OF REVIEW

Preeclampsia is a common complication of pregnancy and contributes significantly to maternal and fetal morbidity and mortality. A protective hypercoagulable state is often developed during late pregnancy and can evolve into a prothrombotic state in patients with preeclampsia. The underlying mechanism of this prothrombotic transition remains poorly understood. We discuss recent progress in understanding the pathophysiology of preeclampsia and associated prothrombotic state.

RECENT FINDINGS

The hypercoagulable state developed during pregnancy is initiated by placental factors and progresses into the prothrombotic state in preeclampsia when the placenta is subjected ischemic and oxidative injuries. The cause of the preeclampsia-induced prothrombotic state is multifactorial, involving not only placental factors but also maternal conditions, which include genetic predisposition, preexisting medical conditions, and conditions acquired during pregnancy. Endotheliopathy is the primary pathology of preeclampsia and contributes to the prothrombotic state by inducing the dysregulation of coagulation, platelets, and adhesive ligands.

SUMMARY

Patients with preeclampsia often develop a severe prothrombotic state that predisposes them to life-threatening thrombosis and thromboembolism during and after pregnancy. Early recognition and treatment of this prothrombotic state can improve maternal and infant outcomes of preeclampsia patients.

The Society for Obstetric Anesthesia and Perinatology Interdisciplinary Consensus Statement on Neuraxial Procedures in Obstetric Patients With Thrombocytopenia

Because up to 12% of obstetric patients meet criteria for the diagnosis of thrombocytopenia in pregnancy, it is not infrequent that the anesthesiologist must decide whether to proceed with a neuraxial procedure in an affected patient. Given the potential morbidity associated with general anesthesia for cesarean delivery, thoughtful consideration of which patients with thrombocytopenia are likely to have an increased risk of spinal epidural hematoma with neuraxial procedures, and when these risks outweigh the relative benefits is important to consider and to inform shared decision making with patients. Because there are substantial risks associated with withholding a neuraxial analgesic/anesthetic procedure in obstetric patients, every effort should be made to perform a bleeding history assessment and determine the thrombocytopenia etiology before admission for delivery. Whereas multiple other professional societies (obstetric, interventional pain, and hematologic) have published guidelines addressing platelet thresholds for safe neuraxial procedures, the US anesthesia professional societies have been silent on this topic. Despite a paucity of high-quality data, there are now meta-analyses that provide better estimations of risks. An interdisciplinary taskforce was convened to unite the relevant professional societies, synthesize the data, and provide a practical decision algorithm to help inform risk-benefit discussions and shared decision making with patients. Through a systematic review and modified Delphi process, the taskforce concluded that the best available evidence indicates the risk of spinal epidural hematoma associated with a platelet count ≥70,000 × 106/L is likely to be very low in obstetric patients with thrombocytopenia secondary to gestational thrombocytopenia, immune thrombocytopenia (ITP), and hypertensive disorders of pregnancy in the absence of other risk factors. Ultimately, the decision of whether to proceed with a neuraxial procedure in an obstetric patient with thrombocytopenia occurs within a clinical context. Potentially relevant factors include, but are not limited to, patient comorbidities, obstetric risk factors, airway examination, available airway equipment, risk of general anesthesia, and patient preference.

Interleukin-1β and uric acid as potential second-trimester predictive biomarkers of preeclampsia

Methods: The prospective study was conducted at the University Hospital from February 2020 to December 2020. The study population (n = 88) included women who later developed PE (n = 42), as well as women who were healthy at birth (n = 46) in the second trimester of pregnancy. Serum levels of CRP, IL-1β, uric acid, creatinine, AST, ALT, MPV, Hb, PC, vitamin D, Ca, and Mg were compared between the groups.Results: Serum IL-1β and uric acid levels were significantly higher in subjects who eventually developed PE compared with those who did not.Conclusions: IL-1β and uric acid may be a predictive markers for PE. Maternal serum IL-1β and uric acid levels in the second trimester of pregnancy may be a predictive markers for PE.

Low Dose Aspirin in high-risk pregnancies: The volatile effect of acetylsalicylic acid on the inhibition of platelets uncovered by G. Born's light transmission aggregometry

Preeclampsia still represents a life-threatening pregnancy complication, associated with severe maternal and neonatal morbidity and mortality. Low-dose Aspirin is advised to avoid preeclampsia in high-risk pregnancies worldwide. As Aspirin does not cover all women at risk, the prescription raises questions concerning optimal target population, dosage, and onset of therapy. The aim of this study was to test platelet responsiveness on Aspirin by optical aggegrometry, to gain robust biochemically assessment data of Aspirin in an obstetric cohort. 248 women at high risk for development of preeclampsia were included in the study. Aspirin-prophylaxis was administered either in 100 mg (n = 229) or 150 mg (n = 90) daily. Dosing of 100 mg Aspirin was maintained if testing revealed a sufficient platelet inhibition. If platelet inhibition was insufficient, dosage was increased to 150 mg Aspirin and re-testing was advised. 91 patients (91/229 = 39.7%) presented a sufficient inhibitory Aspirin effect at a dosage of 100 mg, but in 138 patients LTA showed an inadequate Aspirin response (138/229 = 60.3%). In 19 women 150 mg Aspirin was administered as starting dose due to new recommendations. Of all women at 150 mg Aspirin 64 did not properly respond (35.4%). The overall rate of sufficient responding women regardless the Aspirin dose was 64.6%. This study demonstrates still an insufficient inhibition of platelet aggregation in about 1/3 of women even with a dosage of 150 mg Aspirin daily, who might potentially benefit from further increase. These data show, that there is a need for further research to allow a personalized approach for individualized Aspirin therapy, maximizing the preventive benefit for mother and child.

Role of platelet count and mean platelet volume and red cell distribution width in the prediction of preeclampsia in early pregnancy

Introduction:

Mean platelet volume (MPV), platelet count (PC), and red cell distribution width (RDW) are various blood indices that play important role in preeclampsia. This study aimed to evaluate the role of MPV, RDW, and PC for the prediction of preeclampsia in the early second trimester of pregnancy and to observe its correlation with disease severity.

Material and Methods:

A prospective case-control study was conducted for 1 year in the Department of Obstetrics and Gynecology. A total of 543 healthy pregnant women were recruited, after obtaining informed consent and ethical clearance and followed till 6 weeks postpartum, 43 were lost to follow-up. Out of 500 women, nonsevere preeclampsia (NSPE) occurred in 16 women and severe preeclampsia (SPE) in 34 women. Around 51 healthy normotensive pregnant women were recruited after systematic randomization from the same cohort, who had not developed the disease, served as controls. NSPE and SPE were defined as per ACOG 2013b guideline. MPV, RDW, and PC were measured two times by the Siemens Advia analyzer; the first samples were withdrawn at the time of enrolment and the next sample was taken after the development of the disease, and both samples were analyzed.

Results:

MPV was increased with the severity of preeclampsia, diagnostic accuracy was 69.4%, at a cutoff value of ≥9.05 fl and MPV discriminated controls and NSPE with 50.0% sensitivity and 82.4% specificity. To discriminate between controls and SPE, diagnostic accuracy was 74.6% at a cutoff value of ≥9.05 fl, with a sensitivity of 50%. For control versus SPE, MPCs at the cutoff value of ≥2.085 lac/mm³ had sensitivity 52.9% and specificity 66.7%, and diagnostic accuracy 61.2%. For RDW NSPE, at a cutoff value of ≥11.5%, it discriminated against controls and NSPE with 85.3% sensitivity and 49.0% specificity.

Conclusion:

NSPE, MPV, RDW, and PCs had good discriminatory value with the severity of the disease.

Whole blood flow cytometry protocol for the assessment of platelet phenotype, function, and cellular interactions

Platelets are a key component of the hemostatic system and their roles in inflammation via interactions with leukocytes have also gained attention in recent years. Changes in platelet phenotype and function can cause bleeding and/or thrombosis and, as such, monitoring platelet-specific changes is crucial to assessing hemostasis in the clinical setting. Currently, available platelet function tests such as platelet aggregometry and thromboelastography require a large volume of blood, which is a major limitation for the pediatric population. Whole blood flow cytometric analysis of platelets is increasingly utilized in recent years, primarily due to the sensitivity of this method, but also because it only requires a small amount of blood with minimal sample manipulation. We have developed a whole blood flow cytometry methodological approach that enables the assessment of platelet phenotype, function, and their interactions with monocytes and neutrophils.

Preclinical study of innovative peptides mimicking the space structure of the α-helix B of erythropoietin

Introduction: The aim of this study was to examine the effectiveness of innovative peptides obtained by addition of polypeptide motifs with antiaggregation activity (Arg-Gly-Asp, Lys-Gly-Asp and Pro-Gly-Pro) to a peptide mimicking the space structure of the α-helix B of erythropoietin pHBSP (Pyr-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser).

Materials and methods: The cytoprotective activity of innovative peptides mimicking the space structure of the α-helix B of erythropoietin at the doses of 5 μg/ml, 30 μg/ml and 50 μg/ml was studied on human endothelial cell culture in a simulated oxidative stress. An ADMA-like model of preeclampsia was simulated in the experiment. The study was conducted in 260 female Wistar rats, weighing 250–300 g.

Results and discussion: Innovative peptides mimicking the space structure of the α-helix B of erythropoietin retain their cytoprotective activity in a simulated oxidative stress in HUVEC cell culture at the doses of 5 μg/ml, 30 μg/ml, and 50 μg/ml. The compounds with laboratory codes P-αB1 and P-αB3 had the most pronounced cytoprotective activity. Administration of N-nitro-L-arginine-methyl ether to pregnant females for 7 days causes the morphofunctional changes similar to clinical changes in preeclampsia. The innovative peptide under laboratory code P-αB4 at the dose of 50 μg/kg mimicking the space structure of the α-helix B of erythropoietin shows the most pronounced protective properties.

Conclusion: Innovative peptides mimicking the space structure of the α-helix B of erythropoietin have a pronounced positive influence on the morphofunctional disorders in animals with ADMA-like preeclampsia.

Pathophysiology of the Venous Thromboembolism Risk in Preeclampsia

Preeclampsia complicates up to 8% of pregnancies and is a leading cause of fetomaternal morbidity andmortality. Treatment options are limited, with supportive care and delivery of the placenta representing the cornerstone of current management strategies. Derangements in blood coagulation are wellrecognised in this disorder and appear to favour an increased risk of venous thromboembolism among affected women. This risk appears to be most significant in the postpartum period. The mechanisms underlying this increased thrombosis risk remain to be fully elucidated although increased expression of procoagulant factors, endothelial dysfunction, attenuation of endogenous anticoagulant activity and increased platelet activity have been implicated in the prothrombotic tendency. Preeclampsia is also occasionally complicated by life-threatening haemorrhagic events and current evidence suggests that in some severe manifestations of this disease a coagulopathy with a clinical bleeding tendency may be the predominant haemostatic abnormality. Identifying affected women at significant risk of thrombosis and managing the competing thrombotic and haemorrhagic risks continue to be a significant clinical challenge. Derangements in blood coagulation are also implicated in the pathogenesis of preeclampsia; however, the role of antiplatelet or anticoagulant drugs in the prevention and treatment of this disorder remains a source of considerable debate. In addition, the potential role of specific haemostatic markers as diagnostic or screening tools for preeclampsia has also yet to be determined. Further characterisation of the underlying molecular mechanisms would likely be of major translational relevance and could provide insights into the pathogenesis of this disease as well as the associated haemostatic dysfunction.

Maternal Platelets—Friend or Foe of the Human Placenta?

Human pregnancy relies on hemochorial placentation, including implantation of the blastocyst and deep invasion of fetal trophoblast cells into maternal uterine blood vessels, enabling direct contact of maternal blood with placental villi. Hemochorial placentation requires fast and reliable hemostasis to guarantee survival of the mother, but also for the neonates. During human pregnancy, maternal platelet count decreases gradually from first, to second, and third trimester. In addition to hemodilution, accelerated platelet sequestration and consumption in the placental circulation may contribute to a decline of platelet count throughout gestation. Local stasis, turbulences, or damage of the syncytiotrophoblast layer can activate maternal platelets within the placental intervillous space and result in formation of fibrin-type fibrinoid. Perivillous fibrinoid is a regular constituent of the normal placenta which is considered to be an important regulator of intervillous hemodynamics, as well as having a role in shaping the developing villous trees. However, exaggerated activation of platelets at the maternal-fetal interface can provoke inflammasome activation in the placental trophoblast, and enhance formation of circulating platelet-monocyte aggregates, resulting in sterile inflammation of the placenta and a systemic inflammatory response in the mother. Hence, the degree of activation determines whether maternal platelets are a friend or foe of the human placenta. Exaggerated activation of maternal platelets can either directly cause or propagate the disease process in placenta-associated pregnancy pathologies, such as preeclampsia.