Lower circulating angiotensin II levels are related to the severity of preeclampsia and its risk as disclosed by a specific bioassay

Genetic Insights and Neonatal Outcomes in Preeclampsia and Eclampsia: A Detailed Analysis of the RS5707 Genotype

BACKGROUND

Preeclampsia (PE) and eclampsia (E) are severe pregnancy complications with significant maternal and neonatal health impacts. This study explores the association of the rs5707 polymorphism in the renin-angiotensin system (RAS) with PE/E and related neonatal outcomes.

MATERIALS AND METHODS

We conducted a cross-sectional study involving 400 mother-newborn dyads at the "Pius Brinzeu" Emergency Clinical Hospital Timisoara. Participants were divided into a control group (254 normotensive women) and a PE/E group (146 women with PE/E). Genotyping for the rs5707 polymorphism was performed using real-time PCR, and statistical analyses assessed associations with maternal body mass index (BMI) and neonatal outcomes.

RESULTS

The AA genotype of rs5707 was significantly associated with a reduced risk of PE/E and more favorable neonatal outcomes, including higher Apgar scores, greater birth weights, and longer gestational ages. Conversely, the AC genotype correlated with increased maternal BMI and adverse neonatal outcomes. Odds ratios highlighted the protective effect of the AA genotype against PE/E and the increased risk associated with the AC genotype.

CONCLUSIONS

This study revealed the critical role of the rs5707 polymorphism in PE/E development and neonatal health. Genetic screening for rs5707 could enhance early identification and personalized intervention strategies, improving outcomes for both mothers and neonates. Further research is needed to validate these findings across diverse populations and to uncover the underlying mechanisms.

[Epidemiological characterization of COVID-2019 in Mexican pregnant women: a cohort study]

Background

COVID-19 in pregnancy can increase the risk of complications due to the cardiorespiratory and immunological changes typical of pregnancy.

Objective

To report the epidemiological characterization of COVID-19 in Mexican pregnant women.

Material and methods

Cohort study on pregnant women with a positive COVID-19 test, which were followed until delivery and one month later.

Results

758 pregnant women were included in the analysis. Mothers' mean age was 28.8 ± 6.1 years; the majority were workers 497 (65.6%) and with an urban origin (482, 63.6%); the most common blood group was O with 458 (63.0%); 478 (63.0%) were nulliparous women and more than 25% had some comorbidities; the average gestation weeks at infection were 34.4 ± 5.1 weeks; only 170 pregnant women (22.4%) received vaccination; the most frequent vaccine was BioNTech Pfizer (96, 60%); there were no serious adverse events attributed to vaccination. The mean gestational age at delivery was 35.4 ± 5.2 weeks; 85% of pregnancies were cesarean section; the most frequent complication was prematurity (406, 53.5%), followed by preeclampsia (199, 26.2%); there were 5 cases of maternal death and 39 cases of perinatal death.

Conclusions

COVID-19 in pregnancy increases the risk of preterm birth, preeclampsia, and maternal death. Vaccination against COVID-19 in this series showed no risk for pregnant women and their newborns.

Mouse models of preeclampsia with preexisting comorbidities

Preeclampsia is a pregnancy-specific condition and a leading cause of maternal and fetal morbidity and mortality. It is thought to occur due to abnormal placental development or dysfunction, because the only known cure is delivery of the placenta. Several clinical risk factors are associated with an increased incidence of preeclampsia including chronic hypertension, diabetes, autoimmune conditions, kidney disease, and obesity. How these comorbidities intersect with preeclamptic etiology, however, is not well understood. This may be due to the limited number of animal models as well as the paucity of studies investigating the impact of these comorbidities. This review examines the current mouse models of chronic hypertension, pregestational diabetes, and obesity that subsequently develop preeclampsia-like symptoms and discusses how closely these models recapitulate the human condition. Finally, we propose an avenue to expand the development of mouse models of preeclampsia superimposed on chronic comorbidities to provide a strong foundation needed for preclinical testing.

Preeclampsia and the Kidney: Pathophysiology and Clinical Implications

Preeclampsia and other hypertensive disorders of pregnancy are major contributors to maternal morbidity and mortality worldwide. This group of disorders includes chronic hypertension, gestational hypertension, preeclampsia, preeclampsia superimposed on chronic hypertension, and eclampsia. The body undergoes important physiological changes during pregnancy to allow for normal placental and fetal development. Several mechanisms have been proposed that may lead to preeclampsia, including abnormal placentation and placental hypoxia, impaired angiogenesis, excessive pro-inflammatory response, immune system imbalance, abnormalities of cellular senescence, alterations in regulation and activity of angiotensin II, and oxidative stress, ultimately resulting in upregulation of multiple mediators of endothelial cell dysfunction leading to maternal disease. The clinical implications of preeclampsia are significant as there are important short-term and long-term health consequences for those affected. Preeclampsia leads to increased risk of preterm delivery and increased morbidity and mortality of both the developing fetus and mother. Preeclampsia also commonly leads to acute kidney injury, and women who experience preeclampsia or another hypertensive disorder of pregnancy are at increased lifetime risk of chronic kidney disease and cardiovascular disease. An understanding of normal pregnancy physiology and the pathophysiology of preeclampsia is essential to develop novel treatment approaches and manage patients with preeclampsia and hypertensive disorders of pregnancy. © 2023 American Physiological Society. Compr Physiol 13:4231-4267, 2023.

Comparison of serum midkine levels between pregnant women with and without pre-eclampsia: A case-control study from a tertiary hospital

OBJECTIVE

To evaluate changes in maternal serum midkine levels in pre-eclampsia.

METHODS

This study included 40 pregnant women with pre-eclampsia and 66 healthy pregnant women in the control group. Demographic data, laboratory results, and midkine levels were compared between the groups.

RESULTS

The pre-eclampsia and control groups were similar in terms of demographics. The midkine level of pregnant women with pre-eclampsia was significantly higher than that of the controls (0.54 ± 0.23 and 0.31 ± 0.19 ng/mL, respectively, P < 0.001). According to the receiver operating characteristic analysis, the optimal cut-off value of midkine was determined as 0.37 ng/mL, at which it had 75% sensitivity and 74% specificity (area under the curve: 0.815, 95% confidence interval 0.73-0.89, P < 0.001).

CONCLUSION

The serum midkine level was significantly higher in pregnant women with pre-eclampsia. Midkine seems to be associated with complicated inflammatory processes leading to pre-eclampsia. Further study protocols can be planned to investigate the role of midkine in the prediction of pre-eclampsia as a novel marker.

Soluble urinary somatic angiotensin converting enzyme is overexpressed in patients with preeclampsia: a potential new marker for the disease?

OBJECTIVE

The aim of this study was to identify and quantify urinary Angiotensin-Converting-Enzyme (ACE) in hypertensive disorders of pregnancy.

METHODS

Urine samples were analyzed by Western blot. Patients were classified into: normotensive pregnancy (N); preeclampsia and superimposed preeclampsia (PE+SPE); and gestational hypertension (GH).

RESULTS

Somatic ACE protein expression was higher in PE+SPE compared to N and GH. There was a positive correlation between ACE and urinary protein to creatinine ratio, systolic and diastolic blood pressures.

CONCLUSION

These results indicate ACE overexpression in the urine of preeclamptic patients and suggest that it may be a new marker for the disease.

Quantitation of plasma angiotensin II in healthy Chinese subjects by a validated liquid chromatography tandem mass spectrometry method

INTRODUCTION

Quantitation of plasma angiotensin (Ang) II, the active mediator of the renin-angiotensin system (RAS), is challenging due to its low physiological concentration. We report a validated liquid chromatography-mass spectrometry (LCMS) method to overcome this challenge.

METHOD

Ang II was extracted from EDTA plasma by an offline solid-phase extraction procedure with Waters MAX μElution plate. LCMS quantitation was performed on the Waters TQS system, monitoring the 3+ ions of the peptide. The analytical performance of the LCMS method was validated. The stability of Ang II was studied with or without the presence of a protease inhibitor. Local reference intervals were established from 143 healthy normotensive subjects (57% female, 21-60 years old).

RESULTS

The Ang II LCMS method had a measurable range of 3.3 - 700 pmol/L. Between batch precision coefficient of variation was <7% over the Ang II concentrations of 8.6 - 110 pmol/L. No significant matrix interference and carryover was observed. There was no significant difference in Ang II concentration in EDTA blood and plasma for at least 2 hours and 1 hour at room temperature, respectively. Ang II was stable for at least one year when stored at -80 ^o C, with or without the protease inhibitor. Age-dependent Ang II reference intervals were established: 4.4-17.7 pmol/L (21-30 years) and 3.9-12.8 pmol/L (31-60 years).

CONCLUSION

The present LCMS method is suitable for quantitation of Ang II to study the RAS system. Ang II collected at room temperature into EDTA bottles was stable at -80 ^o C for at least 1 year. The first age-dependent reference intervals of plasma Ang II were established for a healthy normotensive Chinese population.

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.

New views on endothelial dysfunction in gestational hypertension and potential therapy targets

The placenta has vital roles in metabolite exchange, fetal growth, and pre-eclampsia (PE). In this review, we discuss the pathogenesis of hypertension in pregnancy, focusing on four major theories to explain PE, discussing endothelial roles in those theories. We focus in particular on the roles of nitric oxide (NO) and prostacyclin (PGI₂) in placental endothelium, and propose new hypotheses for the influence and mechanisms of endothelial NO and PGI₂ signaling pathways in PE.

Plasma angiotensin II levels in women with severe preeclampsia under magnesium sulfate regimen

The role of Renin-Angiotensin-System (RAS) in the pathogenesis of preeclampsia and eclampsia is still unclear. Our aim was to investigate plasma angiotensin II concentration [Ang II] in women with normotensive pregnancies (NP, n = 22) and severe preeclampsia in use of magnesium sulfate (SPE, n = 29). Despite no difference between the groups (SPE: 47.8 pg/ml vs NP: 39.7 pg/ml, p = 0.195), lower maternal age (p = 0.007) and primigravida (p = 0.028) were associated with lower [Ang II]. Plasma [Ang II] increased over the 24 h of magnesium sulfate administration (r = 0.48, p = 0.009). Our findings suggest that RAS may be involved with the mechanism of magnesium protection against eclamptic seizure.

The Role of the Renin-Angiotensin-Aldosterone System in Preeclampsia: a Review

PURPOSE OF REVIEW

Preeclampsia (PE) is a complex human pregnancy-specific condition and is clinically characterized by new onset hypertension and proteinuria in the second half of pregnancy. The precise etiology of PE is unknown, but much of the pathophysiology has been elucidated, and it is accepted that the disorder is multifactorial in nature. Historically, because of the presence of proteinuria, the role of the renin-angiotensin-aldosterone system (RAAS) has been considered in the etiology of PE. However, the results of studies (including maternal circulatory angiotensin II, urinary angiotensinogen, plasma renin and prorenin, AT1 receptor antibodies, and gene polymorphisms) on the role of the RAAS in the etiology of PE have proved controversial. The purpose of this narrative review was to evaluate the contemporary literature on the RAAS and its role in the pathophysiology of pregnancy.

RECENT FINDINGS

The current review shows that although the RAAS has a role in the development of normal pregnancy, it does not have a significant role in the pathophysiology of PE except for the AT1-AA components. Despite many researchers having measured increases in s[P}RR and [P]RR, this may be independent of the RAAS. Our view is in keeping with contemporary thinking that the placenta rather than the RAAS plays a central role in elaborating pro-inflammatory factors (antiangiogenic and angiogenic) into the maternal circulation resulting in widespread endothelial dysfunction in all organ systems including the renal system.

Is pregnancy a risk factor of COVID-19?

This review evaluates whether pregnancy is a risk factor for COVID-19 by looking at the expression of immune markers such as immune cells and cytokines in order to have a better understanding on the pathophysiology of the disease, thus reducing maternal deaths. Pregnant women are more at risk of contracting COVID-19 due to their weakened immune system. Studies demonstrate that COVID-19 is an immune condition which is marked by reduced lymphocytes and elevated selected proinflammatory cytokines. Similar immune expression has been demonstrated in pregnancy by several studies. In addition, the placenta has been shown to possess ACE2 receptors on the villous cytotrophoblast and the syncytiotrophoblast and findings suggest that the coronavirus enters the host cells via these ACE2 receptors. The immune response in pregnancy increases the risk of contracting COVID-19. Both normal pregnancy and COVID-19 are marked by decreased lymphocytes, NKG2A inhibitory receptors, and increased ACE2, IL-8, IL-10, and IP-10 it therefore safer to conclude that pregnancy is a risk factor for COVID-19 development. Furthermore, the presence of the ACE2 receptors in the placenta may increase the risk of mother to baby transmission of the virus. Therefore, more studies investigating the link between pregnancy and COVID-19 are needed.

Preeclampsia beyond pregnancy: long-term consequences for mother and child

Preeclampsia is defined as new-onset hypertension after the 20th wk of gestation along with evidence of maternal organ failure. Rates of preeclampsia have steadily increased over the past 30 yr, affecting ∼4% of pregnancies in the United States and causing a high economic burden (22, 69). The pathogenesis is multifactorial, with acknowledged contributions by placental, vascular, renal, and immunological dysfunction. Treatment is limited, commonly using symptomatic management and/or early delivery of the fetus (6). Along with significant peripartum morbidity and mortality, current research continues to demonstrate that the consequences of preeclampsia extend far beyond preterm delivery. It has lasting effects for both mother and child, resulting in increased susceptibility to hypertension and chronic kidney disease (45, 54, 115, 116), yielding lifelong risk to both individuals. This review discusses recent guideline updates and recommendations along with current research on these long-term consequences of preeclampsia.

Soluble angiotensin IV receptor levels in preeclampsia: is there a variation?

Objective: To measure the concentration of plasma soluble angiotensin IV receptor (sAT-4), a component of the renin-angiotensin system in healthy normotensive pregnancies and preeclampsia.Study design: Stored maternal plasma samples obtained at the time of diagnosis from pregnant women of African ancestry were stratified into normotensive and preeclampsia groups. Preeclampsia was subdivided into early-onset, late-onset, and into and severe preeclampsia. Plasma concentrations of sAT-4 were measured at 450 nm using the ELISA technique (LNPEP KIT).Results: The systolic and diastolic blood pressure (BP) levels of the normotensive group were statistically lower compared to preeclampsia groups (p < .05) and the mean gestational age in early-onset preeclampsia was lower compared to late-onset preeclampsia and the normotensive group (p < .05). Plasma sAT-4 levels were significantly elevated (p < .0001) in the normotensive group (median 1.95, range 1.89-2.02 ng/ml) compared to the preeclampsia group (median 1.55, range 1.42-1.74 ng/ml), regardless of gestational age. Soluble AT-4 was decreased in relation to the severity of preeclampsia (p < .001), the level in preeclampsia without severe features (median 1.57, range 1.42-1.74 ng/ml) was significantly higher than in preeclampsia with severe features (median 1.51, range 1.42-1.55 ng/ml). There was no significant difference in the sAT-4 level between early-onset preeclampsia (1.60 ± 0.13 ng/ml) and late-onset preeclampsia (1.65 ± 0.29 ng/ml) groups (p = .59).Conclusion: Plasma circulating levels of sAT-4 in women with severe features of preeclampsia had lower levels than normotensives and those with preeclampsia without severe features.