Maternal plasma-soluble ST2 concentrations are elevated prior to the development of early and late onset preeclampsia - a longitudinal study

A mitochondrial regulator protein, MNRR1, is elevated in the maternal blood of women with preeclampsia

OBJECTIVE

Preeclampsia, one of the most serious obstetric complications, is a heterogenous disorder resulting from different pathologic processes. However, placental oxidative stress and an anti-angiogenic state play a crucial role. Mitochondria are a major source of cellular reactive oxygen species. Abnormalities in mitochondrial structures, proteins, and functions have been observed in the placentae of patients with preeclampsia, thus mitochondrial dysfunction has been implicated in the mechanism of the disease. Mitochondrial nuclear retrograde regulator 1 (MNRR1) is a newly characterized bi-organellar protein with pleiotropic functions. In the mitochondria, this protein regulates cytochrome c oxidase activity and reactive oxygen species production, whereas in the nucleus, it regulates the transcription of a number of genes including response to tissue hypoxia and inflammatory signals. Since MNRR1 expression changes in response to hypoxia and to an inflammatory signal, MNRR1 could be a part of mitochondrial dysfunction and involved in the pathologic process of preeclampsia. This study aimed to determine whether the plasma MNRR1 concentration of women with preeclampsia differed from that of normal pregnant women.

METHODS

This retrospective case-control study included 97 women with preeclampsia, stratified by gestational age at delivery into early (<34 weeks, n = 40) and late (≥34 weeks, n = 57) preeclampsia and by the presence or absence of placental lesions consistent with maternal vascular malperfusion (MVM), the histologic counterpart of an anti-angiogenic state. Women with an uncomplicated pregnancy at various gestational ages who delivered at term served as controls (n = 80) and were further stratified into early (n = 25) and late (n = 55) controls according to gestational age at venipuncture. Maternal plasma MNRR1 concentrations were determined by an enzyme-linked immunosorbent assay.

RESULTS

1) Women with preeclampsia at the time of diagnosis (either early or late disease) had a significantly higher median (interquartile range, IQR) plasma MNRR1 concentration than the controls [early preeclampsia: 1632 (924-2926) pg/mL vs. 630 (448-4002) pg/mL, p = .026, and late preeclampsia: 1833 (1441-5534) pg/mL vs. 910 (526-6178) pg/mL, p = .021]. Among women with early preeclampsia, those with MVM lesions in the placenta had the highest median (IQR) plasma MNRR1 concentration among the three groups [with MVM: 2066 (1070-3188) pg/mL vs. without MVM: 888 (812-1781) pg/mL, p = .03; and with MVM vs. control: 630 (448-4002) pg/mL, p = .04]. There was no significant difference in the median plasma MNRR1 concentration between women with early preeclampsia without MVM lesions and those with an uncomplicated pregnancy (p = .3). By contrast, women with late preeclampsia, regardless of MVM lesions, had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM: 1609 (1392-3135) pg/mL vs. control: 910 (526-6178), p = .045; and without MVM: 2023 (1578-8936) pg/mL vs. control, p = .01].

CONCLUSIONS

MNRR1, a mitochondrial regulator protein, is elevated in the maternal plasma of women with preeclampsia (both early and late) at the time of diagnosis. These findings may reflect some degree of mitochondrial dysfunction, intravascular inflammation, or other unknown pathologic processes that characterize this obstetrical syndrome.

Relationship between serum soluble suppression of tumorigenicity (ST) 2 and global longitudinal strain in early onset preeclampsia

BACKGROUND

Preeclampsia is one of the leading causes of death in childbearing women worldwide. Hemodynamic changes in preeclampsia can trigger cardiac remodeling as indicated by increase of soluble-ST2 (sST2). Global longitudinal strain were able to detect systolic dysfunction better than the ejection fraction. This study aims to evaluate the correlation between serum levels of sST2 towards GLS in patients with early-onset preeclampsia.

METHODS

This is a cross-sectional observational study with correlation analysis. Subjects were patients with severe preeclampsia with gestational age before 34 weeks at Dr. Hasan Sadikin Central General Hospital Bandung and Bandung Kiwari Regional General Hospital from June to August 2022. Examination of sST2 was carried out through blood samples using the ELISA method. sST2 was measured using Presage ST2 Assay reagent. GLS examination was carried out using speckle tracking technique with EchoPAC. Correlation analysis was conducted using the Pearson test if normally distributed, otherwise Spearman's correlation was conducted. Correlation analysis was followed by linear regression.

RESULTS

A total of 30 patients met the inclusion criteria. The mean age was 30.83 ± 7.09, with 17 (56.7%) multiparous patients. The median sST2 was 145.75 ng/mL, and the median GLS was - 17.4%. Spearman correlation analysis showed that there was a significant positive correlation with moderate strength between sST2 and GLS (r = 0.583; p < 0.002). Linear regression showed that every 1 ng/ml increase in sST2 would give an increase in GLS of 0.014%.

CONCLUSION

There is a significant correlation between sST2 and GLS in patients with early onset severe preeclampsia.

A biomarker for bacteremia in pregnant women with acute pyelonephritis: soluble suppressor of tumorigenicity 2 or sST2

Objective: Sepsis is a leading cause of maternal death, and its diagnosis during the golden hour is critical to improve survival. Acute pyelonephritis in pregnancy is a risk factor for obstetrical and medical complications, and it is a major cause of sepsis, as bacteremia complicates 15-20% of pyelonephritis episodes in pregnancy. The diagnosis of bacteremia currently relies on blood cultures, whereas a rapid test could allow timely management and improved outcomes. Soluble suppression of tumorigenicity 2 (sST2) was previously proposed as a biomarker for sepsis in non-pregnant adults and children. This study was designed to determine whether maternal plasma concentrations of sST2 in pregnant patients with pyelonephritis can help to identify those at risk for bacteremia.Study design: This cross-sectional study included women with normal pregnancy (n = 131) and pregnant women with acute pyelonephritis (n = 36). Acute pyelonephritis was diagnosed based on a combination of clinical findings and a positive urine culture. Patients were further classified according to the results of blood cultures into those with and without bacteremia. Plasma concentrations of sST2 were determined by a sensitive immunoassay. Non-parametric statistics were used for analysis.Results: The maternal plasma sST2 concentration increased with gestational age in normal pregnancies. Pregnant patients with acute pyelonephritis had a higher median (interquartile range) plasma sST2 concentration than those with a normal pregnancy [85 (47-239) ng/mL vs. 31 (14-52) ng/mL, p < .001]. Among patients with pyelonephritis, those with a positive blood culture had a median plasma concentration of sST2 higher than that of patients with a negative blood culture [258 (IQR: 75-305) ng/mL vs. 83 (IQR: 46-153) ng/mL; p = .03]. An elevated plasma concentration of sST2 ≥ 215 ng/mL had a sensitivity of 73% and a specificity of 95% (area under the receiver operating characteristic curve, 0.74; p = .003) with a positive likelihood ratio of 13.8 and a negative likelihood ratio of 0.3 for the identification of patients who had a positive blood culture.Conclusion: sST2 is a candidate biomarker to identify bacteremia in pregnant women with pyelonephritis. Rapid identification of these patients may optimize patient care.

Soluble suppression of tumorigenicity-2 in pregnancy with a small-for-gestational-age fetus and with preeclampsia

OBJECTIVE

Preeclampsia and fetal growth disorders are pregnancy-specific conditions that share common pathophysiological mechanisms. Yet, why some patients develop preeclampsia while others experience fetal growth restriction, or a combination of both clinical presentations, is unknown. We propose that the difference in severity of the maternal inflammatory response can contribute to the clinical phenotypes of preeclampsia vs. small for gestational age (SGA). To assess this hypothesis, we measured maternal plasma concentrations of the soluble isoform of suppression of tumorigenicity-2 (sST2), a member of the interleukin-1 receptor family that buffers proinflammatory responses. Previous reports showed that serum sST2 concentrations rise in the presence of intravascular inflammation and Th1-type immune responses and are significantly higher in patients with preeclampsia compared to those with normal pregnancy. The behavior of sST2 in pregnancies complicated by SGA has not been reported. This study was conducted to compare sST2 plasma concentrations in normal pregnancies, in those with preeclampsia, and in those with an SGA fetus.

METHODS

This retrospective cross-sectional study included women with an SGA fetus (n = 52), women with preeclampsia (n = 106), and those with normal pregnancy (n = 131). Maternal plasma concentrations of sST2 were determined by enzyme-linked immunosorbent assay. Doppler velocimetry of the uterine and umbilical arteries was available in a subset of patients with SGA (42 patients and 43 patients, respectively).

RESULTS

(1) Women with an SGA fetus had a significantly higher median plasma concentration of sST2 than normal pregnant women (p = .008); (2) women with preeclampsia had a significantly higher median plasma concentration of sST2 than those with normal pregnancy (p < .001) and those with an SGA fetus (p < .001); (3) patients with SGA and abnormal uterine artery Doppler velocimetry had a higher median plasma concentration of sST2 than controls (p < .01) and those with SGA and normal uterine artery Doppler velocimetry (p = .02); (4) there was no significant difference in the median plasma sST2 concentration between patients with SGA who had normal uterine artery Doppler velocimetry and controls (p = .4); (5) among patients with SGA, those with abnormal and those with normal umbilical artery Doppler velocimetry had higher median plasma sST2 concentrations than controls (p = .001 and p = .02, respectively); and (6) there was no significant difference in the median plasma sST2 concentrations between patients with SGA who did and those who did not have abnormal umbilical artery Doppler velocimetry (p = .06).

CONCLUSIONS

Preeclampsia and disorders of fetal growth are conditions characterized by intravascular inflammation, as reflected by maternal plasma concentrations of sST2. The severity of intravascular inflammation is highest in patients with preeclampsia.

DHT and Insulin Upregulate Secretion of the Soluble Decoy Receptor of IL-33 From Decidualized Endometrial Stromal Cells

Interleukin 33 (IL-33) signaling regulates most of the key processes of pregnancy, including decidualization, trophoblast proliferation and invasion, vascular remodeling, and placental growth. Accordingly, dysregulation of IL-33, its membrane-bound receptor (ST2L, transducer of IL-33 signaling), and its soluble decoy receptor (sST2, inhibitor of IL-33 signaling) has been linked to a wide range of adverse pregnancy outcomes that are common in women with obesity and polycystic ovary syndrome, that is, conditions associated with hyperandrogenism, insulin resistance, and compensatory hyperinsulinemia. To reveal if androgens and insulin might modulate uteroplacental IL-33 signaling, we investigated the effect of dihydrotestosterone (DHT) and/or insulin on the expression of ST2L and sST2 (along with the activity of their promoter regions), IL-33 and sIL1RAP (heterodimerization partner of sST2), during in vitro decidualization of endometrial stromal cells from 9 healthy women. DHT and insulin markedly upregulated sST2 secretion, in addition to the upregulation of its messenger RNA (mRNA) expression, while the proximal ST2 promoter, from which the sST2 transcript originates, was upregulated by insulin, and in a synergistic manner by DHT and insulin combination treatment. On the other hand, sIL1RAP was slightly downregulated by insulin and IL-33 mRNA expression was not affected by any of the hormones, while ST2L mRNA expression and transcription from its promoter region (distal ST2 promoter) could not be detected or showed a negligibly low level. We hypothesize that high levels of androgens and insulin might lead to subfertility and pregnancy complications, at least partially, through the sST2-dependent downregulation of uteroplacental IL-33 signaling.

The correlation between maternal serum sST2, IL-33 and NT-proBNP concentrations and occurrence of pre-eclampsia in twin pregnancies: A longitudinal study

The primary objective of this study was to determine the longitudinal profile of serum sST2 (soluble suppression of tumorigenicity 2), IL‐33 (interleukin‐33) and NT‐proBNP (N‐terminal pro‐brain natriuretic peptide) concentrations in twin pregnancies with pre‐eclampsia (PE) and those normotensive twins. The secondary objective was to test whether the change of serum sST2,IL‐33 and NT‐proBNP is related to PE in twin pregnancies. This is a longitudinal nested case–control study and all 156 dichorionic (DC) pregnancies were from a prospective cohort of twin pregnancies who received antenatal care and gave two live births at Peking University Third Hospital between October 2017 and September 2020. Four to five milliliters of peripheral blood of each pregnant woman were collected during the following three intervals: (1) 6–11⁺⁶ weeks; (2) 24–27⁺⁶ weeks; (3) 28–31⁺⁶ weeks. We found that sST2 and NT‐proBNP levels increased as pregnancy progressed in normotensive twin pregnancies and further increased in PE group, while no differences were found in IL‐33 levels throughout pregnancy. Then the correlation of biomarker levels with the occurrence of PE was assessed. Our results indicated that combining maternal serum sST2 and NT‐proBNP levels yielded the highest predictive value on the occurrence of PE significantly higher than the predictive value of any markers alone. Interestingly, the predictive value of second trimester (AUC = 0.876, 95%CI 0.824–0.928, LR−0.338, LR+7.67, p < 0.001)was higher than that of early‐third trimester (AUC = 0.832, 95%CI 0.769–0.896, LR−0.29, LR+3.845, p < 0.001). Serum sST2 and NT‐proBNP concentrations during second and early‐third trimester were associated with the occurrence of PE in twin pregnancies.

Association of ST2 Elevation in the Early Third Trimester with Heart Failure and Pre-Eclampsia in the Peripartum Period

Background: Although high-risk pregnancies are common in clinical practice, there are limited data on the association of soluble suppression of tumorigenicity 2 (ST2) with pregnancy-related complications. The rates of maternal complications, including heart failure (HF) during the peripartum period, were evaluated according to the ST2 level. Methods: A single-center retrospective cohort study included and stratified 259 women with high-risk pregnancies in their early third trimester according to the ST2 levels. The primary endpoint was the occurrence of peripartum HF based on symptoms, N-terminal pro-brain natriuretic peptide, or echocardiography associated with fluid retention. The secondary endpoints consisted of pre-eclampsia, silent pleural effusion, and pericardial effusion during the peripartum period. We performed a logistic model for the association between ST2 and maternal complications. Results: Of the 259 patients (mean age: 36.4 years, mean gestational duration: 31.6 weeks), advanced age ≥35 years and twin gestation were the most prevalent risk factors. Patients with ST2 ≥ 35 ng/mL showed enlarged cardiac chambers. Peripartum HF occurred in 2 (1.6%) out of 121 patients with ST2 < 35 ng/mL and in 47 (34%) out of 138 patients with ST2 ≥ 35 ng/mL. Those with ST2 ≥ 35 ng/mL were more likely to have the secondary endpoints (40.6% vs. 5.8%, p < 0.001). After adjustment, ST2 ≥ 35 ng/mL was associated with a six-fold occurrence of peripartum HF and a four-fold increase in the secondary endpoints. Conclusions: In women with high-risk pregnancies, peripartum HF and pre-eclampsia were not uncommon, and ST2 ≥ 35 ng/mL in the third trimester was independently related to maternal complications.

Relationship between Serum Soluble Suppression of Tumorigenicity (ST) 2 and Global Longitudinal Strain in Pre-eclampsia at Delivery and 1 Year After

BACKGROUND: Pre-eclampsia is characterized by severe inflammatory response and endothelial dysfunction that could lead to myocardial injury and remodeling. Biomarker examination such as soluble Suppression of Tumorigenicity 2 (sST2), which has been used as a marker for myocardial fibrosis and Global Longitudinal Strain (GLS) by echocardiography could be used to predict mortality and detect subclinical myocardial dysfunction. AIM: The purpose of this study was to determine the correlation between serum levels of sST2 and GLS in patients with pre-eclampsia 1 year postpartum. METHODS: This was a cross-sectional study with correlation analysis. GLS examination was done using EchoPAC workstation. Maternal plasma of sST2 was measured using the Presage ST2 Assay. Rank-Spearman correlation analysis was conducted to analyze the correlation between GLS and sST2 at delivery and 1 year postpartum. RESULTS: There were 30 subjects with pre-eclampsia who fulfilled the criteria. Average age was 33 ± 6 years and majority were multipara (76.7%) and early onset pre-eclampsia (76.7%) with sST2 value of 66.1 ± 7.7 ng/mL and GLS of −17 ± 0.4%. One year after delivery, the sST2 value is 22 ± 1.4 ng/mL and an average value GLS is −19.7 ± 0.4%. Analysis showed moderate positive correlation between sST2 and GLS at delivery (r = 0.439, p = 0.015), but there was no correlation between sST2 and GLS 1 year after delivery (r = 0.036, p = 0.961). CONCLUSIONS: This study demonstrates a significant correlation between sST2 and GLS at delivery in patients with pre-eclampsia but not in 1 year after delivery.

Differences in maternal soluble ST2 levels in the third trimester of normal pregnancy versus preeclampsia

BACKGROUND

Preeclampsia is associated with intense inflammatory response in pregnancy, and soluble ST2 (sST2) is pathologically increased in this condition. No data exist regarding maternal sST2 levels in normal pregnancy versus preeclampsia in areas of southeast Asia with an ethnic Malay predominance.

MATERIALS AND METHODS

Patients were sorted into normal pregnancy or preeclampsia. Patients with a history of allergic, inflammatory, or malignant disease were excluded. One sample was taken per patient; all samples were taken during the third trimester of pregnancy. Thirty samples from each group were enrolled in the study, totaling 60 samples. Soluble ST2 levels in maternal plasma were measured using the Presage® ST2 Assay according to manufacturer instructions, and data was analyzed using SPSS 23.

RESULTS

Patients in the preeclampsia group were significantly older than those in the normal pregnancy group (p = 0.01). Most patients with preeclampsia presented as early-onset (n = 23). Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly higher (p < 0.001) in the preeclampsia group. Mean sST2 level in the preeclampsia group (85.89 ng/ml) was significantly higher than the normal pregnancy group mean (38.3 ng/ml) during the third trimester (p < 0.001). This study also found a correlation between sST2 and preeclampsia (p < 0.001, r = 0.480), SBP (p < 0.001, r = 0.407), and DBP (p = 0.007, r = 0.342), while preeclampsia was found to be the best explanatory variable of sST2 levels (r = 0.468, p < 0.001). sST2 level> 63.66 ng/ml has sensitivity 50% and specificity 93.3%, with AUC of 0.78 [95% CI 0.66 - 0.90], p < 0.001. The sST2 > 63.66 ng/ml has an OR of 14.0 [95% CI 2.82 - 69.6], p < 0.001 for preeclampsia. The dose-response relationship between sST2 level and preeclampsia was linear.

CONCLUSION

Soluble ST2 levels were increased in both normal pregnancy and preeclampsia but were significantly higher in patients with preeclampsia. Preeclampsia was also found to be the best explanatory variable for the increase of sST2 levels in ethnic Malay predominance.

Maternal circulating concentrations of soluble Fas and Elabela in early- and late-onset preeclampsia

OBJECTIVE

The Fas/Fas ligand (FASL) system and Elabela-apelin receptor signaling pathways are implicated in the pathophysiology of preeclampsia. The aim of the current study was to investigate whether a model combining the measurement of sFas and Elabela in the maternal circulation may serve as a clinical biomarker for early- and/or late-onset preeclampsia more effectively than measures of each biomarker individually.

METHODS

Blood samples were collected from 214 women in the following groups: (1) normal pregnancy sampled <34 weeks of gestation (n = 56); (2) patients who developed early-onset preeclampsia (n = 54); (3) normal pregnancy sampled ≥34 weeks of gestation (n = 52); (4) patients who developed late-onset preeclampsia (n = 52). Maternal circulating soluble Fas and Elabela concentrations were determined using sensitive and validated immunoassays. Two sample t-tests, multivariate logistic regression, and receiver operating characteristic curves were used for analyses.

RESULTS

(1) Women with early-onset preeclampsia, and those with late-onset preeclampsia with placental lesions of maternal vascular malperfusion, had increased concentrations of sFas compared to their gestational age-matched normal controls; (2) women with late-onset preeclampsia, but not those with early-onset preeclampsia, had increased concentrations of Elabela compared to their gestational age-matched counterparts; and (3) an increase in both Elabela and sFas concentrations was more strongly associated with late-onset preeclampsia than early-onset preeclampsia relative to models including either of the markers alone.

CONCLUSIONS

A combined model of maternal sFas and Elabela concentrations provides a stronger association with late-onset preeclampsia than either protein alone. This finding demonstrates the possibility to improve the classification of late-onset preeclampsia by combining the results of both molecular biomarkers.

Integrated trajectories of the maternal metabolome, proteome, and immunome predict labor onset

Estimating the time of delivery is of high clinical importance because pre- and postterm deviations are associated with complications for the mother and her offspring. However, current estimations are inaccurate. As pregnancy progresses toward labor, major transitions occur in fetomaternal immune, metabolic, and endocrine systems that culminate in birth. The comprehensive characterization of maternal biology that precedes labor is key to understanding these physiological transitions and identifying predictive biomarkers of delivery. Here, a longitudinal study was conducted in 63 women who went into labor spontaneously. More than 7000 plasma analytes and peripheral immune cell responses were analyzed using untargeted mass spectrometry, aptamer-based proteomic technology, and single-cell mass cytometry in serial blood samples collected during the last 100 days of pregnancy. The high-dimensional dataset was integrated into a multiomic model that predicted the time to spontaneous labor [R = 0.85, 95% confidence interval (CI) [0.79 to 0.89], P = 1.2 × 10^-40, N = 53, training set; R = 0.81, 95% CI [0.61 to 0.91], P = 3.9 × 10^-7, N = 10, independent test set]. Coordinated alterations in maternal metabolome, proteome, and immunome marked a molecular shift from pregnancy maintenance to prelabor biology 2 to 4 weeks before delivery. A surge in steroid hormone metabolites and interleukin-1 receptor type 4 that preceded labor coincided with a switch from immune activation to regulation of inflammatory responses. Our study lays the groundwork for developing blood-based methods for predicting the day of labor, anchored in mechanisms shared in preterm and term pregnancies.

Protective role of IL33 signaling in negative pregnancy outcomes associated with lipopolysaccharide exposure

Interleukin 33 (IL33) signaling has been implicated in the establishment and maintenance of pregnancy and in pregnancy disorders. The goal of this project was to evaluate the role of IL33 signaling in rat pregnancy. The rat possesses hemochorial placentation with deep intrauterine trophoblast invasion; features also characteristic of human placentation. We generated and characterized a germline mutant rat model for IL33 using CRISPR/Cas9 genome editing. IL33 deficient rats exhibited deficits in lung responses to an inflammatory stimulus (Sephadex G-200) and to estrogen-induced uterine eosinophilia. Female rats deficient in IL33 were fertile and exhibited pregnancy outcomes (gestation length and litter size) similar to wild-type rats. Placental weight was adversely affected by the disruption of IL33 signaling. A difference in pregnancy-dependent adaptations to lipopolysaccharide (LPS) exposure was observed between wild-type and IL33 deficient pregnancies. Pregnancy in wild-type rats treated with LPS did not differ significantly from pregnancy in vehicle-treated wild-type rats. In contrast, LPS treatment decreased fetal survival rate, fetal and placental weights, and increased fetal growth restriction in IL33 deficient rats. In summary, a new rat model for investigating IL33 signaling has been established. IL33 signaling participates in the regulation of placental development and protection against LPS-induced fetal and placental growth restriction.

Cardiac Biomarkers in hypertensive disorders of pregnancy

In recent years, biomarkers have taken a central place in the assessment of cardiovascular diseases – from prediction to management and prognosis. On the other hand, enough evidence exists to assume that hypertensive disorders of pregnancy share a certain connection with cardiovascular diseases – from common risk factors and underlying mechanisms to the presence of a higher risk for women for the development of a great number of cardiovascular diseases, such as arterial hypertension, coronary atherosclerosis, stroke, peripheral artery disease, venous thromboembolism, and even a higher cardiovascular mortality. The key to a better understanding of the unfavorable cardiovascular profile of women with a hypertensive disorder of pregnancy may lie in their assessment with biomarkers, typically used in the field of cardiology. In this review, we have included studies investigating the use of cardiovascular biomarkers during or after a hypertensive pregnancy, namely, natriuretic peptides, high-sensitivity cardiac troponins, growth/differentiation factor 15 (GDF15), soluble suppression of tumorigenicity-2 (sST2), and galectin-3.

Maternal and fetal Leptin and interleukin 33 concentrations in pregnancy complicated by obesity and preeclampsia

Objectives: To evaluate maternal and fetal Leptin and IL33 concentrations in pregnancy complicated by obesity and preeclampsia.Study design: A case-control study including 35 subjects with obesity (18 normotensive and 17 preeclamptic) and 47 normal weight controls (42 normotensive and 5 preeclamptic).Main outcome measures: Leptin and IL33 concentrations in maternal serum during pregnancy and in cord blood; uterine artery and umbilical artery Doppler velocimetry.Results: Subjects with obesity who developed preeclampsia had higher first trimester maternal (41.5, interquartile range (IQR) = 15.7-65.1 ng/ml) Leptin concentrations compared to either normal weight with (25, IQR = 20.4-25.8 ng/ml) and without hypertension (14.26, IQR = 8.2-22.8) (p < .05) or normotensive subjects with obesity (30.3, IQR = 10.4-38.4) (p < .05). Subjects with obesity who developed preeclampsia (2.4, IQR = 1.7-3.2 pg/ml) or not (1.4, IQR = 0.8-2 pg/ml) had lower first trimester maternal IL33 levels when compared to controls without hypertension (4.8, IQR = 2.9-5.9 pg/ml) (p < .001). Cord blood Leptin and IL33 concentrations were significantly correlated to third trimester maternal concentrations (Spearman rho = 0.51, p < .001 and Spearman rho = 0.68, p < .001, respectively). Uterine artery pulsatility index (PI) were significantly and directly correlated with maternal Leptin levels (p < .002) and inversely and statistically correlated with maternal IL33 concentrations (p < .001).Conclusions: Compared to lean controls, pregnant subjects with obesity had higher serum Leptin and lower IL33 concentrations at first trimester and during pregnancy. This difference persisted also for those who later developed preeclampsia. The relationship between maternal serum levels of Leptin and IL33 with uterine artery Doppler pulsatility index strongly suggests a role of these two markers in early placentation.

Effect of magnesium sulfate combined with labetalol on serum sFlt-1/PlGF ratio in patients with early-onset severe pre-eclampsia

The aim of the present study was to investigate the therapeutic effect of magnesium sulfate combined with labetalol on the early-onset severe pre-eclampsia (ES-PE) and explore the role of soluble fms-like tyrosine kinase-1 (sFlT-1), placental growth factor (PlGF), and sFlt-1/PlGF ratio in the treatment. A total of 164 ES-PE patients admitted to the Maternity and Child Health Care Hospital of Hubei (Wuhan, China) were assigned to this observational study. Among them, 83 patients were enrolled in group A and treated with magnesium sulfate combined with labetalol hydrochloride, and 81 patients were enrolled in group B and treated with magnesium sulfate. The therapeutic effect, adverse reactions and pregnancy outcomes in the two groups were analyzed. Serum sFlt-1 and PlGF concentrations, before and after treatment, were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of pre-treatment serum sFlt-1/PlGF ratio for the clinical outcome. The effective rate was significantly higher in group A than that in group B. Group A presented superior pregnancy outcomes over group B. The serum sFlt-1 concentration and sFlt-1/PlGF ratio after treatment were significantly lower than those before treatment in groups A and B, whereas PlGF concentration was significantly higher after treatment in both groups. After treatment, group A had markedly lower serum sFlt-1 concentration and sFlt-1/PlGF ratio than group B, and markedly higher PlGF concentration than group B. The area under curve (AUC) of serum sFlt-1/PlGF ratio before treatment for the prediction of the clinical efficacy was 0.737. In conclusion, magnesium sulfate combined with labetalol could be effectively used for the treatment of ES-PE. The results of ELISA revealed that the balance of sFlT-1 and PlGF was improved after treatment and the sFlT-1/PlGF ratio was decreased. The assessment of sFlt-1/PlGF ratio before treatment was shown to have a certain predictive value for the efficacy of ES-PE treatment.

Multiplex Analysis of Circulating Maternal Cardiovascular Biomarkers Comparing Preeclampsia Subtypes

Preeclampsia, a hypertensive pregnancy disorder, links to increased long-term maternal cardiovascular disease (CVD). The risk is further increased with early-onset preeclampsia (EPE) and delivery of a growth-restricted child. We hypothesized that circulating biomarkers associated with CVD risk differed between preeclampsia subtypes and controls. We compared EPE; n=37, delivery <week 34, late-onset preeclampsia (LPE); n=29, delivery ≥week 34, and normotensive controls (n=49) using Olink Proseek multiplex CVD I assay (targeting 92 biomarkers). We stratified analysis to uteroplacental spiral artery acute atherosis presence in preeclampsia patients, sharing morphological similarities with atherosclerosis. We found 47 CVD-related biomarkers differing between the groups, 42 markers between normotensive controls and EPE, 28 markers between normotensive controls and LPE, and 9 markers between EPE and LPE. Among these 9 markers, ST2 (ST2 protein), MMP (matrix metalloproteinase) 1, MMP3, and fractalkine (CX3CL1) were uniquely dysregulated in EPE. Principal component (PC) analysis of the differing markers identified 4 clusters (named PC1-PC4) that largely separated the preeclampsia and control groups as well as pregnancies with low and high circulating PlGF (placental growth factor). The combination of the single markers PlGF, ST2, MMP1, MMP3, and CX3CL1 had a high discriminatory property to differentiate between EPE and LPE. Preeclampsia with acute atherosis or with fetal growth restriction could be differentiated by Olink biomarkers as compared with preeclampsia without these features. We identified specific CVD-related biomarkers in pregnancy depending on preeclampsia subtypes and uteroplacental acute atherosis. Assessment of these pregnancy measured biomarkers' relation to long-term cardiovascular dysfunction and hard end points is warranted.

Expression of IL-33 Receptor Is Significantly Up-Regulated in B Cells During Pregnancy and in the Acute Phase of Preterm Birth in Mice

Interleukin-33 (IL-33) is a mucosal alarmin belonging to the IL-1 cytokine family and is now recognized to have a key role in innate and adaptive immunity, contributing to tissue homeostasis and response to environmental stresses. In addition, IL-33 has also been shown to work as a positive regulator that initiates and maintains a Th2 immune response. In the context of pregnancy, it has been recently demonstrated that upon certain stress conditions, such as an infection induced inflammation, IL-33 is released from the uterine mucosa and triggers decidual B cells to produce anti-inflammatory molecules, which in turn restore immune homeostasis and prevents the development of preterm birth. In this study we therefore performed a detailed characterization of IL-33 receptor (Il1rl1 or ST2) expression in B cells during normal pregnancy, as well as in a mouse model of preterm birth. We observed that splenic B cells significantly up-regulate the expression of Il1rl1 during pregnancy and identified the B1 B cell population as the main ST2-expressing B cell subset. A further kinetic analysis showed that percentages of ST2-expressing B1 B cells are significantly augmented on days 12 and 14 of pregnancy, both in the spleen and peritoneal cavity of pregnant mice, and then drop toward the end of pregnancy to the levels observed in non-pregnant animals. Furthermore, using a mouse model of LPS-induced preterm birth, we demonstrated that not only are the percentages of ST2-expressing B1 B cells significantly enlarged in the spleen during the acute phase of preterm birth, but decidual B cells also significantly up-regulate ST2 expression as compared to term-pregnant mice. Overall, our results suggest a functional role of ST2 expression in B cells during pregnancy and reinforce the importance of the IL-33/ST2 axis in B cells as a critical mechanism to control inflammation-induced preterm birth.

Doppler ultrasound and photoplethysmographic assessment for identifying pregnancy-induced hypertension

The current study investigated whether placentation and systemic inflammation are associated with pregnancy-induced hypertension (PIH) or pre-eclampsia (PE), and evaluated some measurable indexes for assessment of maternal factors contributing to high-risk pregnancy. Photoplethysmographic reflection index (PPG RI), uterine artery (UtA) pulsatile index (PI) and reflection index (RI), as well as maternal serum placental growth factor (PlGF) and soluble endoglin (sEng) were measured in pregnant women with singleton pregnancy at the gestational age of 22 to 23 weeks. Study subjects were women with normal pregnancy (NP, n=24), PIH (n=14) and PE (n=16). It was found that individuals in the PIH group exhibited higher UtA RI and UtA PI values, as well as PPG RI values compared with individuals in the NP group. Individuals in the PE group had the highest UtA RI, UtA PI and PPG RI values among these 3 groups. UtA and PPG results were significantly different in PIH and PE groups compared with the NP group. Significant differences were found in both PlGF and sEng levels between PIH and PE groups. A strong inverse across-subject correlation was found between PlGF and sEng levels. A weak inverse correlation was found between PlGF and UtA RI, and PlGF and UtA PI. A moderate inverse correlation was found between PlGF and PPG RI. A moderate positive correlation was found between either sEng and UtA RI or sEng and UtA PI. A very strong positive correlation was found between sEng and PPG RI. Taken together, the current results indicated that maternal effects related to cardiovascular adaptation to placentation and systemic inflammation exhibited significant differences between NP and PIH or PE groups. Therefore, assessment of UtA and PPG could be used for identifying high-risk pregnancy.

The prediction of early preeclampsia: Results from a longitudinal proteomics study

OBJECTIVES

To identify maternal plasma protein markers for early preeclampsia (delivery <34 weeks of gestation) and to determine whether the prediction performance is affected by disease severity and presence of placental lesions consistent with maternal vascular malperfusion (MVM) among cases.

STUDY DESIGN

This longitudinal case-control study included 90 patients with a normal pregnancy and 33 patients with early preeclampsia. Two to six maternal plasma samples were collected throughout gestation from each woman. The abundance of 1,125 proteins was measured using high-affinity aptamer-based proteomic assays, and data were modeled using linear mixed-effects models. After data transformation into multiples of the mean values for gestational age, parsimonious linear discriminant analysis risk models were fit for each gestational-age interval (8-16, 16.1-22, 22.1-28, 28.1-32 weeks). Proteomic profiles of early preeclampsia cases were also compared to those of a combined set of controls and late preeclampsia cases (n = 76) reported previously. Prediction performance was estimated via bootstrap.

RESULTS

We found that 1) multi-protein models at 16.1-22 weeks of gestation predicted early preeclampsia with a sensitivity of 71% at a false-positive rate (FPR) of 10%. High abundance of matrix metalloproteinase-7 and glycoprotein IIbIIIa complex were the most reliable predictors at this gestational age; 2) at 22.1-28 weeks of gestation, lower abundance of placental growth factor (PlGF) and vascular endothelial growth factor A, isoform 121 (VEGF-121), as well as elevated sialic acid binding immunoglobulin-like lectin 6 (siglec-6) and activin-A, were the best predictors of the subsequent development of early preeclampsia (81% sensitivity, FPR = 10%); 3) at 28.1-32 weeks of gestation, the sensitivity of multi-protein models was 85% (FPR = 10%) with the best predictors being activated leukocyte cell adhesion molecule, siglec-6, and VEGF-121; 4) the increase in siglec-6, activin-A, and VEGF-121 at 22.1-28 weeks of gestation differentiated women who subsequently developed early preeclampsia from those who had a normal pregnancy or developed late preeclampsia (sensitivity 77%, FPR = 10%); 5) the sensitivity of risk models was higher for early preeclampsia with placental MVM lesions than for the entire early preeclampsia group (90% versus 71% at 16.1-22 weeks; 87% versus 81% at 22.1-28 weeks; and 90% versus 85% at 28.1-32 weeks, all FPR = 10%); and 6) the sensitivity of prediction models was higher for severe early preeclampsia than for the entire early preeclampsia group (84% versus 71% at 16.1-22 weeks).

CONCLUSION

We have presented herein a catalogue of proteome changes in maternal plasma proteome that precede the diagnosis of preeclampsia and can distinguish among early and late phenotypes. The sensitivity of maternal plasma protein models for early preeclampsia is higher in women with underlying vascular placental disease and in those with a severe phenotype.

Placental Ageing in Adverse Pregnancy Outcomes: Telomere Shortening, Cell Senescence, and Mitochondrial Dysfunction

Preeclampsia is a multisystemic pregnancy disorder and a major cause of maternal and neonatal morbidity and mortality worldwide. The exact pathophysiology of preeclampsia remains unclear; however, it is speculated that the various pathologies can be attributed to impaired vascular remodelling and elevated oxidative stress within the placenta. Oxidative stress plays a key role in cell ageing, and the persistent presence of elevated oxidative stress precipitates cellular senescence and mitochondrial dysfunction, resulting in premature ageing of the placenta. Premature ageing of the placenta is associated with placental insufficiency, which reduces the functional capacity of this critical organ and leads to abnormal pregnancy outcomes. The changes brought about by oxidative insults are irreversible and often lead to deleterious modifications in macromolecules such as lipids and proteins, DNA mutations, and alteration of mitochondrial functioning and dynamics. In this review, we have summarized the current knowledge of placental ageing in the aetiology of adverse pregnancy outcomes and discussed the hallmarks of ageing which could be potential markers for preeclampsia and fetal growth restriction.

Elevated soluble-St2 concentrations in preeclampsia correlate with echocardiographic parameters of diastolic dysfunction and return to normal values one year after delivery

Objectives: To compare soluble-ST2 (sST2) concentrations in patients with severe features of preeclampsia and healthy pregnant controls before as well as 1 year after delivery. Another objective was to assess potential correlation between sST2 concentrations and myocardial function.Methods: Patients with singleton pregnancy complicated by severe features of preeclampsia and healthy controls were included in a prospective observational study. Plasma sST2 concentrations were measured within 24 h before delivery and 1 year after delivery. Standard two-dimensional and Doppler echocardiography was performed at the time of first sST2 measurement before delivery. Mann-Whitney U test was used to compare sST2 values in preeclamptic patients versus controls. Kendall's tau was used to assess correlation between sST2 values and echocardiographic measures of left ventricular systolic and diastolic function (p < .05 significant).Results: We included 24 patients with severe preeclampsia and 29 controls. One year after delivery, sST2 concentrations were available for 24 (45%) participants (13 in preeclampsia group and 11 controls). Concentrations of sST2 were markedly elevated in patients with severe preeclampsia compared to healthy controls before delivery (p = .04), but not 1 year after delivery (p = .80). There was no significant correlation between sST2 and parameters of systolic function. In preeclamptic patients, we found a significant inverse correlation between sST2 and markers of diastolic function: peak early mitral inflow velocity E (Kendall's tau = -0.40; p = .02), peak early diastolic myocardial velocities at septal and lateral mitral annulus (e') (Kendall's tau = -0.354, p = .04) and ratio between e' and peak systolic myocardial velocities at the septal and lateral mitral annulus (e'/s') (Kendall's tau = -0.362, p = .04).Conclusions: Preeclampsia with severe features is associated with increased maternal plasma concentrations of sST2, which return to normal values in the first year after delivery. Higher sST2 levels in preeclamptic patients correlate with impaired parameters of left ventricular diastolic function.

ELABELA plasma concentrations are increased in women with late-onset preeclampsia

Objective: ELABELA is a newly discovered peptide hormone that appears to be implicated in the mechanisms leading to preeclampsia, independently of angiogenic factors. The aim of the current study was to investigate whether women with early- or late-onset preeclampsia have altered ELABELA plasma concentrations compared to gestational-age-matched normal pregnant women.Methods: This retrospective cross-sectional study focused on the maternal plasma samples collected from 232 women with a singleton pregnancy who were allocated into the following groups: (1) early-onset preeclampsia (<34 weeks of gestation, N = 56); (2) late-onset preeclampsia (≥34 weeks of gestation, N = 57); and (3) gestational-age-matched controls with a normal pregnancy [(<34 weeks of gestation, N = 59); (≥34 weeks of gestation, N = 60)]. ELABELA plasma concentrations were determined using a validated enzyme immunoassay.Results: (1) ELABELA plasma concentrations are higher in patients with late-onset preeclampsia compared with those from gestational-age-matched controls with a normal pregnancy [median: 7.99 ng/mL (IQR, 5.3-13.95 ng/mL) versus median: 4.17 ng/mL (IQR, 3-11.19 ng/mL), p =.001]; (2) ELABELA plasma concentrations in patients with early-onset preeclampsia do not differ from those of normal pregnant women [median: 6.09 ng/mL (IQR, 2.8-10.66 ng/mL) versus median: 4.02 ng/mL (IQR, 3.26-7.49), p = .32]; and (3) ELABELA plasma concentrations are higher in patients with late-onset preeclampsia compared to those with early-onset preeclampsia [median: 7.99 ng/mL (IQR, 5.3-13.95 ng/mL) versus median: 6.09 ng/mL (IQR, 2.8-10.66 ng/mL), p = .01].Conclusion: ELABELA plasma concentrations are higher in patients with late-onset preeclampsia than in those with a normal pregnancy. However, women with early-onset preeclampsia have similar ELABELA plasma concentrations to those with a normal pregnancy. These findings provide insight into the ELABELA axis during the human syndrome of preeclampsia. In addition, these data support the concept that different pathophysiologic mechanisms are implicated in early- and late-onset preeclampsia.