Accurate Prediction of Total PlGF (Placental Growth Factor) From Free PlGF and sFlt-1 (Soluble Fms-Like Tyrosine Kinase-1): Evidence for Markedly Elevated PlGF Levels in Women With Acute Fatty Liver of Pregnancy

Maternal serum PlGF associates with 3D power doppler ultrasound markers of utero-placental vascular development in the first trimester: the rotterdam periconception cohort

OBJECTIVE (S)

Circulating angiogenic factors are used for prediction of placenta-related complications, but their associations with first-trimester placental development is unknown. This study investigates associations between maternal angiogenic factors and utero-placental vascular volume (uPVV) and utero-placental vascular skeleton (uPVS) as novel imaging markers of volumetric and morphologic (branching) development of the first-trimester utero-placental vasculature.

METHODS

In 185 ongoing pregnancies from the VIRTUAL Placenta study, a subcohort of the ongoing prospective Rotterdam Periconception cohort, three-dimensional power Doppler ultrasounds of the placenta were obtained at 7-9-11 weeks gestational age (GA). The uPVV was measured as a parameter of volumetric development and reported the vascular quantity in cm3. The uPVS was generated as a parameter of morphologic (branching) development and reported the number of end-, bifurcation- crossing- or vessel points and total vascular length. At 11 weeks GA, maternal serum biomarkers suggested to reflect placental (vascular) development were assessed: placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng). sFlt-1/PlGF and sEng/PlGF ratios were calculated. Multivariable linear regression with adjustments was used to estimate associations between serum biomarkers and uPVV and uPVS trajectories.

RESULTS

Serum PlGF was positively associated with uPVV and uPVS development (uPVV: β = 0.39, 95% CI = 0.15;0.64; bifurcation points: β = 4.64, 95% CI = 0.04;9.25; crossing points: β = 4.01, 95% CI = 0.65;7.37; total vascular length: β = 13.33, 95% CI = 3.09;23.58, all p-values < 0.05). sEng/PlGF ratio was negatively associated with uPVV and uPVS development. We observed no associations between sFlt-1, sEng or sFlt-1/PlGF ratio and uPVV and uPVS development.

CONCLUSION(S)

Higher first-trimester maternal serum PlGF concentration is associated with increased first-trimester utero-placental vascular development as reflected by uPVV and uPVS. Clinical trial registration number Dutch Trial Register NTR6854.

The value of angiogenetic biomarkers in the detection of early onset fetal growth restriction

OBJECTIVE

The identification of fetal growth restriction (FGR) due to uteroplacental insufficiency is important to improve perinatal outcomes. To distinguish FGR from small for gestational age (SGA), FGR consensus definition is currently based on biometry and/or additional biophysical parameters. This study aims to verify if this definition might be modified by including circulating angiogenic factors.

STUDY DESIGN

This historical cohort study included singleton pregnancies with SGA fetuses after 20 weeks. All patients underwent detailed ultrasound and measurements of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) at first assessment. ISUOG criteria for FGR were applied. Total PlGF was calculated using free PlGF, sFlt-1 and a receptor pharmacology model, and multiple of the median (MoM) values for sFlt-1, free PlGF, total PlGF and sFlt-1/PlGF ratio were calculated to adjust for gestational age.

RESULTS

72 pregnancies with SGA were first evaluated at median (IQR) of 28+5 (26+2 -31+3) weeks' gestation, and 51 fetuses (70.8 %) satisfied the FGR consensus definition. Pregnancies with FGR showed significantly lower levels of free and total PlGF MoM (0.12, 95 % IQR: 0.07-0.36 vs 0.32, 95 % IQR: 0.20-0.53, p = 0.008) and 0.26, 95 % CI: 0.16-0.55 vs 0.43, 95 % IQR: 0.23-0.53, p = 0.028) respectively; and higher sFlt-1 MoM (4.62, 95 % IQR: 1.80-7.30 vs 1.74, 95 % IQR:1.11-3.61, p = 0.014) than pregnancies not classified as FGR. Free and total PlGF MoM correlated significantly with gestational age at delivery (r = 0.776, p < 0.001 and r = 0.707, p < 0.001, respectively). sFlt-1 MoM and sFlt-1/PlGF ratio MoM also correlated with gestational age at delivery (r = -0.681, p < 0.001 and r = -0.823, p < 0.001). Six cases identified as FGR at first ultrasound were not confirmed at birth showing significantly higher levels of free PlGF MoM (0.77, 95 % IQR: 0.27-3.07 vs 0.17, 95 % IQR: 0.08-0.43, p = 0.022).

CONCLUSION

These findings show that total as well as free PlGF levels are lower in pregnancies affected with placental growth restriction. Angiogenic biomarkers might improve the differentiation between placental growth restriction and constitutional smallness. Further studies are needed to determine how to integrate them into the current definitions of FGR.

Tumor Necrosis Factor Inhibitor Use Increases Birthweight in Pregnant Women With Rheumatoid Arthritis Independently of the Soluble Fms-Like Tyrosine Kinase-1/Placental Growth Factor Ratio

BACKGROUND

To study whether the use of TNF (tumor necrosis factor) inhibitors (TNFi) by pregnant women with rheumatoid arthritis affects sFlt-1 (soluble Fms-like tyrosine kinase-1), PlGF (placental growth factor), or their impact on birthweight.

METHODS AND RESULTS

sFlt-1 and PlGF were measured in all trimesters of pregnancy in the Preconception Counseling in Active Rheumatoid Arthritis study and were compared according to the use of TNFi. The association of sFlt-1 and PlGF with birthweight in relation to TNFi was determined. The study included 158 women, of whom 52.5% used TNFi during pregnancy. Both sFlt-1 and PlGF increased during pregnancy, whereas their ratio declined. Taking into consideration the trimester-related variation in levels of sFlt-1 and PlGF, after correction for relevant confounders, the sFlt-1/PlGF ratio was not significantly different between patients who did or did not use TNFi (sFlt-1/PlGF ratio in the second trimester compared with the first trimester: estimated change 8.17 [95% CI, 2.54-26.29], P=0.79; sFlt-1/PlGF ratio in the third trimester compared with the first trimester: estimated change 6.25 [95% CI, 1.73-22.50], P=0.25). In women who did not use TNFi, birthweight was significantly lower (3180 versus 3302 g; P=0.03), and sFlt-1 displayed a negative correlation with birthweight (r=-0.462, P<0.001) and birthweight percentile (r=-0.332, P=0.008). In TNFi users, these correlations were absent.

CONCLUSIONS

TNF inhibitor use increases birthweight in pregnant women with rheumatoid arthritis independently of the sFlt-1/PlGF ratio.

REGISTRATION

http://clinicaltrials.gov. Unique identifier: NCT01345071.

Statins Prevent the Deleterious Consequences of Placental Chemerin Upregulation in Preeclampsia

BACKGROUND

Chemerin, an inflammatory adipokine, is upregulated in preeclampsia, and its placental overexpression results in preeclampsia-like symptoms in mice. Statins may lower chemerin.

METHODS

Chemerin was determined in a prospective cohort study in women suspected of preeclampsia and evaluated as a predictor versus the sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio. Chemerin release was studied in perfused placentas and placental explants with or without the statins pravastatin and fluvastatin. We also addressed statin placental passage and the effects of chemerin in chorionic plate arteries.

RESULTS

Serum chemerin was elevated in women with preeclampsia, and its addition to a predictive model yielded significant effects on top of the sFlt-1/PlGF ratio to predict preeclampsia and its fetal complications. Perfused placentas and explants of preeclamptic women released more chemerin and sFlt-1 and less PlGF than those of healthy pregnant women. Statins reversed this. Both statins entered the fetal compartment, and the fetal/maternal concentration ratio of pravastatin was twice that of fluvastatin. Chemerin constricted plate arteries, and this was blocked by a chemerin receptor antagonist and pravastatin. Chemerin did not potentiate endothelin-1 in chorionic plate arteries. In explants, statins upregulated low-density lipoprotein receptor expression, which relies on the same transcription factor as chemerin, and NO release.

CONCLUSIONS

Chemerin is a biomarker for preeclampsia, and statins both prevent its placental upregulation and effects, in an NO and low-density lipoprotein receptor-dependent manner. Combined with their capacity to improve the sFlt-1/PlGF ratio, this offers an attractive mechanism by which statins may prevent or treat preeclampsia.

Reduced myocardial work in asymptomatic heavy alcohol use and its correlation with epicardial adipose tissue volume and serum biomarkers

BACKGROUND

It is unclear whether long-term heavy alcohol use leads to early cardiac function decline.

HYPOTHESIS

Long-term heavy alcohol use developed reduced cardiac function in subclinical status by analyzing myocardial work (MW). Epicardial adipose tissue (EAT) volume and serum biomarkers contribute to identify potential factors sensitive in predicting early cardiac function decline.

METHODS

We enrolled 31 asymptomatic participants with heavy alcohol use and 33 age and sex-matching nondrinking individuals. Participants underwent echocardiography, MW analysis, EAT volume measurement, serum biochemical examinations, and body composition assessment. We used multivariate linear regression to identify correlation between MW and total cholesterol (TC), EAT volume, and placental growth factor (PlGF). To determine global work efficiency (GWE) below the normal reference value of 96%, we developed receiver operating curves with area under curve (AUC) to compare different combinations of TC, EAT volume, and PlGF.

RESULTS

All 64 participants were male. GWE was reduced in the alcohol use group compared with the control group (96, interquartile range [IQR] = [95-97.75] vs. 97, IQR = [97-98], p = .004). TC was positively associated with GWE (β = .434, 95% confidence interval [CI] = 0.228 to 1.328, p = .008), whereas EAT volume (β = -.398, 95% CI = -0.000446 to -0.000093, p = .005) and PlGF (β = -.493, 95% CI = -1.010 to -0.230, p = .004) were inversely associated with GWE. The most significant AUC for reduced GWE was TC + EAT volume (0.851, 95% CI = 0.671 to 1, p = .006).

CONCLUSION

Asymptomatic heavy alcohol use has shown early reduced cardiac function which can be associated with altered fat metabolism, suggesting individuals with alcohol use and abnormal fat metabolism need to be alert to heart damage.

Angiogenic imbalance in pre-eclampsia and fetal growth restriction: enhanced soluble fms-like tyrosine kinase-1 binding or diminished production of placental growth factor?

OBJECTIVES

To assess levels of total placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and free PlGF in women with pre-eclampsia (PE) with or without a small-for-gestational-age (SGA) neonate in order to establish whether low free PlGF levels associated with PE and SGA are due to enhanced sFlt-1 binding or decreased PlGF production.

METHODS

This was a secondary analysis of a prospective multicenter cohort study involving 407 pregnancies with suspected or confirmed PE, in which total PlGF levels were calculated from measured sFlt-1 and free PlGF levels. The control group included women who were suspected to have PE at a certain point in pregnancy but did not develop PE. The analysis was stratified according to whether PE was early- or late-onset (gestational age < 34 weeks vs ≥ 34 weeks) and according to the presence of SGA at birth, which was used as a proxy of fetal growth restriction in the absence of Doppler ultrasound and biometric data.

RESULTS

In early-onset PE, both women with and those without SGA had lower free (19 and 45 pg/mL) and total (44 and 100 pg/mL) PlGF levels compared with women without PE (free and total PlGF, 300 and 381 pg/mL, respectively). SGA alone did not affect free and total PlGF in this condition (free and total PlGF, 264 and 352 pg/mL, respectively). Observations in women with late-onset PE were similar, although the changes were more modest. Both SGA (gestational age < 34 weeks) and PE were individually associated with increased sFlt-1 and, in women with both PE and SGA, the upregulation of sFlt-1 occurred in a synergistic manner, thus resulting in the highest sFlt-1/free PlGF ratio in this group. This occurred in both early- and late-onset PE.

CONCLUSIONS

Particularly in pregnancies with early-onset PE and SGA, diminished PlGF production is an important cause of low free PlGF levels. Under such conditions, sFlt-1 lowering is unlikely to restore the angiogenic balance. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Preeclampsia and eclampsia: the conceptual evolution of a syndrome

Preeclampsia, one of the most enigmatic complications of pregnancy, is considered a pregnancy-specific disorder caused by the placenta and cured only by delivery. This article traces the condition from its origins-once thought to be a disease of the central nervous system, recognized by the occurrence of seizures (ie, eclampsia)-to the present time when preeclampsia is conceptualized primarily as a vascular disorder. We review the epidemiologic data that led to the recommendation to use diastolic hypertension and proteinuria as diagnostic criteria, as their combined presence was associated with an increased risk of fetal death and the birth of small-for-gestational-age neonates. However, preeclampsia is a multisystemic disorder with protean manifestations, and the condition can be present even in the absence of hypertension and proteinuria. Toxins gaining access to the maternal circulation have been proposed to mediate the clinical manifestations-hence, the term "toxemia of pregnancy," which was used for several decades. The search for putative toxins has challenged investigators for more than a century, and a growing body of evidence suggests that products of an ischemic or a stressed placenta are responsible for the vascular changes that characterize this syndrome. The discovery that the placenta can produce antiangiogenic factors, which regulate endothelial cell function and induce intravascular inflammation, has been a major step forward in the understanding of preeclampsia. We view the release of antiangiogenic factors by the placenta as an adaptive response to improve uterine perfusion by modulating endothelial function and maternal cardiovascular performance. However, this homeostatic response can become maladaptive and lead to damage of target organs during pregnancy or the postpartum period. Early-onset preeclampsia has many features in common with atherosclerosis, whereas late-onset preeclampsia seems to result from a mismatch of fetal demands and maternal supply, that is, a metabolic crisis. Preeclampsia, as it is understood today, is essentially vascular dysfunction unmasked or caused by pregnancy. A subset of patients diagnosed with preeclampsia are at greater risk of the subsequent development of hypertension, ischemic heart disease, heart failure, vascular dementia, and end-stage renal disease. However, these adverse events may be the result of a preexisting vascular pathologic process; it is not known if the occurrence of preeclampsia increases the baseline risk. Therefore, the understanding, prediction, prevention, and treatment of preeclampsia are healthcare priorities.