sFlt-1 Concentrations Research Articles

P3-08-03: Exercise Increases Soluble Vascular Endothelial Growth Factor Receptor-1 (sFlt-1) in the Circulation of Adult Women.

Abstract Background: Physical inactivity increases the risk of several different cancers, including breast cancer. Soluble fms-like tyrosine kinase-1 (sFlt-1) is an extra-cellular Ig-like domain of the VEGF receptor-1 that is released into the extracellular space and circulation where it inhibits the activities of VEGF. Over-expression of sFlt-1 has been shown to inhibit ovarian tumor growth in gene therapy experiments. The present study tests the hypothesis that exercise can increase sFlt-1 in the circulation of adult women. Material and Methods: 63 African American and Caucasian adult woman volunteers aged 18–44 were enrolled into a prospective exercise study. All the participants walked on a treadmill for 30 minutes at a moderate intensity (40-60% heart rate reserve), and oxygen consumption (VO2) was quantified by utilizing a metabolic cart. Blood samples were collected before and immediately after exercise. The exercise test was conducted between the first and seventh day of the participant's menstrual cycle. The plasma concentrations of sFlt-1, unbound VEGF, and endostatin were measured using ELISA kits from R and D Systems. Results: Plasma levels of sFlt-1 were 67.8±3.7 pg/ml immediately after exercise (30 minutes), significantly higher than basal levels of 54.5±3.3 pg/ml before exercise (P<0.01; n=63). The % increase in sFlt-1 levels before and after exercise in adult women was 54%. There was no significant difference in the % increase of sFlt-1 levels between African American and Caucasian groups (P=0.5334). There was no significant difference in plasma levels of endostatin before (92.4±4.4 ng/ml) and immediately after (93.8±4.4 ng/ml; P=0.8216) exercise. The basal plasma levels of unbound VEGF (21.5±4.3 pg/ml) ware similar to the plasma levels of VEGF (22.5±4.6 pg/ml; P=0.8652) immediately after exercise. Discussion: We previously reported that plasma levels of sFlt-1 significantly increased 30 minutes after exercise in adult men, in which plasma levels of unbound-VEGF significantly decreased and plasma levels of endostatin significantly increased 2 hours after exercise. Until now, there has been no data on whether exercise increases plasma sFlt-1 levels in women. Our study is the first to show that exercise in adult women significantly increases plasma levels of sFlt-1. VEGF pathways have both autocrine and paracrine effects for promoting breast cancer progression. Previous studies have demonstrated that sFlt-1 inhibits the activities of VEGF and suppresses ovarian tumor growth in mice. Exercise-induced plasma levels of sFlt-1 could be an important clinical biomarker to explore the mechanisms of exercise training in reducing breast cancer progression. The sFtl-1 is produced in the microvascular and macrovascular endothelial cells that exist throughout the skeletal muscle tissues. It is therefore plausible that release of sFlt-1 from the skeletal muscles into the circulation might be due to exercise-dependent reductions in oxygen tension in the skeletal muscle. In future studies, we will determine whether sFlt-1 can be released directly from the exercised muscle. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-08-03.

Circulating anti-angiogenic factors during hypertensive pregnancy and increased risk of respiratory distress syndrome in preterm neonates

Objective: To test the hypothesis that high circulating concentrations of maternal anti-angiogenic factors are associated with increased risk of respiratory distress syndrome (RDS). Study Design: This is a nested case-control study of nulliparous women who delivered less than 37 weeks of gestation within the Calcium for Preeclampsia Prevention (CPEP) trial. The study included 116 women with preeclampsia or gestational hypertension and 323 normotensive controls. Soluble fms-like tyrosine kinase 1 (sFlt1), placental growth factor (PlGF) and soluble endoglin (sEng) in maternal serum were measured at 21–32 weeks of gestation. Results: Preterm infants born to hypertensive mothers were more likely to develop RDS (22.5% vs. 20.9%, p = 0.03). After adjustment for gestational age at delivery, the odds ratio for the relationship between hypertension in pregnancy and RDS was 2.18 (95% CI 1.08–4.39). In hypertensive pregnancies women whose infants developed RDS had significantly higher circulating mean sFlt1 levels during midpregnancy (21–32 weeks of gestation) even after adjustment for gestational age at delivery (21,516 pg/mL vs. 7,000 pg/mL, p = 0.01). Conclusions: Preterm preeclampsia and gestational hypertension, characterized by high circulating levels of sFlt1, are associated with a twofold increased risk of RDS in infants delivered before 37 weeks. Among women with these hypertensive pregnancies circulating sFlt1 concentrations during midpregnancy were substantially higher in women whose infants developed RDS.

First trimester serum angiogenic/anti-angiogenic status in twin pregnancies: relationship with assisted reproduction technology

The risk of pre-eclampsia (PE) increases in twin pregnancies, especially when assisted reproduction technologies (ART) are used. The aim of this study was to assess angiogenic/anti-angiogenic factors in maternal serum in the first trimester of twin pregnancies and establish if the mode of conception influences angiogenic status. This prospective study enrolled women with twin (n = 61) and singleton (n = 50) pregnancies. Dichorionic twin pregnancies were divided into two groups according to their mode of conception. Singleton pregnancies were used as the control group. Soluble fms-like tyrosine kinase (sFlt-1), free placental growth factor (PlGF) and soluble endoglin (sEng) concentrations were measured in the first trimester maternal serum. In the first trimester, women with twin pregnancies had higher serum concentrations of the anti-angiogenic factor sFlt-1 than that with singleton pregnancies (3924 ± 250 versus 2426 ± 162 pg/ml, respectively; P < 0.001). Maternal serum PlGF concentrations were lower in singleton pregnancies than those in twin pregnancies (37 ± 3.7 versus 59 ± 5.6, respectively; P < 0.001). Serum concentrations of sFlt-1 were higher in twin pregnancies conceived by ART than those in spontaneous twin pregnancies (4313 ± 389 versus 3522 ± 300 pg/ml, respectively; P < 0.05). No differences between groups were observed for sEng. In the first trimester, twin pregnancies conceived using ART showed a heightened anti-angiogenic status that could explain the increased risk of PE in these cases.

Expression of growth arrest and DNA damage-inducible 45α and p38 mitogen-activated protein kinase in placentas of women complicated with preeclampsia

Objective To evaluate the expression of Gadd45α and p38 MAPK in placentas and the correlations of Gadd45α protein and serum soluble vascular endothelial growth factor receptor-1 (sFlt-1) and soluble endoglin (sEng) in preeclampsia(PE). Methods Fifty-four pregnant women who delivered from September 2009 to March 2010 in the First Affiliated Hospital of Chongqing Medical University were chosen as the subjects. They were classified into mild preeclampsia group (n=20),severe preeclampsia group (n=16) and the control group (normal pregnant women underwent elective cesarean sections at term without labor and perinatal complications, n=18). Western blot and immunohistochemistry were employed to determine the expression and localization of Gadd45α and p-p38 MAPK protein respectively. Gadd45α mRNA level was determined by quantitative real-time PCR. The levels of seum sFlt-1 and sEng were measured by enzyme-linked immunosorbent assay (ELISA). One-way ANOVA and LSD-t test were applied for statistical analysis. Results (1)Immunohistochemistry identified that the positive stained cells were mostly located in trophoblast cells in normotensive placentas, whereas in preeclamptic placentas Gadd45α protein and p-p38 MAPK protein were detected in trophoblast and endothelial cells, as well as a few stromal cells at increased levels.(2)The mRNA levels of Gadd45α was significantly elevated in mild and severe preeclampsia groups compared to the control group (2.10±0.11 and 3.33±0.13 vs 1.01±0.18, P＜0.05), and Gadd45α mRNA level in severe group was significantly higher than in mild group (P＜0.05).(3)The data of Western blot revealed that the Gadd45α protein levels in each group were 0.22±0.11, 0.65±0.15 and 1.34±0.17, respectively, with significant differences between each group(P＜0.05). The p-p38 MAPK protein levels in each group were 0.32±0.08, 0.72±0.12 and 1.45±0.21, respectively, with significant differences between each group (P＜0.05). p38 MAPK protein levels in the total groups showed no difference(P＞0.05).(4)Compared with the control group, sFlt-1 and sEng concentrations in maternal circulation were significantly increasing in mild and severe preeclampsia groups, and concentrations in severe group were significantly higher than those in mild group (P＜0.05).(5) There were positive correlations between Gadd45α protein levels and the concentrations of serum sFlt-1 and sEng in each group( r=0.88 and 0.87, respectively all P＜0.05). Conclusions Upregulation of Gadd45α in preeclampsia placentas may play an important role in the pathogenesis of preeclampsia. It may induce the increased maternal serum levels of sFlt-l and sEng by activating p38 MAPK signaling pathway, leading to deficient cytotrophoblastic invasion and abnormal placental vascular reconstruction during pregnancy. Key words: Pre-eclampsia; Nuclear proteins; Cell cycle proteins; p38 Mitogen-activated protein kinases; Vascular endothelial growth factor receptor-1; Receptors, cell surface; Antigens, CD

Soluble fms-Like Tyrosine Kinase-1 (sFlt-1) and Serum Placental Growth Factor (PlGF) as Biomarkers for Ectopic Pregnancy and Missed Abortion

Diagnosis of early pregnancy failure is hampered by the lack of reliable serological markers. We assessed whether a single serum measurement of placental growth factor (PlGF) and the soluble Flt-1 (sFlt-1) receptor of vascular endothelial growth factor at 6-8 wk gestation could differentiate failed pregnancies, whether ectopic pregnancies (EP) or missed abortions (MA), from healthy intrauterine pregnancies (IUP). We conducted a prospective clinical study at a tertiary university hospital between January 2009 and February 2011. A total of 78 consecutive patients (38 EP, 40 MA) with failed early pregnancy and 50 IUP (control group) participated in the study. Determination of serum PlGF and sFlt-1 has been carried out by ELISA. Gene expression of PlGF and Flt-1 in trophoblasts was performed by RT-PCR. We investigated whether a single, combined serum measurement of the above markers could contribute to the differential diagnosis. PlGF and sFlt-1 concentration was lower in both EP (mean, 14.60 ± 3.42/178.16 ± 76.03 pg/ml) and MA (mean, 16.25 ± 4.73/399.42 ± 337.54 pg/ml) compared to IUP (mean, 21.64 ± 5.68/1390.32 ± 655.37 pg/ml). sFlt-1 (P = 0.033) and sFlt-1/PlGF ratio (P = 0.029) but not PlGF had the ability to discriminate MA from EP. Compared to women with viable IUP, mRNA gene expression levels of PlGF and Flt-1 were considerably lower in women with MA and in women with EP. Combined measurement of sFlt-1 and PlGF levels can differentiate normal from failed pregnancies, whereas sFlt-1 as well as sFlt-1/PlGF ratio can also discriminate EP from MA. PlGF and Flt-1 gene expression in trophoblasts from women with EP and MA appears impaired.

Levels of soluble fms-like tyrosine kinase one in first trimester and outcomes of pregnancy: a systematic review

Angiogenic factors are involved in formation of new blood vessels required for placental development and function; and critical for fetal growth and development. Soluble fms-like tyrosine kinase 1(sFlt-1) is an anti-angiogenic protein that inhibits formation of new blood vessels resulting in potential pregnancy complications. The objective of this study was to undertake a systematic review to assess levels of sFlt-1 in early pregnancy and association with adverse pregnancy outcomes. PubMed and Medline databases and reference lists were searched up to July 2010. Inclusion criteria were pregnant women, blood sample taken during first trimester and assessment/reporting of sFlt-1 concentrations and subsequent pregnancy complications. Twelve relevant studies were identified of 71 to 668 women. No pooling of results was undertaken due to variation in sFlt-1 concentrations (range, 166-6,349 pg/ml amongst controls), samples used (serum, plasma), different summary statistics (mean, median, odds ratio) and outcome definitions applied. Levels of sFlt-1 were generally higher among women who developed preeclampsia (11 studies) or gestational hypertension (two studies), but not significantly different to normotensive women in most studies. There was no consistent pattern in association between sFlt-1 concentrations and fetal growth restriction (4 studies); and levels were non-significantly higher for women with postpartum bleeding (1 study) and significantly lower for stillbirths (1 study).This review found no clear evidence of an association between sFlt-1 levels in first trimester and adverse pregnancy outcomes. However, findings were affected by methodological, biological and testing variations between studies; highlighting the need for consistent testing of new biomarkers and reporting of outcome measures.

Maternal angiogenic profile in pregnancies that remain normotensive

Objective We sought to determine if maternal characteristics are associated with angiogenic profile in the first and second trimester of normotensive pregnancies. Study design Circulating levels of maternal placental like growth factor (PlGF), soluble fms-like tyrosine kinase receptor (sFlt1), and soluble endoglin (sEng) were measured in serum samples collected during the first (median 11.3 weeks) and second trimester (median 17.1 weeks) of 182 normotensive pregnancies. Diastolic blood pressure (DBP), systolic blood pressure (SBP), and mean arterial pressure (MAP) were measured at the same visits when samples were collected to measure angiogenic factors. Linear regression analysis was used to examine associations of the angiogenic measures with maternal characteristics. The association between blood pressure measures and concentrations of angiogenic factors was evaluated using Spearman correlation and linear regression analysis. Results In adjusted analyses, nulliparous women had higher sFlt1 concentrations in both first ( p = 0.06) and second ( p = 0.001) trimester. Higher BMI was associated with greater sFlt1 concentrations in both the first ( p = 0.004) and second trimester ( p = 0.008), but significantly lower sEng concentrations in both trimesters ( p = 0.002 for first trimester and p = 0.0009 for second). Nulliparity and higher BMI also were associated with higher sFlt1/PLGF anti-angiogenic ratios in both first ( p = 0.05 and p = 0.007, respectively) and second trimesters ( p = 0.003 and p = 0.02, respectively). First trimester sFlt1 levels were weakly correlated with first trimester SBP ( r s = 0.18, p = 0.03) and MAP ( r s = 0.16, p = 0.04). Second trimester sEng levels were inversely associated with second trimester MAP ( r s = −0.17, p = 0.05). Including blood pressure measures in the linear regression models did not change the reported associations of angiogenic factors with maternal characteristics. Conclusions These results demonstrate that even early in normotensive pregnancies maternal characteristics are associated with variations in angiogenic profile across this population.

Soluble vascular endothelial growth factor (VEGF) receptor-1 inhibits migration of human monocytic THP-1 cells in response to VEGF

We aimed to investigate the regulation and contribution of vascular endothelial growth factor (VEGF) and sFlt-1(1-3) to human monocytic THP-1 migration. Ad-sFlt-1/FLAG, a recombinant adenovirus carrying the human sFlt-1(1-3) (the first three extracellular domains of FLT-1, the hVEGF receptor-1) gene, was constructed. L929 cells were infected with Ad-sFlt-1/FLAG and the expression of sFlt-1 was detected by immunofluorescent assay and ELISA. Corning(®) Transwell(®) Filter Inserts containing polyethylene terephthalate (PET) membranes with pore sizes of 3μm were used as an experimental model to simulate THP-1 migration. Five VEGF concentrations (0, 0.1, 1, 10 and 100ng/ml), four concentrations of sFlt-1(1-3)/FLAG expression supernatants (0.1, 1, 10 and 100ng/ml), and monocyte chemoattractant protein-1 (MCP-1, 10ng/ml) were used to test the ability of THP-1 cells to migrate through PET membranes. The sFlt-1(1-3) gene was successfully recombined into Ad-sFlt-1/FLAG. sFlt-1(1-3) was expressed in L929 cells transfected with Ad-sFlt-1/FLAG. THP-1 cell migration increased with increasing concentrations of VEGF, while cell migration decreased with increasing concentrations of sFlt1(1-3)/FLAG. sFlt1(1-3)/FLAG had no effect on MCP-1-induced cell migration. This study demonstrated that VEGF is able to elicit a migratory response in THP-1 cells, and that sFlt-1(1-3) is an effective inhibitor of THP-1 migration towards VEGF.

Time-course of sFlt-1 and VEGF-A release in neutropenic patients with sepsis and septic shock: a prospective study

BackgroundSeptic shock is the most feared complication of chemotherapy-induced febrile neutropenia. So far, there are no robust biomarkers that can stratify patients to the risk of sepsis complications. The VEGF-A axis is involved in the control of microvascular permeability and has been involved in the pathogenesis of conditions associated with endothelial barrier disruption such as sepsis. sFlt-1 is a soluble variant of the VEGF-A receptor VEGFR-1 that acts as a decoy receptor down-regulating the effects of VEGF-A. In animal models of sepsis, sFlt-1 was capable to block the barrier-breaking negative effects of VEGF-A and to significantly decrease mortality. In non-neutropenic patients, sFlt-1 has been shown to be a promising biomarker for sepsis severity.MethodsWe prospectively evaluated concentrations of sFlt-1 and VEGF-A at different time-points during febrile neutropenia, and evaluated the association of these levels with sepsis severity and septic shock development.ResultsNeutropenic patients that evolved with septic shock (n = 10) presented higher levels of sFlt-1 and VEGF-A measured 48 hours after fever onset than patients with non-complicated sepsis (n = 31) and levels of these biomarkers correlated with sepsis severity scores. Estimation of the diagnostic accuracy of sFlt-1 levels for the discrimination of patients that evolved to septic shock yielded promising results in our study population.DiscussionOur data suggest that sFlt-1 and VEGF-A could be useful biomarkers for sepsis severity in patients with febrile neutropenia. In addition, the kinetics of sFlt-1 release in patients that evolve to septic shock suggest that the sFlt-1 could be a salvage compensatory mechanism in patients with septic shock, but that the magnitude of the sFlt-1 release observed in human sepsis is not sufficient to reproduce the beneficial anti-VEGF-A effects observed in animal models of sepsis.

Effects of maternal serum on permeability of glomerular endothelial cell membrane

The mechanism of injury on the human glomerular endothelial cells (ciGENC) induced by preeclampsia serum was investigated. Concentration of maternal serum sFlt-1 protein was detected by ELISA. Fluorescently-labeled bovine serum albumin infiltrating through lower chamber of Transwell was measured by multifunction microplate reader. Morphologic change of ciGENC was observed under inverted phase contrast microscope. The concentration of sflt-1 in preeclampsia groups was significantly increased as compared with control group (P<0.01). Permeability in preeclampsia groups was significantly increased as compared with control group (P<0.01). By contrast with severe preeclampsia group, the permeability of ciGENC monolayer in mild preeclampsia group was decreased significantly (P<0.05). Intervention of exogenous VEGF significantly decreased permeability of ciGENC in preeclampsia groups. It was concluded that sFlt-1 increased ciGENC permeability by damaging integrity of endothelial barrier function.

Study on p38 mitogen activated protein kinase in vascular endothelial cells dysfunction in preeclampsia

To study expression and activation of p38 mitogen activated protein kinase (MAPK) in vascular endothelial cells dysfunction in preeclampsia. From Sept. 2009 to Mar. 2010, 54 pregnant women underwent deliveries in the First Affiliated Hospital of Chongqing Medical University were enrolled in this study, including 20 patients in mild preeclampsia group, 16 patients in severe preeclampsia group and 18 women with term cesarean section without perinatal complications as control group. Placental endothelial cells were labeled by CD₃₄ to assay microvessel density (MVD) of each group. Immunohistochemical SP and western blot were used to detect localization and expression of p-p38 MAPK protein, respectively. The levels of sera soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) were measured by ELISA. (1) The MVD of placenta were 103 ± 3 in control group, 81 ± 5 in mild preeclampsia group and 63 ± 4 in severe group, respectively, which showed statistical difference among each group (P < 0.05). (2) The expression of p38 MAPK protein were 0.84 ± 0.05 in control group, 0.90 ± 0.14 in mild group and 0.86 ± 0.18 in severe group, which did not reach remarkable difference among each group (P > 0.05). The expression of p-p38 MAPK protein were 0.13 ± 0.05 in control group, 0.59 ± 0.12 in mild group and 1.16 ± 0.18 in severe group, which show statistical difference among each group (P < 0.05). (3) The localization of p-p38 was in trophoblast, endothelial cells and a few stromal cells in placenta. (4) The level of sFlt-1 and sEng: (1) The concentration of sFlt-1 and sEng were (5.2 ± 0.3) and (10.9 ± 0.4) µg/L in control group, (12.5 ± 1.2) and (20.4 ± 5.3) µg/L in mild group and (19.3 ± 3.0) and (29.5 ± 3.7) µg/L in severe group. When drawing paired comparison in those groups, the differences showed statistical difference (P < 0.05). (2) There were positive correlations between p-p38 MAPK protein levels and the concentrations of serum sFlt-1, sEng in preeclampsia groups (r = 0.68, P < 0.05; r = 0.87, P < 0.05). The remarkable activation of the p38 MAPK in the placenta of patients with preeclampsia induced the increased levels of sFlt-l and sEng in maternal serum, which confer the injury of vascular endothelial cells that caused the significant decline of MVD in placentas. p38 MAPK signaling might be one of the key pathways in vascular endothelial cell dysfunction in preeclampsia.

Pré-eclâmpsia: estresse oxidativo, inflamação e disfunção endotelial

Preeclampsia is a systemic syndrome characterized by inflammatory and antiangiogenic states. The pathogenesis of preeclampsia involves deficient trophoblast invasion that is responsible for altered uterine blood flow and placental oxidative stress. The damaged placenta produces higher concentrations of sFlt-1, a soluble receptor for VEGF and PlGF that is released in the maternal circulation and is involved in endothelial dysfunction. Actually, all processes involved in inflammation, endothelial dysfunction and oxidative stress are strongly correlated and act in a synergistic way. Recent data have shown that an increase in serum concentrations of sFlt-1 initiates 5 to 6 weeks before the clinical manifestations of preeclampsia and these alterations correlate with a decrease in serum concentrations of PlGF. Therefore, both sFlt-1 and PlGF have been suggested to be useful for an early-diagnosis of preeclampsia. The knowledge about the role of antiangiogenic factors in the pathogenesis of preeclampsia has raised the possibility of a therapy involving these factors.In this article we revisited the pathogenesis of preeclampsia addressing its antiangiogenic and inflammatory states.In conclusion, we correlated these alterations with the higher risk for cardiovascular diseases presented by these women in future life.

Follicular Fluid-Specific Distribution of Vascular Endothelial Growth Factor Isoforms and sFlt-1 in Patients Undergoing IVF and Their Correlation With Treatment Outcomes

To investigate the distribution of vascular endothelial growth factor (VEGF) isoforms and soluble form of VEGF receptor 1 (sFlt-1) in the follicular fluid (FF) of in vitro fertilization (IVF) patients in relationship to age, body mass index (BMI), diagnosis of polycystic ovary syndrome (PCOS), and their correlation with IVF outcomes. Prospective study. VEGF( 121) and VEGF(165) isoforms were detected using Western blotting and pixel density analysis. The concentration of sFlt-1 was determined by enzyme-linked immunosorbent assay (ELISA). In vitro fertilization outcomes measured included number of oocytes retrieved, fertilization rate, and clinical pregnancy. Statistical analysis used the Kruskal-Wallis and Mann-Whitney U test where appropriate. There was a statistically significant association between higher VEGF(165) levels and the diagnosis of PCOS, BMI ≥ 30, and age ≥40 years. In vitro fertilization cycles resulting in pregnancy were linked to statistically lower VEGF(165) levels in the FF. No statistically significant trend was identified in levels of VEGF(121) or sFlt-1 relative to patient characteristics or IVF outcomes. Our results suggest that elevated VEGF(165) levels are associated with less favorable patient characteristics and clinical IVF outcomes.

Soluble fms-Like Tyrosine Kinase 1 (sFlt1), Endoglin and Placental Growth Factor (PlGF) in Preeclampsia among High Risk Pregnancies

BackgroundDifferences in circulating concentrations of antiangiogenic factors sFlt1 and soluble endoglin (sEng) and the pro-angiogenic growth factor PlGF are reported to precede the onset of preeclampsia weeks to months in low-risk pregnant women. The objective of this study was to investigate whether similar changes can be detected in pregnant women at high-risk to develop the syndrome.MethodsThis study is a secondary analysis of the NICHD MFMU trial of aspirin to prevent preeclampsia in high-risk pregnancies. Serum samples were available from 194 women with pre-existing diabetes, 313 with chronic hypertension, 234 with multifetal gestation, and 252 with a history of preeclampsia in a previous pregnancy. Samples collected across pregnancy were analyzed in a blinded fashion for sFlt1, sEng and PlGF.ResultsThe odds of developing preeclampsia were significantly increased among women with multiple fetuses for each 2-fold elevation in sFlt1, sEng and the ratio of angiogenic factors (e.g. OR 2.18, 95% CI 1.46-3.32), and significantly decreased for each 2-fold elevation in circulating PlGF (OR 0.50, 95% CI 0.30-0.82) between 7 and 26 weeks' gestation. Cross-sectional analysis of the angiogenic factors across gestation showed significant differences during the third trimester in women who develop preeclampsia compared with appropriate controls in all high-risk groups. However, when data were examined in relation to the gestational week when preeclampsia was diagnosed only sFlt1 was significantly higher 2 to 5 weeks before the clinical onset of preeclampsia and only in women with previous preeclampsia.ConclusionsThe pattern of elevated concentrations of sFlt1 and sEng, and low PlGF in high-risk pregnant subjects who develop preeclampsia is similar to that reported in low-risk pregnant women. However, differences in these factors among high-risk women who do and do not develop preeclampsia are modest, and do not appear to be clinically useful predictors in these high-risk pregnant women.

T2 Angiogenic factors in preeclampsia

To show soluble fms-like tyrosine kinase 1 (sFlt1) levels in sera from patients with hydatidiform mole, which is known to predispose women to severe early-onset preeclampsia.Comparative study.University hospital and surrounding community hospitals.Seven women with pathologically diagnosed complete hydatidiform mole (mole group), 21 gestational- and maternal-age–matched women who did not develop any pregnant complication during their pregnancy (control group), and eight women who subsequently developed preeclampsia (preclinical preeclampsia group).Blood samples were taken before and after evacuations of hydatidiform mole.Concentrations of sFlt1 and free placental growth factor (PlGF) in serum were measured by ELISA.Serum sFlt1 concentrations were significantly higher in the mole group compared with the control group and the preclinical preeclampsia group. In contrast, serum free PlGF concentrations were significantly lower in the mole group. In the mole group, there was a significant negative correlation between sFlt1 and PlGF serum concentrations. After the evacuation of hydatidiform mole, the level of serum sFlt1 decreased dramatically.Elevated levels of sFlt1 were noted in molar gestations and may play in a role in early-onset preeclampsia reported in such pregnancies.

M15.4 Low maternal PlGF across pregnancy identifies a subset of women with preterm preeclampsia; type 1 vs. type 2 preeclampsia?

To show soluble fms-like tyrosine kinase 1 (sFlt1) levels in sera from patients with hydatidiform mole, which is known to predispose women to severe early-onset preeclampsia.Comparative study.University hospital and surrounding community hospitals.Seven women with pathologically diagnosed complete hydatidiform mole (mole group), 21 gestational- and maternal-age–matched women who did not develop any pregnant complication during their pregnancy (control group), and eight women who subsequently developed preeclampsia (preclinical preeclampsia group).Blood samples were taken before and after evacuations of hydatidiform mole.Concentrations of sFlt1 and free placental growth factor (PlGF) in serum were measured by ELISA.Serum sFlt1 concentrations were significantly higher in the mole group compared with the control group and the preclinical preeclampsia group. In contrast, serum free PlGF concentrations were significantly lower in the mole group. In the mole group, there was a significant negative correlation between sFlt1 and PlGF serum concentrations. After the evacuation of hydatidiform mole, the level of serum sFlt1 decreased dramatically.Elevated levels of sFlt1 were noted in molar gestations and may play in a role in early-onset preeclampsia reported in such pregnancies.

M9.3 Association of maternal, paternal and fetal single nucleotide polymorphisms in vascular endothelial growth factor family genes with preeclampsia

To assess the ability of first trimester maternal serum (FTMS) soluble Fms-like tyrosine kinase (sFlt-1)/placental growth factor (PlGF) ratio in the first trimester threatened miscarriage (FTTM) to predict fetal loss in early pregnancy and adverse pregnancy outcomes when pregnancy continued to ⩾30 weeks to start suitable antenatal care as early as possible.A case control prospective cross-sectional study.320 cases of TM, 7–12 weeks’ gestation and 320 normal controls 7–12 weeks’ gestation without vaginal bleeding and other manifestations of FTTM and delivered at ⩾30 weeks’ gestation were enrolled in the study. All were primigravidae. Estimation of FTMS sFlt-1 and PlGF in the first trimester of TM and controls by enzyme-like immunosorbent assay (ELISA) and follow up of them till delivery were done. Adverse pregnancy outcomes encountered were gestational hypertension (GH), preeclampsia (PE), intrauterine growth restriction (IUGR), abruptio placentae, spontaneous preterm labor (PTL), placenta previa, preterm premature rupture of membranes (PPROM) and retained placenta.All adverse pregnancy outcomes were significantly (P < 0.05) higher in FTTM than in controls (44.52% vs. 17.5%). In FTTM MS concentrations of sFlt-1 and PlGF and sFlt-1/PlGF ratio were markedly reduced if fetal loss was encountered. sFlt-1/PlGF ratio <51.71 (cut-off point) predicted fetal loss with sensitivity 90.32%, specificity 98.47%, positive predicted value 93.33% and negative predictive value 97.60%. Patients that developed adverse pregnancy outcomes related to impaired placentation as GH, PE, IUGR, PTL <34 weeks’ gestation and abruptio placentae had reduced FTMS PlGF and increased sFlt-1/PlGF ratio, in both FTTM and controls. Soluble Flt-1/PlGF ratio >74.6 (cut-off point) predicted these adverse pregnancy outcomes with sensitivity 88.70%, specificity 95.40, positive predictive value 90.16% and negative predictive value 94.68% – adverse pregnancy outcomes not related to placental impairment as PLT >34 weeks’ gestation, PPROM, placenta previa and retained placenta were not predicted by sFlt-1/PlGF ratio because in these conditions FTMS concentration of these factors were normal.1-Adverse outcomes late in pregnancy (⩾30 weeks’ gestation) were more common in FTTM. 2-Diminished FTMS concentration of sFlt-1 and PlGF as well as sFlt-1/PlGF ratio <51.71 may predict fetal loss in FTTM. 3-In FTTM and normal controls FTMS PlGF was reduced and sFlt-1/PlGF ratio >74.6 may predict development of adverse outcomes characterized by impaired placentation. 4-Adverse pregnancy outcomes not related to impaired placentation were associated with normal FTMS concentration of sFlt-1 and PlGF and were not predicted by sFlt-1/PlGF ratio.

Periodic assessment of plasma sFlt-1 and PlGF concentrations and its association with placental morphometry in gestational hypertension (GH) - a prospective follow-up study

BackgroundHypertensive disorders in pregnancy contributes to about 12% of maternal deaths in Malaysia and similarly worldwide. Early detection and adequate management are preventable strategies. Biochemical markers of abnormal angiogenesis would be more specific in early detection than routine blood pressure and proteinuria measurements. The aim of this study was to estimate maternal plasma PlGF and sFlt-1 levels in pregnant women with gestational hypertension at three intervals of pregnancy and correlate these biomarker levels with placental morphometry.MethodsVenous blood samples (antepartum, intrapartum and post partum periods) were drawn to estimate for sFlt-1 and PlGF levels while placental tissue samples were examined for placental morphometry.ResultsPlGF levels were lower in gestational hypertension (GH) compared to normotensive during antepartum and intrapartum period, whereas sFlt-1 levels were elevated in GH at antepartum, intrapartum and postpartum intervals during pregnancy. An inverse relationship between these two biomarkers was observed through correlation analysis. PlGF levels were inversely correlated with total villous surface area of the placental periphery (TCsa-C) and villous capillarization (VC-C) of the placental periphery.ConclusionWe established periodic values of for sFlt-1 and PlGF levels for the first time in an ethnically diverse Malaysian setting. We suggest the development of GH in women is related to defective capillarization. In demonstrating periodic changes, this study suggest the possibility of developing GH and other long term health complications as a result of prolonged exposure to sFlt-1. The correlation between PlGF levels and morphometric findings also support possible capillarization defect.

Marinobufagenin is an upstream modulator of Gadd45a stress signaling in preeclampsia

Preeclampsia (PE) is a hypertensive disorder of pregnancy, in which marinobufagenin (MBG), a circulating cardiotonic steroid, is increased. The Gadd45a stress sensor protein is an upstream modulator of the pathophysiological changes observed in PE. However, the effects of MBG on Gadd45a stress signaling remain unknown. We examined the expression of Gadd45a, the sFlt-1 receptor, and p38, as well as caspase 3 and 8 activities in placental samples from four groups of rats. These were: normal pregnant (NP, n = 8); pregnant rats which received weekly injections of desoxycorticosterone acetate and 0.9% saline as their drinking water (PDS, n = 9); normal pregnant rats injected with MBG (NPM, n = 8); and PDS rats injected with resibufogenin (RBG), an in vivo antagonist of MBG (PDSR, n = 8). Utilizing human cytotrophoblast (CTB) cells, we examined the effect of MBG on these stress signaling proteins in vitro. Placental Gadd45a expression, caspase 3 and 8 activities, sFlt-1 concentrations, and sFlt-1 receptor expression were significantly higher in PDS and NPM compared to NP and PDSR rats. Gadd45a protein was significantly upregulated in the CTB cells when MBG was present in concentrations ≥1 nM. Treatment with MBG (≥ 1 nM) also significantly arrested cell cycle progression and activated the expression of the Gadd45a-mediated stress signaling proteins. Inhibition of Gadd45a through RNAi-mediation attenuated MBG-induced CTB cell stress signaling. In conclusion, MBG is involved in the alteration in Gadd45a stress signaling both in vivo and in vitro and RBG prevents these changes when administered in vivo.

Relation Between Maternal Angiogenic Factors and Utero-Placental Resistance in Normal First- and Second-Trimester Pregnancies

Objective. Soluble endoglin (sEng) is a novel antiangiogenic protein and elevated sEng concentrations in maternal circulation are closely related to preeclampsia and HELLP syndrome. As the perfusion of the uterine arteries as well as the dynamics of angiogenic factors between first and second trimester have prognostic value regarding pregnancy outcome, it was the aim of this study to investigate the relation between maternal angiogenic factors and uterine Doppler parameters. Study design. The longitudinal study includes 50 normal pregnancies. Pulsatility index (PI) of the uterine arteries was detected by Doppler ultrasound in first and second trimester. In parallel, maternal sEng and soluble fms-like tyrosine kinase 1 (sFlt1) concentration was measured using ELISA. Results. In the first trimester, the sEng concentrations were 4.92 ± 1.36 ng/mL and the uterine PI was 1.14 ± 0.28. In the second trimester, the maternal sEng concentration decreased significantly to 3.99 ± 0.63 ng/mL (p < 0.05) which was associated by a decrease of the uterine PI to 0.78 ± 0.15 (p < 0.001). Soluble fms-like tyrosine kinase 1 concentrations did not differ significantly between first and second trimester (423 ± 333 vs. 444 ± 291 pg/mL). There was a significant negative correlation between sEng and uterine resistance in the second trimester (r = −0.416; p < 0.001). Conclusions. In normal pregnancy, parallel to the fall of utero-placental resistance, there is a physiological decline of the maternal sEng concentration between first and second trimester. In second trimester, there is a negative correlation between sEng and uterine Doppler parameters.