sFlt-1 Levels Research Articles

Cordycepin Alleviates Lipopolysaccharides-Induced Preeclampsia-Like Impairments in Rats

ABSTRACT Introduction Preeclampsia is a serious pregnancy complication that can lead to life-threatening conditions such as seizures, strokes, and even death. A dysregulated inflammatory response in the placenta plays a crucial role in the development of preeclampsia. Cordycepin, known for its anti-inflammatory and antioxidant properties, was the focus of this study, which aimed to investigate its effects on preeclampsia. Methods A preeclampsia-like rat model was established via tail vein injection of lipopolysaccharides (LPS) at a dose of 1 μg/kg in pregnant rats. These rats were then treated with cordycepin at doses of 5, 25, or 50 mg/kg from embryonic day 6 (E6) today 18 (E18). Systolic blood pressures and urinary protein levels were monitored, and pregnancy outcomes, such as fetal body length and weight, were measured. The expression of target genes or proteins was assessed by qPCR, ELISA, and Western blot. Results Our findings revealed that cordycepin significantly reduced systolic blood pressure and proteinuria in preeclampsia-like rats. Additionally, cordycepin improved pregnancy outcomes, as shown by increased fetal body length and weight. The treatment also lowered serum sFlt-1 levels, elevated PIGF levels, decreased placental pro-inflammatory cytokine levels (IL-1β, TNF-α, IL-6, MCP-1, and MIP-2), and raised levels of anti-inflammatory cytokine IL-10 level in preeclampsia-like rats. Furthermore, cordycepin helped restore macrophage population imbalances, increasing M1-type macrophage markers (iNOS, TNF-α, and IL-1β) and reducing M2-type macrophage markers (Arg 1, IL-10, and TGF-β). Conclusion This study suggests that cordycepin alleviates LPS-induced preeclampsia by reducing placental inflammation and correcting the M1/M2 macrophage imbalance, offering potential therapeutic benefits for managing preeclampsia.

Growth factor dysregulation and placental dysfunction

The article is devoted to the study of angiogenic and antiangiogenic vascular growth factors in placental dysfunction, which is of great importance in obstetrics and perinatology. The study of growth factors as predictors of the development of placental dysfunction makes it possible to determine in advance the development of many obstetric pathologies, including preeclampsia and fetal growth retardation, which is of great practical importance. The authors conducted an immunological study of pregnant women with placental dysfunction and pregnant women with a physiological pregnancy. Purpose of the study: to study serum growth factors in women with placental dysfunction. We examined 47 pregnant women with a gestation period of 26-40 weeks, with a diagnosis of placental dysfunction, who were under observation in the obstetric department of the city maternity complex No. 3 of the city of Tashkent. The control group consisted of 35 women with a physiological pregnancy. All women underwent an immunological blood test: cellular and humoral immunity, as well as cytokines (VEGF-A, PlGF, sFlt-1, sFlt-1/PlGF) were studied. Based on the results obtained, the authors suggest that an increased level of soluble sFlt-1 and a simultaneous decrease in the levels of VEGF-A and PlGF in pregnant women at 26-40 weeks of gestation may portend the development of pregnancy complications, including preeclampsia and fetal growth restriction, and increase the risk of premature birth. Ddelivery due to impaired placental blood flow and oxygen deficiency for the fetus, lead to deterioration of microcirculation, and insufficient levels of VEGF-A and PlGF can contribute to vascular endothelial dysfunction, which can also contribute to the development of preeclampsia. The studied angiogenic and antiangiogenic vascular growth factors are important indicators and can serve as markers for predicting pregnancy complications for active medical intervention in maintaining the health of both mother and child.

SFlt-1/PLGF ratio: A promising marker for early detection of preeclampsia in the second and third trimester

: Preeclampsia (PE), characterized by endothelial dysfunction, remains a significant concern in obstetrics due to its association with maternal and fetal morbidity and mortality. One significant contributor to the clinical manifestations of PE is the imbalance in the placental release of various angiogenesis regulatory factors into the maternal circulation. Low levels of the pro-angiogenic biomarker Placental Growth Factor (PLGF) and high levels of antiangiogenic biomarker sFlt-1 (soluble Fms like tyrosine kinase -1) levels are detectable several weeks before the clinical presentation of PE, making them a promising marker for early diagnosis.: This study investigates the utility of the sFlt-1/PLGF ratio in predicting and diagnosing preeclampsia during the second and third trimesters of pregnancy.: A prospective cohort study was conducted with 150 study participants comprising normotensive controls and preeclamptic cases, diagnosed based on blood pressure and proteinuria criteria. Serum samples collected in the second trimester (24-28 weeks) and third trimester (>28 weeks) were analyzed for PLGF and sFlt-1 levels using ELISA kit method. The sFlt-1/PLGF ratio was calculated and evaluated for its diagnostic accuracy through ROC curve analysis.: Significantly lower PLGF levels and higher sFlt-1 levels in preeclamptic pregnancies compared to normotensive pregnancies were seen in both trimesters (p < 0.001). The sFlt-1/PLGF ratio was markedly elevated in preeclampsia, showing strong predictive characteristics with an AUC of 0.929 (sensitivity 90%, specificity 90%) in the second trimester and an AUC of 0.986 (sensitivity 90%, specificity 96.7%) in the third trimester. These findings highlight the potential of the sFlt-1/PLGF ratio as a biomarker for early detection and risk stratification in pregnancies complicated by preeclampsia.

Alteration in sB7-H4 Serum Levels and Placental Biomarker Expression after Therapeutic Plasma Exchange in Early-Onset Preeclampsia Patients.

Therapeutic plasma exchange (TPE) is a widely used treatment for numerous diseases including pregnancy-related conditions. Our prior study on 20 early-onset preeclampsia patients undergoing TPE revealed a significant extension in pregnancy duration and reduced serum levels of sFlt-1, sFlt-1/PlGF, and sEndoglin. Here, we investigated the impact of TPE on serum sB7-H4, an immunological checkpoint molecule, and placental proteins (Flt-1, Eng, B7-H4, iNOS, TNF-α) in TPE-treated early-onset preeclampsia patients (N = 12, 23 + 2-28 + 5 weeks), conventionally treated counterparts (N = 12, 23 + 5-30 weeks), and gestational age-matched controls (N = 8, 22 + 4-31 + 6 weeks). Immunoblotting, ELISA, and co-immunohistochemistry were used for biomarker analysis, including placental inflammation factors (iNOS, TNF-α). The results showed that TPE extended pregnancy by a median of 6.5 days in this cohort of early-onset preeclampsia. Serum sB7-H4, sFlt-1, and sEndoglin levels decreased, along with reduced expression of their membrane-bound proteins in placental tissue upon TPE treatment. Moreover, TPE-treated patients displayed reduced placental inflammation compared to preeclampsia patients receiving standard-of-care treatment. In conclusion, TPE may improve pregnancy outcomes in early-onset preeclampsia by lowering circulating levels of sB7-H4, sFlt-1, and sEndoglin, as well as reducing placental inflammation. This translational approach holds promise for enhancing placental function and extending gestation in high-risk pregnancies including very preterm PE or HELLP cases.

Impaired Endothelium-Dependent Vasodilation and Increased Levels of Soluble Fms-like Tyrosine Kinase-1 Induced by Reduced Uterine Perfusion Pressure in Pregnant Rats: Evidence of Protective Effects with Sodium Nitrite Treatment in Preeclampsia.

Preeclampsia (PE) is a hypertensive disorder of pregnancy and is associated with increases in soluble fms-like tyrosine kinase-1 (sFlt-1) and reductions in nitric oxide (NO) levels. Placental ischemia and hypoxia are hypothesized as initial pathophysiological events of PE. Nitrite (NO metabolite) may be recycled back to NO in ischemic and hypoxic tissues. Therefore, this study examined the sodium nitrite effects in an experimental model of PE. Pregnant rats received saline (Preg group) or sodium nitrite (Preg + Na-Nitrite group). Pregnant rats submitted to the placental ischemia received saline (RUPP group) or sodium nitrite (RUPP + Na-Nitrite group). Blood pressure, placental and fetal weights, and the number of pups were recorded. Plasma levels of NO metabolites and sFlt-1 were also determined. Vascular and endothelial functions were also measured. Blood pressure, placental and fetal weights, the number of pups, NO metabolites, sFlt-1 levels, vascular contraction, and endothelium-dependent vasodilation in the RUPP + Na-Nitrite rats were brought to levels comparable to those in Preg rats. In conclusion, sodium nitrite may counteract the reductions in NO and increases in sFlt-1 levels induced by the placental ischemia model of PE, thus suggesting that increased blood pressure and vascular and endothelial dysfunctions may be attenuated by sodium nitrite-derived NO.

The Predictive Value of sFlt-1/PlGF Ratio for Postpartum Preeclampsia

Abstract Background Preeclampsia (PE) is a leading cause of maternal mortality, affecting 5% to 8% of pregnancies worldwide. Postpartum PE typically develops within the first 48 hours and can occur up to 6 weeks after childbirth and requires immediate clinical management. However, overdiagnosis may lead to unnecessary hospital admissions and overuse of medical resources. The ratio of soluble fms like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) has been evaluated as a tool to predict PE, but its utility in the postpartum setting is yet to be established. Methods In this study, we conducted a non-interventional, prospective study at NewYork-Presbysterian-Weill Cornell Hospital, measuring serum sFlt-1 and PlGF levels using Elecsys® and cobas e411 analyzer. The primary aim was to determine the predictive accuracy of the sFlt-1/PlGF ratio in postpartum PE, focusing on its sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) using a cutoff 38, as established in the PROGNOSIS study. Results Among 47 participants, 9 (19.1%) developed postpartum PE. The sFlt-1/PlGF ratio was significantly higher for the women who developed PE (55.9, IQR, 48.6-196.2) than for women without PE (19.9, IQR, 5.8-29.1). There was no significant difference in age, first-trimester body-mass index (BMI), gestational week of delivery, smoking status and nulliparous between PE and non-PE groups. Moreover, the sFlt-1/PlGF ratio at 38 cutoff point had a sensitivity of 77.8% (95% CI, 45.0-93.7) and a specificity of 81.6% (95% CI, 66.6-90.8), with a PPV of 50.0% (95% CI, 33.9-66.1). Notably, it demonstrated a high NPV of 93.9% (95% CI, 80.4-98.3). Conclusion Our findings suggest that the sFlt-1/PlGF ratio may be used as a predictor of postpartum PE, highlighting its significance in managing postpartum PE.

Maternal Thyroid Function and Biochemical Markers of Placental Function in Early Pregnancy.

A link between maternal thyroid function and the placental biomarkers, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), has been brought forward. This study aimed to describe their association in early pregnancy. Retrospective cohort study. Eight hundred and fifty-eight pregnant women from the North Denmark Region, 2013, with blood samples drawn in early pregnancy. Thyroid-stimulating hormone (TSH), free thyroxine (fT4), thyroid-peroxidase antibodies (TPO-Ab), thyroglobulin antibodies (Tg-Ab) (ADVIA Centaur XPT, Siemens Healthineers), sFlt-1 and PlGF (Kryptor Compact, ThermoFisher Scientific) were measured. The association between maternal TSH and fT4 and percentile (pc) levels of sFlt-1 and PlGF (< 25th pc, 25-75th pc, > 75th pc) was evaluated using regression analysis and reported as adjusted beta coefficient (aβ). The frequency of maternal thyroid autoantibodies (TPO-Ab > 60 U/mL or Tg-Ab > 33 U/mL) by pc levels of sFlt-1 and PlGF was compared using chi-squared test. Higher levels (> 75th pc) of sFlt-1 associated with lower TSH (aβ 0.62, 95% CI: 0.51-0.76) and higher fT4 (aβ 1.03, 95% CI: 1.01-1.05). Higher levels of PlGF associated with lower TSH (aβ 0.82, 95% CI: 0.69-0.98), but not with levels of fT4 (aβ 1.00, 95% CI: 0.97-1.02). No association with maternal thyroid autoantibodies was found (TPO-Ab: sFlt-1: p-value 0.5 and PlGF: p-value 0.1; Tg-Ab: sFlt-1: p-value 0.7 and PlGF: p-value 0.1). In a large cohort of Danish pregnant women, higher levels of sFlt-1 and PlGF associated with maternal thyroid function in early pregnancy, while there was no association with maternal thyroid autoantibodies.

A-308 Placental Growth Factor Kryptor Immunoassay Reveals Quality Control Imprecision and Drift

Abstract Background The utility and value of determining the soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1/PlGF) ratio for predicting the likelihood of progression to pre-eclampsia in pregnant women admitted with hypertension are increasingly becoming widely recognized. A key finding of the multi-center PRAECIS trial (NEJM Evid 2022;1(12)) is the observation that sFlt-1/PlGF ratios ≥ 40 correlate with higher risk for adverse maternal outcomes. The sFlt-1 and PlGF immunoassays performed on the ThermoFisher Scientific B·R·A·H·M·S Kryptor autoanalyzer became the first FDA-approved tests in 2023 for determining sFlt-1/PlGF ratio. In this study, an evaluation of the analytical performance of the sFlt-1 and PlGF KRYPTOR immunoassays was performed, which included analyte measuring range (AMR), accuracy, precision, and stability studies. Methods Calibration and QC materials (consisting of lyophilized recombinant human proteins), test reagents and solutions, and consumables were purchased and provided by ThermoFisher Scientific. Analytical runs were performed according to vendor’s instructions by trained medical laboratory scientists. Between-day precision of our two instruments for both immunoassays was assessed by assaying all three levels of sFlt-1 and PlGF QC materials, as well as patient serum pools with low PlGF concentration, once to twice daily for multiple consecutive days. Results While the analytical performance of the sFlt-1 immunoassay was robust and performed according to expectation (within-day CV &amp;lt;1% and between-day CV &amp;lt;3%), the PlGF immunoassay was surprisingly less reliable. Imprecision and inaccuracy of the PlGF immunoassay at the low end of its analytical measurement range was reflected by both sporadically out-of-control between-day measurements of all three QC levels (with target ranges of 24 - 36 pg/mL, 80 - 120 pg/mL, and 320 - 480 pg/mL), as well as slow downward drifts of particularly the low level QC material. In one instance, a downtrend was observed from 28 pg/mL to 14 pg/mL over 6 days, even with fresh reagents, solutions, and calibration. Such shortened stability of the PlGF assay does not meet the vendor’s claims of calibration stability of 15 days and onboard kit stability of 29 days. Using vendor’s provided material, the AMR of both sFlt-1 and PlGF were adequately verified and showed excellent linearity (r2&amp;gt; 0.99). Conclusions Despite low level QC imprecision and drift, the sFlt-1/PlGF ratios determined using the B·R·A·H·M·S Kryptor analyzers are acceptable for clinical use but with the caveat that we will perform batch testing with bracketing QCs and conduct stringent QC monitoring, frequent calibrations, and reduce the onboard kit stability as defined by ThermoFisher Scientific. Our findings serve as a reminder that FDA approval does not preclude thorough verification studies of any assay prior to implementation for clinical use.

A-311 Evaluating the Predictive Value of the sFlt-1/PlGF Ratio in Hypertensive Pregnancies for Preeclampsia

Abstract Background Preeclampsia (PE) is a hypertensive pregnancy disorder affecting around 5% of all pregnancies, and it continues to be a leading cause of maternal and neonatal morbidity and mortality in the United States. The incidence of hypertensive pregnancies is on the rise, attributed to the increasing prevalence of obesity and chronic hypertension. The development of a straightforward diagnostic test to accurately differentiate PE from gestational or chronic hypertension is crucial to avoid unnecessary hospitalizations. Despite the ongoing development of prediction models for PE, conventional clinical and laboratory measures have not been effective in predicting disease progression. Recent research has focused on the ratio of two serum biomarkers: soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), particularly in patients with a clinical suspicion of PE in acute settings. These studies have shown promise, with many indicating that the sFlt-1/PlGF ratio can effectively predict the presence or absence of PE. This study was conducted to assess the predictive value of the sFlt-1/PlGF ratio in pregnancies complicated by hypertension, aiming to contribute to the early detection and management of PE. Methods Pregnant individuals with hypertensive disorders at or above the age of 18 receiving prenatal care at NewYork-Presbysterian-Weill Cornell Hospital were enrolled in this study. We measured the levels of sFlt-1 and PlGF using fully automated Elecsys immunoassays (Roche Diagnostics). Subsequently, a prospective analysis of the serum sFlt-1/PlGF ratio was performed. A receiver operating characteristic (ROC) curve was used to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the ratio in predicting PE. To assess the prognostic accuracy of the sFlt-1/PlGF ratio, patients were randomly assigned to a development and a validation cohort at a ratio of 30:70. Results We collected a total of 137 serum samples of hypertensive pregnancies, with all ≥20 weeks of gestational age (GA). Of these, 47 (34.3%) developed PE within 2 weeks. The samples were divided into two cohorts: 98 were included in the development cohort, and 39 in the validation cohort. Within these groups, 34 (34.7%) of the development cohort and 13 (33.3%) of the validation cohort developed PE within 2 weeks, respectively. In the development cohort, the median sFlt-1/PlGF ratio was 85 (Interquartile range, [IQR], 44-164) among pregnant women who developed PE within 2 weeks. This was significantly higher compared to a median ratio of 8 (IQR, 3-35) observed in those who did not develop PE (p&amp;lt;0.001). The area under the ROC curve was 0.87, indicating good discriminative ability. An optimized cutoff ratio of 38 was determined, based on the max of combined sensitivity and specificity. When applied into the validation cohort, this cutoff yields a 90% (95% confidence interval [CI], 70-97) NPV and 58% (95%CI, 37-76) PPV with an 85% sensitivity (95%CI, 58-96) and a 69% specificity (95%CI, 50-83). Conclusions In women with a hypertensive disorder of pregnancy presenting GA≥20 weeks of gestation, the measurement of serum sFlt-1/PlGF ratio demonstrated clinical value in predicting the development of PE.

Intermanufacturer assessment of diagnostic performance of angiogenic ratio vs glycosylated fibronectin in women with suspected pre-eclampsia.

To compare the diagnostic performance of different manufacturers' immunoassays for the soluble fms-like tyrosine kinase-1 (sFlt-1)-to-placental growth factor (PlGF) ratio with that of a point-of-care test for glycosylated fibronectin (GlyFn) in women with suspected pre-eclampsia (PE). This was a prospective, single-center, double-blinded, non-interventional study of East Asian women with a singleton pregnancy who presented with hypertension with or without clinical features of PE after 20 weeks' gestation between January 2020 and March 2022. Maternal serum samples were collected at the time of presentation, and subsequent management followed the departmental protocol, based on gestational age, severity of hypertension, fetal condition and presence of severe PE features. Women diagnosed with PE at presentation were excluded. PE was diagnosed according to the 2018 International Society for the Study of Hypertension in Pregnancy classification. Levels of sFlt-1 and PlGF were measured using the Cobas e411 (Roche Diagnostics), BRAHMS KRYPTOR (ThermoFisher Scientific) and iMAGIN 1800 (Ningbo-Aucheer) platforms. GlyFn levels were measured using the Lumella™ GlyFn PoC test (Diabetomics). The predictive performance of each test to rule out PE within 7 days and rule in PE within 28 days from the date of presentation was assessed. Based on the PROGNOSIS study, a sFlt-1/PlGF ratio of ≤ 38 on the Roche platform was used to predict the absence of PE within 7 days. The sFlt-1/PlGF ratio was classified as high or low using platform-specific thresholds equivalent to a Roche sFlt-1/PlGF ratio of 38, which were derived using Passing-Bablok regression. GlyFn was categorized as high or low using two reported clinical management thresholds (263 μg/mL and 510 μg/mL). Overall, 236 women with suspected PE were included, of whom 70 (29.7%) were diagnosed with PE; 36 (51.4%) and 70 (100%) developed PE within 7 days and 28 days, respectively. Eighty-eight (37.3%) women had a sFlt-1/PlGF ratio of > 38 on the Roche platform, 79 (33.5%) women had a sFlt-1/PlGF ratio of > 55 on the KRYPTOR platform and 96 (40.7%) women had a sFlt-1/PlGF ratio of > 40 on the iMAGIN 1800 platform. Furthermore, 62 (26.3%) and four (1.7%) women had a GlyFn level of > 263 μg/mL and > 510 μg/mL, respectively. The negative predictive value (NPV) of the sFlt-1/PlGF ratio measured on the Roche, KRYPTOR and iMAGIN 1800 platforms to rule out PE within 7 days after presentation was 83.3%, 82.0% and 82.9%, respectively, while that for GlyFn > 263 μg/mL and > 510 μg/mL was 82.6% and 70.4%, respectively. The corresponding positive predictive values (PPV) to rule in PE within 28 days after presentation were 50.5%, 52.3% and 46.7%, respectively, for the sFlt-1/PlGF ratio, and 35.4% and 50.0%, respectively, for GlyFn > 263 μg/mL and > 510 μg/mL. The predictive performance of different manufacturers' assays for the sFlt-1/PlGF ratio to rule in and rule out PE were similar once standardized to a common threshold. Our findings suggest that the sFlt-1/PlGF ratio and GlyFn using a cut-off of 263 μg/mL can both be utilized to rule out PE within 7 days after assessment, with a moderate NPV. The PPV for ruling in PE within 28 days remains poor. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Discussion on the evaluation of the therapeutic efficacy of uterine artery blood flow parameters and serum PLGF and sFlt-1 in patients with recurrent spontaneous abortion

ObjectiveTo investigate the effects of different drug treatments on uterine artery blood flow parameters, serum placental growth factor (PLGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and sFlt-1/PLGF in patients with recurrent spontaneous abortion and to explore the predictive value of uterine artery blood flow parameters, serum PLGF, sFlt-1, and sFlt-1/PLGF for pregnancy outcomes.MethodsThis retrospective cohort study included 173 patients who experienced recurrent spontaneous abortion and 100 control patients. Patients with recurrent spontaneous abortion were divided into an aspirin group (75 patients), aspirin combined with low molecular weight heparin (LMWH) group (68 patients), and non-drug group (30 patients) based on different drug treatments. Uterine artery blood flow parameters at gestational weeks 30-31+6 were monitored for the four groups, and serum samples were collected at gestational weeks 30-31+6 to measure the levels of serum PLGF and sFlt-1 and calculate the sFlt-1/PLGF ratio.Results1. Uterine artery blood flow parameters at gestational weeks 30-31+6 were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 2. Serum PLGF levels and the sFlt-1/PLGF ratio at gestational weeks 30-31+6 were significantly lower in the non-drug group than in the aspirin group, combined drug group, and control group, while serum sFlt-1 levels were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 3. Serum PLGF, sFlt-1, and sFlt-1/PLGF had lower diagnostic efficiency for predicting hypertensive disorders during pregnancy than the combined diagnostic efficiency of serum PLGF, sFlt-1, and sFlt-1/PLGF with uterine artery blood flow parameters at gestational weeks 30-31+6.ConclusionAspirin and aspirin combined with LMWH can upregulate serum PLGF and decrease serum sFlt-1 levels in patients with recurrent spontaneous abortion, reduce the miscarriage rate, and significantly improve pregnancy outcomes. The combination of serum PLGF, sFlt-1, sFlt-1/PLGF, and uterine artery blood flow parameters can effectively predict hypertensive disorders during pregnancy.

Research on the Improvement of Endothelial Cell Function and Trophoblast Apoptosis in Rats with Preeclampsia by Tanshinone IIA

Background Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, often the kidneys. Recent studies suggest that endothelial dysfunction and trophoblast apoptosis are involved in the pathogenesis of preeclampsia. Purpose To investigate the effects of tanshinone IIA (TIIA) on clinical symptoms, vascular endothelial function, and placental trophoblast apoptosis in preeclampsia rats. Materials and Methods Twenty-four pregnant Sprague-Dawley rats, between 8 and 10 weeks old, were randomly divided and allocated into three groups: Control, model, and treatment, with each group consisting of 8 rats. The control group received normal saline injections via the tail vein; the model group received NG-nitro-l-arginine methyl ester (l-NAME) to induce preeclampsia, followed by normal saline injections; and the treatment group received TIIA (10 mg/kg) via tail vein injection after preeclampsia induction with l-NAME. Various parameters were measured, including tail artery systolic pressure, 24-hour proteinuria, offspring and placental weight, levels of endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), placental growth factor (PLGF), and soluble FMS-like tyrosine kinase 1 (sFlt-1) in serum, and expression of B-cell lymphoma-2 (Bcl-2) and Bcl-2-related X protein (Bax) in placental trophoblasts. Results TIIA treatment led to decreased tail artery systolic pressure and 24-hour urine protein levels, increased body and placental weights of offspring, and favorable changes in serum levels of ET-1, sFlt-1, eNOS, and PLGF. Moreover, TIIA treatment resulted in decreased Bax levels and apoptosis in placental trophoblasts, along with increased Bcl-2 levels. Conclusion TIIA can improve the clinical symptoms of preeclampsia in rats induced by l-NAME, alleviate the apoptosis of placental trophoblast cells, and improve vascular endothelial function.

Relationship between maternal serum sFlt-1 level and placenta accreta spectrum disorders in the third trimester

PurposeThis study aims to evaluate whether the third-trimester soluble fms-like tyrosine kinase-1 (sFlt-1) serum levels could be related to placenta accreta spectrum (PAS) disorders and the severity of postpartum blood loss.MethodsThis was a nested case–control study which compared serum sFlt-1 level between gravid women with or without PAS disorders. Spearman correlation analysis was conducted to explore the relationship between sFlt-1 level and the volume of postpartum blood loss. Confounding factors were adjusted to avoid the impact on the results.ResultsSixty gravid women were enrolled: 36 women in the PAS group and 24 women in the non-PAS group. Women in the PAS group had a median sFlt-1 level of 9407.1 [2745.9–21,691.5] pg/ml, whereas women in the non-PAS group had a median sFlt-1 level of 25,779.2 [14317.1–35,626.7] pg/ml, (p < 0.001). The sFlt-1 level was negatively related to the volume of postpartum blood loss (r = − 0.358, p = 0.041). After adjusting for maternal age and gestational age at blood taking, sFlt-1 level showed no significant relationship with PAS disorders (p = 0.245) and postpartum blood loss (p = 0.526).ConclusionThird-trimester sFlt-1 serum level is not independently associated with PAS disorders or postpartum blood loss after adjusting for confounding factors.

GPER Stimulation Attenuates Cardiac Dysfunction in a Rat Model of Preeclampsia.

Preeclampsia poses a substantial clinical challenge, characterized by maternal hypertension, cardiac dysfunction, and persistent cardiovascular risks for both the mother and offspring. Despite the known roles of the estrogen receptor (GPER [G protein-coupled estrogen receptor]) in placental development, its impact on cardiovascular aspects within a preeclampsia animal model remains unexplored. We propose that G-1, a GPER agonist, could have the potential to regulate not only hypertension but also cardiac dysfunction in rats with preeclampsia. To explore the influence of G-1 on preeclampsia, we used the reduced uterine perfusion pressure (RUPP) model. RUPP rats were administered either G-1 (100 µg/kg per day) or hydralazine (25 mg/kg per day). We conducted echocardiography to probe the intricate cardiac effects of G-1. The RUPP rat model revealed signs of hypertension and cardiac dysfunction and alterations in gene and protein expression within placental and heart tissues. G-1 treatment reduced blood pressure and reversed cardiac dysfunction in rats with preeclampsia. In contrast, administration of the vasodilator hydralazine reduced blood pressure without an improvement in cardiac function. In addition, while G-1 treatment restored the levels of sFLT-1 (soluble fms-like tyrosine kinase-1) in RUPP rats, hydralazine did not normalize this antiangiogenic factor. The therapeutic intervention of G-1 significantly mitigated the cardiovascular dysfunction observed in the RUPP rat model of preeclampsia. This discovery underscores the broader significance of understanding GPER's role in the context of preeclampsia-related cardiovascular complications.

Abstract P195: Vascular MAPK/ERK Activation in sFTL-1-Induced Preeclampsia In Vivo

Vascular endothelial growth factor (VEGF) inhibition is linked to the development of hypertension and proteinuria in preeclampsia. This occurs as anti-angiogenic factors from the placenta contribute to pregnancy-related hypertension disorder. Soluble VEGF receptor fms-like tyrosine kinase-1 (sFLT-1) is an anti-angiogenic factor that counteracts VEGF. Levels of sFLT-1 are three times higher in preeclamptic placentas compared to those from normotensive pregnancies, and plasma sFLT-1 levels increase with the severity of preeclampsia. Infusing sFLT-1 in rodents induces hypertension, proteinuria, and glomerular endotheliosis, resembling the human condition of preeclampsia. Currently, there is no effective pharmacological treatment of preeclampsia, and in severe cases, early delivery is often the only effective treatment. In this study, we aim to determine how sFLT-1 exposure affects the activation of the vascular MAPK/ERK pathway and the contractility of the aorta ex-vivo using wire myography, to assess if the MAPK/ERK pathway can be a therapeutic target in preeclampsia. To this end, we treated pregnant female C57BL/6 mice from embryonic day E7.5 to E18.5 with either sFLT-1 (3.7mg/kg/day) or vehicle (phosphate-buffered saline) delivered by osmotic minipumps (intraperitoneal) and carried out non-invasive tail-cuff blood pressure measurements. After sacrifice, we isolated descending thoracic aorta for isometric tension measurements in a wire myograph. Infusion of sFLT-1 resulted in marked systolic blood pressure (SBP) elevation (D increase of 14 mmHg, P=0.0003) and augmented aortic phosphorylated-ERK activation (2-fold increase, P=0.040) by western blot and displayed impaired acetylcholine-induced endothelial relaxation in thoracic aortic segments (P&lt;0.05), providing in vivo evidence of increased vascular p-ERK activation, accompanied by higher SBP and endothelial dysfunction in sFLT-1 - indued mouse model of preeclampsia. Future experiments are aimed to test the effect of pharmacological ERK inhibition in sFLT-1 infusion in vivo . We hypothesize that sFLT-1-induced rise in SBP and vascular p-ERK could be prevented in vivo by treatment with the pharmacological ERK inhibitor.

Value of the biomarker soluble tyrosine kinase 1 type fms (sFLT-1) in the diagnosis and prognosis of sepsis: a systematic review

IntroductionThe present systematic review analyses the role of soluble fms-like tyrosine kinase-1 (sFLT-1) as an indirect biomarCker of endothelial dysfunction in sepsis or septic shock from articles published in Pubmed between 2010 and March 2022. Materials and methodsA systematic review of studies studying sFLT-1 monitoring in intensive care units in adults with sepsis or septic shock vs. controls for sepsis diagnosis and prognosis has been carried out (PROSPERO CRD42023412929 Registry). ResultsThe endothelial dysfunction of sepsis is one of the keys to the development of the disease. VEGF binds to sFlt-1 acting as a competitive inhibitor of VEGF signalling in endothelial cells and thus neutralizes its pro-inflammatory effects. Endothelial dysfunction is reflected in increased sFLT-1 levels. High values of sFLT-1 were used for the differential diagnosis of sepsis versus other inflammatory pathologies, septic shock versus other types of shock, were elevated over time, estimation of disease prognosis, correlation with sepsis severity, organ dysfunction, and mortality prediction. ConclusionsIt is evident that sepsis is based on endothelial dysfunction. sFLT-1 is one of the main biomarkers of microvascular alteration and is a predictive diagnostic and prognostic biomarker.

Utility of placental biomarkers and fetoplacental Dopplers in predicting likely placental pathology in early and late fetal growth restriction – A prospective study

IntroductionThe aim of this study was to evaluate the association between placental abnormalities, placental biomarkers, and fetoplacental Dopplers in a cohort of pregnancies complicated by fetal growth restriction (FGR). We also ascertained the risk of perinatal mortality, severe neurological morbidity, and severe non-neurological morbidity by type of placental abnormality. MethodsThis was a prospective cohort study. Multivariable logistic regression was used to evaluate the effect of early vs. late FGR, placental biomarkers and fetoplacental Dopplers on Maternal Vascular Malperfusion (MVM) which was the commonest placental abnormality identified. ResultsThere were 161 (53.5 %) early FGR and 140 (46.5 %) late FGR cases. MVM abnormalities were present in 154 (51.2 %), VUE in 45 (14.6 %), FVM in 16 (5.3 %), DVM in 14 (4.7 %) and CHI in 4 (1.3 %) cases. The odds of MVM were higher in early compared to late FGR cohort (OR 1.89, 95%CI 1.14, 3.14, p = 0.01). Low maternal PlGF levels <100 ng/L (OR 2.34, 95%CI 1.27,4.31, p = 0.01), high sFlt-1 level (OR 2.13, 95%CI 1.35, 3.36, p = 0.001) or elevated sFlt-1/PlGF ratio (OR 3.48, 95%CI 1.36, 8.91, p = 0.01) were all associated with MVM. Increased UA PI > 95th centile (OR 2.91, 95%CI 1.71, 4.95, p=<0.001) and mean UtA PI z-score (OR 1.74, 95%CI 1.15, 2.64, p = 0.01) were associated with higher odds of MVM. Rates of severe non-neurological morbidity were highest in the MVM, FVM, and CHI cohorts (44.8 %, 50 %, and 50 % respectively). ConclusionMVM was the commonest placental abnormality in FGR, particularly in early-onset disease. Low maternal PlGF levels, high sFlt-1 levels, elevated sFlt-1/PlGF ratio, and abnormal fetoplacental Dopplers were also significantly associated with MVM. MVM, FVM, and CHI abnormalities were associated with lower median birthweight, higher rates of preterm birth, operative birth for non-reassuring fetal status, and severe neonatal non-neurological morbidity.

Predictive and Diagnostic Value of the Angiogenic Proteins in Patients With Chronic Kidney Disease.

Our objective was to investigate the predictive and diagnostic accuracy of the angiogenic proteins sFlt-1 (soluble fms-like tyrosine kinase-1) and PlGF (placental growth factor) for preterm preeclampsia and explore the relationship between renal function and these proteins. We completed a blinded, prospective, longitudinal, observational study of patients with chronic kidney disease followed at a tertiary center (2018-2023). Serum samples were obtained at 3 time points along gestation (planned sampling): 12-16, 18-22, and 28-32 weeks. In addition, samples were obtained whenever preeclampsia was suspected (indicated sampling). sFlt-1 and PlGF levels remained concealed until the study ended. The primary outcome was preterm preeclampsia. The planned and indicated samples were used to estimate the predictive and diagnostic accuracy of the angiogenic proteins, respectively. Of the 97 participants, 21 (21.6%) experienced preterm preeclampsia. In asymptomatic patients with chronic kidney disease, the angiogenic proteins were predictive of preterm preeclampsia only when sampled in the third trimester, in which case the sFlt-1/PlGF ratio (false positive rate of 37% for a detection rate of 80%) was more predictive than either sFlt-1 or PlGF in isolation. In patients with suspected preeclampsia, the diagnostic accuracy of the sFlt-1/PlGF ratio (false positive rate of 26% for a detection rate of 80%) was higher than that of sFlt-1 and PlGF in isolation. Diminished renal function was associated with increased levels of PlGF. sFlt-1 and PlGF can effectively predict and improve the diagnostic accuracy for preterm preeclampsia among patients with chronic kidney disease. The optimal sFlt-1/PlGF ratio cutoff to rule out preeclampsia may need to be lower in patients with impaired renal function.

Soluble Fms-like tyrosine kinase-1 as an endothelial dysfunction biomarker associated with pulmonary hypertension in adult patients with beta-thalassemia major.

The etiology of vascular problems in beta-thalassemia has been linked to endothelial damage. Antiangiogenic proteins such as soluble Fms-like tyrosine kinase-1 (sFLT-1) inhibit the signaling of vascular endothelial growth factor and placental growth factor, resulting in a decrease in the development of new blood vessels. Additionally, they promote the maturation of existing blood vessels and lead to endothelial dysfunction. This study aimed to assess the role of sFLT-1 in adult patients with beta-thalassemia major (TM) as a biomarker of endothelial dysfunction and its association with pulmonary hypertension (PHT). A total of 90 subjects were recruited and categorized into two groups: 45 patients with beta-TM, who were further divided based on the presence or absence of PHT, and 45 healthy individuals served as a control group. Serum sFLT-1 was determined using the enzyme-linked immunosorbent assay technique. The results revealed that Beta-TM patients had higher sFLT-1 levels than the control group. In addition, patients with PHT had significantly higher sFLT-1 levels compared to those without PHT. The levels of sFLT-1 were positively correlated with von Willebrand factor, serum ferritin, and high-sensitivity C-reactive protein. Regression analyses demonstrated a significant association between high sFLT-1 levels and the occurrence of PHT. Additionally, sFLT-1 (at a cutoff value of 8.84 pg/mL) demonstrated a sensitivity of 83.30% and a specificity of 80.0% in diagnosing thalassemic patients with PHT. In conclusion, beta-TM patients with elevated serum levels of sFLT-1 are at risk of developing endothelial dysfunction and subsequent development of PHT.

Abstract Tu003: The angiotensinogen/vasorin ratio in peripheral blood, a biomarker for preeclampsia

Background: Preeclampsia (PE) significantly impacts maternal and perinatal health worldwide. Despite limited treatment options, predictive tests could help in early diagnosis and personalized treatment/prevention strategies. Current biomarker, such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placenta growth factor (PIGF) offer reasonable negative predictive values, but their use as positive predictive markers is limited. Using unbiased discovery proteomics on urine extracellular vesicles (EV), followed by verification by ELISA and western blotting we identified a novel biomarker candidate for PE, vasorin (VASN), which is significantly decreased in PE, along with a known mediator of PE, angiotensinogen (AGT), that was significantly increased in PE as biomarker candidates. Hypothesis: Levels of AGT, VASN and their ratios in peripheral blood can be utilized as biomarkers for PE. Goals/Aims: 1) To determine gestational age (GA)-dependence of AGT, VASN and AGT/VASN plasma levels in human and murine pregnancy. 2) To assess disease association of AGT, VASN and AGT/VASN in a cohort of pregnant women with PE with severe features (sPE) and gestational age-matched normotensive pregnant women (NTP) and in a murine model of PE. Methods: Plasma was collected from GA-matched NTP and sPE. Timed pregnant mice were injected with adenoviral vector (AD) encoding sFLT-1 on embryonic day 10.5 (mouse PE), or with AD encoding enhanced green fluorescent protein injection (mouse control). AGT and VASN were measured by ELISA in human samples and were quantified by western blotting in murine samples. Results: AGT and AGT/VASN showed negative correlations with GA, while VASN levels showed positive correlation with GA in NTP and in mouse controls. PlGF and sFLT-1 levels had weak/no correlations with GA. AGT and AGT/VASN were significantly higher in sPE and mouse PE, while VASN was significantly decreased in sPE and mouse PE as compared to NTP and mouse controls, respectively. To differentiate between sPE vs NTP with receiver operating characteristic curve (ROC) for AGT/VASN: AUC (0.90), Sensitivity =92%, Specificity = 85% at AGT/VASN&gt;81.6. Conclusion: AGT and AGT/VASN ratio increase, and VASN decrease can serve as biomarkers for PE.