Vascular endothelial growth factors and risk of cardio-renal events: Results from the CREDENCE trial.

BACKGROUND: Circulating concentrations of vascular endothelial growth factor (VEGF) family members may be abnormally elevated in type 2 diabetes (T2D). The roles of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFLT-1), and VEGF-A in cardio-renal complications of T2D are not established. METHOD: The 2602 individuals with diabetic kidney disease (DKD) from the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation trial were randomized to receive canagliflozin or placebo and followed for incident cardio-renal outcomes. PlGF, sFLT-1, and VEGF-A were measured at baseline, year 1, and year 3. Primary outcome was a composite of end-stage kidney disease, doubling of the serum creatinine, or renal/cardiovascular death. Cox proportional hazard regression was used to investigate the association between biomarkers with adverse clinical events. RESULTS: At baseline, individuals with higher PlGF levels had more prevalent cardiovascular disease compared to those with lower values. Treatment with canagliflozin did not meaningfully change PlGF, sFLT-1, and VEGF-A concentrations at years 1 and 3. In a multivariable model, 1 unit increases in baseline log PlGF (hazard ratio [HR]: 1.76, 95% confidence interval [CI]: 1.23, 2.54, P-value = .002), sFLT-1 (HR: 3.34, [95% CI: 1.71, 6.52], P-value < .001), and PlGF/sFLT-1 ratio (HR: 4.83, [95% CI: 0.86, 27.01], P-value = .07) were associated with primary composite outcome, while 1 unit increase in log VEGF-A did not increase the risk of primary outcome (HR: 0.96 [95% CI: 0.81, 1.07]). Change by 1 year of each biomarker was also assessed: HR (95% CI) of primary composite outcome was 2.45 (1.70, 3.54) for 1 unit increase in 1-year concentration of log PlGF, 4.19 (2.18, 8.03) for 1 unit increase in 1-year concentration of log sFLT-1, and 21.08 (3.79, 117.4) for 1 unit increase in 1-year concentration of log PlGF/sFLT-1. Increase in 1-year concentrations of log VEGF-A was not associated with primary composite outcome (HR: 1.08, [95% CI: 0.93, 1.24], P-value = .30). CONCLUSIONS: People with T2D and DKD with elevated levels of PlGF, sFLT-1, and PlGF/sFLT-1 ratio were at a higher risk for cardiorenal events. Canagliflozin did not meaningfully decrease concentrations of PlGF, sFLT-1, and VEGF-A. CLINICAL TRIAL: CREDENCE, https://clinicaltrials.gov/ct2/show/NCT02065791.

Reference Interval of Soluble FMS­like Tyrosine Kinase­1 in Non-Pregnant and Pregnant Females: A Novel Biomarker for Pre-eclampsia.

OBJECTIVE: To determine the reference interval of soluble FMS-like tyrosine kinase-1 (sFIt-1) in healthy, non-pregnant and pregnant females. STUDY DESIGN: Observational study. Place and Duration of the Study: Department of Chemical Pathology, Chughtai Institute of Pathology, Lahore, from January to May 2023. METHODOLOGY: Blood samples were collected from 120 disease-free non-pregnant females of reproductive age group and 120 disease-free pregnant females with singleton fetuses from 15 to 28 weeks of gestational age. Healthy reference individuals were selected by correlating history with medical disorders like diabetes mellitus, hypertension, autoimmune diseases, inherited disorders, and by excluding any other drug history. All findings were recorded on health screening questionnaire. Levels of sFlt-1 were measured by a fully automated immunoassay analyser Cobas e601. Kolmogorov-Smirnov test was applied. The value of p <0.05 was considered significant. The 2.5th and 97.5th percentiles were computed at 90% CI by using the formula 0.025x (n+1) and 0.975x (n+1) which corresponded to rank number 1 and 7, respectively. The reference interval was calculated by the Rank-based method. RESULTS: Reference interval of sFlt-1 in non-pregnant and pregnant females were determined on the basis of 2.5th and 97.5th percentiles which were 57.7 to 118.5 pg/mL and 563.5 to 3288.0 pg/mL, respectively. CONCLUSION: The present study determined reference interval of sFlt-1 in healthy, non-pregnant and pregnant females in Lahore. KEY WORDS: Reference interval, Soluble FMS-like tyrosine kinase-1, Pre-eclampsia, Rank-based method.

Aspirin Discontinuation at 24 to 28 Weeks' Gestation in Pregnancies at High Risk of Preterm Preeclampsia: A Randomized Clinical Trial.

Importance: Aspirin reduces the incidence of preterm preeclampsia by 62% in pregnant individuals at high risk of preeclampsia. However, aspirin might be associated with an increased risk of peripartum bleeding, which could be mitigated by discontinuing aspirin before term (37 weeks of gestation) and by an accurate selection of individuals at higher risk of preeclampsia in the first trimester of pregnancy. Objective: To determine whether aspirin discontinuation in pregnant individuals with normal soluble fms-like tyrosine kinase-1 to placental growth factor (sFlt-1:PlGF) ratio between 24 and 28 weeks of gestation was noninferior to aspirin continuation to prevent preterm preeclampsia. Design, Setting, and Participants: Multicenter, open-label, randomized, phase 3, noninferiority trial conducted in 9 maternity hospitals across Spain. Pregnant individuals (n = 968) at high risk of preeclampsia during the first-trimester screening and an sFlt-1:PlGF ratio of 38 or less at 24 to 28 weeks of gestation were recruited between August 20, 2019, and September 15, 2021; of those, 936 were analyzed (intervention: n = 473; control: n = 463). Follow-up was until delivery for all participants. Interventions: Enrolled patients were randomly assigned in a 1:1 ratio to aspirin discontinuation (intervention group) or aspirin continuation until 36 weeks of gestation (control group). Main Outcomes and Measures: Noninferiority was met if the higher 95% CI for the difference in preterm preeclampsia incidences between groups was less than 1.9%. Results: Among the 936 participants, the mean (SD) age was 32.4 (5.8) years; 3.4% were Black and 93% were White. The incidence of preterm preeclampsia was 1.48% (7/473) in the intervention group and 1.73% (8/463) in the control group (absolute difference, -0.25% [95% CI, -1.86% to 1.36%]), indicating noninferiority. Conclusions and Relevance: Aspirin discontinuation at 24 to 28 weeks of gestation was noninferior to aspirin continuation for preventing preterm preeclampsia in pregnant individuals at high risk of preeclampsia and a normal sFlt-1:PlGF ratio. Trial Registration: ClinicalTrials.gov Identifier: NCT03741179 and ClinicalTrialsRegister.eu Identifier: 2018-000811-26.

Vascular Endothelial Growth Factor and Its Soluble Receptor in Systemic Lupus Erythematosus Patients.

Vascular endothelial growth factor (VEGF) is a major regulator of physiological and pathological angiogenesis. Its soluble receptor (sVEGFR) is a potent VEGF antagonist. Systemic lupus erythematosus (SLE) is an autoimmune disease with a diverse array of clinical manifestations that affect virtually any organ. We aimed to analyze the relationship of VEGF and sVEGFR with SLE disease-related features including disease activity, damage, and severity. Serum levels of VEGF165 isoform and sVEGFR (receptor 1) were assessed in 284 well-characterized patients with SLE. Linear regression analysis was performed to analyze the relationship of disease characteristics with both VEGF and sVEGFR. Patients with a disease damage index (SLICC score) equal to or greater than 1 had significantly elevated serum levels of VEGF and sVEGFR. Regarding disease-specific features, musculoskeletal manifestations were the disease feature most commonly associated with the upregulation of both VEGF and sVEGFR. SLE disease damage is associated with higher levels of VEGF and sVEGFR.

Associations Between Soluble fms-Like Tyrosine Kinase-1 and Placental Growth Factor and Disease Severity Among Women With Preterm Eclampsia and Preeclampsia.

Background The angiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are postulated to be pathogenic disease drivers of preeclampsia. If true, then circulating levels should become more deranged with increasing disease severity. Methods and Results We investigated the association between circulating sFlt-1 and PlGF levels and severe adverse maternal outcomes among 348 women with preeclampsia. Compared with 125 women with preeclampsia without severe features, 25 women with preeclampsia and any of hemolysis, elevated liver enzymes, low platelet count syndrome, disseminated intravascular coagulation, or severe renal involvement had sFlt-1 levels that were 2.63-fold higher (95% CI, 1.81-3.82), sFlt-1/PlGF levels that were 10.07-fold higher (95% CI, 5.36-18.91) and PlGF levels that were 74% lower (adjusted fold change, 0.26 [95% CI, 0.18-0.39]). Compared with 125 women with preeclampsia without severe features, 37 with eclampsia had sFlt-1 levels that were 2-fold higher (2.02 [95% CI, 1.32-3.09]), sFlt-1/PIGF levels that were 4.71-fold higher (95% CI, 2.30-9.66) and PIGF levels that were 63% lower (0.43-fold change [95% CI, 0.27-0.68]). Compared with those without severe features, preeclampsia with severe hypertension (n=146) was also associated with altered angiogenic levels (sFlt-1, 1.71-fold change [95% CI, 1.39-2.11]; sFlt/PlGF, 2.91 [95% CI, 2.04-4.15]; PlGF, 0.59 [95%CI 0.47-0.74]). We also found that sFlt-1 and PlGF levels were altered by the number of maternal complications experienced. Conclusions Further angiogenic imbalance among women with preeclampsia is likely a pathogenic disease driver responsible for the life-threatening maternal complications.

Distinguishing placenta accreta from placenta previa via maternal plasma levels of sFlt-1 and PLGF and the sFlt-1/PLGF ratio.

INTRODUCTION: Our study aimed to distinguish patients with placenta accreta (crete, increta, and percreta) from those with placenta previa using maternal plasma levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PLGF) and the sFlt-1/PLGF ratio. METHODS: We obtained maternal plasma from 185 women in late pregnancy and sorted them into three groups: 72 women with normal placental imaging results (control group), 50 women with placenta previa alone (PP group), and 63 women with placenta previa and placenta accreta (PAS group). The concentrations of sFlt-1 and PLGF in the maternal plasma were measured using ELISA kits and the sFlt-1/PLGF ratio was calculated. RESULT: The median (min-max) sFlt-1 levels and the sFlt-1/PLGF ratio in the PAS group (12.8 ng/ml, 3.8-34.2 ng/ml) (133, 14-361) were lower than in the PP group (28.7 ng/ml, 13.1-60.3 ng/ml) (621, 156-2013) (p < 0.0001 and P < 0.0001, respectively). The median (min-max) PLGF levels in the PAS group (108 pg/ml, 38-679 pg/ml) was higher than that in the PP group (43 pg/ml, 12-111 pg/ml) (p < 0.0001 and p < 0.0001, respectively). The area under the ROC of the sFlt-1 levels, PLGF levels, and sFlt-1/PLGF ratio were 0.91, 0.90, and 0.99, respectively; the cut-off values were 18.9 ng/ml, 75.9 pg/ml, and 229.5, respectively. The concentration of sFlt-1 and sFlt-1/PLGF ratio were associated with the volume of blood loss (-.288*, -.301*). DISCUSSION: The concentrations of sFlt-1 and PLGF and ratio of plasma sFlt-1/PLGF may distinguish patients with placenta accreta from those with placenta previa.

sFlt-1/PlGF Ratio at 24 Weeks Gestation in Twin Pregnancies as a Predictor of Preeclampsia or Fetal Growth Restriction.

INTRODUCTION: The objective was to elucidate if the sFlt-1/PlGF ratio at 24 weeks in twin pregnancies could be useful to select patients who subsequently develop diseases related to placental dysfunction, such as preeclampsia or fetal growth restriction (FGR). METHODS: This was a prospective study among all twin pregnancies followed up at a tertiary hospital. The sFlt-1/PlGF ratio was determined at 24 weeks. RESULTS: A total of 108 patients with a twin gestation were included. Pregnant women who developed preeclampsia and/or FGR displayed a significantly higher sFlt-1/PlGF ratio at 24 weeks, compared to those who did not develop these diseases (20.3 vs. 4.3, p = 0.002). The mean sFlt-1/PlGF ratio was not significantly different between patients who subsequently developed preeclampsia compared with those that developed FGR (29.8 vs. 18.45, p = 0.42). A sFlt-1/PlGF ratio ≥17 at 24 weeks is associated with a significant increase in the frequency of preeclampsia (odds ratio, 37.13 [95% confidence interval, 4.78-288.25]; p = 0.002), and FGR (odds ratio, 39.58 [95% confidence interval, 6.31-248.17]; p < 0.001). The addition of maternal characteristics and mean pulsatility index of the uterine arteries to the sFlt-1/PlGF ratio at 24 weeks enhances the identification of patients who develop preeclampsia or FGR. CONCLUSION: The sFlt-1/PlGF ratio at 24 weeks in twin pregnancies, combined with the mean pulsatility index of the uterine arteries and maternal characteristics, could select patients who develop preeclampsia or FGR. These patients might benefit from a close follow-up in order to avoid maternal-fetal adverse outcomes.

The feasibility of soluble Fms-Like Tyrosine kinase-1 (sFLT-1) and Placental Growth Factor (PlGF) ratio biomarker in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers in Kuala Lumpur, Malaysia.

BACKGROUND: Preeclampsia significantly contributes to maternal and perinatal morbidity and mortality. It is imperative to identify women at risk of developing preeclampsia in the effort to prevent adverse pregnancy outcomes through early intervention. Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) level changes are noticeable several weeks before the onset of preeclampsia and its related complications. This study evaluated the feasibility of the sFlt-1/PlGF biomarker ratio in predicting preeclampsia and adverse pregnancy outcomes using a single cut-off point of >38. METHODS: This is a prospective cohort study conducted at a single tertiary centre, in an urban setting in Kuala Lumpur, Malaysia, between December 2019 and April 2021. A total of 140 medium to high risk mothers with singleton pregnancies were recruited at ≥20 weeks' gestation. sFlt-1/PlGF ratio was measured and the participant monitored according to a research algorithm until delivery. The primary outcome measure was incidence of preeclampsia and the secondary outcome measure was incidence of other adverse pregnancy outcomes. RESULTS: The overall incidence of preeclampsia was 20.7% (29/140). The mean sFlt-1/PlGF ratio was significantly higher in preeclampsia (73.58 ± 93.49) compared to no preeclampsia (13.41 ± 21.63) (p = 0.002). The risk of preeclampsia (adjusted OR 28.996; 95% CI 7.920-106.164; p<0.001) and low Apgar score (adjusted OR 17.387; 95% CI 3.069-98.517; p = 0.028) were significantly higher among women with sFlt-1/PlGF ratio >38 compared with sFLT-1/PlGF ratio ≤38. The area under the receiver-operator characteristic curve (AUC) for a combined approach (maternal clinical characteristics and biomarker) was 86.9% (p<0.001, 95% CI 78.7-95.0) compared with AUC biomarker alone, which was 74.8% (p<0.001, 95% CI 63.3-86.3) in predicting preeclampsia. The test sensitivity(SEN) was 58.6%, specificity (SPEC) 91%,positive predictive value (PPV) 63% and negative predictive value (NPV) 89.3% for prediction of preeclampsia. For predicting a low Apgar score at 5 minutes, the SEN was 84.6%, SPEC 87.4%, PPV 40.7%, and NPV 98.2%; low birth weight with SEN 52.6%,SPEC 86.0%, PPV 37.0%, NPV 92.0%; premature delivery with SEN 48.5%, SPEC 89.5%, PPV 59.3%, NPV 84.7% and NICU admission with SEN 50.0%, SPEC 85.8%, PPV 37.0% and NPV 91.2%. CONCLUSIONS: It is feasible to use single cut-off point of >38 ratio of the biomarkers sFlt-1/PlGF in combination with other parameters (maternal clinical characteristics) in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers without restricting outcome measurement period to 1 and 4 weeks in a single urban tertiary centre in Kuala Lumpur, Malaysia.

Soluble Fms-like tyrosine kinase-1 (sFlt-1) is associated with subclinical and clinical atherosclerotic cardiovascular disease: The Dallas Heart Study.

BACKGROUND AND AIMS: Soluble Fms-like tyrosine kinase-1 (sFlt-1) plays a role in angiogenesis, atherogenesis, and preeclampsia. The relationship of sFlt-1 with markers of subclinical atherosclerosis and future atherosclerotic cardiovascular disease (ASCVD) events in a generally healthy population is unknown. METHODS: Participants in the Dallas Heart Study with sFlt-1 measured were included (n = 3292). Abdominal aortic atherosclerosis was measured by MRI and coronary artery calcium (CAC) by CT. The cohort was also followed for subsequent ASCVD events (CV death, MI, stroke, unstable angina, revascularization). Multivariable linear and logistic regression analyses and Cox regression analyses were performed adjusting for demographics and traditional cardiac risk factors. RESULTS: sFlt-1 levels were higher in older individuals, males, and African Americans, and tracked with most traditional risk factors. sFlt-1 was significantly associated with higher prevalence of aortic plaque [OR 1.33 (95% CI 1.02-1.73)], greater abdominal aortic wall thickness (p<0.01) and aortic plaque area (p<0.02) but no difference in coronary artery calcification. There were 322 ASCVD events over 12 years of follow-up. Higher sFlt-1 levels associated with increased ASCVD events in unadjusted (16.1% vs. 8.9%, p<0.001, quartile 4 vs. quartile 1) and adjusted analyses (HR 1.58 [1.14-2.18], p<0.01, quartile 4 vs. quartile 1). Findings were unchanged when analyzing sFlt-1 as a continuous variable or when excluding those with a history of ASCVD. CONCLUSIONS: In a population-based cohort, sFlt-1 is associated with measures of subclinical aortic atherosclerosis and clinical ASCVD events. Future studies are warranted on the therapeutic potential of targeting sFlt-1 for atherosclerotic disease.

Comparison of circulating total sFLT-1 to placental-specific sFLT-1 e15a in women with suspected preeclampsia.

INTRODUCTION: Soluble fms-like tyrosine kinase 1 (sFLT-1), a circulating anti-angiogenic factor that binds and antagonizes placental growth factor (PlGF), appears key to preeclamptic pathophysiology. Two main sFLT-1 splice variants exist: sFLT-1 e15a and sFLT-1 i13. Total sFLT-1/PlGF ratios are increasingly used clinically; we explore whether using placental-specific sFLT-1 e15a improves test performance compared with total sFLT-1 in preeclampsia diagnosis. METHODS: Consent was obtained for serum sampling from 96 women with suspected preeclampsia. Total sFLT-1 and PlGF were quantified using the B.R.A.H.M.S Kryptor Compact Plus automated immunoassay platform, and sFLT-1 e15a by custom enzyme-linked immunosorbent assay. Test performance was then assessed by subsequent diagnosis. RESULTS: Of 96 participants, 32 did not develop preeclampsia, 32 had early-onset (<34 weeks') disease and 32 had late-onset (≥34 weeks') disease. In those with preeclampsia, median sFLT-1 and sFLT-1 e15a were significantly increased (7361.0 vs 2463.0 pg/mL, and 946.6 vs 305.4 ng/mL respectively; p < 0.001 for both), and PlGF significantly reduced (43.5 vs 154.4 pg/mL; p < 0.001) compared to those without preeclampsia. Those with early-onset, compared to late-onset, preeclampsia chiefly had lower median PlGF levels (16.0 vs 57.3; p < 0.001), which contributed to higher sFLT-1/PlGF and sFLT-1 e15a/PlGF ratios (830.1 vs 86.7, and 109258.9 vs 12608.7 respectively; p < 0.001 for both). DISCUSSION: sFLT-1 e15a performs comparably to total sFLT-1 in women with suspected preeclampsia, however with higher translational burden. Our results support the expanding clinical use of the sFLT-1/PlGF ratio in suspected preeclampsia, particularly early-onset, to assist with disease diagnosis.

sFlt-1/PlGF ratio for prediction of preeclampsia in clinical routine: A pragmatic real-world analysis of healthcare resource utilisation.

BACKGROUND: We investigated the impact of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio to predict short-term risk of preeclampsia on clinical utility and healthcare resource utilisation using real-world data (RWD), and compared findings with health economic modelling from previous studies. METHODS AND FINDINGS: This retrospective analysis compared data from the German population of a multicentre clinical study (PROGNOSIS, n = 203; sFlt-1/PlGF ratio blinded and unavailable for decision-making) with RWD from University Hospital Leipzig, Germany (n = 281; sFlt-1/PlGF ratio used to guide clinical decision-making). A subgroup of the RWD cohort with the same inclusion criteria as the PROGNOSIS trial (RWD prediction only, n = 99) was also included. sFlt-1/PlGF ratio was measured using fully automated Elecsys® sFlt-1 and PlGF immunoassays (cobas e analyser; Roche Diagnostics). A similar proportion of women in the RWD and PROGNOSIS cohorts experienced preeclampsia (14.95% vs. 13.79%; p = 0.7938); a smaller proportion of women in the RWD prediction only cohort experienced preeclampsia versus PROGNOSIS (6.06%; p = 0.0526). In women with preeclampsia, median gestational age at delivery (weeks) was comparable in the RWD and PROGNOSIS cohorts (34.0 vs. 34.3, p = 0.5895), but significantly reduced in the RWD prediction only cohort versus PROGNOSIS (27.1, p = 0.0038). sFlt-1/PlGF ratio at baseline visit was not statistically significantly different for the RWD and PROGNOSIS cohorts, irrespective of preeclampsia outcome. Hospitalisations for confirmed preeclampsia were significantly shorter in the RWD cohort versus PROGNOSIS (median 1 vs. 4 days, p = 0.0093); there was no significant difference between RWD prediction only and PROGNOSIS (3 days, p = 0.9638). All-cause hospitalisations were significantly shorter in the RWD (median 1 day; p<0.0001) and RWD prediction only (1 day; p<0.0001) cohorts versus PROGNOSIS (3 days). CONCLUSIONS: This study supports the findings of previous studies, showing that routine clinical use of the sFlt-1/PlGF ratio may result in shorter duration of hospitalisations, with potential economic benefits.

Association of soluble Flt-1 with heart failure and cardiac morphology: The MESA angiogenesis study.

BACKGROUND: Soluble Fms-like tyrosine kinase 1 (sFlt-1) may inhibit angiogenesis. Higher levels of sFlt-1 are associated with worse prognosis in prevalent heart failure patients. The aim of this study was to better understand the role of sFlt-1 in heart failure pathogenesis by characterizing relationships between sFlt-1, cardiac morphology, and the composite outcome of incident heart failure or cardiovascular (CV) death in in a multiethnic cohort free of CV disease at baseline. METHODS: sFlt-1 was measured in 1,381 participants in the Multi-Ethnic Study of Atherosclerosis Angiogenesis sub-study. Linear regression was used to estimate the association between sFlt-1 and cardiac morphology and Cox proportional hazard regression was used to estimate associations with incident heart failure or CV mortality. RESULTS: Over a median follow-up of 13.1 years, higher sFlt-1 levels were associated with incident heart failure or CV mortality independent from CV risk factors or NT-proBNP levels (HR 1.17, 95% CI 1.10-1.26, p < 0.001). Higher sFlt-1 levels were also associated with greater baseline left ventricular (LV) mass by cardiac MRI and increased loss of LV mass over the 10 years following the baseline exam (p-value 0.02 for each), but this association was no longer statistically significant after adjustment for baseline NT-proBNP (p = 0.11 and 0.10 respectively). CONCLUSIONS: Baseline sFlt-1 levels are associated with incident heart failure and cardiovascular mortality independent of traditional CV risk factors or NT-proBNP. An association was also found with cardiac mass but was no longer significant after adjustment for NT-proBNP.

Preeclampsia at delivery is associated with lower serum vitamin D and higher antiangiogenic factors: a case control study.

BACKGROUND: Preeclampsia is characterized by decreased trophoblastic angiogenesis leading to abnormal invasion of spiral arteries, shallow implantation and resulting in compromised placentation with poor uteroplacental perfusion. Vitamin D plays an important role in pregnancy influencing implantation, angiogenesis and placental development. The objective of this study was to determine whether there is an association between serum vitamin D levels, and anti-angiogenic factors at the time of delivery and the occurrence of preeclampsia. METHODS: This nested case control study analyzed frozen serum samples at the time of delivery and related clinical data from women with singleton liveborn pregnancies who had participated in studies of the NICHD Stillbirth Collaborative Research Network. Women with a recorded finding of preeclampsia and who had received magnesium sulfate treatment prior to delivery were considered index cases (N = 56). Women without a finding of preeclampsia were controls (N = 341). RESULTS: Women with preeclampsia had 14.5% lower serum vitamin D levels than women in the control group (16.5 ng/ml vs. 19 ng/ml, p = 0.014) with 64.5% higher sFlt-1 levels (11,600 pg/ml vs. 7050 pg/ml, p < 0.001) and greater than 2 times higher endoglin levels (18.6 ng/ml vs. 8.7 ng/ml, < 0.001). After controlling for gestational age at delivery and maternal BMI, vitamin D levels were 0.88 times lower (P = 0.051), while endoglin levels were 2.5 times higher and sFlt-1 levels were 2.1 times higher than in control pregnancies (P < 0.001). CONCLUSIONS: Women with preeclampsia at time of delivery have higher maternal antiangiogenetic factors and may have lower maternal serum vitamin D levels. These findings may lead to a better understanding of the underlying etiology of preeclampsia as well as possible modifiable treatment options which could include assuring adequate levels of maternal serum vitamin D prior to pregnancy.

Maternal Cardiac Function at Midgestation and Development of Preeclampsia.

BACKGROUND: Preeclampsia (PE) is an independent risk factor for adverse maternal cardiovascular outcomes. The role of maternal cardiac function in the pathophysiology of PE remains unclear. OBJECTIVES: This study sought to describe differences in cardiac function at midgestation between women who develop PE and those with uncomplicated pregnancy and to establish whether routine cardiac assessment at midgestation can improve performance of screening for PE achieved by established biomarkers. METHODS: Mean arterial pressure was measured, medical history was obtained, and left ventricular (LV) systolic and diastolic functions were assessed using standard echocardiography and speckle tracking imaging. Uterine artery pulsatility index and serum placental growth factor and soluble fms-like tyrosine kinase-1 were measured. RESULTS: In 4,795 pregnancies, 126 (2.6%) developed PE. Following multivariable analysis, peripheral vascular resistance was significantly higher and LV global longitudinal systolic strain, ejection fraction, cardiac output, and left atrial area were mildly lower in women who developed PE compared to those who did not. There was a weak association between maternal cardiovascular indices and biomarkers of placental perfusion and function. Cardiac indices did not improve the performance of screening for PE on top of maternal risk factors, mean arterial pressure, and biomarkers of placental perfusion and function. CONCLUSION: Women who develop PE have an increase in peripheral vascular resistance and a mild reduction in LV functional cardiac indices long before PE development. However, cardiac indices do not improve the performance of screening for PE; thus, their routine clinical use is not advocated.

sFlt-1/PlGF ratio in hypertensive disorders of pregnancy in patients affected by COVID-19.

OBJECTIVES: To analyze soluble Fms-like tyrosine Kinase 1 (sFlt-1) and Placental Growth Factor (PlGF) ratio concentrations in COVID-19 pregnant patients with and without Hypertensive Disorders of Pregnancy (HDP), compared with non COVID-19 pregnant patients with HDP and a control group. STUDY DESIGN: We recruited and obtained a complete follow-up of 19 COVID-19 pregnant patients with HDP and of 24 COVID-19 normotensive pregnant patients. Demographic, clinical and sFlt-1/PlGF ratio findings were compared with a group of 185 non COVID-19 pregnant patients with HDP and 41 non COVID normotensive patients. Findings were based on univariate analysis and on a multivariate adjusted model, and a case by case analysis of COVID-19 pregnant patients with an abnormal sFlt-1/PlGF ratio > 38 at recruitment. MAIN OUTCOME MEASURES: sFlt-1/PlGF ratio. RESULTS: We confirmed a significant higher prevalence of HDP in women affected by COVID-19 compared to control population. sFlt-1/PlGF ratio was found high in HDP patients, with and without of Sars-Cov2 infection. COVID-19 patients with worse evolution of the disease showed greater rates of obesity and other comorbidities. sFlt/PlGF ratio proved not to be helpful in the differential diagnosis of the severity of this infection. CONCLUSIONS: COVID-19 pregnant patients showed a higher prevalence of HDP compared to non COVID-19 controls, as well as higher comorbidity rates. In spite of the possible common endothelial target and damage, between Sars-Cov-2 infection and HDP, the sFlt1/PlGF ratio did not correlate with the severity of this syndrome.

Prediction of preeclampsia throughout gestation with maternal characteristics and biophysical and biochemical markers: a longitudinal study.

BACKGROUND: The current approach to predict preeclampsia combines maternal risk factors and evidence from biophysical markers (mean arterial pressure, Doppler velocimetry of the uterine arteries) and maternal blood proteins (placental growth factor, soluble vascular endothelial growth factor receptor-1, pregnancy-associated plasma protein A). Such models require the transformation of biomarker data into multiples of the mean values by using population- and site-specific models. Previous studies have focused on a narrow window in gestation and have not included the maternal blood concentration of soluble endoglin, an important antiangiogenic factor up-regulated in preeclampsia. OBJECTIVE: This study aimed (1) to develop models for the calculation of multiples of the mean values for mean arterial pressure and biochemical markers; (2) to build and assess the predictive models for preeclampsia based on maternal risk factors, the biophysical (mean arterial pressure) and biochemical (placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin) markers collected throughout pregnancy; and (3) to evaluate how prediction accuracy is affected by the presence of chronic hypertension and gestational age. STUDY DESIGN: This longitudinal case-cohort study included 1150 pregnant women: women without preeclampsia with (n=49) and without chronic hypertension (n=871) and those who developed preeclampsia (n=166) or superimposed preeclampsia (n=64). Mean arterial pressure and immunoassay-based maternal plasma placental growth factor, soluble vascular endothelial growth factor receptor-1, and soluble endoglin concentrations were available throughout pregnancy (median of 5 observations per patient). A prior-risk model for preeclampsia was established by using Poisson regression based on maternal characteristics and obstetrical history. Next, multiple regression was used to fit biophysical and biochemical marker data as a function of maternal characteristics by using data collected at 8 to 15+6, 16 to 19+6, 20 to 23+6, 24 to 27+6, 28 to 31+6, and 32 to 36+6 week intervals, and observed values were converted into multiples of the mean values. Then, multivariable prediction models for preeclampsia were fit based on the biomarker multiples of the mean data and prior-risk estimates. Separate models were derived for overall, preterm, and term preeclampsia, which were evaluated by receiver operating characteristic curves and sensitivity at fixed false-positive rates. RESULTS: (1) The inclusion of soluble endoglin in prediction models for all preeclampsia, together with the prior-risk estimates, mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1, increased the sensitivity (at a fixed false-positive rate of 10%) for early prediction of superimposed preeclampsia, with the largest increase (from 44% to 54%) noted at 20 to 23+6 weeks (McNemar test, P<.05); (2) combined evidence from prior-risk estimates and biomarkers predicted preterm preeclampsia with a sensitivity (false-positive rate, 10%) of 55%, 48%, 62%, 72%, and 84% at 8 to 15+6, 16 to 19+6, 20 to 23+6, 24 to 27+6, and 28 to 31+6 week intervals, respectively; (3) the sensitivity for term preeclampsia (false-positive rate, 10%) was 36%, 36%, 41%, 43%, 39%, and 51% at 8 to 15+6, 16 to 19+6, 20 to 23+6, 24 to 27+6, 28 to 31+6, and 32 to 36+6 week intervals, respectively; (4) the detection rate for superimposed preeclampsia among women with chronic hypertension was similar to that in women without chronic hypertension, especially earlier in pregnancy, reaching at most 54% at 20 to 23+6 weeks (false-positive rate, 10%); and (5) prediction models performed comparably to the Fetal Medicine Foundation calculators when the same maternal risk factors and biomarkers (mean arterial pressure, placental growth factor, and soluble vascular endothelial growth factor receptor-1 multiples of the mean values) were used as input. CONCLUSION: We introduced prediction models for preeclampsia throughout pregnancy. These models can be useful to identify women at risk during the first trimester who could benefit from aspirin treatment or later in pregnancy to inform patient management. Relative to prediction performance at 8 to 15+6 weeks, there was a substantial improvement in the detection rate for preterm and term preeclampsia by using data collected after 20 and 32 weeks' gestation, respectively. The inclusion of plasma soluble endoglin improves the early prediction of superimposed preeclampsia, which may be valuable when Doppler velocimetry of the uterine arteries is not available.

Rule-in and rule-out of pre-eclampsia using DELFIA Xpress PlGF 1-2-3 and sFlt-1: PlGF ratio.

OBJECTIVES: The objective of this study was to explore and validate thresholds for Placental growth factor (PlGF) and soluble fms-like tyrosine-kinase 1 (s-Flt-1) (as s-Flt-1: PlGF ratio), to rule-in and rule-out disease in women with suspected pre-eclampsia, using DELFIA® Xpress PlGF1-2-3 and sFlt-1 assays. STUDY DESIGN: 369 samples from women with suspected or confirmed pre-eclampsia were analysed from a prospective cohort study. MAIN OUTCOME MEASURES: Serum PlGF and sFlt-1: PlGF were quantified using DELFIA® Xpress PlGF1-2-3 and DELFIA® Xpress sFlt-1 tests. Performances were evaluated at established and exploratory thresholds. Low PlGF concentration and sFlt-1: PlGF AUROC were compared. RESULTS: PlGF 1-2-3 concentration thresholds were confirmed to have high performance for rule-in (<50 pg/ml) and rule-out (≥150 pg/ml) pre-eclampsia within seven days (20-33+6 Weeks <50 pg/ml: Negative predictive value (NPV) 90.7% (95% CI 83.9, 95.3); ≥150 pg/ml: NPV 94.8% (95% CI 88.4, 98.3)) and 28 days (20-33+6 Weeks <50 pg/ml: Negative predictive value (NPV) 83.9% (95% CI 76.0, 90.0); ≥150 pg/ml: NPV 92.8% (95% CI 85.7, 97.0)). Optimal sFlt-1: PlGF thresholds for rule-in were ≥ 70 before 34 weeks and ≥ 90 after 34 weeks, and <50 to rule-out pre-eclampsia. Low PlGF alone had comparable performance to sFlt-1: PlGF, but test performance for both was reduced in women with Kidney Disease. CONCLUSIONS: DELFIA® Xpress PlGF1-2-3 and sFlt-1 assays for pre-eclampsia rule-in and rule-out have comparable performance to other established assays, and could be an alternative for clinical use. Performance was not enhanced by use of sFlt-1: PlGF ratio, suggesting that PlGF alone could provide a cheaper alternative to dual biomarker testing.

Clinical interpretation and implementation of the sFlt-1/PlGF ratio in the prediction, diagnosis and management of preeclampsia.

Preeclampsia is associated with significant morbidity and mortality for mother and baby. Although around 30% of all pregnancies are evaluated for preeclampsia, diagnosis is difficult, especially in patients who have overlying symptoms from other diseases. Discovery of circulating angiogenic factors in the pathogenesis of preeclampsia has been a major advance for both diagnosis and prognosis. The anti-angiogenic factor, soluble fms-like tyrosine kinase 1 (sFlt-1) and the pro-angiogenic factor, placental growth factor (PlGF), can be measured in plasma and serum and are usually reported as a ratio, which specifically relates to the onset and severity of preeclampsia. The sFlt-1/PlGF ratio has a very high negative predictive value in ruling out the development of preeclampsia within 7 days among women with suspected preeclampsia. Currently, there is no clear consensus on the practical use of angiogenic biomarkers in the detection and management of preeclampsia in routine clinical practice. While major international clinical guidelines exist, they do not define which specific parameters signal patient admission, or outpatient evaluation of suspected preeclampsia, and most clinicians follow local practices. Better guidance is needed on risk stratification among women with suspected preeclampsia, as well as among women at high risk for preeclampsia. Prediction of adverse outcomes in women, after the clinical diagnosis of preeclampsia, is also important. This report has been developed following a meeting of international experts and aims to guide clinicians in the management of pregnant women at risk of preeclampsia using the sFlt-1/PlGF ratio test.

Determination of serum vascular endothelial growth factor (VEGF) and VEGF receptor levels with VEGF gene polymorphisms in patients with Behçet's uveitis.

BACKGROUND: Behçet's disease (BD) is a chronic inflammatory vasculitis affecting multiple organs. Uveitis is frequently seen in patients with BD, especially in Turkish population. OBJECTIVES: To investigate vascular endothelial growth factor (VEGF) gene polymorphisms along with the levels of VEGF and VEGF receptors in patients with Behçet's uveitis (BU). MATERIAL AND METHODS: Fifty-five BD-associated uveitis patients and 30 ageand sex-matched controls were included in this case-control study. The genotypes of the single nucleotide poymorphisms (SNPs): rs2010963 (+405G), rs3025039 (+936T) and rs699947 (-2598A) of the VEGF-A gene were determined using real-time polymerase chain reaction (RT-PCR) and serum levels of VEGF and VEGF receptors were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: No associations of the VEGF gene polymorphisms were observed in BD uveitis patients, but arthritis was present in 53.3% of patients not possessing CT genotype in C3025039→T polymorphism (p = 0.024). Although there were no statistically significant differences in serum VEGF-A, VEGF-C and soluble vascular endothelial growth factor receptor-3 (sVEGFR-3) levels (p < 0.05), serum vascular endothelial growth factor receptor-1 (VEGFR-1) and sVEGFR-3 levels were significantly higher in the BD group (p < 0.001 and p = 0.001, respectively). In addition, VEGF-C/soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) ratio was significantly higher (p < 0.001), while VEGF-A/VEGFR-1 and VEGF-C/sVEGFR-3 ratios were significantly lower (p < 0.001 and p = 0.033, respectively) in BD patients compared to controls. Also, VEGF-C/sVEGFR-3 (p = 0.024, r = 0.37) and VEGF-C/sVEGFR-2 (p = 0.020, r = 0.38) ratios were positively correlated with disease duration. CONCLUSIONS: The significant changes in sVEGFR-3 levels and VEGF-C/sVEGFR-3 ratio has shown that lymphangiogenesis processes might take place in the pathogenesis of BD uveitis, and these parameters can be important indicators of evaluation of BD patients with uveitis together with disease duration.

Increased levels of soluble fms-like tyrosine kinase-1 are associated with adverse outcome in pregnant women with COVID-19.

OBJECTIVE: In addition to the lungs, the placenta and the endothelium can be affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are markers of endothelial dysfunction and could potentially serve as predictors of severe coronavirus disease 2019 (COVID-19). We aimed to investigate the association of serum concentrations of sFlt-1 and PlGF with the severity of COVID-19 in pregnancy. METHODS: This was a prospective cohort study carried out in a tertiary care hospital in Mexico City, Mexico. Symptomatic pregnant women with a positive reverse-transcription quantitative polymerase chain reaction test for SARS-CoV-2 infection who fulfilled the criteria for hospitalization were included. The primary outcome was severe pneumonia due to COVID-19. Secondary outcomes were intensive care unit (ICU) admission, viral sepsis and maternal death. sFlt-1 levels were expressed as multiples of the median (MoM). The association between sFlt-1 and each adverse outcome was explored by logistic regression analysis, adjusted for gestational age for outcomes occurring in more than five patients, and the predictive performance was assessed by receiver-operating-characteristics-curve analysis. RESULTS: Among 113 pregnant women with COVID-19, higher sFlt-1 MoM was associated with an increased probability of severe pneumonia (adjusted odds ratio (aOR), 1.817 (95% CI, 1.365-2.418)), ICU admission (aOR, 2.195 (95% CI, 1.582-3.047)), viral sepsis (aOR, 2.318 (95% CI, 1.407-3.820)) and maternal death (unadjusted OR, 5.504 (95% CI, 1.079-28.076)). At a 10% false-positive rate, sFlt-1 MoM had detection rates of 45.2%, 66.7%, 83.3% and 100% for severe COVID-19 pneumonia, ICU admission, viral sepsis and maternal death, respectively. PlGF values were similar between women with severe and those with non-severe COVID-19 pneumonia. CONCLUSION: sFlt-1 MoM is higher in pregnant women with severe COVID-19 and has the capability to predict serious adverse pregnancy events, such as severe pneumonia, ICU admission, viral sepsis and maternal death. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.