Plasma cellular fibronectin as a measure of endothelial involvement in preeclampsia and intrauterine growth retardation

Diagnostic Accuracy of Serum Glycosylated Fibronectin in Prediction of Preeclampsia: A Nested Case-Control Study

BACKGROUND

Preeclampsia is a life-threatening complication of pregnancy that occurs in approximately 7% of all pregnancies. In India, the incidence of preeclampsia is 8%-10% and the prevalence is 5.4%, whereas the prevalence of hypertensive disorders of pregnancy is 7.8%.

AIM AND OBJECTIVES

This study was aimed at evaluating the diagnostic accuracy of serum glycosylated fibronectin (S. GlyFn) in the prediction of preeclampsia.

METHODS

A nested case-control study was carried out for 16 months in the department of obstetrics and gynecology. A total of 240 women were recruited and followed after written consent and ethical clearance. Six were lost to follow-up, 15 had second-trimester abortions (excluded from the study), and 32 women developed hypertensive disorders of pregnancy (cases), out of which 1 woman developed antepartum eclampsia, 10 women developed preeclampsia with severe features, and 21 women developed preeclampsia without severe features. One hundred and eighty-seven women remained normotensive throughout the pregnancy until 6 weeks postpartum. After randomization, out of these samples, 54 were analyzed and considered controls. Levels of S. GlyFn were estimated using an ELISA kit using the ELISA technique.

RESULTS

The mean S. GlyFn level was significantly higher at the time of enrollment among those women who later developed preeclampsia (127.59 ± 27.68 ng/m) as compared to controls (107.79-53.51 ng/mL). GlyFn at a cutoff value of 126.70 ng/mL significantly (P = 0.034) discriminates cases of preeclampsia with severe features from healthy controls with a sensitivity of 90.00%, a specificity of 63.00%, a 31.03% positive predictive value, and 97.14% negative predictive value.

CONCLUSION

S. GlyFn, at a cutoff value of 126.70 ng/mL, had good sensitivity to discriminate PE from normotensive and was also a good prognostic marker.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Serum complement proteomics reveal biomarkers for hypertension disorder of pregnancy and the potential role of Clusterin

INTRODUCTION

Hypertension disorder of pregnancy (HDP) is one of the leading causes of maternal and foetal illness. The aim of the current study was to identify and verify novel serum markers for HDP.

METHODS

A label-free LC-MS/MS method was used to establish the serum proteomic profiles of 12 pre-HDP (before clinical diagnosis of HDP) pregnancies and verify prioritized candidates in the verification set of 48 pre-HDP pregnancies. These biomarkers were revalidated by ELISA in an independent cohort of 88 pre-HDP pregnancies. Subsequently, the candidate biomarkers were histologically analysed by immunohistochemistry, and function was evaluated in TEV-1 cells.

RESULTS

We identified 33 proteins with significantly increased abundance and 14 with decreased abundance (peptide FDR ≤ 1%, P < 0.05). Complement was one of the top enriched components in the pre-HDP group compared with the control group. Three complement factors (CLU, CFHR5, and CRP) were significantly increased in the three sets, of which CLU was a critical factor for the development of HDP (OR = 1.22, P < 0.001). When these three factors and body weight were combined, the AUC was 0.74, with a sensitivity of 0.67 and specificity of 0.68 for HDP prediction compared with normal pregnancy. In addition, inflammation-induced CLU could inhibit the invasion of TEV-1 cells.

CONCLUSIONS

Complement proteins may play an essential role in the occurrence of HDP by acting on trophoblast cells. CLU may be a high-risk factor for HDP, and the models combining candidates show reasonable screening efficiency of HDP in the first half of pregnancy.

Giants in Obstetrics and Gynecology Series: A profile of James M. Roberts, MD

Dr. James Roberts has made seminal contributions to the understanding of the physiology of pregnancy, and, in particular, to the mechanisms of disease responsible for preeclampsia. His research includes endothelial cell dysfunction, oxidative stress, and other factors that play a role in the pathogenesis of preeclampsia; the use of antioxidant therapy to prevent the syndrome; identification of clinical subtypes of preeclampsia; and assessment of the long-term cardiovascular risk of the disorder. Dr. Roberts is currently an investigator at the Magee-Womens Research Institute and a Professor of Obstetrics, Gynecology, and Reproductive Sciences, Endocrinology, and Clinical and Translational Medicine at the University of Pittsburgh. He was the founding Director of the Magee-Womens Research Institute, and formerly the Elsie Hilliard Hillman Chair in Women’s and Infants’ Health Research at the University of Pittsburgh. For his many original contributions to the understanding of preeclampsia and other obstetrical syndromes, Dr. Roberts is herein recognized as a “Giant in Obstetrics and Gynecology.”

Trophoblast-endothelium signaling involves angiogenesis and apoptosis in a dynamic bioprinted placenta model

Trophoblast invasion and remodeling of the maternal spiral arteries are required for pregnancy success. Aberrant endothelium-trophoblast crosstalk may lead to preeclampsia, a pregnancy complication that has serious effects on both the mother and the baby. However, our understanding of the mechanisms involved in this pathology remains elementary because the current in vitro models cannot describe trophoblast-endothelium interactions under dynamic culture. In this study, we developed a dynamic three-dimensional (3D) placenta model by bioprinting trophoblasts and an endothelialized lumen in a perfusion bioreactor. We found the 3D printed perfusion bioreactor system significantly augmented responses of endothelial cells by encouraging network formations and expressions of angiogenic markers, cluster of differentiation 31 (CD31), matrix metalloproteinase-2 (MMP2), matrix metalloproteinase-9 (MMP9), and vascular endothelial growth factor A (VEGFA). Bioprinting favored colocalization of trophoblasts with endothelial cells, similar to in vivo observations. Additional analysis revealed that trophoblasts reduced the angiogenic responses by reducing network formation and motility rates while inducing apoptosis of endothelial cells. Moreover, the presence of endothelial cells appeared to inhibit trophoblast invasion rates. These results clearly demonstrated the utility and potential of bioprinting and perfusion bioreactor system to model trophoblast-endothelium interactions in vitro. Our bioprinted placenta model represents a crucial step to develop advanced research approach that will expand our understanding and treatment options of preeclampsia and other pregnancy-related pathologies.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Mechanisms and Clinical Significance of Endothelial Dysfunction in High-Risk Pregnancies

The maternal cardiovascular system undergoes critical anatomic and functional adaptations to achieve a successful pregnancy outcome which, if disrupted, can result in complications that significantly affect maternal and fetal health. Complications that involve the maternal cardiovascular system are among the most common disorders of pregnancy, including gestational hypertension, preeclampsia, gestational diabetes, and impaired fetal growth. As a central feature, maternal endothelial dysfunction is hypothesized to play a predominant role in mediating the pathogenesis of these high-risk pregnancies, and as such, might proceed and precipitate the clinical presentation of these pregnancy disorders. Improving or normalizing maternal endothelial function in high-risk pregnancies might be an effective therapeutic strategy to ameliorate maternal and fetal clinical outcomes.

Maternal endothelial damage as a disorder shared by early preeclampsia, late preeclampsia and intrauterine growth restriction

INTRODUCTION

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are separate disease entities that have frequently been reported as sharing the same pathogenesis. In both of them, angiogenesis disorders and generalized endothelial damage with an accompanying inflammation are the dominant symptoms. In this study, we attempted to prove that both these processes demonstrate the same profile in early PE, late PE and IUGR patients, while the only difference is in the degree of exacerbation of the lesions.

PATIENTS, MATERIALS AND METHODS

In 167 patients divided into four groups, three of those with early PE, late PE and IUGR and one control group, fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), high sensitive c-reactive protein (hsCRP) and fibronectin were determined. The behavior of these parameters in each of the groups was studied, and correlations between them were sought for.

RESULTS

Higher concentrations of sFlt-1, hsCRP and fibronectin and a lower concentration of PlGF were found in the study groups compared to the control group. Significant correlations were observed between the factors concerned.

CONCLUSIONS

The higher values of disordered angiogenesis markers, endothelial damage markers and inflammatory markers both in the PE and the intrauterine growth restriction (IUGR) groups suggest the existence of shared disorders in the development of these pathologies. The correlations between disordered angiogenesis markers and endothelial damage markers argue in favor of a mutual relationship between these two processes in the development of pathologies evolving as secondary to placental ischemia. The results obtained confirm that the lesion profiles are the same in both PE and IUGR patients, which can be utilized in developing common diagnostic criteria.

Lack of Fibronectin Extra Domain A Alternative Splicing Exacerbates Endothelial Dysfunction in Diabetes

Glucose-induced changes of artery anatomy and function account for diabetic vascular complications, which heavily impact disease morbidity and mortality. Since fibronectin containing extra domain A (EDA + FN) is increased in diabetic vessels and participates to vascular remodeling, we wanted to elucidate whether and how EDA + FN is implicated in diabetes-induced endothelial dysfunction using isometric-tension recording in a murine model of diabetes. In thoracic aortas of EDA^−/−, EDA^+/+ (constitutively lacking and expressing EDA + FN respectively), and of wild-type mice (EDA^wt/wt), streptozotocin (STZ)-induced diabetes impaired endothelial vasodilation to acetylcholine, irrespective of genotype. However STZ + EDA^−/− mice exhibited increased endothelial dysfunction compared with STZ + EDA^+/+ and with STZ + EDA^wt/wt. Analysis of the underlying mechanisms revealed that STZ + EDA^−/− mice show increased oxidative stress as demonstrated by enhanced aortic superoxide anion, nitrotyrosine levels and expression of NADPH oxidase NOX4 and TGF-β1, the last two being reverted by treatment with the antioxidant n-acetylcysteine. In contrast, NOX1 expression and antioxidant potential were similar in aortas from the three genotypes. Interestingly, reduced eNOS expression in STZ + EDA^+/+ vessels is counteracted by increased eNOS coupling and function. Although EDA + FN participates to vascular remodelling, these findings show that it plays a crucial role in limiting diabetic endothelial dysfunction by preventing vascular oxidative stress.

Third Trimester Maternal Plasma Total Fibronectin Levels in Pregnancy-Induced Hypertension: Results of a Tertiary Center

The aim of this study was to evaluate maternal plasma total fibronectin values in pregnancy-associated hypertension in women in the third trimester of pregnancy. A total of 125 pregnant women at the 24th week of gestation participated in this study. Nonpregnant normotensive women were included as control group (n = 30). Plasma samples for fibronectin were obtained at the 24th, 28th, and 32nd weeks of gestation from all pregnant patients. From this cohort, 10 patients met the criteria for the diagnosis of gestational hypertension and 15 women met the stringent requirements of preeclampsia, whereas 100 patients were normotensive later in gestation. Plasma total fibronectin levels were determined by radial immunodiffusion technique. Data were analyzed using the SPSS program. The mean plasma fibronectin levels of the pregnant women in whom gestational hypertension and preeclampsia developed were significantly higher at the 24th, 28th, and 32nd weeks in comparison to normotensive pregnant women (p < 0.001). However, throughout the period from the 24th to 32nd weeks of pregnancy, plasma total fibronectin levels did not exhibit a significant change in normotensive pregnant patients or in patients with preeclampsia and gestational hypertension. There was also no correlation between plasma fibronectin levels and gestational age, mean arterial pressure, birth weight, and 5-minute Apgar scores in all groups (p < 0.05). The elevated maternal plasma fibronectin level over 40 mg/dL is capable of predicting preeclampsia with a sensitivity of 73% and a specificity of 92%. These results suggest that serial plasma fibronectin measurements before 24 weeks’ of gestation may be helpful in the early detection of preeclampsia in normotensive gravid women who are destined to become clinically preeclamptic.

Ischemic placental syndrome--prediction and new disease monitoring

The last decade has seen an improved understanding of the cause of the development of pathologies such as gestational hypertension, preeclampsia, intrauterine growth restriction, intrauterine fetal death or placental abruption. Nowadays, we know that most conditions within this group share the same pathogenesis, the cause of which is placental ischemia. The following review is an attempt to propose a new method for prediction, diagnosis and--above all--appropriate monitoring of pregnant women and fetuses developing the ischemic placental syndrome with the use of tests that are new but yet widely available in clinical diagnosis. They are closely related to the condition's pathogenesis, therefore their elevated levels may predate clinical symptoms, and--most importantly--they correlate with syndrome aggravation and the occurrence of complications. Perhaps, the new look will allow us to improve perinatal results by reducing mortality and severe complications in pregnant women and fetal deaths resulting from sudden intrauterine fetal death or placental abruption.

Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Objective: Endocan, a dermatan sulphate proteoglycan produced by endothelial cells, is considered a biomarker for endothelial cell activation/dysfunction. Preeclampsia is characterized by systemic vascular inflammation, and endothelial cell activation/dysfunction. Therefore, the objectives of this study were to determine whether: (1) plasma endocan concentrations in preeclampsia differ from those in uncomplicated pregnancies; (2) changes in plasma endocan concentration relate to the severity of preeclampsia, and whether these changes are specific or observed in other obstetrical syndromes such as small-for-gestational age (SGA), fetal death (FD), preterm labor (PTL) or preterm prelabor rupture of membranes (PROM); (3) a correlation exists between plasma concentration of endocan and angiogenic (placental growth factor or PlGF)/anti-angiogenic factors (soluble vascular endothelial growth factor receptor or sVEGFR-1, and soluble endoglin or sEng) among pregnancies complicated by preeclampsia; and (4) plasma endocan concentrations in patients with preeclampsia and acute pyelonephritis (both conditions in which there is endothelial cell activation) differ.

Method: This cross-sectional study included the following groups: (1) uncomplicated pregnancy (n = 130); (2) preeclampsia (n = 102); (3) pregnant women without preeclampsia who delivered an SGA neonate (n = 51); (4) FD (n = 49); (5) acute pyelonephritis (AP; n = 35); (6) spontaneous PTL (n = 75); and (7) preterm PROM (n = 64). Plasma endocan concentrations were determined in all groups, and PIGF, sEng and VEGFR-1 plasma concentrations were measured by ELISA in the preeclampsia group.

Results: (1) Women with preeclampsia had a significantly higher median plasma endocan concentration than those with uncomplicated pregnancies (p = 0.004); (2) among women with preeclampsia, the median plasma endocan concentration did not differ significantly according to disease severity (p = 0.1), abnormal uterine artery Doppler velocimetry (p = 0.7) or whether diagnosis was made before or after 34 weeks gestational age (p = 0.3); (3) plasma endocan concentration in women with preeclampsia correlated positively with plasma anti-angiogenic factor concentrations [sVEGFR-1: Spearman rho 0.34, p = 0.001 and sEng: Spearman rho 0.30, p = 0.003]; (4) pregnancies complicated by acute pyelonephritis with bacteremia had a lower median plasma endocan concentration than pregnancies complicated by acute pyelonephritis without bacteremia (p = 0.004), as well as uncomplicated pregnancies (p = 0.001); and (5) there was no significant difference in the median plasma endocan concentration between uncomplicated pregnancies and those complicated by FD, delivery of an SGA neonate, PTL or preterm PROM (other members of the “great obstetrical syndromes”; each p > 0.05).

Conclusion: Median maternal plasma endocan concentrations were higher preeclampsia and lower in acute pyelonephritis with bacteremia than in uncomplicated pregnancy. No significant difference was observed in the median plasma endocan concentration between other great obstetrical syndromes and uncomplicated pregnancies. The difference in the direction of change of endocan in preeclampsia and acute pyelonephritis with bacteremia may be consistent with the view that both disease entities differ in pathogenic mechanisms, despite their associations with systemic vascular inflammation and endothelial cell activation/dysfunction.

Preeclampsia and cardiovascular disease share genetic risk factors on chromosome 2q22

OBJECTIVE

Four putative single nucleotide polymorphism (SNP) risk variants at the preeclampsia susceptibility locus on chromosome 2q22; rs2322659 (LCT), rs35821928 (LRP1B), rs115015150 (RND3) and rs17783344 (GCA), were recently shown to associate with known cardiovascular risk factors in a Mexican American cohort. This study aimed to further evaluate the pleiotropic effects of these preeclampsia risk variants in an independent Australian population-based cohort.

METHODS

The four SNPs were genotyped in the Western Australian Pregnancy Cohort (Raine) Study that included DNA, clinical and biochemical data from 1246 mothers and 1404 of their now adolescent offspring. Genotype association analyses were undertaken using the SOLAR software.

RESULTS

Nominal associations (P<0.05) with cardiovascular risk factors were detected for all four SNPs. The LCT SNP was associated with decreased maternal height (P=0.005) and decreased blood glucose levels in adolescents (P=0.022). The LRP1B SNP was associated with increased maternal height (P=0.026) and decreased maternal weight (P=0.044). The RND3 SNP was associated with decreased triglycerides in adolescents (P=0.001). The GCA SNP was associated with lower risk in adolescents to be born of a preeclamptic pregnancy (P=0.003) and having a mother with prior preeclamptic pregnancy (P=0.033).

CONCLUSIONS

Our collective findings support the hypothesis that genetic mechanisms for preeclampsia and CVD are, at least in part, shared, but need to be interpreted with some caution as a Bonferroni correction for multiple testing adjusted the statistical significance threshold (adjusted P<0.001).

The vascular endothelial growth factor family in adverse pregnancy outcomes

BACKGROUND

Pre-eclampsia, small-for-gestational-age infants, preterm birth and recurrent miscarriage complicate a significant number of pregnancies. The vascular endothelial growth factor (VEGF) family of angiogenic growth factors is implicated in the pathophysiology of these complications. We aimed to elucidate the role of these angiogenic factors in placentation and to evaluate the predictive value of their protein concentrations and genetic variations in pregnancy complications.

METHODS

We performed a systematic search of PubMed, and retrieved original articles. The search included a combination of terms such as VEGF-A, placental growth factor (PlGF), kinase insert domain receptor, fms-like-tyrosine-kinase receptor 1, soluble fms-like-tyrosine-kinase receptor 1, pre-eclampsia, small-for-gestational-age infants, preterm birth, recurrent miscarriage, placenta, prediction and polymorphisms.

RESULTS

This review summarizes the current knowledge of the roles of the VEGF family in early placentation and of the abnormalities in maternal plasma and placental expression of angiogenic proteins in adverse pregnancy outcomes compared with normal pregnancy. PlGF and sFLT-1 in combination with other clinical and biochemical markers in late first or second trimester appear to predict early-onset pre-eclampsia with a high sensitivity and specificity. However, VEGF family proteins do not have sufficient power to accurately predict late-onset pre-eclampsia, small-for-gestational age pregnancies or preterm birth. Functional polymorphisms in these angiogenic genes are implicated in pregnancy complications, but their contribution appears to be minor.

CONCLUSIONS

Although the VEGF family has important roles in normal and complicated pregnancy, the current predictive value of the VEGF family as biomarkers appears to be limited to early-onset pre-eclampsia.

Maternal levels of prostacyclin, thromboxane, ICAM, and VCAM in normal and preeclamptic pregnancies

PROBLEM

To evaluate whether impaired endothelial function and endothelial inflammatory response occur in parallel in the women with preeclampsia.

METHOD OF STUDY

Venous blood was drawn from normal (n=40) and severe preeclamptic (sPE) (n=40) pregnant women when they were admitted to the L&D Unit and 24 hrs after delivery. Plasma and serum samples were extracted and measured for 6-keto PGF1α and TXB(2) (stable metabolites of PGI2 and TXA2), and intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) by ELISA. Data are analyzed by Mann-Whitney test and paired t-test. The statistical significance is set as P<0.05. Results  Plasma 6-keto PGF1α levels were significantly reduced at admission and 24hr after delivery in sPE compared to normal pregnant controls, P<0.01. The ratio of 6-keto PGF1α and TXB(2) was significant less in sPE than that in normal pregnant controls before delivery. There was no significant difference for ICAM and VCAM levels between normal and patients with sPE before and after delivery.

CONCLUSION

Maternal 6-keto PGF1α levels and the ratio of 6-keto PGF1α and TXB(2) were decreased in patients with sPE compared to normal pregnant controls. In contrast, maternal ICAM and VCAM levels were not different between the two groups. These data suggest that serum ICAM and VCAM levels may not be sensitive inflammatory biomarkers for preeclampsia.

Could alterations in maternal plasma visfatin concentration participate in the phenotype definition of preeclampsia and SGA?

OBJECTIVE

Women with preeclampsia and those who delivered a small-for-gestational-age (SGA) neonate share several mechanisms of disease, including chronic uteroplacental ischemia and failure of physiologic transformation of the spiral arteries. However, the clinical manifestation of these obstetrical syndromes is remarkably different. It has been proposed that an altered maternal metabolic state, as well as a unique circulating cytokines milieu, predispose women to develop either preeclampsia or SGA. Compelling evidence suggests that adipose tissue orchestrates both metabolic pathways and immunological responses via the production of adipokines. Visfatin is a novel adipocytokine with metabolic and immunomodulating properties. The objective of this study was to determine whether preeclampsia and SGA are associated with alterations in maternal circulating visfatin concentrations.

METHODS

This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 158); (2) patients with preeclampsia (n = 43) of which 32 had an AGA and 11 had an SGA neonate; (3) patients without preeclampsia who delivered an SGA neonate (n = 55). Maternal plasma visfatin concentrations were measured by ELISA. Nonparametric tests and multiple linear regression analysis were used.

RESULTS

(1) Women who delivered an SGA neonate had a higher median maternal plasma visfatin concentration than those with a normal pregnancy (20.0 ng/ml, interquartile range: 17.2-24.6 vs. 15.2 ng/ml, 12.1-19.2, respectively; P < 0.001) and than those with preeclampsia (14.5 ng/ml, 12.5-18.7; P < 0.001); (2) the median maternal plasma visfatin concentration did not differ significantly between patients with preeclampsia and those with a normal pregnancy (P = 0.8); (3) among patients with preeclampsia, there was no significant difference in the median maternal plasma visfatin concentration between those with or without an SGA neonate (P = 0.5); (4) in a linear regression model, delivery of an SGA neonate and pregestational body mass index were independently associated with increased visfatin concentration after adjustment for confounding factors (maternal age, smoking, gestational age at blood collection and the presence of preeclampsia or SGA).

CONCLUSION

(1) Patients with SGA, but not those with preeclampsia, had a higher maternal plasma visfatin concentration than those with a normal pregnancy; (2) this finding suggests differential involvement of visfatin in SGA and preeclampsia; (3) we propose that changes in circulating maternal visfatin concentration may be implicated in the phenotypic definitions and distinction of preeclampsia and SGA.

Leukocytes of pregnant women with small-for-gestational age neonates have a different phenotypic and metabolic activity from those of women with preeclampsia

OBJECTIVE

Preeclampsia and pregnancies complicated by small-for-gestational age (SGA) neonates share several underlying mechanisms of disease. However, while an exaggerated systemic maternal inflammatory response is regarded as one of the hallmarks of the pathogenesis of preeclampsia, the presence of a similar systemic intra-vascular inflammation in mothers of SGA neonates without hypertension is controversial. The aim of this study was to determine phenotypic and metabolic changes in granulocytes and monocytes of women who develop preeclampsia and those who deliver an SGA neonate, compared to normal pregnant women.

METHODS

This cross-sectional study included patients with a normal pregnancy (n = 33), preeclampsia (n = 33), and an SGA without preeclampsia (n = 33), matched for gestational age at blood sample collection. Granulocyte and monocyte phenotypes were determined by flow cytometry, using monoclonal antibodies against selective cluster of differentiation (CD) antigens. The panel of antibodies included the following: CD11b, CD14, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Intracellular reactive oxygen species (iROS) were assessed at the basal state and after stimulation (oxidative burst). Results were reported as mean channel brightness (MCB) or intensity of detected fluorescence. Analysis was conducted with non-parametric statistics. A p-value < 0.01 was considered statistically significant.

RESULTS

(1) Women who delivered an SGA neonate had a higher MCB of CD11b in granulocytes and monocytes than those with a normal pregnancy (p < 0.001 for both); (2) patients with preeclampsia had a lower median MCB of CD62L in granulocytes (p = 0.006) and a higher median basal iROS and oxidative burst in monocytes than women with an SGA neonate (p = 0.003 and p = 0.002, respectively).

CONCLUSION

Pregnancies complicated by the delivery of an SGA neonate are characterized by a higher activation of maternal peripheral leukocytes than in normal pregnancies, but lower than in pregnancies complicated by preeclampsia.

Role of nutrition in the risk of preeclampsia

Preeclampsia (PE) accounts for about one-quarter of the cases of maternal mortality and ranks second among the causes of pregnancy-associated maternal deaths in Canada and worldwide. The identification of an effective strategy to prevent PE is a priority and a challenge for research in obstetrics. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet in the etiology of PE has recently received increased attention. The objective of this paper is to provide an overview of the literature concerning 1) the current understanding of the pathogenesis of PE, 2) the biological plausibility and potential mechanisms underlying the associations between maternal dietary exposures, nutrition, and the risk of PE, and 3) the epidemiological findings of maternal nutrient intake in relation to the risk of PE.

Fetal fibronectin as a predictor of preterm birth

Preterm delivery remains the leading cause of perinatal mortality and occurs in approximately 7-9% of pregnancies. The main problem for the obstetrician is the inability to detect women at risk from this complication. The presence of fetal fibronectin (fFN) in cervicovaginal secretions has been proposed as a specific predictor of preterm delivery. Immunohistochemical studies suggest that fFN is present in the extracellular matrix of the decidua basalis next to the intervillus space. It has been studied intensively in symptomatic patients and has a positive predictive value of 43-79%. It has also a negative predictive value of 99.7% for birth within 7 days and 93% for delivery before 37 weeks. Similarly, in high-risk asymptomatic women, it has been proved a useful screening tool for the prediction of preterm delivery, yielding a sensitivity of 43-92%, a specificity of 52-93%, a positive predictive value of 43-85% and a negative predictive value of 86-99%. In low-risk asymptomatic women, fFN has a sensitivity of 63-73%, a specificity of 80-98%, a positive predictive value of 13-36% and a negative predictive value of 95-97%. In women presenting with preterm contractions, a negative test may make one withhold potentially dangerous tocolytic therapy. In asymptomatic women this test can identify patients who have a very high risk for early delivery. Women identified as being high-risk can be offered steroid injections in order to improve lung maturity in preterm babies. Additionally, they can be counselled about the signs and symptoms of preterm labour, so that they can seek medical advice before labour is actually established. However, extensive research is still needed, as no clear benefit in preventing preterm birth using this test, has been shown so far.

The maternal plasma soluble vascular endothelial growth factor receptor-1 concentration is elevated in SGA and the magnitude of the increase relates to Doppler abnormalities in the maternal and fetal circulation

OBJECTIVES

The soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1), an antagonist to vascular endothelial growth factor and placental growth factor, has been implicated in the pathophysiology of preeclampsia. Preeclampsia and pregnancy complicated with small for gestational age (SGA) fetuses share some pathophysiologic derangements, such as failure of physiologic transformation of the spiral arteries, endothelial cell dysfunction, and leukocyte activation. The objectives of this study were to: (1) determine whether plasma concentrations of sVEGFR-1 in mothers with SGA fetuses without preeclampsia at the time of diagnosis are different from those in patients with preeclampsia or normal pregnant women, and (2) examine the relationship between plasma concentrations of sVEGFR-1 and Doppler velocimetry in uterine and umbilical arteries in patients with preeclampsia and those with SGA.

STUDY DESIGN

A cross-sectional study was conducted to determine the concentrations of the soluble form of VEGFR-1 in plasma obtained from normal pregnant women (n = 135), women with SGA fetuses (n = 53), and patients with preeclampsia (n = 112). Patients with SGA fetuses and those with preeclampsia were sub-classified according to the results of uterine and umbilical artery Doppler velocimetry examinations. Plasma concentrations of sVEGFR-1 were determined by an ELISA. Since these concentrations change with gestational age, differences among various subgroups were statistically estimated with the delta value, defined as the difference between the observed and expected plasma sVEGFR-1 concentration. The expected values were derived from regression analysis of plasma sVEGFR-1 concentrations in normal pregnancy. Regression analysis and univariate and multivariate analysis were employed.

RESULTS

(1) Mothers with SGA fetuses had a mean plasma concentration of sVEGFR-1 higher than normal pregnant women (p < 0.001), but lower than patients with preeclampsia (p < 0.001). (2) Among patients with SGA fetuses, only those with abnormal uterine artery Doppler velocimetry had a mean plasma sVEGFR-1 concentration significantly higher than normal pregnant women (p < 0.001). (3) Among mothers with SGA fetuses in whom Doppler velocimetry was performed (n = 41), those with abnormalities in both the uterine and umbilical artery velocimetry had the highest mean delta of sVEGFR-1 plasma concentration (mean +/- standard deviation (SD): 0.69 +/- 0.29). Conversely, patients who had normal Doppler velocimetry in both uterine and umbilical arteries had the lowest mean delta (mean +/- SD: 0.09 +/- 0.29) of sVEGFR-1 plasma concentrations (ANOVA; p < 0.001). (4) Among patients with preeclampsia in whom Doppler velocimetry was performed (n = 69), those with abnormalities in both the uterine and umbilical artery velocimetry had the highest mean delta sVEGFR-1 plasma concentration (mean +/- SD: 1.01 +/- 0.22) among all groups classified (ANOVA; p < 0.001). (5) Among patients with SGA and those with preeclampsia, there was a relationship (Chi-square for trend p < 0.001 for both) between the severity of Doppler velocimetry abnormalities and the proportion of patients who had high delta sVEGFR-1 plasma concentrations (defined as a concentration two standard deviations (2SD) above the mean delta of normal pregnant women). (6) Multiple regression analysis suggested that the diagnostic category (e.g., SGA or preeclampsia), Doppler abnormalities, and gestational age at blood sampling were associated with an increase in plasma sVEGFR-1 concentrations (p < 0.001).

CONCLUSIONS

These observations provide support for the participation of the soluble receptor of vascular endothelial growth factor in the pathophysiology of SGA with abnormal uterine artery Doppler velocimetry and preeclampsia. An excess of sVEGFR-1 is released into the maternal circulation of patients with preeclampsia and those with SGA fetuses, as abnormalities of impedance to blood flow involve uterine and umbilical circulation.

Low maternal concentrations of soluble vascular endothelial growth factor receptor-2 in preeclampsia and small for gestational age

OBJECTIVES

Preeclampsia is considered an anti-angiogenic state. A role for the anti-angiogenic factors soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble endoglin in preeclampsia has been proposed. Soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) has been detected in human plasma, and the recombinant form of this protein has anti-angiogenic activity. There is a paucity of information about maternal plasma sVEGFR-2 concentrations in patients with preeclampsia and those without preeclampsia with small for gestational age (SGA) fetuses. This study was conducted to determine whether: (1) plasma sVEGFR-2 concentration changes throughout pregnancy; and (2) preeclampsia and SGA are associated with abnormalities in the maternal plasma concentration of sVEGFR-2.

STUDY DESIGN

This cross-sectional study included non-pregnant women (n = 40), women with normal pregnancies (n = 135), women with an SGA fetus (n = 53), and women with preeclampsia (n = 112). SGA was defined as an ultrasound-estimated fetal weight below the 10(th) percentile for gestational age that was confirmed by neonatal birth weight. Plasma concentrations of sVEGFR-2 were determined by ELISA.

RESULTS

(1) There was no significant difference in the mean plasma concentration of sVEGFR-2 between non-pregnant women and those with normal pregnancies (p = 0.8); (2) patients with preeclampsia and those without preeclampsia with SGA fetuses had a lower mean plasma concentration of sVEGFR-2 than that of women with normal pregnancies (p < 0.001 for both); and (3) there was no significant difference in the mean plasma concentration of sVEGFR-2 between patients with preeclampsia and those without preeclampsia with SGA (p = 0.9).

CONCLUSIONS

Preeclampsia and SGA are associated with low plasma concentrations of sVEGFR-2. One interpretation of the findings is that plasma sVEGFR-2 concentration could reflect endothelial cell function.

Placenta and fetal growth restriction

The placenta, as the vector for all maternal-fetal oxygen and nutrient exchange, is a principal influence on birthweight. Placental weight summarizes laterally expanding growth of the chorionic disc, and villous arborization yielding the nutrient exchange surface. These different growth dimensions alter fetoplacental weight ratio and ponderal index, and thus may modify placental functional efficiency. The placenta may show a range of histopathologies, some of which are also associated with fetal growth restriction. Different fetal intrinsic abilities to compensate for gross and histo-pathology may clarify the imperfect relationships between fetal growth and both intrauterine pathology, and the long-term health risks associated with poor fetal growth.

Evidence of endothelial dysfunction in preeclampsia and risk of adverse pregnancy outcome

The purpose of this study is to investigate whether endothelial dysfunction, as assessed by elevated cellular fibronectin (cFN), in women with preeclampsia is associated with an increased risk of preterm and/or small-for-gestational-age (SGA) births. Maternal plasma cFN was measured by enzyme-linked immunosorbent assay in samples collected at admission to delivery in 605 normotensive women, 171 women with transient hypertension, and 187 women with preeclampsia. Logistic regression was used to estimate the risk for preterm delivery, SGA, or both. Elevated cFN in women with preeclampsia was associated with an increased risk of both preterm and SGA births (odds ratio, 3.0; confidence interval [CI], 1.0-8.7) compared with women with preeclampsia without elevated cFN. The risk of preterm birth was 14.7-fold higher (CI, 8.1-26.7) and the risk of SGA was 6.8-fold higher (CI, 3.5-13.1) in women with preeclampsia, hyperuricemia, and elevated cFN compared with normotensive women. Elevated cFN is prevalent among women with preeclampsia and identifies women at increased risk of preterm delivery and SGA.

The gonadotropins: tissue-specific angiogenic factors?

The gonadotropins, whose members are human chorionic gonadotropin (hCG), lutenizing hormone (LH) and follicle-stimulating hormone (FSH) are a well characterized hormone family known to regulate reproductive functions in both females and males. Recent studies indicate that they can modulate the vascular system of reproductive organs. It was shown that gonadotropins not only influence the expression of vascular endothelial growth factor (VEGF) and both its receptors VEGFR-1 and -2, but also modulate other ubiquitously expressed angiogenic factors like the angiopoietins and their receptor Tie-2, basic fibroblast growth factor or placental-derived growth factor. Some recent data indicates a possible direct action of gonadotropins on endothelial cells. Thus, the gonadotropins act as tissue-specific angiogenic factors providing an optimal vascular supply during the menstrual cycle and early pregnancy in the female reproductive tract as well as in testis. In pathological conditions (e.g. preeclampsia, intrauterine growth restriction, ovarian hyperstimulation or endometriosis), these tightly regulated interactions between the gonadotropins and the ubiquitous angiogenic factors appear to be disturbed. The intent of this short manuscript is to review the current knowledge of the regulatory role of the gonadotropins in vasculo- and angiogenesis. We also review angiogenic actions of thyroid-stimulating hormone (TSH), a glycoprotein closely related to gonadotropins, which display strong gonodal actions.

Endothelial activation and cell adhesion molecule concentrations in pregnant women living at high altitude

OBJECTIVES

Maternal physiology at high altitude could be considered to resemble an intermediate state between preeclampsia and normal pregnancy. The objective of the current study was to determine if cell adhesion molecules, known to be increased in preeclampsia, are increased with chronic maternal and placental hypoxia (due to high-altitude residence) in the absence of preeclampsia.

METHODS

Serum was collected from women residing at 3100 m or 1600 m in the three trimesters of pregnancy and postpartum. Vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and intercellular adhesion molecule-1 (ICAM-1) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

General linear model (GLM) repeated measures analysis of VCAM-1, E-selectin, and ICAM-1 data showed there were no statistically significant effects of gestation within either the high- or moderate-altitude groups or between the different altitudes.

CONCLUSION

The increase in cell adhesion molecules reported in preeclampsia is not present in pregnant women at high altitude, suggesting that maternal systemic hypoxia is not responsible for this pathway of endothelial cell activation in preeclampsia.

Maternal plasma cellular fibronectin concentrations in normal and preeclamptic pregnancies: a longitudinal study for early prediction of preeclampsia

OBJECTIVE

The purpose of this study was to examine cellular fibronectin levels throughout normotensive and preeclamptic pregnancies and to analyze its predictive value for the detection of preeclampsia within the second trimester of pregnancy.

STUDY DESIGN

Blood samples were collected at 4-week intervals from 378 healthy, nulliparous women who were recruited before 16 weeks of gestation. Preeclampsia developed in 26 patients; 52 normotensive control subjects were matched from the same cohort. Plasma samples were assayed for ED-B fibronectin by enzyme-linked immunosorbent assay. Trends were compared between groups. Predictive values were determined with the use of second trimester assessments.

RESULTS

In both groups, fibronectin levels rose as pregnancy advanced, but in women with preeclampsia, this increase was significantly higher (94.5% vs 31.8%; P =.006). Throughout pregnancy, patients with preeclampsia exhibited significantly higher fibronectin levels than did control subjects. As early as 9 to 12 weeks of gestation, a difference was established (preeclampsia, 3.72 +/- 0.21; control, 2.94 +/- 0.22 microg/mL [mean +/- SEM]; P =.008). The best cutoff point and time interval to calculate predictive values were 3.8 microg/mL and 22 to 26 weeks of gestation, respectively. Sensitivity, specificity, and positive and negative predictive values were 73%, 87%, 29%, and 98%, respectively; the odds ratio was 16.1 (95% CI, 8.6-30.2).

CONCLUSION

In women in whom clinical preeclampsia developed, endothelial damage seemed to be present since early gestation. Cellular fibronectin levels of >or=3.8 microg/mL within 22 to 26 weeks of gestation may help in the early detection of preeclampsia in healthy nulliparous women.

Vascular mechanisms of increased arterial pressure in preeclampsia: lessons from animal models

Normal pregnancy is associated with reductions in total vascular resistance and arterial pressure possibly due to enhanced endothelium-dependent vascular relaxation and decreased vascular reactivity to vasoconstrictor agonists. These beneficial hemodynamic and vascular changes do not occur in women who develop preeclampsia; instead, severe increases in vascular resistance and arterial pressure are observed. Although preeclampsia represents a major cause of maternal and fetal morbidity and mortality, the vascular and cellular mechanisms underlying this disorder have not been clearly identified. Studies in hypertensive pregnant women and experimental animal models suggested that reduction in uteroplacental perfusion pressure and the ensuing placental ischemia/hypoxia during late pregnancy may trigger the release of placental factors that initiate a cascade of cellular and molecular events leading to endothelial and vascular smooth muscle cell dysfunction and thereby increased vascular resistance and arterial pressure. The reduction in uterine perfusion pressure and the ensuing placental ischemia are possibly caused by inadequate cytotrophoblast invasion of the uterine spiral arteries. Placental ischemia may promote the release of a variety of biologically active factors, including cytokines such as tumor necrosis factor-alpha and reactive oxygen species. Threshold increases in the plasma levels of placental factors may lead to endothelial cell dysfunction, alterations in the release of vasodilator substances such as nitric oxide (NO), prostacyclin (PGI(2)), and endothelium-derived hyperpolarizing factor, and thereby reductions of the NO-cGMP, PGI(2)-cAMP, and hyperpolarizing factor vascular relaxation pathways. The placental factors may also increase the release of or the vascular reactivity to endothelium-derived contracting factors such as endothelin, thromboxane, and ANG II. These contracting factors could increase intracellular Ca(2+) concentrations ([Ca(2+)](i)) and stimulate Ca(2+)-dependent contraction pathways in vascular smooth muscle. The contracting factors could also increase the activity of vascular protein kinases such as protein kinase C, leading to increased myofilament force sensitivity to [Ca(2+)](i) and enhancement of smooth muscle contraction. The decreased endothelium-dependent mechanisms of vascular relaxation and the enhanced mechanisms of vascular smooth muscle contraction represent plausible causes of the increased vascular resistance and arterial pressure associated with preeclampsia.

Recent Insights into the pathogenesis of pre-eclampsia

Pre-eclampsia is more than pregnancy induced hypertension. The emerging view described in this presentation is that pre-eclampsia is secondary to the interactions of reduced placental perfusion with diverse maternal factors that alter endothelial function. The maternal contribution is from factors that antedate pregnancy and are influenced by the usual metabolic adaptations of pregnancy. The endothelium and other targets for the effects of these interactions are more sensitive to insults during pregnancy because of activation of the inflammatory cascade as a normal part of pregnancy. At least part of the response to reduced placental perfusion may be a fetal adaptive response to attempt to overcome the reduced delivery of nutrients. A reasonable convergence point for the interaction is at the level of oxidative stress. This hypothesis has both encouraging and discouraging corollaries. The diversity of maternal factors argues that there will be no single gene to explain the disorder and no single 'magic bullet' to treat the disorder. However, it is encouraging that the recognition of maternal predisposition to the disorder directs therapy to prevent pre-eclampsia at a specific target in subsets of women. Finally, the suggestion that some of the maternal alterations are due to fetal adaptive responses encourages careful choices of agents and meticulous infant follow up in well planned clinical trials.

Pregnancy outcomes and community health: the POUCH study of preterm delivery

In light of the social/ethnic disparity in preterm delivery (PTD) rates, the Pregnancy Outcomes and Community Health (POUCH) Study takes a broad view of the determinants of PTD by attempting to link underlying biological and psychosocial factors. The relationships between placental pathology, maternal biomarkers, and antecedent psychosocial factors are evaluated in three hypothesised pathways of PTD - one characterised primarily by infection, one by maternal vascular disease, and one by premature elevations in corticotropin releasing hormone in the absence of histological evidence of placental pathology. Within each pathway, an emphasis is placed on understanding the roles of stress and of maternal serum alpha-fetoprotein, an early biomarker associated with PTD. The POUCH Study enrolls pregnant women from five Michigan communities. Information about these women and their environments is gathered through detailed interviews and collection of biological samples including hair, urine, saliva, blood, vaginal fluid, and vaginal smear at 15-26 weeks of gestation. We have chosen to focus on the second trimester--a time when pathological processes may have evolved to a detectable stage, but generally before the onset of biological changes that accompany labour. This focus is consistent with the long-range goal of early detection/intervention and prevention of PTD.

Pathophysiology of preeclampsia and the role of serotonin

Hypertensive disorders constitute the most common medical complications of pregnancy. In normal pregnancy, impressive physiological changes take place in the maternal cardiovascular system. Morphological changes are the result of invasion of migratory trophoblast cells into the walls of the spiral arteries. After destruction of elastic, muscular and neural tissue in the media, the trophoblast cells get incorporated into the vessel wall and the endothelial lining of the spiral arteries is restored. The physiological changes create a low-resistance, low-pressure, high-flow system with the absence of maternal vasomotor control. Biochemical adaptations in maternal vasculature include changes in the prostaglandin system, the renin-angiotensin-aldosteron system and the kallikrein-kinin system. In preeclampsia, physiological changes in the spiral arteries are confined to the decidual portion of the arteries. Myometrial segments remain anatomically intact and fail to dilate. In addition, the adrenergic nerve supply is left intact. The cause of this impaired endovascular trophoblast invasion is not yet elucidated. But in combination with the imbalance between vasodilator and vasoconstrictor eicosanoids, it gives rise to reduced perfusion of the intervillous space. In the absence of an adequate production of antiaggregatory prostacyclin (PGI(2)), nitric oxide, or both, surface-mediated platelet activation is supposed to occur on the surface of the spiral arteries. Because platelets are the principal source of circulating serotonin, the increased platelet aggregation in preeclampsia causes an increase in serotonin levels. Interaction of serotonin with serotonin(1)- or serotonin(2)-receptors depends on the state of the endovascular trophoblast or endothelium in the spiral arteries and has opposite effects with regard to vasodilating and vasoconstrictive influences.

Plasma levels of cellular fibronectin in diabetes

OBJECTIVE

Cellular fibronectin is an endothelium-derived protein involved in subendothelial matrix assembly. Elevated plasma levels of cellular fibronectin therefore reflect loss of endothelial cell polarization or injury to blood vessels. Consequently, elevated plasma levels of circulating cellular fibronectin have been described in clinical syndromes with vascular damage, although not in diabetes or atherosclerosis.

RESEARCH DESIGN AND METHODS

We determined fibronectin levels in 52 patients with type 1 diabetes, 50 patients with type 2 diabetes, 54 patients with a history of ischemic stroke, 23 patients with renal artery stenosis, and 64 healthy subjects.

RESULTS

Circulating cellular fibronectin was significantly elevated in patients with diabetes (4.3 +/- 2.8 microg/ml) compared with patients with ischemic stroke (2.0 +/- 0.9 microg/ml), patients with renovascular hypertension (1.7 +/- 1.1 microg/ml), and healthy subjects (1.4 +/- 0.6 microg/ml). Patients with diabetes and at least one cardiovascular risk factor had an almost 2.5-fold increase in cellular fibronectin compared with diabetic subjects without such a risk factor. In multivariate regression analysis, higher triglycerides, current or past cigarette smoking, and higher urinary albumin excretion were independently associated with an increase in circulating cellular fibronectin in diabetes.

CONCLUSIONS

These results suggest that circulating cellular fibronectin may be a marker protein for endothelial cell activation, especially in diabetes. Prospective studies are needed to explore this possibility

The predictive value of plasma fibronectin concentration on fetal growth retardation at earlier stage of the third trimester

In order to evaluate the predictive value of maternal plasma fibronectin (FN) concentration at 24-34 weeks on fetal intrauterine growth retardation (IUGR), a prospective double-blinded study was performed. The maternal plasma FN concentrations were measured by using a rate nephelometric procedure in the 130 initial normal nulliparous pregnant woman at 24-34 gestational weeks. The outcome of pregnancies and birth weight of their infants were followed up. IUGR was defined as that the birth weight was less than the 10th percentile for gestational age. The receiver operating characteristic curves and predictive values of FN predicting on outcome of pregnancy with IUGR were analyzed. The results showed that: (1) In a cohort of 130 initially normal nulliparous pregnant women, IUGR occurred in 14 cases during the follow-up; (2) The plasma FN levels in the women with IUGR (467.58 +/- 104.43 mg/L) were significantly higher than in the normal control group (299.44 +/- 105.55 mg/L, P < 0.01). However, there was no significant difference in the mean maternal age, gravidity, sampling gestational ages, delivering gestational ages between the two groups (P > 0.05); (3) The areas under ROC curve for predicting the outcome of pregnancy in IUGR was 0.893; (4) At the cut point of 475 mg/L FN level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index for predicting the outcomes of pregnancy in IUGR were 57.14%, 95.69%, 61.54%, 94.87%, 0.5455 respectively. It was concluded that the maternal plasma FN might be used as an earlier predictor for screening of IUGR.

Flow-mediated vasodilation and plasma fibronectin levels in preeclampsia

To clarify the vascular endothelial function in pregnant women with hypertensive disorders, we assessed the flow-mediated vasodilation in the radial artery and compared it with plasma fibronectin levels. We determined flow-mediated vasodilation by measuring the change in radial artery diameter during hyperemia in 58 normal pregnant women, 22 preeclamptic pregnant women, and 15 pregnant women with chronic hypertension. In 41 of the 95 pregnant women, we measured the plasma fibronectin levels. Flow-mediated vasodilation in preeclamptic women was significantly less than that in normal pregnant women (P:<0.001). In chronic hypertensive women, flow-mediated vasodilation was significantly less than that in normal pregnant women (P:<0.001) but more than that in preeclamptic women (P:<0.001). Flow-mediated vasodilation showed significant negative correlation with plasma fibronectin levels (P:<0.001, r=0.73). Our results indicate that the endothelial function can be noninvasively assessed in pregnant women with hypertensive disorders by measuring the flow-mediated vasodilation of the radial artery with high-resolution ultrasound.

Serial plasma fibronectin levels in pre-eclamptic and normotensive women

OBJECTIVE

Endothelial cell damage has been put forward as an underlying factor for development of pre-eclampsia. This study was carried out to see if fibronectin, which is a marker of endothelial damage, could be used as a marker of pre-eclampsia.

METHODS

A longitudinal study was conducted on 100 normotensive primigravidae registered before 20 weeks of gestation. These subjects were followed until delivery and three blood samples were collected, first at registration, i.e. before 20 weeks, second around 28 weeks and third at 36 weeks or later till delivery. Fibronectin levels were assayed by ELISA and women observed for any signs of pre-eclampsia.

RESULTS

Fourteen subjects developed pre-eclampsia. Fibronectin levels were observed to rise as pregnancy advanced but the rise was significantly higher in subjects who developed pre-eclampsia. The fibronectin levels were also significantly higher in these 14 subjects even in the first sample, i.e. before 20 weeks of gestation when compared with normotensive subjects (P < 0.01).

CONCLUSIONS

Fibronectin levels could be used as an early valuable biomarker for the development of pre-eclampsia.

Tissue factor levels and high ratio of fibrinopeptide A:D-dimer as a measure of endothelial procoagulant disorder in pre-eclampsia

To assess coagulation activation and endothelial cell injury in normotensive and pre-eclamptic pregnant women, a comparison was made of plasma levels of tissue factor, fibronectin, fibrinopeptide A and D-dimer. Samples were taken from 50 nonpregnant women, 40 normotensive pregnant women in the third trimester and 27 women with pre-eclampsia after diagnosis and before treatment. High levels of fibrinopeptide A and D-dimer were found in pre-eclamptic women. Moreover, the ratio fibrinopeptide A:D-dimer was much greater in the pre-eclampsia group than in normotensive pregnant women. The levels of fibronectin and tissue factor were also higher in the pre-eclampsia group. The increase of tissue factor levels suggests an alteration of the extrinsic coagulation pathway in pre-eclampsia. The increase of fibrinopeptide A:D-dimer ratio shows that the activation of coagulation is associated with a relative hypofibrinolysis in pre-eclampsia.

Etiology and pathogenesis of preeclampsia: current concepts

The etiology of preeclampsia is unknown. At present, 4 hypotheses are the subject of extensive investigation, as follows: (1) Placental ischemia-Increased trophoblast deportation, as a consequence of ischemia, may inflict endothelial cell dysfunction. (2) Very low-density lipoprotein versus toxicity-preventing activity-In compensation for increased energy demand during pregnancy, nonesterified fatty acids are mobilized. In women with low albumin concentrations, transporting extra nonesterified fatty acids from adipose tissues to the liver is likely to reduce albumin's antitoxic activity to a point at which very-low density lipoprotein toxicity is expressed. (3) Immune maladaptation-Interaction between decidual leukocytes and invading cytotrophoblast cells is essential for normal trophoblast invasion and development. Immune maladaptation may cause shallow invasion of spiral arteries by endovascular cytotrophoblast cells and endothelial cell dysfunction mediated by an increased decidual release of cytokines, proteolytic enzymes, and free radical species. (4) Genetic imprinting-Development of preeclampsia-eclampsia may be based on a single recessive gene or a dominant gene with incomplete penetrance. Penetrance may be dependent on fetal genotype. The possibility of genetic imprinting should be considered in future genetic investigations of preeclampsia.

Maternal and fetal plasma concentrations of endothelin, lipidhydroperoxides, glutathione peroxidase and fibronectin in relation to abnormal umbilical artery velocimetry

OBJECTIVE

To study plasma concentrations of endothelin (ET), lipidhydroperoxides (LOOH), glutathione peroxidase (GSHpx) and fibronectin in relation to abnormal umbilical artery velocimetry.

STUDY DESIGN

Plasma concentrations of ET, LOOH, GSHpx and fibronectin were measured in fetal and maternal venous blood in: (i) a control group (n=10); (ii) in pregnancies complicated by intrauterine growth retardation (IUGR) (n=6) or preeclampsia (n=5) with positive end diastolic flow; and in (iii) pregnancies complicated by absent or reversed end diastolic (ARED) flow in the umbilical artery (n=18). All children were delivered by primary caesarean section.

RESULTS

The significantly highest maternal and fetal ET concentrations were found in plasma collected in pregnancies complicated by ARED flow in the umbilical artery. Maternal fibronectin levels were significantly raised in the ARED flow group. Maternal plasma ET levels were lowest in pregnancies complicated by IUGR. The maternal and fetal plasma concentrations of LOOH and GSHpx did not differ significantly between the groups.

CONCLUSION

Abnormal Doppler velocimetry, especially ARED flow is associated with elevated maternal and fetal plasma levels of ET. The exact mechanism causing the placental vasoconstriction is unknown yet, but oxidative stress seems not to be involved.

Circulating cellular fibronectin may be a natural ligand for the hepatic asialoglycoprotein receptor: possible pathway for fibronectin deposition and turnover in the rat liver

It has been postulated that the in vivo removal of many plasma glycoproteins after desialylation is mediated by their interaction with a specific endocytic receptor on hepatocytes called the asialoglycoprotein receptor (ASGP-R), which is known to have a high affinity for specific carbohydrate residues, such as galactose. However, this mechanism has never been proven in vivo, nor has a naturally occurring ligand for the ASGP-R been identified. We investigated the influence of the terminal galactose residues on plasma fibronectin (pFn) on its liver deposition and turnover in adult rats, using neuraminidase to remove sialic acid residues to expose galactose residues. We also tested the hypothesis that the normal presence of a large amount of terminal galactose residues in cellular Fn (cFn) may allow cFn to serve as a natural ligand readily able to interact with the ASGP-R. In contrast to the slow clearance of normal pFn from the blood, cFn and desialylated pFn (aFn) displayed a rapid plasma clearance (P < .001) with greater than 50% of both the 125I-cFn or 125I-aFn depositing in the liver within 15 minutes. The enhanced plasma removal and liver deposition of both 125I-cFn and 125I-aFn was competitively inhibited (P < .01) by prior intravenous infusion of excess asialofetuin, which can selectively bind to the ASGP-R. The enzymatic addition of terminal sialic acid residues onto cFn to "mask" or "cap" the normally exposed galactose residues delayed the rapid plasma removal of cFn. Accelerated degradation of 125I-aFn and 125I-cFn as compared with 125I-pFn was demonstrated in vitro by both primary cultures of normal rat hepatocytes or incubated (37 degrees C) tissue slices of livers harvested from normal rats after in vivo preloading with tracer 125I-Fn forms. Thus, the ASGP-R appears to directly participate in the rapid in vivo removal of cFn from the blood, while native pFn may be removed by an alternative pathway unless it can become desialylated in vivo. These findings suggest that cFn may be a naturally occurring ligand that does not require desialylation before removal by the ASGP-R on hepatocytes.

The prediction of preeclampsia: reassessment of clinical value of increased plasma levels of fibronectin

OBJECTIVE

To determine whether assessment of plasma fibronectin in primigravidae could predict the pregnant women expected to become preeclamptic.

METHODS

We performed a prospective blinded analysis of 156 apparently normotensive primigravidae in an outpatient clinic. Blood samples were taken at 6 week intervals from the 18th week and immediately after delivery or at the onset of preeclampsia. Plasma fibronectin was evaluated by ELISA. Evolution with gestational age was studied using regression curves.

RESULTS

We had 148 normal primigravidae (592 determinations). In three women, increased fibronectin anticipated preeclampsia by 3-4 weeks. Five women showed high levels only at the onset of preeclampsia. Sensitivity, specificity, positive and negative predictive values of increased fibronectin levels were 37.5% (95% CI=3.3-71.7), 96.6% (95% CI=93.7-99.6), 37.5% (95% CI=3.3-71.7) and 96.6% (95% CI=93.7-99.6), respectively.

CONCLUSIONS

This study shows that plasma fibronectin levels could represent a specific marker for preeclampsia. Its sensitivity has to be improved but its high negative predictive value strongly argues against the development of preeclampsia within the next 4 weeks after the blood sampling.

Fetal plasma levels of circulating endothelial cell adhesion molecules in normal and preeclamptic pregnancies

OBJECTIVE

Circulating levels of endothelial cell adhesion molecules are elevated in women with preeclampsia. The aim of the present study was to determine levels of these molecules in the fetal circulation of normal pregnancies and pregnancies complicated by preeclampsia.

STUDY DESIGN

Fetal plasma samples from the umbilical vein and peripheral maternal plasma and serum sample were collected at delivery from women with preeclampsia and women with normal pregnancy. Women with non-proteinuric pregnancy-induced hypertension (PIH) were excluded from the study. A sandwich ELISA technique was employed to quantitate concentrations of soluble ICAM-1 (CD54), VCAM-1 (CD106), and E-selectin (CD62E).

RESULTS

The normal values of soluble endothelial cell adhesion molecules in the fetal circulation were determined as 162+/-45 ng/ml for ICAM-1, 1612+/-582 ng/ml for VCAM-1, and 154+/-58 ng/ml for E-selectin. They were found to markedly differ from the corresponding normal values in the maternal circulation (sICAM-1: 247+/-65 ng/ml; sVCAM-1: 715+/-170 ng/ml; sE-selectin: 34+/-14 ng/ml). The concentrations of sICAM-1, sVCAM-1, and sE-selectin were significantly elevated in women with preeclampsia compared to healthy control pregnant women. In contrast, there was no difference in the circulating fetal concentrations of these molecules between normal pregnancies and pregnancies complicated by preeclampsia.

CONCLUSIONS

Normal values of sICAM-1, sVCAM-1, and sE-selectin in fetal circulation are markedly different from the values obtained for healthy adults. Plasma concentrations of these molecules are elevated in women with preeclampsia but not in the fetal circulation of preeclamptic pregnancies suggesting that based on the analysis of soluble adhesion molecules the fetal circulation may not be affected by the factor(s) that lead to disturbed endothelial cell function in women with preeclampsia.

Endothelial-cell permeability and protein kinase C in pre-eclampsia

BACKGROUND

Oedema and vascular leakage play a part in the pathogenesis of pre-eclampsia. We tested the hypothesis that serum from pre-eclamptic patients increases endothelial-cell permeability and examined possible signal-transduction pathways.

METHODS

We studied eight patients with pre-eclampsia, eight normotensive pregnant women, eight non-pregnant women, five pregnant patients with pre-existing hypertension, and four hypertensive non-pregnant women. Cultured human umbilical-vein endothelial-cell monolayers were used and permeability was measured by albumin flux. The part played by protein kinase C (PKC) signalling was examined by down-regulation with phorbol ester and with the inhibitors Goe 6976 and staurosporine. PKC isoforms were assessed by western blot and confocal microscopy. Antisense oligodesoxynucleotides (ODN) were used to test for specific PKC isoforms.

FINDINGS

Serum from pre-eclamptic women increased endothelial permeability significantly (by 100%, p<0.01). The change in permeability decreased rapidly after delivery. Serum from normotensive pregnant women and non-pregnant women had no effect. Permeability was not influenced by serum from patients with essential hypertension or pregnant patients with pre-existing hypertension. Serum from pre-eclamptic patients induced a translocation of PKC isoforms alpha and epsilon within the cells. Goe 6976 and staurosporine (10(-8) mol/L) inhibited the increase in permeability induced by serum from pre-eclamptic patients. Down-regulation of PKC alpha and, to a lesser extent, PKC epsilon by antisense ODN also inhibited the pre-eclampsia-induced permeability increase.

INTERPRETATION

Serum from pre-eclamptic patients contains a factor or factors that increase endothelial-cell permeability. The effect of pre-eclamptic serum may be mediated by PKC alpha and epsilon.

Preeclamptic nephropathy -- an endothelial lesion. A morphological study with a review of the literature

OBJECTIVE

We investigated wether an endothelial lesion, postulated in pathogenesis of preeclampsia (PE) in general, is also pathogenetically relevant in the characteristic renal lesions of PE, presenting as special glomerular alterations, designated as "preeclamptic nephropathy".

STUDY DESIGN

Renal biopsies of 90 women with PE were analyzed by light microscopy (LM), immunohistology (IH) and electron microscopy (EM). Corresponding with clinical data clinicomorphological correlations were performed.

RESULTS

In IH and EM the altered glomeruli demonstrate an endothelial lesion. Consecutive morphological reactions could be revealed by EM, allowing a subdivision in different stages of disease. The late stage indicates the reversibility of these renal lesions. Close correlations were found between clinical and morphological data. Focal glomerulosclerosis presents a hyperperfusion lesion, developing only facultatively in PE as a result of hyperfiltration.

CONCLUSION

In preeclamptic nephropathy the first morphological substrate of renal changes with the key to pathogenesis presents itself as an endothelial lesion. This results in a disturbance of glomerular basement membrane permeability and in an imbalance of different mediator systems, with dominance of vasoconstrictive reactions but also coagulative-, reparation-, and proliferation-processes, leading to the characteristic glomerular alterations of preeclamptic nephropathy.

Circulating endothelial cell adhesion molecules as diagnostic markers for the early identification of pregnant women at risk for development of preeclampsia

OBJECTIVE

The aim of the current study was to determine levels of circulating endothelial cell adhesion molecules during preeclampsia and to assess their predictive value as diagnostic markers for the early identification of pregnant women at risk of developing preeclampsia.

STUDY DESIGN

Plasma samples were obtained from women with preeclampsia; the syndrome of hemolysis, elevated liver enzymes, and low platelets; uncomplicated pregnancy-induced hypertension; and women with normal pregnancy. In addition, longitudinal plasma profiles of pregnant women were randomly collected to determine individual profiles of circulating endothelial cell adhesion molecules. A sandwich enzyme-linked immunosorbent assay technique was used to quantitate concentrations of soluble intercellular adhesion molecule-1 (CD54), vascular cell adhesion molecule-1 (CD106), E-selectin (CD62E), platelet endothelial cell adhesion molecule (CD31), and P-selectin (CD62P).

RESULTS

Plasma levels of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and platelet endothelial cell adhesion molecule-1 were significantly elevated in women with preeclampsia compared with healthy control pregnant women. Longitudinal analysis of soluble plasma intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 levels during pregnancy revealed that these molecules (1) show little variation in healthy pregnant women, (2) do not vary during normal pregnancy, and (3) are significantly elevated in women with preeclampsia and the syndrome of hemolysis, elevated liver enzymes, and low platelets compared with control pregnant women and those with uncomplicated pregnancy-induced hypertension. Analysis of soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 levels in longitudinal profiles of pregnant women identified significantly elevated levels of these molecules in the plasma of preeclampsia-prone women 3 to 15 weeks before the onset of clinical symptoms.

CONCLUSION

Elevated soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 measurements during pregnancy can be considered as major risk factors. Elevated levels of these substances in the plasma of pregnant women with preeclampsia support the concept of a primary endothelial cell involvement in the pathogenesis of preeclampsia. Although currently based on a limited database, significantly elevated levels of soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in the plasma of otherwise healthy pregnant women suggest a very high predictive value of these molecules for the earliest identification of women at risk of developing preeclampsia.

Maternal plasma fibronectin: a predictor of preterm delivery

OBJECTIVE

Current opinion holds that there are several distinct groups among patients with preterm labour: one of them is characterized by bacterial infection, another one by the presence of placental vascular abnormalities with endothelial damage. The aim of this study was to investigate plasma fibronectin, a suspected biochemical marker of endothelial damage, as an indicator for pregnancies with a high risk of preterm delivery.

METHODS

Plasma fibronectin levels were measured in patients with preterm labour (n = 80) and in healthy pregnant women with uncomplicated (control) pregnancies (n = 64) between the 22nd and 36th week of gestation. Furthermore, the plasma concentrations of fibronectin in 15 newborns at term and ten babies born preterm were measured to study the relationship between preterm delivery and plasma fibronectin concentration in newborns. Fibronectin was measured by nephelometry.

RESULTS

The mean concentration of fibronectin in patients with preterm labour was 0.44 g/l (S.D., 0.15) vs. 0.25 g/l (S.D., 0.12) in uncomplicated control pregnancies matched for gestational age. In control patients who actually delivered at term, fibronectin values were found to be lower than in control patients who underwent preterm delivery (0.25 g/l; S.D., 0.05; vs. 0.46 g/l; S.D., 0.15; P < 0.05). Particularly high values were detected in patients with preterm labour delivering before 32 weeks of gestation (0.60 g/l; S.D., 0.16). There was no significant difference between fibronectin concentrations in the umbilical arterial and venous blood of premature infants and mature infants. Leucocyte concentration, bacteriological smear and cervical dilatation did not correlate with fibronectin concentrations in patients with preterm delivery or controls.

CONCLUSION

We conclude that the higher plasma concentrations of fibronectin in women with preterm labour may be a biochemical marker and a predictor of preterm delivery.