Elevated Serum Levels of Interleukin-6, Interleukin-1β and Human Chorionic Gonadotropin in Pre-eclampsia

IL-1 beta but not the NALP3 inflammasome is an important determinant of endothelial cell responses to necrotic/dangerous trophoblastic debris

INTRODUCTION

Necrotic but not apoptotic trophoblastic debris can induce endothelial cell activation but the mechanism by which endothelial cells distinguish apoptotic from necrotic debris is unclear. The NALP3 inflammasome is a pattern recognition receptor that macrophages employ to recognise "danger signals" in necrotic cell corpses. In this study, we hypothesized that endothelial cells can identify and respond to necrotic trophoblastic debris via the NALP3 inflammasome.

METHODS

The effect of trophoblastic debris on endothelial expression of NALP3 inflammasome components was investigated using qRT-PCR, immunoassays and fluorescent caspase 1 activity assay. IL-1β in was quantified by ELISA. Endothelial cell activation was measured by cell surface ICAM expression and monocytes adhesion assay.

RESULTS

The NALP3 inflammasome was expressed in resting vascular endothelial cells and is involved in endothelial response to danger signals. However, exposure to necrotic trophoblastic debris did not significantly alter the expression of any of the three components of the NALP3 inflammasome at the mRNA level, nor was caspase-1 activation increased. Conditioned media from endothelial cells exposed to necrotic trophoblastic debris contained elevated levels of IL-1β which was derived from the necrotic debris and which contributed to endothelial cell activation.

DISCUSSION

Necrotic trophoblastic debris induced endothelial cell activation through the IL-1β/IL-1R pathway. However, the NALP3 inflammasome in endothelial cells was not involved in this process.

Serum free β-human chorionic gonadotropin in the three trimesters of pregnancy: effects of maternal characteristics and medical history

OBJECTIVE

To define the contribution of maternal variables which influence the measured level of maternal serum free β-human chorionic gonadotropin (β-hCG) in screening for pregnancy complications.

METHODS

Maternal characteristics and medical history were recorded and serum free β-hCG was measured in women with a singleton pregnancy attending for three routine hospital visits at 11 + 0 to 13 + 6, 19 + 0 to 24 + 6 and 30 + 0 to 34 + 6 weeks' gestation. For pregnancies delivering phenotypically normal live births or stillbirths ≥ 24 weeks' gestation, variables from maternal demographic characteristics and medical history that are important in the prediction of free β-hCG were determined from a linear mixed-effects multiple regression.

RESULTS

Serum free β-hCG was measured in 94 985 cases in the first trimester, 7879 in the second trimester and 8424 in the third trimester. Significant independent contributions to serum free β-hCG were provided by gestational age, maternal weight, age and racial origin, cigarette smoking, method of conception, diabetes mellitus and family history of pre-eclampsia (PE) in the mother of the patient. The effects of some variables were similar and those for others differed in each trimester. Random-effects multiple regression analysis was used to define the contribution of maternal variables that influence the measured level of serum free β-hCG and express the values as multiples of the median (MoMs). The model was shown to provide an adequate fit of MoM values for all covariates both in pregnancies that developed PE and in those without this pregnancy complication.

CONCLUSIONS

A model was fitted to express measured serum free β-hCG across the three trimesters of pregnancy as MoMs after adjusting for variables from maternal characteristics and medical history that affect this measurement.

Interleukin-1 family cytokines and their regulatory proteins in normal pregnancy and pre-eclampsia

Maternal systemic inflammation is a feature of pre-eclampsia, a condition in pregnancy characterized by hypertension and proteinuria. Pre-eclampsia is caused by the placenta; many placental factors contribute to the syndrome's progression, and proinflammatory cytokines have been identified previously as one such mediator. The interleukin (IL)-1 family of cytokines are key regulators of the inflammatory network, and two naturally occurring regulatory molecules for IL-1 family cytokines, IL-1RA and sST2, have been found previously to be elevated in maternal blood from women with pre-eclampsia. Here we investigate more recently identified IL-1 family cytokines and regulatory molecules, IL-1RAcP, IL-37, IL-18BP, IL-36α/β/γ/Ra and IL-38 in pre-eclampsia. Pregnant women have more circulating IL-18BP and IL-36Ra than non-pregnant women, and sIL-1RAcP is elevated from women with pre-eclampsia compared to normal pregnancies. The placenta expresses all the molecules, and IL-37 and IL-18BP are up-regulated significantly in pre-eclampsia placentas compared to those from normal pregnancies. Together, these changes contribute to the required inhibition of maternal systemic cytotoxic immunity in normal pregnancy; however, in pre-eclampsia the same profile is not seen. Interestingly, the increased circulating levels of sIL-1RAcP and increased placental IL-18BP and IL-37, the latter of which we show to be induced by hypoxic damage to the placenta, are all factors which are anti-inflammatory. While the placenta is often held responsible for the damage and clinical symptoms of pre-eclampsia by the research community, here we show that the pre-eclampsia placenta is also trying to prevent inflammatory damage to the mother.

Relationships among psychosocial factors, biomarkers, preeclampsia, and preterm birth in African American women: a pilot

AIM

To explore the relationships among psychosocial factors (optimism, uncertainty, social support, coping, psychological distress), biomarkers (cortisol, cytokines), preeclampsia, and preterm birth in African American women.

METHODS

Forty-nine pregnant African American women completed psychosocial questionnaires and had blood collected for biomarkers between 26 and 36 weeks of gestation. Birth outcomes were obtained from birth records.

RESULTS

Women reporting higher levels of social support had lower levels of pro-inflammatory cytokines (IL-2, IL-5, and IL-6). Surprisingly, compared with low-risk pregnant women, women diagnosed with preeclampsia reported more optimism and less avoidance, and had lower levels of cortisol and IFN-γ. Similarly, compared to women with full-term birth, women with preterm birth reported higher levels of optimism and lower levels of avoidance, and had lower levels of IL-10.

CONCLUSION

Psychosocial factors influence inflammation and pregnancy outcomes. Close assessment and monitoring of psychosocial factors may contribute to improved pregnancy outcomes.

Interleukin-1β-31C/T and -511T/C polymorphisms were associated with preeclampsia in Chinese Han population

Objective

The purpose of our study is to investigate the relationship between IL-1β -31C/T (rs1143627) and -511T/C (rs16944) polymorphisms and the preeclampsia (PE), and analyze the Linkage disequilibrium (LD) and haplotype frequency of the two polymorphism loci.

Methods

Polymorphisms at -31C/T and -511T/C of IL-1β were genotyped with the method of polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) in 232 PE and 447 control subjects. Genotype and allele frequencies between case-control groups were compared by chi-square(X²) tests. Two-point LD and haplotype frequency analyses were done with the software Haploview4.2.

Results

Significant statistical differences were found between PE and control groups regarding genotype and allele frequencies of the two polymorphisms of IL-1β (For IL-1β -31C/T: X² = 11.478, P = 0.003; For IL-1β-511T/C: X² = 9.687, P = 0.008). LD analysis revealed that the IL-1β -31C/T SNP was in high LD with the IL-1β-511C/T SNP(D′ = 0.92, r² = 0.79). Both CT and TC haplotypes showed significant differences between case and control groups. Only the plasma level of Prothrombin Time had a significantly statistical difference among TT, CT and CC groups of the preeclamptic two polymorphisms of IL-1β-31C/T and -511T/C (for IL-1β-31C/T, F = 1.644, P = 0.01; F = 1.587, P = 0.016).

Conclusion

Our results revealed IL-1β was associated with the PE in Chinese Han population. The CT haplotype may increase the risk of PE, while haplotype TC could be considered as a protective haplotype of PE.

Reduced syncytin-1 expression in choriocarcinoma BeWo cells activates the calpain1-AIF-mediated apoptosis, implication for preeclampsia

Placentas associated with preeclampsia are characterized by extensive apoptosis in trophoblast lineages. Syncytin-1 (HERVWE1) mediates the fusion of cytotrophoblasts to form syncytiotrophoblasts, which assume the placental barrier, fetal-maternal exchange and endocrine functions. While decreased syncytin-1 expression has been observed in preeclamptic placentas, it is not clear if this alteration is involved in trophoblast apoptosis. In the current study, we found that siRNA-mediated knockdown of syncytin-1 led to apoptosis in choriocarcinoma BeWo, a cell line of trophoblastic origin. Characterization of the apoptotic pathways indicated that this effect does not rely on the activation of caspases. Rather, decreased syncytin-1 levels activated the apoptosis inducing factor (AIF) apoptotic pathway by inducing the expression, cleavage, and nuclear translocation of AIF. Moreover, calpain1, the cysteine protease capable of cleaving AIF, was upregulated by syncytin-1 knockdown. Furthermore, treatment with calpain1 inhibitor MDL28170 effectively reversed AIF cleavage, AIF nuclear translocation, and cell apoptosis triggered by syncytin-1 downregulation, verifying the specific action of calpain1-AIF pathway in trophoblast apoptosis. We confirmed that preeclamptic placentas express lower levels of syncytin-1 than normal placentas, and observed an inverse correlation between syncytin-1 and AIF/calpain1 mRNA levels, a result consistent with the in vitro findings. Immunohistochemistry analyses indicated decreased syncytin-1 and increased AIF and calpain1 protein levels in apoptotic cells of preeclamptic placentas. These findings have for the first time revealed that decreased levels of syncytin-1 can trigger the AIF-mediated apoptosis pathway in BeWo cells. This novel mechanism may contribute to the structural and functional deficiencies of syncytium frequently observed in preeclamptic placentas.

Decreased seizure threshold in an eclampsia-like model induced in pregnant rats with lipopolysaccharide and pentylenetetrazol treatments

Objective

Eclampsia is a poorly understood but potentially fatal complication of pregnancy. Research to date on this disorder has been hampered by the lack of a suitable animal model. To correct this deficiency, this report describes the generation of a rat eclampsia-like model using pentylenetetrazol (PTZ) in a previously established rat preeclampsia model.

Method

Rats were administered lipopolysaccharide (1.0 µg/kg) by tail vein injection on gestational day 14 to establish preeclampsia (PE). PE and control rats (non-pregnant, NP; normal-pregnant, P) were injected intraperitoneally (i.p.) with PTZ (40 mg/kg) to induce seizures. In separate experiments, MgSO₄ (270 mg/kg IP) was injected in advance of PTZ into PE rats to observe its effect on PTZ-induced seizures.

Results

PE conditions were verified in rats after LPS administration by significantly higher blood pressure (P<0.01) and urinary albumin excretion (P<0.05), elevated sFlt-1 (P<0.05) and decreased PlGF serum levels (P<0.05), and evidence of hepatic dysfunction compared to control groups. PTZ successfully induced seizure activity in all groups studied. Latency to seizure was significantly (P<0.01) less in the PE-PTZ group (73.2±6.6 sec.) than in PTZ-treated controls (107.0±7.4 sec.). Pretreatment with MgSO₄ prolonged (P<0.05) latency to seizure, shortened seizure duration and decreased seizure rates. Significant increased (P<0.05) in the serum levels of the inflammatory cytokines TNF-α and IL-1β in PE and PE-PTZ groups, and decreased (P<0.05) in their levels following MgSO₄ administration.

Conclusion

This PTZ-induced eclampsia-like rat model is comparable to the human condition of eclampsia and may serve as a useful research tool for future studies of this disease. The increased inflammatory cytokines in preeclampsia are coincident with a decreased threshold for PTZ-induced seizures, suggesting that an inflammatory mechanism may contribute to the susceptibility to seizure activity and inflammation might have an important role in eclampsia.

Interleukin-4 deficiency induces mild preeclampsia in mice

OBJECTIVE

Inflammation is necessary for successful pregnancy; however, excessive inflammation plays a central role in the development of the pregnancy-specific hypertensive disorder preeclampsia. Numerous anti-inflammatory cytokines are decreased in women with preeclampsia but the role of individual cytokines in blood pressure regulation during pregnancy is unknown. Therefore, we examined whether the lack of the potent anti-inflammatory cytokine interleukin-4 (IL-4) would be sufficient to elicit a preeclampsia-like syndrome in mice, and when coupled with immune system activation that these symptoms would be further augmented.

METHODS

Measures of splenic immune cells, placental inflammation, blood pressure, endothelial function, and urinary protein excretion were performed in pregnant IL-4-deficient mice as well as in pregnant IL-4-deficient mice treated with the Toll-like receptor 3 agonist polyinosinic:polycytidylic (poly I:C).

RESULTS

Pregnant IL-4-deficient mice exhibited altered splenic immune cell subsets, increased levels of pro-inflammatory cytokines, placental inflammation, mild hypertension, endothelial dysfunction, and proteinuria compared to pregnant control mice. Compared to pregnant control mice treated with poly I:C which exhibit preeclampsia-like symptoms, poly I:C-treated pregnant IL-4-deficient mice exhibited a further increase in pro-inflammatory cytokine levels, which was associated with augmented SBP and endothelial dysfunction.

CONCLUSION

Collectively, these data show that the absence of IL-4 is sufficient to induce mild preeclampsia-like symptoms in mice due to excessive inflammation. Thus, the anti-inflammatory effects of IL-4 are important in preventing hypertension during pregnancy.

The relationship of hypovitaminosis D and IL-6 in preeclampsia

OBJECTIVE

Vitamin D deficiency has been linked to the pathogenesis of preeclampsia. Given the demonstrated antiinflammatory function of vitamin D in multiple organ systems including trophoblast cells and placenta, we hypothesized that vitamin D deficiency contributes to the development of preeclampsia through increased inflammation, as indicated by elevated interleukin (IL)-6 concentrations.

STUDY DESIGN

Plasma samples from a large preeclampsia cohort study were examined in 100 preeclamptic and 100 normotensive pregnant women. Comparisons of vitamin D and IL-6 concentrations used Student t test and χ(2) test or their nonparametric counterparts. A logistic regression model assessed the association among vitamin D, IL-6 concentrations, and preeclampsia risk.

RESULTS

The mean concentration of 25-hydroxyvitamin D was 49.4 ± 22.6 nmol/L in normotensives and 42.3 ± 17.3 nmol/L in preeclamptic women (P = .01). The median (interquartile range: Q1, Q3) concentrations of IL-6 were 2.0 (1.3, 3.4) pg/mL and 4.4 (2.2, 10.0) pg/mL in the control and preeclampsia groups, respectively (P < .01). We observed a significant association between IL-6 elevation and preeclampsia (odds ratio, 4.4; 95% confidence interval, 1.8-10.8; P < .01) and between vitamin D deficiency and preeclampsia (odds ratio, 4.2; 95% confidence interval, 1.4-12.8; P = .04). However, there was no association between vitamin D deficiency and IL-6 elevation.

CONCLUSION

Third-trimester IL-6 elevation and vitamin D deficiency were independently associated with the risk of preeclampsia. We found no evidence to support the hypothesis that vitamin D deficiency alters the pathogenesis of preeclampsia by activation of inflammation as assessed by IL-6 concentration.

Identification of interleukin-1 beta, but no other inflammatory proteins, as an early onset pre-eclampsia biomarker in first trimester serum by bead-based multiplexed immunoassays

OBJECTIVE

This study aimed to determine the predictive value of growth factors, cardiovascular, and immunological markers for first trimester identification of early onset pre-eclampsia (PE).

METHODS

In a retrospective case-control study, maternal serum samples of 35 early onset PE cases and 35 controls were analysed by multiplexed immunoassays, to determine serum concentrations of 41 proteins whose functionality can be associated with PE pathogenesis. All levels were converted into multiples of the gestation-specific normal median. For prediction modelling, proteins that were found to be significant were combined with previously obtained values of three established PE markers, that is, placental growth factor, placental protein 13, and pregnancy-associated plasma protein A. Prediction modelling was used to determine predicted detection rates for 5% and 10% false-positive rates.

RESULTS

Three of the proteins examined in this study, interleukin-1 beta (IL-1β), fibrinogen, and carcinoembryonic antigen, showed significantly different serum levels at p < 0.05. In prediction modelling, only IL-1β added predictive value to the three previously established biomarkers, by increasing detection from 38.2% to 44.1% at a 5% false-positive rate.

CONCLUSIONS

This study indicates that IL-1β has potential to improve first trimester prediction of pre-eclampsia. Studies on larger cohorts will be needed to validate these findings.

High levels of heat shock protein 70 are associated with pro-inflammatory cytokines and may differentiate early- from late-onset preeclampsia

Preeclampsia (PE), a specific syndrome of pregnancy, can be classified into early and late onset, depending on whether clinical manifestations occur before or after 34 weeks' gestation. We determined whether plasma concentrations of Hsp60 and Hsp70 were related to circulating cytokine levels, as well as kidney and liver functions, in early- and late-onset PE. Two hundred and thirty-seven preeclamptic women (95 with early- and 142 with late-onset PE) were evaluated. Plasma levels of Hsp60, Hsp70, and their specific antibodies, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1, IL-10, IL-12, and soluble TNF-α-receptor I (sTNFRI) concentrations, were determined by enzyme-linked immunosorbent assay (ELISA). Concentrations of Hsp70, TNF-α, IL-1β, IL-12, and sTNFRI were significantly elevated in patients with early-onset PE compared with women with late-onset PE; IL-10 levels were significantly lower in the early-onset PE group. Concentrations of urea, uric acid, proteinuria, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) were also significantly higher in early-onset PE. The percentage of infants with intrauterine growth restriction was also significantly higher in women with early-onset PE. There were positive correlations between Hsp70 levels and TNF-α, TNFRI, IL-1β, IL-12, GOT, GPT, LDH, and uric acid concentrations in early-onset PE group. Thus, early-onset PE was associated with greater maternal and fetal impairment. There are differences in pathophysiology between early- and late-onset PE, highlighting by the difference in Hsp70 levels.

If we know so much about preeclampsia, why haven't we cured the disease?

Preeclampsia has been recognized for at least 100 years. In the last 20 years, the consideration of the disorder as more than simply hypertension in pregnancy has led to an explosion in knowledge about preeclampsia pathophysiology. It is now evident that for most cases of preeclampsia, the root cause is the placenta. Relatively reduced placental perfusion leads to inflammation, oxidative stress, and endoplasmic reticulum stress, which converge to modify maternal physiology, with endothelium an important target. Although preeclampsia is characteristically diagnosed in the last third of pregnancy, it is evident that many of these pathophysiological changes can be detected long before clinically evident disease. Furthermore, it is evident that the "maternal constitution," including genetic, behavioral, and metabolic factors, influences the maternal response to the abnormal placentation of preeclampsia. These insights would seem to provide a guide for the prediction of the disorder in early pregnancy, along with targets for intervention. However, this has not been the case. Predictive tests guided by this knowledge do not predict well and several interventions guided by the expanded understanding of pathophysiology do not prevent the disease. We propose that these failures are secondary to the fact that preeclampsia is more than one disorder. Further, we suggest that future progress toward prediction and prevention will require research guided by this concept.

Tumor necrosis factor-alpha, interleukin-6, and interleukin-10 levels are altered in preeclampsia: a systematic review and meta-analysis

PROBLEM

Published reports testing the association between cytokine levels and preeclampsia are conflicting. This comprehensive systematic review and meta-analysis aimed at testing the association between preeclampsia and maternal circulating tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-10.

METHOD OF STUDY

A systematic literature search of studies reporting maternal circulating TNF-α, IL-6, and IL-10 in women with preeclampsia and normotensive pregnant women was conducted yielding 41, 28, and 12 eligible reports, respectively.

RESULTS

Both mild preeclampsia and severe preeclampsia were associated with elevated TNF-α [mean difference (MD) = 7.34 pg/mL, 95% CI 5.02-9.66 and MD = 7.91 pg/mL, 95% CI 4.72-11.10, respectively] and IL-6 (MD = 61.01 pg/mL, 95% CI 14.24-107.77 and MD = 28.54 pg/mL, 95% CI 15.90-41.17, respectively) in the third trimester. Preeclampsia was also associated with elevated levels of IL-10 (MD = 5.54, 95% CI 0.69-10.38). The systematic review of studies reporting median data was in consensus with the parametric data.

CONCLUSION

This systematic review and meta-analysis with accompanying summary of non-parametric data shows elevated maternal circulating TNF-α, IL-6, and IL-10 levels in preeclampsia.

Severe preeclampsia goes along with a cytokine network disturbance towards a systemic inflammatory state

Although preeclampsia causes high maternal/fetal morbidity and mortality, the etiology of this multi-system disorder still remains to be elucidated. Herein, we have characterized the cytokine plasma levels in severe preeclamptic women compared to normotensive pregnant and non-pregnant women, aiming to better understand the immunological network and its clinical significance for the pathogenesis and severity of preeclampsia. A total of 219 women were selected. The study population was composed of three groups referred as severe preeclamptic, normotensive pregnant and non-pregnant women. Cytokine plasma levels were determined using commercially available kits, Cytometric Beads Array - CBA to quantify TNF-α, IFN-γ, IL-4, IL-5, IL-10, IL-1β, IL-6, IL-8 and IL-12. Our findings demonstrated that severe preeclamptic state is associated with high levels of pro-inflammatory cytokines IL-8, IL-6, and IFN-γ (P < 0.05 for all) whereas normotensive pregnancy evolves high levels of regulatory cytokine IL-10 (P < 0.05). Moreover, an outstanding pro-inflammatory "cytokine signature" could be observed in severe preeclamptic women display, while an overall regulatory state is the hallmark for normotensive pregnancy. In summary, our data showed that elevated levels of pro-inflammatory cytokines in the maternal circulation with a deviation in the "IL-8 × IL-6" axis towards IFN-γ might drive the cytokine network in preeclamptic women towards an excessive systemic inflammatory state.

The obstetric syndromes: clinical relevance of placental hormones

Preterm delivery, preeclampsia and intrauterine growth restriction are the major diseases of pregnancy. A key role in their pathogenesis is played by the placenta, which is the source of hormones and other important regulatory molecules providing the metabolic and endocrine homeostasis of the fetal-placental unit. Since obstetric syndromes are characterized by important maternal and neonatal morbidity and mortality worldwide, numerous efforts have been made over the years to prevent and treat them. Due to their complex pathogenesis, however, the therapy is poor and not very effective. Therefore, great emphasis is currently given to the prevention of these diseases through the identification of biochemical and biophysical markers, among which placental factors play a crucial role. The increasing knowledge of the role of placental molecules can indeed lead to the development of new therapeutic and diagnostic tools.

Silibinin attenuates oxidative metabolism and cytokine production by monocytes from preeclamptic women

Silibinin is a polyphenolic plant flavonoid with anti-inflammatory properties. The present study investigated the effect of silibinin on oxidative metabolism and cytokine production - tumor necrosis factor-alpha (TNF-α), interleukin (IL)12, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, IL-10, and transforming growth factor beta (TGF-β1) - by peripheral blood monocytes (PBM) from preeclamptic pregnant women. It is a case-controlled study involving women with preeclampsia (PE, n = 30) compared with normotensive pregnant (NT, n = 30) and with non-pregnant (NP, n = 30) women. Monocytes were obtained and cultured with or without silibinin (5 μM or 50 μM) for 18 h. Superoxide anion (O2-) and hydrogen peroxide (H2O2) release were determined by specific assays, and cytokine levels were determined by immunoenzymatic assays (ELISA). Monocytes from preeclamptic women cultured without stimulus released higher levels of O22, H2O2 and TNF-α, and lower levels of IL-10 and TGF-β1 than did monocytes from NT and NP women. Treatment in vitro with silibinin significantly inhibited spontaneous O2- and H2O2 release and TNF-α production by monocytes from preeclamptic women. The main effect of silibinin was obtained at 50 μM concentration. Thus, silibinin exerts anti-oxidative and anti-inflammatory effects on monocytes from preeclamptic pregnant women by inhibiting the in vitro endogenous release of reactive oxygen species and TNF-α production.

Quantitative ELISAs for serum soluble LHCGR and hCG-LHCGR complex: potential diagnostics in first trimester pregnancy screening for stillbirth, Down's syndrome, preterm delivery and preeclampsia

BACKGROUND

Soluble LH/hCG receptor (sLHCGR) released from placental explants and transfected cells can be detected in sera from pregnant women. To determine whether sLHCGR has diagnostic potential, quantitative ELISAs were developed and tested to examine the correlation between pregnancy outcome and levels of serum sLHCGR and hCG-sLHCGR complex.

METHODS

Anti-LHCGR poly- and monoclonal antibodies recognizing defined LHCGR epitopes, commerical anti-hCGbeta antibody, together with recombinant LHCGR and yoked hCGbeta-LHCGR standard calibrators were used to develop two ELISAs. These assays were employed to quantify serum sLHCGR and hCG-sLHCGR at first trimester human pregnancy.

RESULTS

Two ELISAs were developed and validated. Unlike any known biomarker, sLHCGR and hCG-sLHCGR are unique because Down's syndrome (DS), preeclampsia and preterm delivery are linked to both low (less than or equal to 5 pmol/mL), and high (equal to or greater than 170 pmol/mL) concentrations. At these cut-off values, serum hCG-sLHCGR together with PAPP-A detected additional DS pregnancies (21%) which were negative by free hCGbeta plus PAPP-A screening procedure. Therefore, sLHCGR/hCG-sLHCGR has an additive effect on the current primary biochemical screening of aneuploid pregnancies. More than 88% of pregnancies destined to end in fetal demise (stillbirth) exhibited very low serum hCG-sLHCGR(less than or equal to 5 pmol/mL) compared to controls (median 16.15 pmol/mL, n = 390). The frequency of high hCG-sLHCGR concentrations (equal to or greater than 170 pmol/mL) in pathological pregnancies was at least 3-6-fold higher than that of the control, suggesting possible modulation of the thyrotropic effect of hCG by sLHCGR.

CONCLUSIONS

Serum sLHCGR/hCG-sLHCGR together with PAPP-A, have significant potential as first trimester screening markers for predicting pathological outcomes in pregnancy.

Calcitriol downregulates TNF-α and IL-6 expression in cultured placental cells from preeclamptic women

Placenta is an important source and target of hormones that contribute to immunological tolerance and maintenance of pregnancy. In preeclampsia (PE), placental calcitriol synthesis is low; whereas pro-inflammatory cytokines levels are increased, threatening pregnancy outcome. Previously, we showed that calcitriol inhibits Th-1 cytokines under experimental inflammatory conditions in normal trophoblasts. However, a study of the regulation of inflammatory cytokines by calcitriol in trophoblasts from a natural inflammatory condition, such as PE, is still lacking. Therefore, the aim of the present study was to investigate calcitriol effects upon TNF-α, IFN-γ, IL-6 and IL-1β in cultured placental cells from preeclamptic women by using qPCR and ELISA. Placentas were collected after cesarean section from preeclamptic women and enriched trophoblastic preparations were cultured in the absence or presence of different calcitriol concentrations during 24h. In these cell cultures, pro-inflammatory cytokines TNF-α and IL-6 secretion and mRNA expression were downregulated by calcitriol (P<0.05). No significant effects of calcitriol upon IFN-γ and IL-1β were observed. In addition, basal expression of TNF-α, IL-6 and IL-1β decreased as the cells formed syncytia. Our study supports an important autocrine/paracrine role of placental calcitriol in controlling adverse immunological responses at the feto-maternal interface, particularly in gestational pathologies associated with exacerbated inflammatory responses such as preeclampsia.

Placental secretion of interleukin-1 and interleukin-1 receptor antagonist in preeclampsia: effect of magnesium sulfate

Preeclampsia is a pregnancy-specific disorder characterized by hypertension and systemic endothelial dysfunction. Interleukin (IL)-1β is a possible mediator of maternal endothelial dysfunction in preeclampsia. Serum IL-1β as well as its natural inhibitor IL-1 receptor antagonist (IL-1Ra) were reported to be increased in women with preeclampsia. In the current study, we addressed the role of the placenta in controlling the circulatory levels of IL-1β and its natural inhibitor IL-1Ra in preeclampsia, and the possible effect of magnesium sulfate (MgSO(4)) on these levels. Using an ex vivo placental perfusion system, placentas from preeclamptic (n = 9) and normotensive (n = 6) pregnancies were perfused in presence or absence of MgSO(4). Perfusate samples were collected from the maternal and the fetal circulations of the perfusion system, and IL-1β and IL-1Ra were examined by enzyme-linked immunoassay (ELISA). Preeclamptic placentas secreted higher levels of IL-1β (P < 0.001), and a tendentious higher levels of IL-1Ra, mainly into the maternal circulation, as compared with normotensive placentas, although no differences in IL-1β:IL-1Ra ratio were detected. However, there was only tendentious increase in the secretion levels of IL-1β or IL-1Ra into the fetal circulation of preeclamptic placentas, when compared with normotensive placentas. Administration of MgSO(4) to preeclamptic placentas resulted in an attenuation of the increased secretion of IL-1β into the maternal circulation (P < 0.001), and in a tendentious reduction in IL-1Ra. However, IL-1β:IL-1Ra ratio in preeclamptic placentas was not affected by MgSO(4). Interestingly, exposure of normotensive placenta to MgSO(4) resulted only in increased levels of IL-1Ra in the maternal circulation, without affecting IL-1β levels or IL-1β:IL-1Ra ratio. These findings suggest that the placenta may contribute to the elevation in serum IL-1β and IL-1Ra in preeclampsia by increased secretion of these cytokines into the maternal circulation, and that MgSO(4) is able to attenuate this increased secretion of IL-1β, and possibly IL-1Ra, in preeclampsia.

Comparison of interleukin-6 levels in maternal and umbilical cord blood in early- and late-onset preeclampsia

PURPOSE

Increased inflammatory response and cytokines are claimed to play a significant role in the etiology of preeclampsia. Interleukin-6 (IL-6) is a proinflammatory cytokine. Limited number of studies evaluating IL-6 levels in preeclamptic patients have produced conflicting results. Therefore, the present study sought to compare maternal and umbilical cord serum levels of IL-6 in early- and late-onset preeclamptic pregnancies as well as in normal pregnancies.

MATERIALS AND METHODS

A total of 69 participants were enrolled in the study. The control group consisted of 24 participants with normal pregnancies. Preeclampsia group consisted of 45 participants. The preeclampsia group was further classified into the subgroups of early- and late-onset preeclampsia. Late-onset preeclampsia group consisted of 24 women whereas early-onset preeclampsia group consisted of 21 women. Serum and umbilical cord samples of IL-6 were compared.

RESULTS

There was no significant difference between maternal and umbilical cord serum IL-6 concentrations between the preeclampsia and control group. No significant difference was observed in maternal and umbilical cord serum IL-6 levels between early- and late-onset preeclampsia groups.

CONCLUSION

Our results do not support an increase in IL-6 levels in patients with early- and late-onset preeclampsia. The clinical relevance of our findings needs to be further investigated.

Biomarkers of coagulation, inflammation, and angiogenesis are independently associated with preeclampsia

PROBLEM

Although preeclampsia has been associated with inflammation, coagulation, and angiogenesis, their correlation and relative contribution are unknown.

METHOD OF STUDY

About 114 women with preeclampsia, 31 with early onset (EOP) and 83 with late onset preeclampsia (LOP), and 100 normal pregnant controls were included. A broad panel of 32 biomarkers reflecting coagulation, inflammation, and angiogenesis was analyzed.

RESULTS

Preeclampsia was associated with decreased antithrombin, IL-4 and placental growth factor levels and with increased C3a, pentraxin-3, and sFlt-1 levels, with more marked differences in the EOP group. The Th1-associated chemokines CXCL10 and CXCL11 were significantly higher in the preeclampsia and EOP group than in controls, respectively. No correlations between the biomarkers were found in preeclampsia. Multivariate logistic regression tests confirmed the results.

CONCLUSIONS

Cytokines, chemokines and complement activation seem to be part of a Th1-like inflammatory reaction in preeclampsia, most pronounced in EOP, where chemokines may be more useful than cytokines as biomarkers. Biomarkers were not correlated suggesting partly independent or in time separated mechanisms.