Maternal Serum Interleukin-10, Interleukin-2 and Interleukin-6 in Pre-Eclampsia and Eclampsia

Aspirin resistance in pregnancy is associated with reduced interleukin-2 (IL-2) concentrations in maternal serum: Implications for aspirin prophylaxis for preeclampsia

OBJECTIVES

To evaluate the impact of aspirin resistance on the incidence of preeclampsia and maternal serum biomarker levels in pregnant individuals at high-risk of preeclampsia receiving low dose aspirin (LDA).

STUDY DESIGN

We performed a secondary analysis of a randomized, placebo-controlled trial of LDA (60 mg daily) for preeclampsia prevention in high-risk individuals (N = 524) on pregnancy outcomes and concentrations of PLGF, IL-2, IL-6, thromboxane B2 (TXB2), sTNF-R1 and sTNF-R2 from maternal serum.

MAIN OUTCOME MEASURES

LDA-resistant individuals were defined as those having a TXB2 concentration >10 ng/ml or <75 % reduction in concentration at 24-28 weeks after LDA administration. Comparisons of outcomes were performed using a Fisher's Exact Test. Mean concentrations of maternal serum biomarkers were compared using a Student's t-test. Pearson correlation was calculated for all pairwise biomarkers. Longitudinal analysis across gestation was performed using linear mixed-effects models accounting for repeated measures and including BMI and maternal age as covariates.

RESULTS

We classified 60/271 (22.1 %) individuals as LDA-resistant, 179/271 (66.1 %) as LDA-sensitive, and 32/271 (11.8 %) as non-adherent. The prevalence of preeclampsia was not significantly different between the LDA and placebo groups (OR = 1.43 (0.99-2.28), p-value = 0.12) nor between LDA-sensitive and LDA-resistant individuals (OR = 1.27 (0.61-2.8), p-value = 0.60). Mean maternal serum IL-2 concentrations were significantly lower in LDA-resistant individuals relative to LDA-sensitive individuals (FDR < 0.05).

CONCLUSIONS

These results suggest a potential role for IL-2 in the development of preeclampsia modulated by an individuals' response to aspirin, presenting an opportunity to optimize aspirin prophylaxis on an individual level to reduce the incidence of preeclampsia.

Deciphering the immunological interactions: targeting preeclampsia with Hydroxychloroquine's biological mechanisms

Preeclampsia (PE) is a complex pregnancy-related disorder characterized by hypertension, followed by organ dysfunction and uteroplacental abnormalities. It remains a major cause of maternal and neonatal morbidity and mortality worldwide. Although the pathophysiology of PE has not been fully elucidated, a two-stage model has been proposed. In this model, a poorly perfused placenta releases various factors into the maternal circulation during the first stage, including pro-inflammatory cytokines, anti-angiogenic factors, and damage-associated molecular patterns into the maternal circulation. In the second stage, these factors lead to a systemic vascular dysfunction with consecutive clinical maternal and/or fetal manifestations. Despite advances in feto-maternal management, effective prophylactic and therapeutic options for PE are still lacking. Since termination of pregnancy is the only curative therapy, regardless of gestational age, new treatment/prophylactic options are urgently needed. Hydroxychloroquine (HCQ) is mainly used to treat malaria as well as certain autoimmune conditions such as systemic lupus and rheumatoid arthritis. The exact mechanism of action of HCQ is not fully understood, but several mechanisms of action have been proposed based on its pharmacological properties. Interestingly, many of them might counteract the proposed processes involved in the development of PE. Therefore, based on a literature review, we aimed to investigate the interrelated biological processes of HCQ and PE and to identify potential molecular targets in these processes.

DAMPs are able to skew CD4+ T cell subsets and increase the inflammatory profile in pregnant women with preeclampsia

Preeclampsia (PE) is characterized by abnormal activation of the immune system. The intense systemic inflammatory reaction, could be related to the presence of molecules released after cell stress or death, that are capable of inducing inflammation and are known as damage-associated molecular patterns (DAMP). This study evaluated the profile of T cells through the analysis of transcription factors and the cytokines produced after culture with or without DAMPs: heat shock protein 70 (Hsp70), hyaluronan (HA) and monosodium urate (MSU). Twenty pregnant women with PE, 20 normotensive (NT) pregnant women and 20 non-pregnant (NP) women were studied. The results showed polarization toward Th1/Th17 and a decrease in Th2/Treg profiles in preeclamptic women associated with elevated levels of TNF, IFN-γ, and IL-17A and diminished levels of TGF-β1 and IL-10 when compared to the normotensive group. In addition, preeclamptic women had a higher percentage of cells co-expressing T-bet/GATA-3 and T-bet/RORγt and fewer T-bet/FoxP3 cells when compared to normotensive group. MSU induced an increase in IFN-γ and IL-22 in all studied groups. MSU, HA, and Hsp70 induced significant higher production of TNF in the PE and NP groups. The PE group showed elevated levels of TGF-β1 after incubation with MSU, HA, and Hsp70, whereas HA and Hsp70 decreased TGF-β1 production in NT group. The results suggest that these alarmins may play a role in the activation of innate and adaptive immune systems by skewing CD4 + T cells and increasing the release of inflammatory cytokines, thereby contributing to the pathogenesis of this important syndrome.

Maternal one carbon metabolism and interleukin-10 &-17 synergistically influence the mode of delivery in women with Early Onset Pre-Eclampsia

OBJECTIVE

Studies on One Carbon Metabolism (OCM), Interleukins-10 &-17 (IL-10/-17) & βhCG in pre-eclampsia and its delivery outcome (preterm birth) reveal contradictory results, attributed to clinical heterogeneity (early/late onset pre-eclampsia) or preterm/term birth. Disturbed OCM also influences IL-10 &-17 during pregnancy. We sought to investigate the synergism between OCM and IL-10/-17 mediated immune-regulation through βhCG in Early onset pre-eclampsia (EO-PE) patients, delivering preterm, among North Indian women.

STUDY DESIGN

Case-control study with a total of 399 pregnant women (EO-PE delivering preterm = 199; Normotensives delivering at term = 200). Maternal genotypes & biochemical estimations along with fetal genotypes on subset (n = 72) pertaining to OCM and IL-10/-17 regulation were assessed.

MAIN OUTCOME MEASURES

Association of 1) maternal plasma levels with EO-PE 2) maternal and fetal genotypes with EO-PE. 3) Effect of Hyper-homocysteinemia (surrogate of disturbed OCM) on differential immune regulation (IL10,-17, βhCG) in EO-PE and mode of delivery.

RESULTS

Hyper-homocysteinemia posed an increased risk of three folds for EO-PE. Both, folate and B12 deficiencies were associated with elevated homocysteine in EO-PE. Further, MTHFR 677TT homozygotes was present only in EO-PE indicating its detrimental role. However, maternal IL17-197AA genotype showed decreased risk for EO-PE. Furthermore, elevated maternal plasma IL-17 along with elevated IL-10 & βhCG were observed in EO-PE. Taken together, altered homocysteine metabolism was associated with high IL10 in EO-PE; and was more pronounced in spontaneous vaginal deliveries as compared to induced/caesarean section deliveries.

CONCLUSIONS

We report homocysteine mediated IL-10 &17 dysregulation and its influence on mode of delivery in EO-PE, possibly through initiation of cervical ripening. Further, these could serve potential biomarkers of EO-PE & its delivery outcome among vulnerable populations with similar nutritional & genetic predispositions.

Preeclamptic Women Have Decreased Circulating IL-10 (Interleukin-10) Values at the Time of Preeclampsia Diagnosis: Systematic Review and Meta-Analysis

A key immunomodulatory cytokine, IL-10 (interleukin-10), has been shown to be dysregulated in preeclampsia, a pregnancy-specific hypertensive disorder, further characterized by multi-system involvement. However, studies have reported inconsistent findings about circulating IL-10 levels in preeclamptic versus normotensive pregnancies. The aim of the present systematic review and meta-analysis was to assess circulating IL-10 levels in preeclamptic and normotensive pregnancies at 2 time points: before, and at the time of preeclampsia diagnosis. PubMED, EMBASE, and Web of Science databases were searched to include all published studies examining circulating IL-10 levels in preeclamptic and normotensive pregnancies. Differences in IL-10 levels were evaluated by standardized mean differences. Of 876 abstracts screened, 56 studies were included in the meta-analysis. Circulating IL-10 levels were not different before the time of active disease (standardized mean differences, -0.01 [95% CI, -0.11 to 0.08]; P=0.76). At the time of active disease, women with preeclampsia (n=1599) had significantly lower IL-10 levels compared with normotensive controls (n=1998; standardized mean differences, -0.79 [95% CI, -1.22 to -0.35]; P=0.0004). IL-10 levels were lower in both early/severe and late/mild forms of preeclampsia. Subgroup analysis revealed that IL-10 measurement methodology (ELISA or multiplex bead array) and the sample type (plasma or serum) significantly influenced the observed differences, with the use of sera paired with ELISA technology providing the best distinction in IL-10 levels between preeclamptic and normotensive pregnancies. These findings support the role of decreased IL-10 levels in the pathophysiology of preeclampsia. Future studies should address the therapeutic potential of IL-10 in preeclampsia.

Glutathione-S-transferase M1 polymorphism and pro-inflammatory cytokines tumour necrosis factor-α and interleukin-1β are associated with preeclampsia in Serbian women

PROBLEM

Preeclampsia has a multifactorial origin with genetic, immunological, and environmental factors described as main contributors to its onset. This study aimed to investigate glutathione-S-transferase M1 (GSTM1) and glutathione-S-transferase T1 (GSTT1) gene polymorphisms, the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and the potential relationship between GST polymorphisms and cytokine expression levels in preeclampsia and uncomplicated pregnancy.

METHOD OF STUDY

This prospective case-control study included 50 women with preeclampsia and 50 healthy pregnant women. DNA and RNA were extracted from women leukocytes. Deletion polymorphisms were analyzed by PCR, while cytokine mRNA expression was analyzed by real-time PCR.

RESULTS

GSTM1 null genotype with present GSTT1 increased the risk for preeclampsia development. Deletion of GSTT1 without deletion of GSTM1 increased the risk for early preeclampsia. Relative mRNA expression of TNF-α was significantly higher in preeclampsia compared to healthy pregnant women (P = 0.006). Expression of IL-1β was significantly higher in severe and late preeclampsia compared to the control group (P = 0.005, P = 0.007, respectively). A significant positive correlation between TNF-α and IL-1β was observed (Spearman's ρ = 0.312, P = 0.028) and between IL-1β and IL-6, in preeclampsia group (Spearman's ρ = 0.296, P = 0.037). IL-1β was significantly increased in patients with GSTT1 null genotype (P = 0.015) while IL-6 was increased in patients with GSTM1 null genotype (P = 0.015).

CONCLUSIONS

GSTM1 null genotype represents a risk factor for preeclampsia development, while GSTT1 null genotype favors early preeclampsia. Preeclampsia is also associated with increased expression of pro-inflammatory cytokines, predominantly TNF-α and IL-1β.

Determining Whether Hypertensive Status and Stress Level Are Associated With Inflammatory Markers

BACKGROUND

Hypertensive disorders are common pregnancy complications in the United States. Although the exact mechanism underlying hypertensive disorders in pregnancy is unknown, there is evidence of involvement of a maladaptive maternal inflammatory response. Psychological maternal stress experienced during pregnancy can increase the risk of a hypertensive disorder by altering the maternal inflammatory response.

OBJECTIVES

The purpose of this analysis was to evaluate the relationships of hypertensive status and stress with inflammatory biomarkers throughout pregnancy.

METHOD

A 1:2 case-control design was used to analyze secondary data longitudinally with repeated measures of a multicenter, culturally and ethnically diverse pregnant population. Demographic data, psychological stress, and serum inflammatory data were analyzed. The sample consisted of 30 pregnant women with hypertension and 61 normotensive women. Measurements were taken once in each trimester of pregnancy.

RESULTS

Trimester-specific levels of inflammatory biomarkers varied based on stress and hypertensive status. IL-6 was elevated in the hypertensive, high-stress group, while IL-8 was greater among those with high stress, regardless of hypertensive status or trimester. For IL-1α and IL-1β, there was a significant stress-by-trimester interaction, while IL-10 was associated with a significant three-way interaction among stress level, hypertension status, and trimester.

CONCLUSIONS

The associations of stress and hypertensive status with inflammatory biomarkers are complex. Stress and hypertension were associated with changes in inflammatory response. Hypertensive women with high stress experienced a heightened anti-inflammatory response, potentially a compensatory mechanism. To better understand this relationship, further longitudinal studies are warranted.

Pre-eclampsia: the role of highly active antiretroviral therapy and immune markers

PURPOSE OF THE REVIEW

This review highlights the role immune cells and markers such as natural killer (NK) cells, cytokines and human leukocyte antigen (HLA-G) play in predisposing HIV-infected women who are on HAART to develop PE, thus contributing to a better understanding and early diagnosis of PE with a subsequent reduction in maternal foetal and neonatal deaths.

RECENT FINDINGS

Pregnant women infected with the Human Immunodeficiency Virus (HIV) have a 25% risk of mother to child transmission. This risk, however, decreases to 2% if the women is on treatment. Highly active antiretroviral therapy (HAART) is the recommended treatment for both pregnant and non-pregnant women infected with HIV. Treatment with HAART is reported to potentiate predisposition to the development of hypertensive disorders of pregnancy such as pre-eclampsia (PE). Pre-eclampsia accounts for 7-10% of abnormal pregnancies worldwide. Studies demonstrate that pregnant women with HIV have PE at lower frequencies than uninfected women, however, the converse is observed upon HAART initiation. HIV-infected women on HAART exhibit a greater tendency to develop PE, emanating from immune reconstitution induced by HAART. There is paucity of information as to the pathogenesis of PE upon HAART initiation and there are, therefore, controversial data as to whether HAART predisposes women to a lower, equal or higher risk of PE development compared to the general population, further investigations on the impact of HIV infection and HAART on the immune response and rate of PE development in HIV infected pregnant women are urgently needed.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Maternal Micronutrients, Omega-3 Fatty Acids and Gene Expression of Angiogenic and Inflammatory Markers in Pregnancy Induced Hypertension Rats

BACKGROUND AND AIMS

Preeclampsia is a disorder of pregnancy and is associated with inflammation and altered angiogenesis. The present study examines the effect of micronutrient and omega-3 fatty acid supplementation (individual, as well as combined) on genes involved in inflammation and angiogenesis, as well as global DNA methylation levels in a pregnancy induced hypertension (PIH) rat model.

METHODS

Pregnant Wistar rats were randomly assigned to six dietary groups: control, PIH (Pregnancy induced hypertension) Induced; PIH Induced with micronutrient supplements with vitamin B₁₂ (PIHB), folate (PIHF), omega-3 fatty acid (PIHO), and combined supplementation (PIHC) (micronutrients and omega-3 fatty acids). Half the dams were dissected on 20 d of gestation to collect placental tissue, and half were allowed to deliver normally on 22 d of gestation and were assigned to a postnatal control diet. The offspring were dissected at 3 month of age.

RESULTS

PIH induction increased the mRNA levels of the pro inflammatory cytokine IL-6 (p <0.01), while lowering the placental anti inflammatory cytokine IL-10 (p <0.05) at d20 of gestation. It also increased the expression of TNF-α (p <0.05) in the liver of 3 month old offspring. The combined supplementation of folic acid, vitamin B₁₂ and omega-3 fatty acids improved placental IL-10 levels and decreased TNF-α levels in offspring livers.

CONCLUSION

Our data indicate that a combined supplementation of vitamin B₁₂, folic acid and omega-3 fatty acid was useful for the better management of preeclampsia in an animal model.

Association between cytokine profile and transcription factors produced by T-cell subsets in early- and late-onset pre-eclampsia

Pre-eclampsia (PE) is an obstetric pathology characterized by abnormal activation of the innate and adaptive immune systems dependent on the imbalance of T helper subsets. The present study aimed to evaluate the gene and protein expression of T helper type 1 (Th1)/Th2/Th17/regulatory T (Treg) cell transcription factors in peripheral blood lymphocytes from pregnant women with PE employing quantitative RT-PCR and flow cytometry techniques, as well as the cytokine profile produced by these CD4+ T-cell subsets in the plasma of pregnant women with PE, classified as early-onset PE (n = 20), late-onset PE (n = 20) and normotensive pregnant women (n = 20). Results showed a higher percentage of CD4+ T cells expressing the RORc transcription factor (Th17) and a lower percentage of cells expressing FoxP3 (Treg) in women with early-onset PE compared with late-onset PE and normotensive groups. A lower gene expression of GATA-3 transcription factor was detected in cells of women with early-onset PE compared with the late-onset PE group. Endogenous plasma levels of interleukin-6 (IL-6), IL-17 and tumour necrosis factor-α were significantly higher in the early-onset PE group than in the late-onset PE and normotensive groups, whereas IL-4 (Th2 profile) and IL-22 (Th17 profile), were not significantly different between the studied groups. The endogenous levels of transforming growth factor-β and IL-10 were significantly lower in the pre-eclamptic than in the normotensive groups of the same gestational age, with a significant difference between early- and late-onset PE. The results show that in women with PE there is an imbalance between inflammatory and anti-inflammatory profiles in CD4+ T-cell subsets, with polarization to Th17 profiles in the early-onset PE, considered as the severe form of PE.

Evaluation of maternal systemic inflammatory response in preeclampsia

OBJECTIVE

To evaluate the systemic inflammatory response in preeclampsia compared to normal pregnancy.

MATERIALS AND METHODS

The following serum parameters were determined in three groups of patients: leukocytes, neutrophils, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and certain markers of oxidative stress. Fetal status was assessed based on the gestational age at which birth occurred, on the Apgar score, and on fetal weight.

RESULTS

In preeclampsia, a higher systemic inflammatory status was found compared to normal pregnancy. Gestational age at birth, fetal weight, and Apgar score were significantly lower in the group with preeclampsia compared to normal pregnancy.

CONCLUSION

In preeclampsia, there is an increased systemic inflammatory response compared to normal pregnancy, which can influence fetal status at birth.

Supplementation of maternal omega-3 fatty acids to pregnancy induced hypertension Wistar rats improves IL10 and VEGF levels

OBJECTIVES

Our recent study demonstrates the beneficial effect of a combined supplementation of vitamin B12, folic acid, and docosahexaenoic acid in reducing the severity of pregnancy induced hypertension (PIH). It is also known to be associated with angiogenic imbalance and inflammation. The current study examines whether the individual/combined supplementation of folic acid, vitamin B12 and omega-3 fatty acid during pregnancy can ameliorate the inflammatory markers and restore the angiogenic balance in a rat model of PIH.

MATERIALS AND METHODS

There were total of six groups, control and five treatment groups: PIH Induced; PIH+vitamin B12; PIH+folic acid; PIH+Omega-3 fatty acids and PIH+combined micronutrient supplementation (vitamin B12+folic acid+omega-3 fatty acids). Hypertension during pregnancy was induced using L- Nitroarginine methylester (L-NAME; 50mg/kg body weight/day). Dams were dissected at d20 of gestation and placental tissues were collected for further analysis.

RESULTS

Animals from the PIH induced group demonstrated lower (p<0.01 for both) IL-10 and VEGF levels as compared to control. However, PIH induction did not alter the protein levels of eNOS, IL-6, Flt and mRNA levels of VEGF and VEGFR-1/ Flt-1. Individual micronutrient supplementation of vitamin B12 and folate did not offer benefit. In contrast individual omega-3 fatty acid as well as combined micronutrient supplementation showed IL-10 and VEGF levels comparable to that of control.

CONCLUSION

Omega 3 fatty acid supplementation plays a key role in reducing inflammation in pregnancy induced hypertension.

Expression of Myostatin in Intrauterine Growth Restriction and Preeclampsia Complicated Pregnancies and Alterations to Cytokine Production by First-Trimester Placental Explants Following Myostatin Treatment

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are major obstetric health problems. Higher levels of T-helper (Th) 1 (proinflammatory) cytokines have been observed in pregnancies complicated with PE and IUGR; this is in contrast to the predominant Th2 (anti-inflammatory) cytokine environment found in uncomplicated pregnancies. Myostatin is best known as a negative regulator of muscle development and reportedly has a role in fat deposition, glucose metabolism, and cytokine modulation (outside the placenta). Myostatin concentrations in plasma and protein expression in placental tissue are significantly higher in women with PE. Expression of myostatin in IUGR and PE-IUGR and the effect of this protein on the cytokine production from the placenta is unknown. In the current study, significant differences were identified in the expression of myostatin in pregnancies complicated with IUGR, PE, and PE with IUGR. Furthermore, cytokine production by first-trimester placental tissues was altered following myostatin treatment.

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.

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.

Maternal plasma concentrations of sST2 and angiogenic/anti-angiogenic factors in preeclampsia

OBJECTIVES

Angiogenic/anti-angiogenic factors have emerged as one of the promising biomarkers for the prediction of preeclampsia. Since not all patients with preeclampsia can be identified by these analytes, the search for additional biomarkers continues. The soluble form of ST2 (sST2), a protein capable of binding to interleukin (IL)-33 and thus contributing to a Th1-biased immune response, has been reported to be elevated in maternal plasma of women with preeclampsia. The aims of this study were to examine: (1) differences in maternal plasma concentrations of sST2 and IL-33 between women diagnosed with preeclampsia and those having uncomplicated pregnancies; (2) the relationship between sST2, umbilical and uterine artery Doppler velocimetry, and the severity of preeclampsia; and (3) the performance of sST2 and angiogenic/anti-angiogenic factors in identifying patients with preeclampsia at the time of diagnosis.

METHODS

This cross-sectional study included women with preeclampsia (n = 106) and women with an uncomplicated pregnancy (n = 131). Plasma concentrations of sST2, IL-33, soluble vascular endothelial growth factor receptor (sVEGFR)-1, soluble endoglin (sEng) and placental growth factor (PlGF) were determined by enzyme linked immune sorbent assay. Area under the receiver operating characteristic curve (AUC) for the identification of preeclampsia was examined for each analyte.

RESULTS

(1) Patients with preeclampsia had a higher mean plasma concentrations of sST2 than those with an uncomplicated pregnancy (p < 0.0001), while no significant difference in the mean plasma concentration of IL-33 between the two groups was observed; (2) the magnitude of this difference was greater in early-onset, compared to late-onset disease, and in severe compared to mild preeclampsia; (3) sST2 plasma concentrations did not correlate with the results of uterine or umbilical artery Doppler velocimetry (p = 0.7 and p = 1, respectively) among women with preeclampsia; (4) sST2 correlated positively with plasma concentrations of sVEGFR1-1 and sEng (Spearman's Rho = 0.72 and 0.63; each p < 0.0001), and negatively with PlGF (Spearman's Rho = -0.56, p < 0.0001); and (5) while the AUC achieved by sST2 and angiogenic/anti-angiogenic factors in identifying women with preeclampsia at the time of diagnosis were non-significantly different prior to term (<37 weeks of gestation), thereafter the AUC achieved by sST2 was significantly less than that achieved by angiogenic/anti-angiogenic factors.

CONCLUSIONS

Preeclampsia is associated with increased maternal plasma concentrations of sST2. The findings that sST2 concentrations do not correlate with uterine or umbilical artery Doppler velocimetry in women with preeclampsia suggest that elevated maternal plasma sST2 concentrations in preeclampsia are not related to the increased impedance to flow in the utero-placental circulation. The performance of sST2 in identifying preeclampsia at the time of diagnosis prior to 37 weeks of gestation was comparable to that of angiogenic/anti-angiogenic factors. It remains to be elucidated if an elevation of maternal plasma sST2 concentrations in pregnancy is specific to 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.

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.

Interleukin-6 in pregnancy and gestational disorders

IL6 is a multifunctional cytokine with pivotal roles in the inflammatory response and in directing T cell differentiation in adaptive immunity. IL6 is widely expressed in the female reproductive tract and gestational tissues, and exerts regulatory functions in embryo implantation and placental development, as well as the immune adaptations required to tolerate pregnancy. Here, we summarise the current understanding of how membrane-bound and soluble receptors mediate IL6 signalling to regulate leukocytes and non-haemopoietic cells. We review the published literature regarding the expression and actions of IL6 in the uterus, decidua and placenta, and studies implicating this cytokine in pregnancy disorders. Elevated IL6 is frequently evident in the altered cytokine profiles characteristic of unexplained infertility, recurrent miscarriage, preeclampsia and preterm delivery. Notably, there is compelling evidence indicating altered systemic IL6 trans-signalling in women prone to recurrent miscarriage, with excessive IL6 bioavailability potentially inhibiting generation of CD4+ T regulatory cells required for pregnancy tolerance. Insufficient local IL6 may also contribute to fetal loss, since IL6 expression is reduced in the endometrium of women with recurrent miscarriage, and in the fetal-placental tissue of CBA×DBA/2 mice. Consistent with the role of IL6 in key reproductive events, Il6 null mutant mice exhibit elevated fetal resorption and delayed parturition. Investigation of the association between IL6 signalling components and T cell responses in pregnant women, as well as detailed analysis of the maternal immune response in IL6-deficient mice, is now required to define the mechanisms by which this cytokine exerts influence on reproductive success.

Oxidative damage, inflammation, and Toll-like receptor 4 pathway are increased in preeclamptic patients: a case-control study

Problem. There was no direct correlation between plasma and placental oxidative damage parameters and inflammation and evidence of TLR4 pathway activation in the placenta in preeclamptic (PE) patients. Method of Study. 33 PE patients and 33 normotensive pregnant women were included. The maternal section of the placenta and blood were collected to the determination of oxidative damage markers (thiobarbituric acid reactive species and protein carbonyls), inflammatory response (interleukin-6 and myeloperoxidase activity), and activation of the TLR-4-NF-kB pathway. Results. An increase of IL-6 levels in both plasma and placenta was observed, but myeloperoxidase activity was not significantly different comparing the groups. Oxidative damage parameters were increased in plasma and placenta in PE patients. A significant increase of the protein levels of TLR-4 and NF-kB was observed in the placenta. Conclusion. The TLR4-NF-kB pathway is upregulated in PE, probably generating local and systemic inflammatory response that is followed by local and systemic oxidative damage.

Inflammatory disturbances in preeclampsia: relationship between maternal and umbilical cord blood

Preeclampsia (PE) is one of the main causes of maternal and fetal mortality and morbidity. PE is associated with an inflammatory state and with oxidative stress, in maternal circulation. Our aim was to evaluate and compare the levels of oxidative stress and inflammatory markers in maternal and umbilical cord blood (UCB), in normal and PE pregnancies. We measured acute-phase proteins (CRP and α1-antitrypsin), proinflammatory cytokines (IL-6 and TNF-α), leukocyte activation (elastase, lactoferrin, sL-selectin, sVCAM, sPECAM), total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), and uric acid levels. We studied 42 healthy pregnant women, 46 PE women, and their neonates. The concentrations of IL-6, TNF-α, α1-antitrypsin, CRP, sVCAM, uric acid, and TBARS were significantly higher, and sL-selectin was significantly lower in PE pregnant women as compared with normotensive pregnant women. In newborns uric acid, α1-antitrypsin, and CRP values were significantly higher in PE; leukocyte count, sL-selectin, lactoferrin, and the ratio elastase/α1-antitrypsin were significantly lower. Our data suggest that PE pregnancy is associated with an enhanced maternal inflammatory condition, which is reflected in fetal circulation. This enhanced inflammatory state seems to be related to endothelial dysfunction and increased cytokine synthesis, rather than with neutrophil activation.

Maternal serum levels of TNF-alpha and IL-6 long after delivery in preeclamptic and normotensive pregnant women

AIM

To evaluate maternal TNF-alpha and IL-6 plasma levels in normotensive pregnant women, women with preeclampsia, and to examine the temporal changes in their levels from the antepartum to the postpartum period correlated with the regression of preeclampsia.

METHOD

A prospective study was performed in the 2nd Department of Obstetrics and Gynecology, University of Athens. Blood samples were obtained: (1) antepartum at the time of clinical diagnosis of the syndrome, 2. 12-14 weeks postpartum.

RESULTS

No statistically significant differences were found in IL-6 levels, whereas a difference was found in TNF-alpha levels between preeclamptic and controls in antepartum period (0.80 pg/ml versus 0.60 pg/ml, P : .04). Long after delivery, TNF-alpha levels were significantly higher in preeclamptic compared to normotensive controls (0.86 pg/ml versus 0.60 pg/ml, P : .004). No difference was observed in TNF-alpha before and after delivery in both groups. No difference was noticed in IL-6 levels in women of normotensive group long after delivery compared to that before delivery. Long after delivery IL-6 levels were statistically significant higher in preeclamptic women compared to normal controls (3.53 ± 0.52 pg/ml versus 1.69 ± 0.48 pg/ml, P : .02).

CONCLUSION

Preeclamptic women remain under a status of increased inflammatory stress up to 12-14 weeks postpartum despite the fact that all the other signs of preeclampsia are resolved.

Are plasma IL-10 levels a useful marker of human clinical tolerance in peanut allergy?

Background

Food allergies are a major component of the burden of allergic disease. Accurate risk assessment for prediction of future clinical reactivity or clinical tolerance is limited by currently available techniques. Recent studies suggest that constitutively elevated global serum levels of IL-10, a cytokine that down-regulates both Th1 and Th2 cytokine production, may be useful in identifying human clinical tolerance to foods.

Objective

Determine the usefulness of constitutive IL-10 levels as a marker of clinical tolerance to peanut in children and adults.

Methodology/Principal Findings

107 subjects who were clinically tolerant to peanut and 94 subjects who were clinically allergic to peanut participated. Plasma was analyzed via ELISA to quantify the frequency of individuals with constitutive IL-10 levels and the intensity of those responses. The data were then stratified by age, gender and clinical status to assess the utility of this putative biomarker in specific at-risk groups. All 201 subjects had readily quantified plasma IL-10. Levels were no higher in subjects who were clinically tolerant to peanut than those in individuals clinically allergic to peanut. Stratification by age, gender or both did not improve the capacity of IL-10 levels to identify clinical tolerance to peanut.

Conclusions/Significance

Plasma IL-10 levels are neither a useful biomarker of clinical tolerance to peanut nor a potential tool for identification of clinical tolerance to peanut in humans.

Oxidative stress and inflammatory markers in normal pregnancy and preeclampsia

AIM

Although previous investigators have demonstrated the presence of oxidative stress and inflammation in preeclampsia, none directly correlate both to preeclampsia.

METHODS

We determined in 35 preeclamptic and 35 normotensive pregnant women plasma levels of thiobarbituric acid reactive species, protein carbonyl, tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6 and IL-10.

RESULTS

Plasma thiobarbituric acid reactive species and protein carbonyls were higher in preeclamptic patients. TNF-alpha and IL-6 (but not IL-1beta or IL-10) were higher in preeclamptic patients. We found significant correlation between plasma IL-6 and carbonyls, and these correlated to blood pressure.

CONCLUSIONS

We demonstrated that some oxidative and inflammatory mediators were altered in preeclampsia, and some correlated to blood pressure.