T helper 1- and T helper 2-type cytokine imbalance in pregnant women with pre-eclampsia

Clinical, oral immunological and microbiological shifts during and after pregnancy

OBJECTIVES

Physiological changes and shifts in the oral microbiota composition during pregnancy may affect the maternal immune system. Uncomplicated pregnancy is associated with a T-helper (Th) 2 predominant cytokine regulation (anti-inflammatory), while oral health deterioration during pregnancy is reflected by severe gingival inflammation, a primarily Th1 cytokine phenotype (pro-inflammatory), and oral microbiome alterations. This prospective observational study aimed to evaluate Th cytokine shifts and changes in the oral microbiota composition in saliva of women before and after birth.

MATERIAL AND METHODS

Saliva (n = 96) was collected before and 6 months after birth, and medical, oral health, and periodontal status were assessed. In a multiplex immunoassay, 10 cytokines were simultaneously analyzed and cumulative Th1 and Th2 cytokine levels and Th1/Th2 ratio were calculated for all groups. Putative periodontal pathogens (n = 6) were evaluated by quantitative real-time polymerase chain reaction.

RESULTS

Th2 cytokine levels were significantly lower (p = 0.014) while pro-inflammatory cytokine levels were significantly higher (p < 0.01) during pregnancy than postpartum. Similar Th1 levels were found between the groups (p = 0.143). Th1 and Th2 cytokines positively correlated with periodontal parameters (p < 0.001) and levels of studied bacteria during pregnancy (p < 0.05).

CONCLUSIONS

This study identified a significantly increased Th1/Th2 cytokine ratio during pregnancy and a positive association with putative periodontal pathogens. This immunological and microbiological deregulation in the oral milieu during pregnancy is suggestive of a destructive inflammatory periodontal profile.

STUDY REGISTRATION

Clinical Trials.gov (Record BAP-2015).

CLINICAL RELEVANCE

Understanding altered oral immunological and microbiological regulation patterns during pregnancy may help improve the inflammatory periodontal profile in pregnant women.

Upregulation of exofacial peroxiredoxin-thioredoxin system of lymphocytes and monocytes in preeclampsia

OBJECTIVES

An imbalanced redox homeostasis resulting in oxidative stress is present in preeclampsia. Peroxiredoxin-1 (PRDX1) and thioredoxin-1 (TRX1) regulatory enzymes are also contributing to the redox homeostasis, but were not investigated so far in preeclampsia. Thus, we have aimed to characterize PRDX1, TRX1 and oxidative stress biomarkers in blood samples of pregnant women with preeclampsia.

STUDY DESIGN

Twelve patients with preeclampsia (PE) were enrolled into the study. Seven third trimester healthy pregnant women (HP) were accepted as control group.

MAIN OUTCOME MEASURES

Peripheral venous blood samples of healthy and preeclamptic pregnant women were analyzed. Plasma level of advanced oxidation protein products (AOPP) was determined by spectrophotometry. The exofacial PRDX1 and TRX1 expression of lymphocytes and monocytes was detected by flow cytometry.

RESULTS

The plasma AOPP level was significantly higher in preeclampsia compared to the healthy pregnant group. Significantly higher percentage of PRDX1 and TRX1 expressing lymphocytes and monocytes were detected in the blood samples of preeclamptic women compared to healthy pregnant controls. The ratio of circulating PRDX1 and TRX1 expressing lymphocytes and monocytes showed a significant inverse correlation with the birth weight of newborns.

CONCLUSIONS

We have revealed that the level of advanced oxidation protein products is increased and the exofacial peroxiredoxin-1 and thioredoxin-1 system in lymphocytes and monocytes is upregulated in preeclampsia. In addition, the ratio of peroxiredoxin-1 and thioredoxin-1 positive circulating lymphocytes and monocytes correlates inversely with the neonatal birth weight, which finding indicates that pregnancies complicated by intrauterine growth restriction are accompanied by a higher level of oxidative stress.

Interferon γ neutralization reduces blood pressure, uterine artery resistance index, and placental oxidative stress in placental ischemic rats

Preeclampsia (PE) is characterized by maternal hypertension, intrauterine growth restriction, and increased cytolytic natural killer cells (cNKs), which secrete interferon γ (IFNγ). However, the precise role of IFNγ in contributing to PE pathophysiology remains unclear. Using the reduced uterine perfusion pressure (RUPP) rat model of placental ischemia, we tested the hypothesis that neutralization of IFNγ in RUPPs will decrease placental reactive oxygen species (ROS) and improve vascular function resulting in decreased MAP and improved fetal growth. On gestation day (GD) 14, the RUPP procedure was performed and on GDs 15 and 18, a subset of normal pregnant rats (NP) and RUPP rats were injected with 10 μg/kg of an anti-rat IFNγ monoclonal antibody. On GD 18, uterine artery resistance index (UARI) was measured via Doppler ultrasound and on GD 19, mean arterial pressure (MAP) was measured, animals were euthanized, and blood and tissues were collected for analysis. Increased MAP was observed in RUPP rats compared with NP and was reduced in RUPP + anti-IFNγ. Placental ROS was also increased in RUPP rats compared with NP rats and was normalized in RUPP + anti-IFNγ. Fetal and placental weights were reduced in RUPP rats, but were not improved following anti-IFNγ treatment. However, UARI was elevated in RUPP compared with NP rats and was reduced in RUPP + anti-IFNγ. In conclusion, we observed that IFNγ neutralization reduced MAP, UARI, and placental ROS in RUPP recipients. These data suggest that IFNγ is a potential mechanism by which cNKs contribute to PE pathophysiology and may represent a therapeutic target to improve maternal outcomes in PE.

Serum Levels of Soluble Fas and Fas Ligand in Iranian Women with Pre-eclampsia

Background

The precise responsible mechanism of pre-eclampsia remains controversial however, recent data suggest a main role of the abnormal activation of the adaptive immune system and Apoptosis. In this study, we have measured serum levels of Fas/Fasl as two important members of extrinsic apoptotic pathway in patient with pre-eclampsia.

Methods

207 participants including 99 pre-eclampsia patients and 108 age and sex-matched normal pregnant women were involved in the case-control study. Plasma sample from each participant was collected and stored at -20 °C until batch processing.Serum levels of Fas and Fas ligand were measured by ELISA for each participant including 99 pre-eclampsia patients and 108 normal pregnant women. Following a test of statistical normality, nonparametric data were analyzed by Mann-Whitney.

Results

sFas levels in case group was significantly higher than controls; 584 (397-892) pg/ml in cases opposed to 341 (213-602) pg/ml in controls (p value< 0.01). sFasL in pre-eclampsia women was a little lower than controls; 255 (173-318) pg/ml and in case group compared to 265.5 (184-381.5) pg/ml in controls.

Conclusion

We have found the increased levels of sFas in patients with pre-eclampsia in compare with the healthy pregnant women. It seems that abnormality in sFAS is related with pre-eclampsia.

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.

Mechanisms of vascular dysfunction in the interleukin-10-deficient murine model of preeclampsia indicate nitric oxide dysregulation

Preeclampsia is a pregnancy-specific hypertensive disorder characterized by proteinuria, and vascular injury in the second half of pregnancy. We hypothesized that endothelium-dependent vascular dysfunction is present in a murine model of preeclampsia based on administration of human preeclamptic sera to interleukin-10-/- mice and studied mechanisms that underlie vascular injury. Pregnant wild type and IL-10-/- mice were injected with either normotensive or severe preeclamptic patient sera (sPE) during gestation. A preeclampsia-like phenotype was confirmed by blood pressure measurements; assessment of albuminuria; measurement of angiogenic factors; demonstration of foot process effacement and endotheliosis in kidney sections; and by accumulation of glycogen in placentas from IL-10-/- mice injected with sPE sera (IL-10-/-sPE). Vasomotor function of isolated aortas was assessed. The IL-10-/-sPE murine model demonstrated significantly augmented aortic contractions to phenylephrine and both impaired endothelium-dependent and, to a lesser extent, endothelium-independent relaxation compared to wild type normotensive mice. Treatment of isolated aortas with indomethacin, a cyclooxygenase inhibitor, improved, but failed to normalize contraction to phenylephrine to that of wild type normotensive mice, suggesting the additional contribution from nitric oxide downregulation and effects of indomethacin-resistant vasoconstricting factors. In contrast, indomethacin normalized relaxation of aortas derived from IL-10-/-sPE mice. Thus, our results identify the role of IL-10 deficiency in dysregulation of the cyclooxygenase pathway and vascular dysfunction in the IL-10-/-sPE murine model of preeclampsia and point towards a possible contribution of nitric oxide dysregulation. These compounds and related mechanisms may serve both as diagnostic markers and therapeutic targets for preventive and treatment strategies in preeclampsia.

The role of neopterin and anti-Mullerian hormone in unexplained recurrent pregnancy loss - a case-control study

This case-control study was conducted to assess whether neopterin (NP) and anti-Mullerian hormone (AMH) can be used as markers in the condition of unexplained recurrent pregnancy loss (RPL). To the best of our knowledge, this is the first work which has studied the association between AMH, NP and RPL. A total of 110 patients were included; 53 women who had at least two consecutive unexplained miscarriages (<12 weeks) made up the study group. The control group was established from 57 women who never had a miscarriage and had at least one healthy birth history. Peripheral blood samples were collected from each patient to analyse the AMH and NP concentrations. The results suggested that mean level of AMH (1.38 ± 0.683 ng/ml) in the patient's group was significantly lower than the control group (1.84 ± 0.718 ng/ml). The mean levels of NP were significantly higher in the patient group (1.69 ± 0.486 vs. 1.38 ± 0.431 ng/ml). IMPACT STATEMENT What is already known about this subject? To the best of our knowledge, no previous studies about the association among AMH, NP and RPL were found in the literature. What do the results of this study add? This pioneer study demonstrates the significant relationship between the unexplained RPL with the increased levels of NP and decreased AMH. What are the implications of these findings for clinical practice and/or further research? NP and AMH may play an effective role in illuminating the condition of unexplained RPL. High levels of NP and low values of AMH in patients with RPL can be used as predictive markers for this clinical situation. If the causes of high levels of NP and low levels of AMH can be better illuminated, new treatments towards these causes can be developed to help such patients become childbearing.

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 Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Elevated vasopressin in pregnant mice induces T-helper subset alterations consistent with human preeclampsia

The pathogenesis of preeclampsia (PreE), a hypertensive disorder of pregnancy, involves imbalanced T helper (TH) cell populations and resultant changes in pro- and anti-inflammatory cytokine release. Elevated copeptin (an inert biomarker of arginine vasopressin (AVP)), secretion precedes the development of symptoms in PreE in humans, and infusion of AVP proximal to and throughout gestation is sufficient to initiate cardiovascular and renal phenotypes of PreE in wild-type C57BL/6J mice. We hypothesize that AVP infusion in wild-type mice is sufficient to induce the immune changes observed in human PreE. AVP infusion throughout gestation in mice resulted in increased pro-inflammatory interferon γ (IFNg) (TH1) in the maternal plasma. The TH17-associated cytokine interleukin (IL)-17 was elevated in the maternal plasma, amniotic fluid, and placenta following AVP infusion. Conversely, the TH2-associated anti-inflammatory cytokine IL-4 was decreased in the maternal and fetal kidneys from AVP-infused dams, while IL-10 was decreased in the maternal kidney and all fetal tissues. Collectively, these results demonstrate the sufficiency of AVP to induce the immune changes typical of PreE. We investigated if T cells can respond directly to AVP by evaluating the expression of AVP receptors (AVPRs) on mouse and human CD4+ T cells. Mouse and human T cells expressed AVPR1a, AVPR1b, and AVPR2. The expression of AVPR1a was decreased in CD4+ T cells obtained from PreE-affected women. In total, our data are consistent with a potential initiating role for AVP in the immune dysfunction typical of PreE and identifies putative signaling mechanism(s) for future investigation.

Maternal plasma-soluble ST2 concentrations are elevated prior to the development of early and late onset preeclampsia - a longitudinal study

OBJECTIVE

The objectives of this study were to determine (1) the longitudinal profile of plasma soluble ST2 (sST2) concentrations in patients with preeclampsia and those with uncomplicated pregnancies; (2) whether the changes in sST2 occur prior to the diagnosis of preeclampsia; and (3) the longitudinal sST2 profile of women with early or late preeclampsia.

MATERIALS AND METHODS

This longitudinal nested case-control study included singleton pregnancies in the following groups: (1) uncomplicated pregnancies (n = 160); and (2) those complicated by early (<34 weeks, n = 9) and late (≥34 weeks, n = 31) preeclampsia. sST2 concentrations were determined by enzyme-linked immunosorbent assays. Mixed-effects models were used for the longitudinal analysis.

RESULTS

(1) Plasma sST2 concentration profiles across gestation differed significantly among cases and controls (p < 0.0001); (2) women with early preeclampsia had higher mean sST2 concentrations than controls at >22 weeks of gestation; cases with late preeclampsia had higher mean concentrations at >33 weeks of gestation (both p < 0.05); and (3) these changes started approximately 6 weeks prior to clinical diagnosis.

CONCLUSIONS

Maternal plasma sST2 concentrations are elevated 6 weeks prior to the clinical diagnosis of preeclampsia. An increase in the maternal plasma concentration of sST2 may contribute to an exaggerated intravascular inflammatory response and/or the Th1/Th2 imbalance in some cases.

The Predominant Th1 Cytokine Profile in Maternal Plasma of Preeclamptic Women Is Not Reflected in the Choriodecidual and Fetal Compartments

OBJECTIVE

Human pregnancy disorders such as preeclampsia are thought to involve variations in cytokine levels. It has been proposed that, in preeclamptic women, a balance favoring the Th1-type over the Th2-type cytokine profile determines local or systemic immunologic responses to pregnancy and that this may cause defective placental implantation and placental ischemia, which activate systemic endothelial cells. The purpose of this study was to determine whether cytokine expression differs in the maternal, choriodecidual, and fetal compartments, and between women with or without preeclampsia.

METHODS

Plasma concentrations of interferon gamma (IFNgamma), interleukin (IL)-2, IL-4, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) in samples obtained from maternal peripheral blood (MPB), choriodecidual (CD), and fetal cord (FC) blood compartments of 17 women with preeclampsia and in 15 normotensive women. Intracellular concentrations of IFNgamma and IL-2 in T lymphocytes were assessed by flow cytometry.

RESULTS

Plasma IFNgamma concentrations in both MPB and CD compartments were significantly higher in preeclamptic than in normotensive women. Maternal plasma IL-4 concentration was significantly lower in preeclamptic than in normotensive women. Intracellular IFNgamma and IL-2 concentrations did not differ significantly between preeclamptic and normotensive women.

CONCLUSIONS

The dominant Th1-type over Th2-type cytokine profile is evident in MPB, but not in the CD and FC blood compartments. This might reflect the complex cytokine networks in the fetal-placental interface and might involve trophoblasts or decidual and endothelial cells, which could account for the increased plasma IFNgamma concentration and T-helper cell number.

Hypothesis: Pentoxifylline explores new horizons in treatment of preeclampsia

Preeclampsia, the leading cause of maternal morbidity and perinatal mortality, initiates as inappropriate immune response to trophoblastic invasion impairs placentation and placental circulation. A poorly perfused placenta generates superoxide anions as well as anti-angiogenic factors and this series of events result in impairment of endothelial function, followed by maternal morbidities such as hypertension, kidney injury and proteinuria. Renal loss of anti-coagulant proteins and subsequent hyper-coagulable state along with endothelial dysfunction accelerates progression of the disease toward eclampsia. Since Pentoxifylline, a methyl-xanthine derivative known for enhancement of vascular endothelial function, down-regulation of many inflammatory cytokines increased during preeclampsia, improvement of placental circulation, reduction of ischemia-reperfusion injury, enhancement of vasodilatation and endothelial function, ameliorating proteinuria, inhibition of platelet aggregation and decreasing risk of preterm labor, which are all amongst morbidities of preeclampsia, here it is hypothesized that Pentoxifylline prevents development of preeclampsia and/or decelerate progression of the disease.

Role of IL-10 -819(t/c) promoter polymorphism in preeclampsia

Preeclampsia is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive immune system. Interleukin-10 affects maternal intravascular inflammation, as well as endothelial dysfunction. The aim of the study was to investigate the association between IL-10 T-819 C polymorphism and preeclampsia. A total of 120 pregnant women with preeclampsia and 120 women with normal pregnancy attending the Gynecological Unit of Government Maternity Hospital, Petlaburz, Hyderabad, India, were considered for the present study. A standard amplification refractory mutation system (ARMS) PCR was carried out for genotyping of IL-10 T-819 C promoter polymorphism in all the participants. Genotypic distribution of the control and patient groups was compared with values predicted by the Hardy-Weinberg equilibrium using χ2 test. Odds ratios (OR) and their respective 95 % confidence intervals were used to measure the strength of association between IL-10 gene polymorphism and preeclampsia. The frequencies of IL-10 T-819 C genotypes, CC, CT, and TT, were 47.5, 28.3, and 24.2 % in women with preeclampsia and 20.8, 48.3, and 30.8 % in the controls, respectively. There is a significant difference in the distribution of genotypes and alleles of IL-10 T-819 C between the two groups (test power = 0.66). The present study suggests that the IL-10 T-819 C gene promoter polymorphism can be a major genetic regulator in the etiology of preeclampsia.

Intrauterine insemination of cultured peripheral blood mononuclear cells prior to embryo transfer improves clinical outcome for patients with repeated implantation failures

Implantation failure is a major limiting factor in assisted reproduction improvement. Dysfunction of embryo–maternal immuno-tolerance pathways may be responsible for repeated implantation failures. This fact is supported by immunotropic theory stipulating that maternal immune cells, essentially uterine CD56+ natural killer cells, are determinants of implantation success. In order to test this hypothesis, we applied endometrium immuno-modulation prior to fresh embryo transfer for patients with repeated implantation failures. Peripheral blood mononuclear cells were isolated from repeated implantation failure patients undergoing assisted reproductive technology cycles. On the day of ovulation induction, cells were isolated and then cultured for 3 days and transferred into the endometrium cavity prior to fresh embryo transfer. This immunotherapy was performed on 27 patients with repeated implantation failures and compared with another 27 patients who served as controls. Implantation and clinical pregnancy were increased significantly in the peripheral blood mononuclear cell test versus control (21.54, 44.44 vs. 8.62, 14.81%). This finding suggests a clear role for endometrium immuno-modulation and the inflammation process in implantation success. Our study showed the feasibility of intrauterine administration of autologous peripheral blood mononuclear cells as an effective therapy to improve clinical outcomes for patients with repeated implantation failures and who are undergoing in vitro fertilization cycles.

Severe preeclampsia: association of genes polymorphisms and maternal cytokines production in Brazilian population

INTRODUCTION

Preeclampsia (PE) is a multi-system disorder of pregnancy characterized by hypertension and proteinuria. Healthy pregnancy is associated with a controlled inflammatory process, which is exacerbated in PE in response to excessive placental stimuli. Gene expression levels can affect inflammation and immune regulation. It is known that differences in cytokine allele frequencies amongst populations may contribute to difference in the incidence of several diseases.

OBJECTIVE

The aim of this study was to investigate the frequency of TNF-α, IL-6, IFN-γ and IL-10 genes polymorphisms and their relationship with the cytokines plasma levels in PE.

METHODS

A total of 281 women were included in this study; 116 with severe PE, 107 normotensive pregnant and 58 non-pregnant women. Cytokine genotyping was carried out by the polymerase chain reaction. The analyzed polymorphisms were: TNF-α (-308 G→A), IL-10 (-1082 G→A), IL-6 (-174 G→C), and IFN-γ (+874 A→T). Cytokine plasma levels were measured by Cytometric Bead Array method.

RESULTS

A higher frequency of the IFN-γ (+874) T/T genotype in severe PE comparing to normotensive pregnant women was found (P<0.001). TNF-α, IL-6 and IFN-γ plasma levels were higher in PE women compared to non-pregnant women (P<0.001; P<0.001; P=0.004). IL-6 and IFN-γ levels were also higher in PE women compared to normotensive pregnant (P<0.001; P=0.010). IL-10 levels were higher in normotensive pregnant women compared to PE (P<0.001). IFN-γ and IL-6 genes polymorphisms influenced the genic expression in PE and normotensive pregnant women, respectively.

CONCLUSIONS

These results suggest that IFN-γ seems to play a role in PE occurrence.

Maternal plasma fetuin-A concentration is lower in patients who subsequently developed preterm preeclampsia than in uncomplicated pregnancy: a longitudinal study

Objective: Fetuin-A is a negative acute phase protein reactant that acts as a mediator for lipotoxicity, leading to insulin resistance. Intravascular inflammation and insulin resistance have been implicated in the mechanisms of disease responsible for preeclampsia (PE). Maternal plasma concentrations of fetuin-A at the time of diagnosis of preterm PE are lower than in control patients with a normal pregnancy outcome. However, it is unknown if the changes in maternal plasma fetuin-A concentrations precede the clinical diagnosis of the disease. We conducted a longitudinal study to determine whether patients who subsequently developed PE had a different profile of maternal plasma concentrations of fetuin-A as a function of gestational age (GA) than those with uncomplicated pregnancies. Methods: A longitudinal case-control study was performed and included 200 singleton pregnancies in the following groups: (1) patients with uncomplicated pregnancies who delivered appropriate for gestational age (AGA) neonates (n = 160); and (2) patients who subsequently developed PE (n = 40). Longitudinal samples were collected at each prenatal visit and scheduled at 4-week intervals from the first or early second trimester until delivery. Plasma fetuin-A concentrations were determined by ELISA. Analysis was performed using mixed-effects models. Results: The profiles of maternal plasma concentrations of fetuin-A differ between PE and uncomplicated pregnancies. Forward analysis indicated that the rate of increase of plasma fetuin-A concentration in patients who subsequently developed PE was lower at the beginning of pregnancy (p = 0.001), yet increased faster mid-pregnancy (p = 0.0017) and reached the same concentration level as controls by 26 weeks. The rate of decrease was higher towards the end of pregnancy in patients with PE than in uncomplicated pregnancies (p = 0.002). The mean maternal plasma fetuin-A concentration was significantly lower in patients with preterm PE at the time of clinical diagnosis than in women with uncomplicated pregnancies (p < 0.05). In contrast, there were no significant differences in maternal plasma fetuin-A concentration in patients who developed PE at term. Conclusions: (1) The profile of maternal plasma concentrations of fetuin-A over time (GA) in patients who develop PE is different from that of normal pregnant women; (2) the rate of change of maternal plasma concentrations of fetuin-A is positive (increases over time) in the midtrimester of normal pregnancy, and negative (decreases over time) in patients who subsequently develop PE; (3) at the time of diagnosis, the maternal plasma fetuin-A concentration is lower in patients with preterm PE than in those with a normal pregnancy outcome; however, such differences were not demonstrable in patients with term PE.

Possible association of IL-4 VNTR polymorphism with susceptibility to preeclampsia

Preeclampsia (PE) is a pregnancy-specific disorder that results in maternal mortality and morbidity. Growing evidence indicated that cytokines are involved in the pathogenesis of PE and interleukin-4 VNTR polymorphism could be implicated in altering the PE risk. The aim of this study was to evaluate the possible association between IL-4 VNTR polymorphism and susceptibility to PE in Iranian population for the first time. Genetic polymorphism was evaluated in 192 PE and 186 healthy control women by polymerase chain reaction method. We found that the VNTR polymorphism of IL-4 gene has significantly increased the risk of preeclampsia (RP2/RP1 versus RP1/RP1, OR, 2.8 [95% CI, 1.7 to 8.8]; P = 0.0001 and RP2/RP2 versus RP1/RP1; P = 0.002). The results showed that carriage of IL-4 VNTR RP2 allele has positive association with preeclampsia susceptibility.

Mesenchymal stem cells ameliorate Th1-induced pre-eclampsia-like symptoms in mice via the suppression of TNF-α expression

Pre-eclampsia (PE) is thought to be a pregnancy-induced autoimmune disease. Despite several strategies carried out for targeting specific factors relevant to its pathogenesis, PE remains potentially fatal to some patients. Here, we reported a way to isolate mesenchymal stem cells (MSCs) from decidua. The MSCs not only exhibited differentiation and self-renewal capacities, they also possessed immunomodulatory functions and secreted some soluble mediators including IL-6, TGF-β, IDO, VEGF and COX-2. Most importantly, the MSCs were specifically provided with the ability to suppress T cells proliferation by IDO in response to inflammatory cytokine IFN-γ. Moreover, we developed a Th1 cell-induced PE mouse model which displayed a high level of pathogenesis factor TNF-α. Strikingly, MSCs-based therapy significantly ameliorated both clinical and histopathological severity of PE symptoms including decreasing the blood pressure and proteinuria, suppressing glomerulonephritis, protecting the feto-placental development. The therapy also reversed abnormal TNF-α expression in uterine and splenic lymphocytes. These data suggest that MSCs may ameliorate Th1-induced PE-like symptoms in mice via the suppression of TNF-α and MSCs-based therapy may provide a potential novel method for PE.

Cytokines as key players in the pathophysiology of preeclampsia

Preeclampsia (PE) is an important, common, and dangerous complication of pregnancy; it causes maternal and perinatal illness and is responsible for a high proportion of maternal and infant deaths. PE is associated with increased blood pressure and proteinuria, with a whole host of other potentially serious complications in the mother and fetus. The maternal syndrome in PE is primarily that of generalized dysfunction of the maternal endothelium, and this generalized endothelial dysfunction appears to be part of an exaggerated systemic inflammatory response that involves maternal leukocytes and proinflammatory cytokines. This review examines evidence that points to a significant role for the maternal immune system; inadequate trophoblast invasion of spiral arteries initiates ischemia and hypoxia in the placenta, resulting in an increased release of proinflammatory cytokines in the placenta. Placental ischemia and hypoxia also cause the enhanced release of trophoblast microparticles into the maternal circulation which stimulates increased induction of proinflammatory cytokines and the activation of maternal endothelial cells. This activation results in a systemic, diffuse endothelial cell dysfunction which is the fundamental pathophysiological feature of this syndrome. Recent evidence also supports important roles for proinflammatory cytokines in hypertension, proteinuria, and edema which are characteristic features of PE.

The Placenta in Toxicology. Part II

During pregnancy, the maternal immune system is challenged by the semiallogeneic fetus, which must be tolerated without compromising fetal or maternal health. This review updates the systemic and local immune changes taking place during human pregnancy, including some examples in rodents. Systemic changes are induced by contact of maternal blood with placental factors and include enhanced innate immunity with increased activation of granulocytes and nonclassical monocytes. Although a bias toward T helper (Th2) and regulatory T cell (Treg) immunity has been associated with healthy pregnancy, the relationship between different circulating Th cell subsets is not straightforward. Instead, these adaptations appear most evidently at the fetal–maternal interface, where for instance Tregs are enriched and promote fetal tolerance. Also innate immune cells, that is, natural killer cells and macrophages, are enriched, constituting the majority of decidual leukocytes. These cells not only contribute to immune regulation but also aid in establishing the placenta by promoting trophoblast recruitment and angiogenesis. Thus, proper interaction between leukocytes and placental trophoblasts is necessary for normal placentation and immune adaptation. Consequently, spontaneous maladaptation or interference of the immune system with toxic substances may be important contributing factors for the development of pregnancy complications such as preeclampsia, preterm labor, and recurrent miscarriages.

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.

[Immunological aspect of pregnancy]

Pregnancy is a temporary semi-allograft that survives for nine months. The importance of this event for the survival of the species justifies several tolerance mechanisms that are put into place at the beginning of pregnancy, some of which occur even at the time of implantation. The presence of multiple tolerance mechanisms and the richness of the means employed underline the central importance of the trophoblast. Understanding these mechanisms, and in particular, their integration into an overall scheme, enables the anomalies encountered in certain pathologies of pregnancy to be placed into context. Understanding these mechanisms and their interruption at the end of pregnancy should improve our understanding of disappointing results from current immunological treatments facilitate the implementation of new prophylactic and therapeutic strategies.

Apoptosis signaling is altered in CD4⁺CD25⁺FoxP3⁺ T regulatory lymphocytes in pre-eclampsia

The aim of our study was to estimate the surface expressions of CD95 (APO-1/Fas) antigen and the intracellular expressions of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in CD4(+)CD25(+)FoxP3(+) T regulatory lymphocytes (Tregs) as well as the percentage of CD8(+)CD28(+) T cytotoxic cells in peripheral blood of patients with pre-eclampsia in comparison with healthy pregnant women in the third trimester of physiological pregnancy. Twenty-four women with pre-eclampsia and 20 normal third trimester pregnant women were included in the study. The lymphocytes were isolated from peripheral blood samples and labeled with monoclonal antibodies. The expressions of surface antigens and intracellular proteins were estimated using flow cytometry. The population of CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower in peripheral blood of patients with pre-eclampsia when compared to normal third trimester pregnant women. The percentages of CD4(+)CD25(+)FoxP3(+) Treg cells that express Bcl-2 protein were significantly lower in peripheral blood of patients with pre-eclampsia when compared to healthy pregnant women, whereas the percentages of CD4(+)CD25(+)FoxP3(+) Treg cells with the expressions of Bax protein did not differ in both groups. Moreover, the mean fluorescence intensity (MFI) of Bcl-2 protein in CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower and MFI of Bax protein significantly higher in pre-eclampsia when compared to the control group. The percentage of CD8(+)CD28(+) T cells did not differ in both studied groups but MFI of CD28 antigen on T CD8(+) cells was significantly higher in pre-eclampsia when compared to the control group. The obtained results suggest that the deficit of CD4(+)CD25(+)FoxP3(+) Treg lymphocytes which is observed in pre-eclampsia may be associated with altered apoptosis signaling in Tregs.

Plasma IL-4, IL-8, IL-12, interferon-γ and CRP levels in pregnant women with preeclampsia, and their relation with severity of disease and fetal birth weight

OBJECTIVE

The aim of the present study was to evaluate the hypothesis that preeclampsia is associated with increased systemic inflammatory responses of Th1-type as well as decreased Th2-type responses compared with normal pregnancy. We also sought to determine whether there was a correlation between these markers with severity of preeclampsia and fetal birth weight.

METHODS

The study population consisted of maternal age, gestational age, and body mass index matched 138 pregnant women; 56 normotensive healthy pregnant women (group 1), 42 women with mild preeclampsia (group 2), 40 women with severe preeclampsia (group 3).

RESULTS

Plasma interleukin (IL)-8 and C-reactive protein (CRP) levels were significantly higher in group 3 than group 1 (p<0.05). Plasma IL-4, IL-12, and interferon (IFN)-γ levels were similar in all groups. Although plasma IL-8 and CRP levels of mild preeclamptic group were higher than control group and lower than severe preeclamptic group, the differences were not statistically significant. There was a positive correlation between IL-12 and fetal birth weight in severe preeclamptic group (p<0.05).

CONCLUSIONS

Elevated maternal serum pro-inflammatory cytokine IL-8 and CRP in severe preeclamptic women compared with normal pregnant women supports the hypothesis that preeclampsia is associated with increased inflammatory responses.

Comparison of maternal serum levels of interleukin-10, interleukin-12, and interleukin-2 in normal and preeclamptic pregnancies

OBJECTIVE

The aim of this study was 2 fold: (1) to compare the maternal serum levels of IL-10, IL-12, and IL-2 in preeclamptic and normal pregnant women, and (2) to study the serum levels of these cytokines in preeclamptic pregnancies with and without intrauterine growth retardation.

STUDY DESIGN

Forty women with singleton pregnancies complicated by preeclampsia (32 severe and 8 mild) and 29 normotensive healthy pregnant women were included in the study. Preeclamptic patients were further divided into 2 groups according to the presence or absence of intrauterine growth retardation. Maternal serum levels of IL-10, IL 12, and IL-2 were compared between these groups using enzyme-linked immunosorbent assays.

RESULTS

Maternal serum levels of IL-10 were significantly higher in the preeclampsia group than in controls (p<0.001). There were no statistically significant differences in maternal serum concentrations of IL-2 and IL-10 between the study and control groups (p>0.05). Serum levels of IL-2 and IL-10 in the patients with preeclampsia complicated by IUGR were elevated in comparison with the uncomplicated preeclampsia group. These differences were statistically significant (p<0.05 for both).

CONCLUSIONS

IL-10 may be involved in the pathologic process of preeclampsia. Increased serum levels of IL-10 and IL-2 in preeclampsia complicated with IUGR suggests a possible role of these cytokines in IUGR.

Lymphocyte calcium influx characteristics and their modulation by Kv1.3 and IKCa1 channel inhibitors in healthy pregnancy and preeclampsia

PROBLEM

Calcium handling of T lymphocytes is altered in healthy pregnancy (HP) and preeclampsia (PE) compared to non-pregnant (non-P) women. We compared the activation-elicited calcium influx in T lymphocytes in HP, PE and non-P women and tested its alteration upon inhibition of Kv1.3 and IKCa1 potassium channels.

METHOD OF STUDY

The alteration of calcium influx was measured in major T-lymphocyte subsets of 9 non-P, HP and PE women with flow cytometry with or without treatment of cells with potassium channel inhibitors.

RESULTS

The elicited calcium response was lower in HP compared to non-P. In HP, calcium influx was sensitive to potassium channel inhibition in CD8 and Th1, but not in Th2 cells. In PE, calcium influx and its sensitivity to inhibition were comparable to non-P.

CONCLUSION

There is a characteristic pattern of calcium influx in T lymphocytes and its sensitivity to potassium channel inhibition in HP that is missing in PE, raising the notion that T-lymphocyte calcium handling may have a role in the characteristic immune status of HP.

Circulating cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia determined by multiplex suspension array

BACKGROUND

Preeclampsia is a severe complication of pregnancy characterized by an excessive maternal systemic inflammatory response with activation of both the innate and adaptive arms of the immune system. Cytokines, chemokines and adhesion molecules are central to innate and adaptive immune processes. The purpose of this study was to determine circulating levels of cytokines, chemokines and adhesion molecules in normal pregnancy and preeclampsia in a comprehensive manner, and to investigate their relationship to the clinical features and laboratory parameters of the study participants, including markers of overall inflammation (C-reactive protein), endothelial activation (von Willebrand factor antigen) and endothelial injury (fibronectin), oxidative stress (malondialdehyde) and trophoblast debris (cell-free fetal DNA).

RESULTS

Serum levels of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, IL-18, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon-gamma-inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were measured in 60 preeclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by multiplex suspension array and ELISA. In normal pregnancy, the relative abundance of circulating IL-18 over IL-12p70 and the relative deficiency of the bioactive IL-12p70 in relation to IL-12p40 might favour Th2-type immunity. Although decreased IL-1ra, TNF-alpha and MCP-1 concentrations of healthy pregnant relative to non-pregnant women reflect anti-inflammatory changes in circulating cytokine profile, their decreased serum IL-10 and increased IP-10 levels might drive pro-inflammatory responses. In addition to a shift towards Th1-type immunity (expressed by the increased IL-2/IL-4 and IFN-gamma/IL-4 ratios), circulating levels of the pro-inflammatory cytokines IL-6 and TNF-alpha, the chemokines IL-8, IP-10 and MCP-1, as well as the adhesion molecules ICAM-1 and VCAM-1, were raised in preeclampsia compared with healthy pregnancy, resulting in an overall pro-inflammatory systemic environment. Increased IP-10, MCP-1, ICAM-1 and VCAM-1 concentrations of preeclamptic patients showed significant correlations with blood pressure values, renal and liver function parameters, as well as with CRP, malondialdehyde, von Willebrand factor antigen and fibronectin levels.

CONCLUSIONS

According to our findings, preeclampsia was associated with an overall pro-inflammatory systemic environment. Elevated amounts of pro-inflammatory cytokines, chemokines and adhesion molecules in the maternal circulation might play a central role in the excessive systemic inflammatory response, as well as in the generalized endothelial dysfunction characteristics of the maternal syndrome of preeclampsia.

Vitamin D effects on pregnancy and the placenta

Vitamin D is a pleiotropic secosteroid hormone important for health and disease prevention. The actions of vitamin D are mediated by the vitamin D receptor that binds the active form of vitamin D [1,25(OH)(2)D] to induce both transcriptional and non-genomic responses. Vitamin D has well known classical functions in calcium uptake and bone metabolism, but more recent work highlights the importance of the nonclassical actions of vitamin D in a variety of cell types. These actions include modulation of the innate and adaptive immune systems and regulation of cell proliferation. Adequate vitamin D intake is essential for maternal and fetal health during pregnancy, and epidemiological data indicate that many pregnant women have sub-optimal vitamin D levels. Notably, vitamin D deficiency correlates with preeclampsia, gestational diabetes mellitus, and bacterial vaginosis, and an increased risk for C-section delivery. Recent work emphasizes the importance of nonclassical roles of vitamin D in pregnancy and the placenta. The placenta produces and responds to vitamin D where vitamin D functions as a modulator of implantation, cytokine production and the immune response to infection. We describe vitamin D metabolism and the cellular responses to vitamin D, and then summarize the role of vitamin D in placental trophoblast, pregnancy and the fetus.

Vitamin D effects on pregnancy and the placenta

Vitamin D is a pleiotropic secosteroid hormone important for health and disease prevention. The actions of vitamin D are mediated by the vitamin D receptor that binds the active form of vitamin D [1,25(OH)(2)D] to induce both transcriptional and non-genomic responses. Vitamin D has well known classical functions in calcium uptake and bone metabolism, but more recent work highlights the importance of the nonclassical actions of vitamin D in a variety of cell types. These actions include modulation of the innate and adaptive immune systems and regulation of cell proliferation. Adequate vitamin D intake is essential for maternal and fetal health during pregnancy, and epidemiological data indicate that many pregnant women have sub-optimal vitamin D levels. Notably, vitamin D deficiency correlates with preeclampsia, gestational diabetes mellitus, and bacterial vaginosis, and an increased risk for C-section delivery. Recent work emphasizes the importance of nonclassical roles of vitamin D in pregnancy and the placenta. The placenta produces and responds to vitamin D where vitamin D functions as a modulator of implantation, cytokine production and the immune response to infection. We describe vitamin D metabolism and the cellular responses to vitamin D, and then summarize the role of vitamin D in placental trophoblast, pregnancy and the fetus.

Soluble human leukocyte antigen-G isoforms in maternal plasma in early and late pregnancy

PROBLEM

Human Leukocyte Antigen (HLA)-G is a class Ib gene located in the human major histocompatibility complex (MHC). Several lines of investigation indicate that the HLA-G molecule is involved in the maternal acceptance of the semi-allogenic fetus during pregnancy and in the development of tolerance. Expression of soluble HLA-G (sHLA-G) is positively correlated with successful in vitro fertilization (IVF) treatments, and aberrant expression of HLA-G in certain complications of pregnancy, such as pre-eclampsia and spontaneous abortion, has been reported. The main purpose of this study was to investigate the levels of different soluble HLA-G isoforms in maternal plasma in early and late pregnancy.

METHOD OF STUDY

Soluble HLA-G (sHLA-G) can be detected in maternal blood, and in this study, two different isoforms of sHLA-G, namely sHLA-G1 generated by shedding of membrane-bound HLA-G1 and HLA-G generated by specific HLA-G transcripts, have been investigated early [median of 16.4 weeks of gestation (GW)] and late (median: 38.9 GW) in pregnancy in an original cohort of 580 pregnant Caucasian women.

RESULTS

Lower concentrations of sHLA-G1 were found late in pregnancy (>32 GW) in a group of women with severe pre-eclampsia compared with controls with uncomplicated pregnancies (P = 0.029, P(C) = 0.09; Mann-Whitney; Logistic regression analysis: P = 0.024, OR = 0.920, 95% CI: 0.855-0.989). However, this was not the case with HLA-G5, and significantly more of the cases with severe pre-eclampsia had detectable plasma HLA-G5 compared with that of the control group (P = 0.013, P(C) = 0.04; Mann-Whitney). Similar findings were not observed in women with gestational hypertension or existing hypertension continuing into pregnancy. Furthermore, there was a trend toward lower maternal plasma sHLA-G1 in a group of women with premature birth (<37 GW) compared with that of the control group (P = 0.028, P(C) = 0.17; Mann-Whitney). On the contrary, HLA-G5 was lower in the control group compared with that in the premature group (P = 0.004, P(C) = 0.02; Mann-Whitney).

CONCLUSION

This study shows in line with other published studies that a high, detectable soluble HLA-G concentration in maternal plasma or serum is not mandatory for a successful pregnancy. However, complications during pregnancy, such as (severe) pre-eclampsia, spontaneous abortion, IUGR, and premature birth, are associated with a low or undetectable level of soluble HLA-G in the maternal blood circulation. Also, this study indicates that sHLA-G1 is the interesting soluble HLA-G isoform in pre-eclampsia, and that low or undetectable levels of HLA-G5 at the end of pregnancy seem to be associated with an uncomplicated normal pregnancy, whereas in severe pre-eclampsia and possibly other pregnancy complications, such as preterm birth and IUGR, the level of HLA-G5 is higher.

Calcitriol inhibits TNF-alpha-induced inflammatory cytokines in human trophoblasts

Elevated placental proinflammatory cytokine release is associated with miscarriage, preterm labor and preeclampsia. Specifically, tumor necrosis factor-alpha (TNF-alpha)-induced cytokines may threaten pregnancy outcome. Since trophoblasts produce calcitriol, a hormone with strong immunosuppressive properties, we assessed the effects of this secosteroid on inflammatory cytokines induced in trophoblasts by challenge with TNF-alpha. The effects of calcitriol on synthesis of mRNAs encoding interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and TNF-alpha were measured by real time RT-PCR. Secreted cytokines were quantified by ELISA. The effects of TNF-alpha on CYP24A1, chorionic gonadotropin (hCG), 3beta-hydroxysteroid dehydrogenase (HSD3B1) and P(450)-aromatase (CYP19) mRNA expression were also studied. TNF-alpha stimulated IL-6, IFN-gamma and its own expression more than 3-fold over controls (P<0.05). Calcitriol inhibited the expression profile of inflammatory cytokine genes in a dose-response manner (P<0.05). This effect was prevented by addition of the vitamin D receptor antagonist TEI-9647. TNF-alpha also significantly inhibited expression of hCG, HSD3B1 and CYP19 genes, and stimulated CYP24A1 gene expression. These data show that calcitriol prevents TNF-alpha induction of inflammatory cytokines through a process likely to be mediated by the vitamin D receptor. We conclude that TNF-alpha inhibits placental hormone synthesis and stimulates calcitriol catabolism by regulating enzymes involved in these processes.

Immunoactivation in preeclampsia: Vdelta2+ and regulatory T cells during the inflammatory stage of disease

Recent data suggest a dominant role of the innate, rather than the adaptive immune system in pregnancy-related immunoregulation. gamma/delta T cells, that comprise a minor subpopulation of human peripheral blood lymphocytes, represent a link between the innate and the acquired immune systems. However little is known about how they function in preeclampsia, which is suggested to be associated with a Th1 predominant immune response. The aim of our study was to investigate the presence and phenotype of Vdelta2+ cells and of regulatory T cells in the pathogenesis of preeclampsia. Since Vdelta2+ T cell function has been shown to be altered in patients with preeclampsia we investigated the expression of perforin, Fas and TIM-3 by Vdelta2+ T cells and the possible role of activating and inhibitory NK cell receptors as well as of regulatory T cells. Vdelta2+ T cells of preeclamptic patients demonstrated an increased perforin and IFNgamma production, which could be explained by dysregulation of NK cell receptor expression. These Th1 polarized cells were less susceptible to apoptosis than Vdelta2+ T cells from healthy pregnant women. Our data suggest that activated Vdelta2+ T cells of preeclamptic women have an increased cytotoxic potential, which may be due to altered expression of NK cell inhibitory and activating receptors. In this study we report a series of observations, which taken together suggest the role of multiple pathways in generating an exaggerated systemic inflammatory response observed in the clinical stage of preeclampsia.

Association of tumor necrosis factor-alpha and interleukin-10 gene polymorphisms in Iranian patients with pre-eclampsia

PROBLEM

Considering that certain cytokines may change during pre-eclampsia (PE), because of functional polymorphisms in their genes, our purpose was to determine the association between tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) gene polymorphisms and development of PE.

METHOD OF STUDY

The genetic polymorphisms of TNF-alpha and IL-10 was studied by polymerase chain reaction-sequence specific primers in the DNA of peripheral blood cell from 160 patients with PE and 100 healthy pregnant women.

RESULTS

We found a significant difference between TNF-alpha A allele (-308) and G allele (-238) in PE patients compared with those of the control groups. A significantly higher C/C genotype frequency of IL-10 (-592 and -819) was observed in the PE patients than in the control groups. In addition, the frequencies of three common IL-10 haplotypes (GCC, ACC, and ATA) did not show any significant difference between the study groups.

CONCLUSION

These findings would support the concept of contribution of TNF-alpha and IL-10 gene polymorphisms in the pathogenesis of PE in our population.

Maternal circulating interferon-gamma and interleukin-6 as biomarkers of Th1/Th2 immune status throughout pregnancy

AIM

T cells may be classified as T helper type 1 (Th1) cells, which synthesize cytokines inducing cellular immunity, or T helper type 2 (Th2), which synthesize cytokines inducing humoral immunity. According to the Th1/Th2 paradigm, it has been postulated that successful pregnancy induces an immune Th2 bias, but it is not yet clear how Th1 and Th2 systems vary simultaneously throughout the pregnancy.

METHODS

Using maternal circulating interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) as biomarkers of Th1 and Th2 cytokines, respectively, we examined the variation of circulating Th1/Th2 ratio in 35 healthy pregnant women from 10 to 40 weeks of pregnancy.

RESULTS

With increasing gestational age, maternal circulating levels of IFN-gamma decrease, whereas those of IL-6 increase. The IFN-gamma/IL-6 ratio switches around the 19th week of pregnancy.

CONCLUSIONS

Our results suggest that maternal systemic IFN-gamma and IL-6 concentrations may be biomarkers of Th1/Th2 immune status during pregnancy. Moreover, our findings showed that contrary to the Th1/Th2 paradigm, the Th1 bias may be prevailing at the beginning of pregnancy, balanced in the middle of pregnancy and supplanted by the Th2 bias at the end of pregnancy.

CXCL10/IP-10: a missing link between inflammation and anti-angiogenesis in preeclampsia?

OBJECTIVE

Interferon (IFN)-gamma inducible protein, CXCL10/IP-10, is a member of the CXC chemokine family with pro-inflammatory and anti-angiogenic properties. This chemokine has been proposed to be a key link between inflammation and angiogenesis. The aim of this study was to determine whether preeclampsia and delivery of a small for gestational age (SGA) neonate are associated with changes in maternal serum concentration of CXCL10/IP-10.

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) non-pregnant women (N = 49); (2) women with normal pregnancies (N = 89); (3) patients with preeclampsia (N = 100); and (4) patients who delivered an SGA neonate (N = 78). SGA was defined as birth weight below the 10th percentile. Maternal serum concentrations of CXCL10/IP-10 were measured by sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) Patients with normal pregnancies had a significantly higher median serum concentration of CXCL10/IP-10 than non-pregnant women (median 116.1 pg/mL, range 40.7-1314.3 vs. median 90.3 pg/mL, range 49.2-214.7, respectively; p = 0.002); (2) no significant correlation was found between maternal serum concentration of CXCL10/IP-10 and gestational age (between 19 and 38 weeks); (3) there were no differences in median serum CXCL10/IP-10 concentrations between patients who delivered an SGA neonate and those with normal pregnancies (median 122.4 pg/mL, range 37.3-693.5 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p > 0.05); (4) patients with preeclampsia had a higher median serum concentration of CXCL10/IP-10 than normal pregnant women (median 156.4 pg/mL, range 47.4-645.9 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p < 0.05); (5) patients with preeclampsia had a higher median concentration of CXCL10/IP-10 than those who delivered an SGA neonate (median 156.4 pg/mL, range 47.4-645.9 vs. median 122.4 pg/mL, range 37.3-693.5, respectively; p < 0.05).

CONCLUSIONS

Patients with preeclampsia have significantly higher serum concentrations of CXCL10/IP-10 than both normal pregnant women and mothers who have SGA neonates. These results are likely to reflect an anti-angiogenic state as well as an enhanced systemic inflammatory response in patients with preeclampsia. Alternatively, since preeclampsia and SGA share several mechanisms of disease, it is possible that a higher concentration of this chemokine may contribute to the clinical presentation of preeclampsia in patients with a similar intrauterine insult.

Maternal serum soluble CD30 is increased in normal pregnancy, but decreased in preeclampsia and small for gestational age pregnancies

OBJECTIVE

Women with preeclampsia and those who deliver small for gestational age (SGA) neonates are characterized by intravascular inflammation (T helper 1 (Th1)-biased immune response). There is controversy about the T helper 2 (Th2) response in preeclampsia and SGA. CD30, a member of the tumor necrosis factor receptor superfamily, is preferentially expressed in vitro and in vivo by activated T cells producing Th2-type cytokines. Its soluble form (sCD30) has been proposed to be an index of Th2 immune response. The objective of this study was to determine whether the maternal serum concentration of sCD30 changes with normal pregnancy, as well as in mothers with preeclampsia and those who deliver SGA neonates.

METHODS

This cross-sectional study included patients in the following groups: (1) non-pregnant women (N = 49); (2) patients with a normal pregnancy (N = 89); (3) patients with preeclampsia (N = 100); and (4) patients who delivered an SGA neonate (N = 78). Maternal serum concentration of sCD30 was measured by a specific and sensitive enzyme-linked immunoassay. Non-parametric tests with post-hoc analysis were used for comparisons. A p value <0.05 was considered statistically significant.

RESULTS

(1) The median sCD30 serum concentration of pregnant women was significantly higher than that of non-pregnant women (median 29.7 U/mL, range 12.2-313.2 vs. median 23.2 U/mL, range 14.6-195.1, respectively; p = 0.01). (2) Patients with preeclampsia had a significantly lower median serum concentration of sCD30 than normal pregnant women (median 24.7 U/mL, range 7.6-71.2 vs. median 29.7 U/mL, range 12.2-313.2, respectively; p < 0.05). (3) Mothers with SGA neonates had a lower median concentration of sCD30 than normal pregnant women (median 23.4 U/mL, range 7.1-105.3 vs. median 29.7 U/mL, range 12.2-313.2, respectively; p < 0.05). (4) There was no significant correlation (r = -0.059, p = 0.5) between maternal serum sCD30 concentration and gestational age (19-38 weeks) in normal pregnant women.

CONCLUSIONS

(1) Patients with preeclampsia and those who deliver an SGA neonate had a significantly lower serum concentration of sCD30 than normal pregnant women. (2) This finding is consistent with the view that preeclampsia and SGA are associated with a polarized Th1 immune response and, perhaps, a reduced Th2 response.

Role of placentally produced inflammatory and regulatory cytokines in pregnancy and the etiology of preeclampsia

Human pregnancy is a metabolic and immune challenge for the mother who has to accommodate in her womb a semi-allogeneic fetus whose energy needs increase tremendously with gestation. Recent compelling research has suggested that proper inflammatory changes and oxidative balance are a requisite for successful pregnancy. The placenta is an integral component of this inflammatory response as it actively produces a variety of cytokines and immunomodulatory hormones. In preeclampsia, a life-threatening disorder of pregnancy that is characterized by widespread damage and dysfunction of the maternal endothelium, placental oxidative stress and aberrant cytokine expression induces an exaggerated maternal systemic inflammatory response to pregnancy.