Detection of interleukin-6, interleukin-8, and interleukin-11 in plasma from women with spontaneous abortion

Association of Genetic Polymorphisms in Long Noncoding RNA HOTTIP with Risk of Idiopathic Recurrent Spontaneous Abortion

The clustered homeobox gene family known as the Hox family plays a fundamental role in the morphogenesis of the vertebrate's embryo. A long noncoding RNA (lncRNA), known as HOTTIP (HOXA transcript at the distal tip), has been functionally characterized and contributed to the pathogenesis of various conditions. The current case-control study was undertaken to examine the gene frequencies and shared alleles of the HOTTIP  gene in Iranian participants with or without idiopathic recurrent spontaneous abortion (RSA). Both ARMS-PCR reaction and RFLP-PCR techniques were employed to detect three HOTTIP polymorphisms (rs2023843C/T, rs78248039A/T, and rs1859168C/A) in a DNA sample of 161 women with RSA and 177 healthy women. We found that the TT genotype of the HOTTIP rs2023843 C/T polymorphism was associated with a lower risk for idiopathic RSA. In contrast, the TT genotype of the HOTTIP rs78248039 A/T polymorphism was correlated with an enhanced risk of RSA. The presence of the A-allele for HOTTIP rs1859168 C/A polymorphism was associated with an increased risk for idiopathic RSA. Haplotype analysis showed that the T/T/A, C/T/A, T/T/C, and T/A/A haplotypes of rs2023843/rs78248039/rs1859168 enhanced RSA susceptibility. Computational analysis predicted that this lncRNA might act as a potential sponge for some microRNAs; therefore, affecting the expression of genes being targeted by them. In addition, both rs2023843 and rs1859168 variants could alter the local secondary structure of HOTTIP. Our results showed that HOTTIP rs2023843C/T, rs78248039A/T, and rs1859168C/A polymorphisms may confer genetic susceptibility to idiopathic RSA in an Iranian population.

IL-6 and IL-8: An Overview of Their Roles in Healthy and Pathological Pregnancies

Interleukin-6 (IL-6) is an acknowledged inflammatory cytokine with a pleiotropic action, mediating innate and adaptive immunity and multiple physiological processes, including protective and regenerative ones. IL-8 is a pro-inflammatory CXC chemokine with a primary function in attracting and activating neutrophils, but also implicated in a variety of other cellular processes. These two ILs are abundantly expressed at the feto-maternal interface over the course of a pregnancy and have been shown to participate in numerous pregnancy-related events. In this review, we summarize the literature data regarding their role in healthy and pathological pregnancies. The general information related to IL-6 and IL-8 functions is followed by an overview of their overall expression in cycling endometrium and at the feto-maternal interface. Further, we provide an overview of their involvement in pregnancy establishment and parturition. Finally, the implication of IL-6 and IL-8 in pregnancy-associated pathological conditions, such as pregnancy loss, preeclampsia, gestational diabetes mellitus and infection/inflammation is discussed.

miR-146b-5p and miR-520h Expressions Are Upregulated in Serum of Women with Recurrent Spontaneous Abortion

Unexplained recurrent spontaneous abortion (URSA) is characterized by two or more consecutive pregnancy losses before the 20th week of gestation with unknown etiology. Dysregulation of microRNAs (miRNAs) expression has been reported in reproductive diseases. This study aimed to compare differentially expressed miRNAs in the serum samples between URSA patients and healthy individuals. URSA cases were confirmed by a gynecologist. Peripheral blood sample was‏ gathered from 9 URSA patients, 15 normal pregnant, and 10 non-pregnant women without abortion history. After separating serum, the expression levels of the miR-101-3p, miR-517c-3p, miR-146b-5p, miR-221-3p, and miR-520 h were measured by qRT-PCR assay. The circulating level of miR-520 h in URSA patients was significantly up-regulated compared with healthy pregnant (P < 0.01) and healthy non-pregnant (P = 0.002) women. Furthermore, miR-520 h expression was significantly different between healthy non-pregnant and pregnant women (P = 0.002). Statistical analysis indicated miR-146b-5p expression was significantly up-regulated in URSA patients compared to normal pregnant women (P = 0.018). However, the transcription level of miR-146b-5p was insignificantly different between normal non-pregnant women and the other two groups. Also, circulating levels of miR-101-3p, miR-221-3p, and miR-517c-3p were not significantly different in the studied groups. Statistical analysis showed significant correlations between both miR-221-3p and miR-517c-3p and other miRNAs (P < 0.05). The circulating levels of miR-520 h and miR-146b-5p could be considered biomarkers for URSA diagnosis. Also, miR-517c-3p and miR-221-3p might play a regulatory role in other miRNAs expressions during pregnancy. Previous work, in contrary to our findings, claims that the expression levels of miR-221-3p, miR-101-3p, and miR-517c-3p increased in plasma and tissue samples of patients with URSA. However, our research for the first time indicates that the expression level of miR-520 h and miR-146b-5p in the serum of these patients has increased. Future investigations are necessary to confirm these findings.

Prostaglandin E2 Receptor 4 (EP4) Affects Trophoblast Functions via Activating the cAMP-PKA-pCREB Signaling Pathway at the Maternal-Fetal Interface in Unexplained Recurrent Miscarriage

Implantation consists of a complex process based on coordinated crosstalk between the endometrium and trophoblast. Furthermore, it is known that the microenvironment of this fetal–maternal interface plays an important role in the development of extravillous trophoblast cells. This is mainly due to the fact that tissues mediate embryonic signaling biologicals, among other molecules, prostaglandins. Prostaglandins influence tissue through several cell processes including differentiation, proliferation, and promotion of maternal immune tolerance. The aim of this study is to investigate the potential pathological mechanism of the prostaglandin E2 receptor 4 (EP4) in modulating extravillous trophoblast cells (EVTs) in unexplained recurrent marriage (uRM). Our results indicated that the expression of EP4 in EVTs was decreased in women experiencing uRM. Furthermore, silencing of EP4 showed an inhibition of the proliferation and induced apoptosis in vitro. In addition, our results demonstrated reductions in β- human chorionic gonadotropin (hCG), progesterone, and interleukin (IL)-6, which is likely a result from the activation of the cyclic adenosine monophosphate (cAMP)- cAMP-dependent protein kinase A (PKA)-phosphorylating CREB (pCREB) pathway. Our data might provide insight into the mechanisms of EP4 linked to trophoblast function. These findings help build a more comprehensive understanding of the effects of EP4 on the trophoblast at the fetal–maternal interface in the first trimester of pregnancy.

Interleukin 11 is upregulated in preeclampsia and leads to inflammation and preeclampsia features in mice

Preeclampsia is a dangerous pregnancy complication, which is often associated with fetal growth restriction and can have serious life-long effects for both mother and baby. While the establishment of the placenta in the first trimester is the sentinel event in the development of preeclampsia little is known of the critical mechanisms of placentation that lead to the syndrome. Locally produced inflammatory cytokines are thought to play a role in the development of preeclampsia. This review summarizes the evidence that interleukin 11 is dysregulated in preeclampsia and contributes to the initiation of preeclampsia via effects on placentation. It discusses the benefits and drawbacks of targeting IL11 as a novel treatment option for preeclampsia.

Interleukin 11: similar or opposite roles in female reproduction and reproductive cancer?

During placental development and carcinogenesis, cell invasion and migration are critical events in establishing a self-supporting vascular supply. Interleukin (IL)-11 is a pleiotropic cytokine that affects the invasive and migratory capabilities of trophoblast cells that form the placenta during pregnancy, as well as various malignant cell types. The endometrium is the site of embryo implantation during pregnancy; conversely, endometrial carcinoma is the most common gynaecological malignancy. Here, we review what is known about the role of IL-11 in trophoblast function and in gynaecological malignancies, focusing primarily on the context of the uterine environment.

Compartmentalized localization of 11β-HSD 1 and 2 at the feto-maternal interface in the first trimester of human pregnancy

Glucocorticoids are engaged in a number of actions at the feto-maternal interface for the establishment of early pregnancy. However, excessive glucocorticoids can be deleterious to fetal development. Therefore, compartmentalized distribution of 11β-hydroxysteroid dehydrogenase 1 and 2 (11β-HSD1 and 2), which regenerates and inactivates cortisol respectively, would ensure an optimal cortisol concentration at the feto-maternal interface for the establishment of early gestation. However, the distribution pattern of 11β-HSD1 and 2 at the feto-maternal interface in early human pregnancy is not clearly defined. Here we showed that 11β-HSD1 distributed extensively on the maternal side including decidual stromal cells and epithelial cells but scarcely on the fetal side except for localization in the fetal blood vessels of the chorionic villi. In contrast, 11β-HSD2 was abundantly localized in syncytial layer of the chorionic villi and the decidual epithelium. In primary cultures, cortisol upregulated not only 11β-HSD1 expression in decidual stromal cells but also 11β-HSD2 expression in villous trophoblasts of early pregnancy. Further studies revealed that cortisol inhibited the expression of interleukin-1β and 6 in decidual stromal cells and villous trophoblasts, and stimulated expression of human chorionic gonadotropin in villous trophoblasts. Collectively, this study has revealed a compartmentalized distribution pattern of 11β-HSD 1 and 2 at the feto-maternal interface, both of which can be upregulated by glucocorticoids, suggesting that a coordinated interaction between 11β-HSD 1 and 2 may exist to ensure an optimal cortisol concentration at discrete locations at the feto-maternal interface for the establishment of early pregnancy.

Immunogenetic contributions to recurrent pregnancy loss

While sporadic pregnancy loss is common, occurring in 15 % of pregnancies, recurrent pregnancy loss (RPL) impacts approximately 5 % of couples. Though multiple causes are known (including structural, hormonal, infectious, autoimmune, and thrombophilic causes), after evaluation, roughly half of all cases remain unexplained. The idiopathic RPL cases pose a challenging therapeutic dilemma in addition to incurring much physical and emotional morbidity. Immunogenetic causes have been postulated to contribute to these cases of RPL. Natural Killer cell, T cell expression pattern changes in the endometrium have both been shown in patients with RPL. Human leukocyte antigen (HLA) and cytokine allelic variations have also been studied as etiologies for RPL. Some of the results have been promising, however the studies are small and have not yet put forth outcomes that would change our current diagnosis and management of RPL. Larger database studies are needed with stricter control criteria before reasonable conclusions can be drawn.

A bioplex analysis of cytokines and chemokines in first trimester maternal plasma to screen for predictors of miscarriage

Background

We have previously shown in two independent cohorts that circulating first trimester Macrophage Inhibitory Cytokine-1 (MIC-1) levels are lower in women in early pregnancy who are destined to miscarriage. While promising, the diagnostic performance of measuring MIC-1 alone was not sufficient for it to be a useful predictive test for miscarriage. Besides MIC-1, there are other cytokines, as well as chemokines, involved in facilitating early pregnancy. We reasoned that screening these factors in maternal plasma could uncover other predictive markers of miscarriage.

Methods

This was a nested case control study, of 78 women from a prospective study of 462 attending the Early Pregnancy Assessment Unit in the first trimester (EPAU) with a threatened miscarriage; 34 of these subsequently miscarried (cases) and 44 went on to have a normal delivery (controls) Cytokines IL-1β, IL-6 and IL-10, and the chemokines, CXCL8, CCL2, CCL5, CCL7 and CX3CL1 were measured in plasma from our cohort.

Results

The cytokines IL-1β, IL-6, IL-10 and the chemokine CXCL8 were not detectable in first trimester plasma. The chemokines CCL2, CCL5, CCL7 and CX3CL1 were detectable in all samples but levels did not vary across 5–12 weeks of gestation among controls. Plasma levels of these chemokines were no different in the miscarriage cohort compared to controls.

Conclusion

The chemokines CCL2, CCL5, CCL7 and CX3CL1 were detectable in plasma during the first trimester while IL-1β, IL-6, IL-10 and CXCL8 were not. However, none of the cytokines and chemokines screened were different in maternal plasma in cases or controls. These therefore do not appear to have potential for application as predictive biomarkers of miscarriage.

Sperm cells induce distinct cytokine response in peripheral mononuclear cells from infertile women with serum anti-sperm antibodies

BACKGROUND AND AIMS

Anti-sperm antibodies in can markedly reduce the likelihood of natural conception. The etiology of this anti-sperm immunity in human females is unknown. We compared the cytokine response of peripheral blood mononuclear cells (PBMCs) from infertile patients with or without anti-sperm antibodies (ASA) and fertile women.

METHODOLOGY/PRINCIPAL FINDINGS

We cultivated the PBMCs together with sperm antigens (whole cells or cell lysate), and screened the supernatants for 40 cytokines by antibody array. When stimulated with whole sperm cells, the PBMCs from patients with ASA produce less IL-3, IL-11, IL-13, ICAM-1, GCSF and more IL-2, IL-4 and IL-12p70 as compared to healthy women. PBMCs from patients with ASA produce typically less IL-13, IL-7, IL-17 and MIG, and more MIP-1β and IL-8, as compared to PBMCs from patients without ASA. In response to sperm cell lysate, PBMCs from infertile women without ASA respond initially by increase in production of growth factors (GCSF, GM-CSF and PDGF-BB) followed by increase in chemokines (e.g. IL-8, MCP-1 and MIP-1β).

CONCLUSIONS

Cellular immune responses to sperm antigens, measured by production of cytokines, differ among infertile women with ASA, infertile women without ASA and healthy women. This difference could play an important role in the initial steps of the infertility pathogenesis.

AP-1 transcription factors, mucin-type molecules and MMPs regulate the IL-11 mediated invasiveness of JEG-3 and HTR-8/SVneo trophoblastic cells

This study examines the IL-11 mediated activation of downstream signaling and expression of effector molecules to resolve the controversies associated with the IL-11 mediated regulation of the invasiveness of two commonly used trophoblastic cell models viz. JEG-3 and HTR-8/SVneo cells. It has been reported that IL-11 increases the invasiveness of JEG-3 cells while, reduces the invasiveness of HTR-8/SVneo cells. Invasion assay performed simultaneously for both the cell lines confirmed the above findings. In addition, HTR-8/SVneo cells showed a higher basal invasiveness than JEG-3 cells. Western blot showed the IL-11 mediated activation of STAT3(tyr705) and STAT1(tyr701) in both the cell lines. However, IL-11 activated the ERK1/2 phosphorylation in JEG-3 cells but, inhibited it in HTR-8/SVneo cells. Within 10 min of IL-11 treatment, p-STAT3(tyr705) was localized inside the nucleus of both the cell lines but, there was enhanced co-localization of protein inhibitor of activated STAT1/3 (PIAS1/3) and p-STAT3(tyr705) in HTR-8/SVneo cells and not in JEG-3 cells. This could be reason for the poor responsiveness of STAT3 responsive genes like mucin 1 (MUC1) in HTR-8/SVneo cells and not in JEG-3 cells. Further, microarray analysis of the IL-11 treated cells revealed differential responsiveness of JEG-3 as compared to HTR-8/SVneo cells. Several family of genes like activator protein-1 (AP-1) transcription factors (Jun and Fos), mucin-type molecules, MMP23B etc showed enhanced expression in IL-11 treated JEG-3 cells while, there was no response or decrease in their expression in IL-11 treated HTR-8/SVneo cells. Expression of these molecules was confirmed by quantitative RT-PCR. In addition, HTR-8/SVneo cells also showed a significant decrease in the expression of MMP2, MMP3 and MMP9 upon IL-11 treatment. Hence, IL-11 mediated differential activation of signaling and expression of effector molecules is responsible for the differential invasive response of JEG-3 and HTR-8/SVneo cells.

Understanding the link between the IL-6 cytokine family and pregnancy: implications for future therapeutics

Cytokines are involved in almost all processes during the menstrual cycle, the fertilization period and pregnancy. They are expressed in numerous reproduction-related body fluids and tissues. Disorders of cytokine expression patterns may cause pregnancy pathologies. Therefore, cytokines have the potential as new biomarkers in different body compartments for a variety of such pathologies. Furthermore, cytokines may also serve to treat fertility and pregnancy disorders. The IL-6-like family of cytokines is an intensively investigated group of cytokines with well-accepted functions in fertility and pregnancy. This article summarizes current knowledge on IL-6-like cytokines in regard of their role in reproduction and their potential for new strategies in the treatment of reproductive pathologies.

Association of IL-1β and IL-6 gene polymorphisms with recurrent spontaneous abortion in a Chinese Han population

As certain cytokines may play a role in unexplained recurrent spontaneous abortion (RSA) and also some cytokine gene polymorphisms may affect the level of cytokine production, the aim of this study was to investigate the relationship between Chinese RSA and polymorphisms of the genes coding for interleukin (IL)-1β (-31C/T, -511C/T, +3954C/T) and IL-6 (-634C/G). Women (n = 162) with at least three consecutive spontaneous abortions and 156 ethnically matched healthy women with at least one successful pregnancy were included. Genotypes were determined using restriction fragment length polymorphism analysis of polymerase chain reaction products. No significant differences were found in the IL-1β-31T, -511T and +3954T distributions between the RSA group and the control group. On the other hand, the frequencies of the IL-6-634GG genotype and -634G allele were significantly decreased in the RSA group versus the control group (genotype: P = 0.0003; allele: P = 0.002), suggesting the IL-6-634C/G polymorphism might be a possible genetic protective factor for RSA.

Association between genetic polymorphisms in cytokine genes and recurrent miscarriage--a meta-analysis

A meta-analysis of association studies was performed to assess whether the reported genetic polymorphisms in cytokine genes are risk factors for recurrent miscarriage (RM). The electronic PubMed database was searched for case-control studies on immunity-related genes in RM. Investigations of a single polymorphism/gene involvement in RM reported more than five times were selected. Aggregating data from seven case-control studies on -308/tumour necrosis factor-alpha polymorphism, the odds ratio (OR) for RM was 1.1 (0.87-1.39) if the polymorphism was considered under a dominant genetic model. In six studies on -1082/interleukin-10 (IL-10) polymorphism, the OR under a dominant model was 0.76 (0.58-0.99), and under a recessive model the OR was 0.90 (0.71-1.15). In five case-control studies on -174/IL-6 polymorphism, the OR for RM under a recessive model was 1.29 (0.69-2.40). The results show a statistically significant association with RM for the -1082/IL-10 genotype.

Leukemia inhibitory factor and interleukin-11: critical regulators in the establishment of pregnancy

Blastocyst implantation into a receptive endometrium is critical to the establishment of pregnancy and is tightly regulated by factors within the blastocyst-endometrial micro-environment. Leukemia inhibitory factor (LIF) and interleukin-11 (IL11) have key roles during implantation. Female mice with a null mutation in the LIF or IL11RA gene are infertile due to a complete failure of implantation or a defective differentiation/decidualization response to the implanting blastocyst, respectively. LIF and IL11 deficiency during pregnancy is associated with infertility and miscarriage in women. Numerous cell populations at the maternal-fetal interface are regulated by LIF/IL11 including the endometrial epithelium, decidualizing stroma, placental trophoblasts and leukocytes. This review focuses on the roles of LIF/IL11 during early pregnancy and highlights their potential as contraceptive targets and therapeutic agents for infertility.

Interleukin 11 inhibits human trophoblast invasion indicating a likely role in the decidual restraint of trophoblast invasion during placentation

Successful pregnancy depends on the precise regulation of extravillous trophoblast (EVT) invasion into the uterine decidua, primarily by decidua-derived factors. In humans, during early pregnancy interleukin 11 (IL11) is maximally expressed in the decidua, with its receptor, IL11 receptor alpha (IL11RA), also identified on invasive EVTs in vivo. Although a role for IL11 in EVT migration has been established, whether it also plays a role in regulating EVT invasion is unknown. We investigated whether IL11 influences human EVT invasion and the signaling pathways and underlying mechanisms that may be involved, using the HTR-8/SVneo immortalized EVT cell line and primary EVTs as models for EVTs. Interleukin 11 (100 ng/ml) significantly inhibited invasion of EVT cells by 40% to 60% (P < 0.001). This effect was abolished by inhibitors of signal transducer and activator of transcription 3 (STAT3) but not of mitogen-activated protein kinase (MAPK) pathways. Interleukin 11 (100 ng/ml) had no effect on matrix metallopeptidases 2 and 9 (MMP2 and MMP9), tissue inhibitors of MMP (TIMP1, TIMP2, and TIMP3), plasminogen activator urokinase (PLAU), plasminogen activator urokinase receptor (PLAUR), and serpin peptidase inhibitors 1 and 2 (SERPINE1 and SERPINE2) in EVT-conditioned media and/or cell lysates. Interleukin 11 (100 ng/ml) also did not regulate EVT cell adhesion or integrin expression. These data demonstrate that IL11 inhibits human EVT invasion via STAT3, indicating a likely role for IL11 in the decidual restraint of EVT invasion during normal pregnancy.

Cytokine gene polymorphisms in recurrent spontaneous abortions: a comprehensive review

PROBLEM

Cytokine gene polymorphism studies in women with recurrent spontaneous abortion (RSA) are reviewed to provide comprehensive understanding and a direction for the future investigation.

METHOD OF STUDY

A search of PubMed was made to identify the published data between 2001 and 2007 regarding RSA and cytokine gene polymorphisms.

RESULTS

Either allele and/or genotype frequencies of the following polymorphisms were reported to be significantly different between women with RSA and controls: IFN-gamma +874A-->T, TA (P = 0.01), AA (P = 0.04); IL-6, -634C-->G CG/GG (P = 0.026); IL-10, -592C-->A CC (P = 0.016); IL-1B -511C (P = 0.035), -31T (P = 0.029); IL-1RA, IL1RN*2 (P = 0.002), and IL1RN*3 (P = 0.002). None of these studies was repeatedly reported by others to be significantly different. Among these, four cytokine polymorphisms (IFN-gamma, +874A-->T; IL-1B -511C; IL-1RA, IL1RN*2, IL1RN*3) were refuted by others and rest of them were studied once.

CONCLUSION

Multiple cytokine polymorphisms were reported to be associated with RSA. However, a majority of studies were not confirmed by other investigators or refuted by others. Inconsistent study results might be related to: (i) the production of these cytokines is partly under genetic controls and other factors affect cytokine levels; (ii) ethnic background, environmental factors, and selection criteria for study populations are different and (iii) the possibilities exist that multiple cytokine gene polymorphisms or other genes in linkage disequilibrium may play a role in RSA.

Interleukin-11 promotes migration, but not proliferation, of human trophoblast cells, implying a role in placentation

Trophoblast growth and invasion of the uterine endometrium are critical events during placentation and are tightly regulated by factors produced within the trophoblast-endometrial microenvironment. Deficiencies in placentation can result in early miscarriage or preeclampsia and intrauterine growth restriction, leading to impaired fetal health. The latter has been linked to major adult health disorders. IL-11 is essential for blastocyst implantation in mice. In humans, IL-11 and its receptor IL-11 receptor alpha (IL-11Ralpha) are maximally expressed in the decidua and chorionic villi during early pregnancy; however, the role of IL-11 in trophoblast function is unknown. Therefore, we examined whether IL-11Ralpha is expressed in human first trimester implantation sites, and whether IL-11 influences proliferation and migration of a human extravillous trophoblast (EVT)-hybridoma cell line and primary EVT cells, used as models for EVT. Immunoreactive IL-11Ralpha localized to subpopulations of interstitial and endovascular EVT cells in vivo. In EVT cells in vitro, IL-11: 1) stimulated phosphorylation of signal transducer and activator of transcription-3; 2) was without effect on EVT cell proliferation; and 3) stimulated significant migration of EVT-hybridoma cells (no endogenous IL-11), whereas in primary EVT, blocking endogenous IL-11 inhibited EVT migration by 30-40%. These data demonstrate that IL-11 stimulates human EVT migration, but not proliferation, likely via signal transducer and activator of transcription-3, indicating an important role for IL-11 in placentation.

Circulating levels of cytokines during pregnancy: thrombopoietin is elevated in miscarriage

OBJECTIVE

To evaluate the hypothesis that cytokine levels are associated with miscarriage risk using serum samples collected before report of miscarriage.

DESIGN

A nested case-control study.

SETTING

Biospecimens from the multisite Collaborative Perinatal Project, University of Florida, laboratory assessment of interleukin (IL)-1 receptor antagonist, IL-1beta, IL-4, IL-6, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, thrombopoietin (TPO), and granulocyte colony-stimulating factor (G-CSF).

PATIENT(S)

Cases of miscarriage (n = 439) were matched to controls (n = 373) by gestational age at sample collection.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Miscarriage.

RESULT(S)

Increased risk of miscarriage was associated with elevated TPO (adjusted odds ratio [OR] 1.16, 95% confidence interval [CI] 1.00-1.36) and decreased G-CSF (adjusted OR 0.78, 95% CI 0.64-0.95). When analysis was restricted to samples collected more than 35 days before miscarriage, the effect of G-CSF was not observed (adjusted OR 0.96, 95% CI 0.72-1.28), whereas increased risk related to higher TPO remained.

CONCLUSION(S)

Circulating levels of TPO may be associated with increased risk of miscarriage.

Reduced expression of interleukin-11 and interleukin-6 in the periimplantation endometrium of excessive ovarian responders during in vitro fertilization treatment

CONTEXT

Impaired implantation in assisted reproduction cycles with high serum estradiol (E2) concentrations may be related to abnormal endometrial functions.

OBJECTIVE

The in vivo expression of T helper type 2 (Th2) cytokines in the periimplantation endometrium of infertile patients was compared between natural and stimulated cycles.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Uterine flushings and endometrial biopsies were collected 7 d after the LH surge in natural cycles or after human chorionic gonadotropin injection in stimulated cycles. Th2 cytokines were determined by immunolocalization and by ELISA. Natural cycles were in group A, whereas stimulated cycles with peak serum E2 of no more than 20,000 pmol/liter (moderate responders) and more than 20,000 pmol/liter (excessive responders) were classified as group B and group C, respectively.

RESULTS

Higher E2 had a negative effect on IL-11 and IL-6 expression in the endometrium and IL-11 concentration in the uterine flushing. In endometrial biopsies, a significantly lower immunostaining of stromal IL-11 (P < 0.001) and glandular IL-6 (P < 0.05) was detected in group C compared with that of groups A and B. IL-11 concentration by ELISA was significantly lower in group C (P < 0.05). Endometrial leukemia inhibitory factor and IL-4 expression was similar in the three groups. In uterine flushings, a significantly higher percentage of women in group C had undetectable IL-11 and a lower IL-11 concentration (P < 0.01) compared with group A, whereas no difference in IL-6 concentration was noted in the three groups.

CONCLUSION

Reduced expression of IL-11 and IL-6 in periimplantation endometrium may account for lower implantation in excessive responders.

Impact of genes related to immune tolerance and inflammation (tumour necrosis factor-α, interleukin-6) on blood pressure, protein excretion and oedema in pregnancy

OBJECTIVE

To test the hypothesis that genetically determined alterations of maternal immune tolerance to a foetal semi-allograft are important for the pathogenesis of hypertensive disorders in pregnancy.

DESIGN

A genetic association study was performed to analyse the impact of genetic polymorphisms known to be involved in immune tolerance on markers of pre-eclampsia.

SETTING

The study was conducted at the Obstetrics Department of the Charité University Hospital, Berlin, Germany.

PARTICIPANTS

A total of 1480 Caucasian women were consecutively included after delivery and genotyped for two polymorphisms: tumour necrosis factor-alpha -308G>A and interleukin-6 -174G>C.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressures, urinary protein excretion and oedema during pregnancy.

RESULTS

Only women carrying at least one mutant allele of both polymorphisms (tumour necrosis factor-alpha A and interleukin-6 C) have a significantly elevated mean systolic blood pressure and diastolic blood pressure at the end of pregnancy. The tumour necrosis factor-alpha A allele on its own is significantly associated with urinary protein excretion in the last trimenon, and the interleukin-6 C allele is independently and significantly associated with new-onset oedema.

CONCLUSIONS

We demonstrate in a large population that common maternal polymorphisms of genes related to immune tolerance and inflammation are associated with blood pressure regulation, urinary protein excretion and oedema during pregnancy. The analysed polymorphisms seem to contribute to the multifactorial pathogenesis of gestational hypertension and pre-eclampsia. The findings support the hypothesis that genetically determined factors of maternal immune tolerance play a role in the pathogenesis of hypertensive disorders in pregnancy.

Uterine extracellular matrix components are altered during defective decidualization in interleukin-11 receptor alpha deficient mice

BACKGROUND

Implantation of the embryo and successful pregnancy are dependent on the differentiation of endometrial stromal cells into decidual cells. Female interleukin-11 receptor alpha (IL-11Ralpha) deficient mice are infertile due to disrupted decidualization, suggesting a critical role for IL-11 and its target genes in implantation. The molecular targets of IL-11 in the uterus are unknown, but it is likely that IL-11 signaling modifies the expression of other genes important in decidualization. This study aimed to identify genes regulated by IL-11 during decidualization in mouse uterus, and to examine their expression and localization as an indication of functional significance during early pregnancy.

METHODS

Decidualization was artificially induced in pseudopregnant wild type (IL11Ra+/+) and IL-11Ralpha deficient (IL11Ra-/-) littermates by oil injection into the uterine lumen, and gene expression analyzed by NIA 15K cDNA microarray analysis at subsequent time points. Quantitative real-time RT-PCR was used as an alternative mRNA quantitation method and the expression and cellular localization of the protein products was examined by immunohistochemistry.

RESULTS

Among 15,247 DNA probes, 13 showed increased and 4 decreased expression in IL11Ra-/- uterus at 48 h of decidualization. These included 4 genes encoding extracellular matrix proteins; collagen III alpha1, secreted acidic cysteine-rich glycoprotein (SPARC), biglycan and nidogen-1 (entactin). Immunohistochemistry confirmed increased collagen III and biglycan protein expression in IL11Ra-/- uterus at this time. In both IL11Ra-/- and wild type uterus, collagen III and biglycan were primarily localized to the outer connective tissue and smooth muscle cells of the myometrium, with diffuse staining in the cytoplasm of decidualized stromal cells.

CONCLUSION

These data suggest that IL-11 regulates changes in the uterine extracellular matrix that are necessary for decidualization.

Cytokines in recurrent pregnancy loss

Cytokines seem to play a critical role in the pathogenesis of unexplained recurrent pregnancy loss (RPL). Th1 cytokines have been shown to exert deleterious effects on pregnancy, inhibiting foetal growth and development. On the other hand, Th2 cytokines have been associated with successful pregnancy. The purpose of this study was to evaluate cytokine production in women with RPL. The studied group comprised 29 women with RPL, with at least three consecutive spontaneous abortions. The control group included 27 women with a history of successful pregnancies and no miscarriage. We determined IL-6 and TNF-alpha production in peripheral blood cultured with LPS, as well as IFN-gamma and TGF-beta induced by PHA stimulation. Cytokines were measured by enzyme-linked immunoabsorbant assay (ELISA) using commercial kits (RD, Amersham-Pharmacia). Mann-Whitney test was applied to compare differences between groups. The level of significance was defined at P < 0.05. We observed significantly higher levels of IFN-gamma (355.8 pg/ml versus 98.0 pg/ml; P = 0.01) and a trend toward increased TNF-alpha production (2410.2 pg/ml versus1980.2 pg/ml; P = 0.07) in RPL women as compared to controls. In relation to IL-6 and TGF-beta, no significant difference was detected between RPL and control groups. In agreement with experimental observations, our data support the hypothesis of Th1 cytokine involvement in the pathogenesis of RPL.

Single nucleotide polymorphisms in the promoter region of the interleukin-6 gene and the risk of recurrent pregnancy loss in Japanese women

OBJECTIVE

To investigate the relationships between recurrent pregnancy loss and single nucleotide polymorphisms (-634C-->G and -174G-->C genotypes) in the promoter region of the interleukin (IL)-6 gene in the Japanese population.

DESIGN

A case-control study.

SETTING

Obstetrics and gynecology department of a university hospital.

PATIENT(S)

Cases were 76 women with recurrent pregnancy loss; controls were 93 fertile women.

INTERVENTION(S)

Determination of IL-6 promoter gene polymorphisms performed by polymerase chain reaction and gel electrophoresis.

MAIN OUTCOME MEASURE(S)

Frequency and distribution of the promoter region of the IL-6 gene allele.

RESULTS

There was a significant difference in the -634C-->G genotype frequency (CC vs. CG/GG) between women with recurrent pregnancy loss and controls. The risk of recurrent pregnancy loss was lower in the carriers of the G allele than in women with the wild type (CC) (odds ratio = 0.46; 95% confidence interval = 0.24-0.91). On the other hand, we did not detect any carrier of -174C among the 169 subjects.

CONCLUSION(S)

The results suggest that, in the Japanese population, women carrying the -634G allele of the IL-6 gene might have a decreased risk of recurrent pregnancy loss.

T-helper 2-cytokine levels in women with threatened abortion

OBJECTIVE

Considering that successful embryo development has been immunologically attributed to a T-helper 2 phenomenon and that threatened abortion is a very frequent but pathogenetically not well-defined clinical entity, our purpose was to investigate serum levels of the main T-helper 2-type cytokines during the evolution of this condition.

STUDY DESIGN

Three T-helper 2-type cytokines (interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-13 (IL-13)) were measured by an enzyme-linked immunosorbent assay (ELISA) in serum of 12 women with threatened abortion both at hospital admission and discharge time. Fourteen women with missed abortion, 14 normal pregnant women and 14 normal non-pregnant women represent study control groups.

RESULTS

Serum concentrations of the selected T-helper 2-type cytokines showed no significant differences in women with threatened abortion with those of normal pregnant and non-pregnant women, whereas showed significantly lower values in women with missed abortion.

CONCLUSION

Our data (a) confirm the concept that first-trimester normal pregnancy is a T-helper 2 phenomenon, (b) show that threatened abortion, when T-helper 2-biased, may tend to a positive evolution of the condition, (c) display that interleukin-10, particularly, may represent a useful diagnostic and prognostic marker for predicting the normal continuance of the pregnancy in threatened abortion, (d) confirm the existence of a T-helper 2-type pattern deficiency in missed abortion, and finally (e) may open the way to new T-helper 2-biased immune therapies in case of difficult first-trimester pregnancies.

Inhibition of Amniotic Interleukin-6 and Prostaglandin E2 Release by Ampicillin

OBJECTIVE

To test the effect of ampicillin on amniotic interleukin-6 (IL-6) and prostaglandin E2 (PGE2) release.

METHODS

In an in vitro study, IL-6 and PGE2 release from amnion-like Wistar Institute Susan Hayflick cells was assayed under basal conditions, as well as after incubation with ampicillin. In an in vivo study, amniotic fluid IL-6 was assayed in a total of 212 patients submitted to genetic amniocentesis during the 17th week of their singleton physiological pregnancy. The study population was subdivided as follows: 92 patients sampled before ampicillin administration, 70 patients sampled 4 hours after administration of 1 g ampicillin, and 50 patients sampled 12 hours after administration of 1 g ampicillin.

RESULTS

At doses ranging from 10-7 to 10-4 M, ampicillin decreased IL-6 release from Wistar Institute Susan Hayflick cells. The drug effect was already statistically significant (-30%; P <.05) at the lowest concentration tested (10-7 M), reaching the maximum (-50%) at 10-6 M after 4 hours of incubation. Moreover, ampicillin concentrations ranging from 10-7 to 10-4 M decreased PGE2 release from Wistar Institute Susan Hayflick cells; maximal inhibition was reached at 10-6 M after 4 hours (-40%; P <.05). Finally, IL-6 levels measured in amniotic fluid of patients sampled 4 hours after ampicillin administration proved strongly and significantly reduced when compared with those sampled either before or 12 hours after treatment (P <.001).

CONCLUSION

The capacity of ampicillin to directly decrease amniotic IL-6 and PGE2 release should be considered in the management of bacterial and nonbacterial inflammatory complications of pregnancy mediated by the cytokine and prostanoid interaction.

Maternal Serum Levels of Pro- Inflammatory Cytokines in Missed and Threatened Abortion

PROBLEM

A study of association between pro-inflammatory cytokines, and missed and threatened abortions with good outcome has been performed.

METHOD OF STUDY

The presence of pro-inflammatory cytokines, namely interleukin (IL)-8 and IL-12 and the soluble interleukin-2 receptor (SIL-2R) was investigated in maternal serum of 12 patients with threatened abortion twice (at admission and discharge), 14 patients with missed abortion, 14 women with healthy first-trimester pregnancy, and 14 normal non-pregnant women, using specific enzyme-linked immunosorbent assays.

RESULTS

SIL-2R and, in particular, IL-12 was detected with significantly higher levels in missed abortion group compared with all other groups. IL-8 was detected with no significant difference among all the groups studied.

CONCLUSIONS

In spite of caution due to the small sizes of the subject samples, these results support a role of the immune system in the first trimester pregnancy and hypothesize that missed abortion may be associated with an enhanced Th1 reactivity, whereas threatened abortion with good outcome resembles the normal pregnancy with a non-enhanced Th1 reactivity.

High levels of intrauterine corticotropin-releasing hormone, urocortin, tryptase, and interleukin-8 in spontaneous abortions

Stress induces CRH secretion that activates hypothalamic-pituitary-adrenal axis and is also abortogenic. In addition to hypothalamus, CRH and its analog urocortin (Ucn) are also secreted locally outside the brain where they activate mast cells leading to inflammation; however, the level of CRH and Ucn or mast cell mediators has not been examined in products of conception (POC). CRH and Ucn were measured by enzyme immunoassay, tryptase by fluoroenzyme immunoassay, and IL-8 by ELISA in POC of 7-9 wk gestation from Caucasian women; they were divided into group I with elective abortions (n = 4), group II with one spontaneous abortion (n = 12), and group III with at least two spontaneous abortions (n = 7). CRH, Ucn, tryptase, and IL-8 levels were higher (P < 0.05) in group III (8683 +/- 1201 pg/g, 7961 +/- 1499 pg/g, 1553 +/- 572 ng/g, and 8317 +/- 1874 pg/g, respectively) than group II (2561 +/- 314 pg/g, 2349 +/- 394 pg/g, 403 +/- 97 ng/g, and 3199 +/- 449 pg/g, respectively) and group I (163 +/- 162 pg/g, 328 +/- 327 pg/g, 72 +/- 31 ng/g, and 3681 +/- 931 pg/g, respectively). Immunostaining of POC showed significantly more tryptase in group III women. High POC levels of CRH and Ucn under stress in habitual spontaneous abortions may activate uterine mast cells to secrete abortogenic tryptase and IL-8.

Serum concentrations of interleukin-2R (IL-2R), IL-6, IL-8, and tumor necrosis factor alpha in patients with ectopic pregnancy

OBJECTIVE

To investigate the diagnostic relevance of serum cytokine concentrations in ectopic pregnancy (EP).

DESIGN

Cohort study.

SETTING

University hospital.

PATIENT(S)

Seventeen women with EP, 22 women with miscarriage, and 33 women with normal intrauterine pregnancy, at comparable stages of gestation.

INTERVENTION(S)

Interleukin (IL)-2 receptor, IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) determination by immunoradiometric assay.

MAIN OUTCOME MEASURE(S)

Serum concentrations of progesterone, beta-hCG, IL-2R, IL-6, IL-8, and TNF-alpha.

RESULT(S)

Serum levels of IL-6 were higher in women with EP than in those with miscarriage and normal pregnancy. Serum levels of TNF-alpha were higher in women with EP than in those with miscarriage and normal pregnancy. Serum levels of IL-8 were higher in women with EP than in those with miscarriage and normal pregnancy. An IL-8 cutoff of >40 pg/mL predicted EP with a sensitivity of 82.4%, a specificity of 81.8%, and positive and negative predictive values of 58.3% and 93.8%. No difference in serum IL-2R levels was found among the groups.

CONCLUSION(S)

Serum IL-8, IL-6, and TNF-alpha concentrations are higher in women with EP than in those with miscarriage and normal pregnancy. Further studies are needed to determine their diagnostic value.