Association between tumor necrosis factor (TNF)-alpha G-308A gene polymorphism and preeclampsia complicated by severe fetal growth restriction

Investigation of the linkage between TNF-alfa rs1800629 polymorphism and preeclampsia risk: A meta-analysis

BACKGROUND

Preeclampsia is a serious medical condition that significantly affects expectant mothers. Growing research showed an inconsistent association between TNF-alfa rs1800629 polymorphism and preeclampsia. The current meta-analysis was aimed at examining the potential impact of rs1800629 variant on preeclampsia.

METHODS

The Cochrane Library, Google Scholar, PubMed, EMBASE, Web of Science, and other databases were searched extensively to locate and select articles up to October 30, 2023. The PRISMA 2020 recommendations were followed to perform this study. Data analysis was done by using Comprehensive Meta analysis (v 3).

RESULTS

We have included 32 articles containing 35 studies with 3,883 patients and 5,821 controls for qualitative and quantitative data analysis. We found a strong relationship between rs1800629 variant with the increased preeclampsia risk in co-dominant model 1 (OR = 1.33, p = 0.019), co-dominant model 2 (OR = 1.43, p = 0.014), dominant model (OR = 1.25, p = 0.044), over-dominant model (OR = 1.31, p = 0.021), and allelic model (OR = 1.24, p = 0.018). This study also revealed a significantly higher risk among the Asian population in the dominant (OR = 2.31, p = 0.036) and allelic model (OR = 2.02, p = 0.028). For the Caucasian population, an increased association between the rs1800629 variant and preeclampsia risk was reported in co-dominant model 1 (OR = 1.37, p = 0.011), co-dominant model 2 (OR = 1.77, p = 0.007), dominant model (OR = 1.32, p = 0.030), recessive (OR = 1.50, p = 0.047), over-dominant (OR = 1.34, p = 0.009), and allelic model (OR = 1.32, p = 0.004). Though our study showed the protective link of the TNF-alfa polymorphism to the preeclampsia risk among the Black population, no significant outcomes were observed in any genetic models (p > 0.05).

CONCLUSION

Overall, the present meta-analysis explored a consistent linkage of the TNF-alfa rs1800629 variant to the preeclampsia risk in different ethnic groups. Additional research is required to confirm the precise relationship between the rs1800629 variant and preeclampsia risk.

Highlighting allelic variations at the interleukin-19 locus in term of preeclampsia predisposing factors and access to an accurate diagnostic/screening option

BACKGROUND

Preeclampsia is the main cause of preterm parturition and maternal-fetal complications. T helper 1 and T helper 2 cytokines balance is a requirement in normal pregnancy and aberrant in this immunologic balance, play an important role in the pathology of preeclampsia. In previous studies single nucleotide polymorphisms have been associated with the alteration of serum cytokine levels.

OBJECTIVE

This study was aimed to discover association between interleukin-13 (rs20541, and rs56035208) and interleukin-19 (rs1028181 (T/C) and rs2243191(T/C)) polymorphisms with susceptibility to preeclampsia.

METHODS

In this case-control study 300 women with and without preeclampsia (n = 150/each) who referred to Zeynabieh Hospital- Shiraz, Iran, from February 2021 to April 2022 were enrolled. For genotyping the interleukin-13 and interleukin-19 polymorphisms, the Allele-specific polymerase chain reaction and direct sequencing method was carried out.

RESULTS

Our statistical results revealed no significant differences in allele and genotype frequencies for interleukin-13 polymorphisms compared to controls. We found that the interleukin-13 polymorphisms are significantly associated with vulnerability to edema at rs20541 position and maternal drinking at rs56035208 position. But it was interesting to note that the differences of both the allele and genotype frequencies of interleukin-19 polymorphisms and their contribution to the risk of preeclampsia susceptibility were significant.

CONCLUSIONS

No risk of preeclampsia was found in all comparisons for interleukin-13 polymorphisms. However, the interleukin-19 polymorphisms were found to confer the risk of preeclampsia in our population.

Evaluation of long noncoding RNA (LncRNA) in pathogenesis of HELLP syndrome: diagnostic and future approach

HELLP syndrome is a disorder during pregnancy which is defined by elevation of liver enzymes, haemolysis, and low platelet count. This syndrome is a multifactorial one and both genetic and environmental components can have a crucial role in this syndrome's pathogenesis. Long noncoding RNAs (lncRNAs), are defined as long non-protein coding molecules (more than 200 nucleotides), which are functional units in most cellular processes such as cell cycle, differentiation, metabolism and some diseases progression. As these markers discovered, there has been some evidence that they have an important role in the function of some organs, such as placenta; therefore, alteration and dysregulation of these RNAs can develop or alleviate HELLP disorder. Although the role of lncRNAs has been shown in HELLP syndrome, the process is still unclear. In this review, our purpose is to evaluate the association between molecular mechanisms of lncRNAs and HELLP syndrome pathogenicity to elicit some novel approaches for HELLP diagnosis and treatment.

Genetic variation in placental insufficiency: What have we learned over time?

Genetic variation shapes placental development and function, which has long been known to impact fetal growth and pregnancy outcomes such as miscarriage or maternal pre-eclampsia. Early epidemiology studies provided evidence of a strong heritable component to these conditions with both maternal and fetal-placental genetic factors contributing. Subsequently, cytogenetic studies of the placenta and the advent of prenatal diagnosis to detect chromosomal abnormalities provided direct evidence of the importance of spontaneously arising genetic variation in the placenta, such as trisomy and uniparental disomy, drawing inferences that remain relevant to this day. Candidate gene approaches highlighted the role of genetic variation in genes influencing immune interactions at the maternal-fetal interface and angiogenic factors. More recently, the emergence of molecular techniques and in particular high-throughput technologies such as Single-Nucleotide Polymorphism (SNP) arrays, has facilitated the discovery of copy number variation and study of SNP associations with conditions related to placental insufficiency. This review integrates past and more recent knowledge to provide important insights into the role of placental function on fetal and perinatal health, as well as into the mechanisms leading to genetic variation during development.

Cytokine-polymorphisms associated with Preeclampsia: A review

BACKGROUND

Preeclampsia (PE) is a syndromic disorder that affects 2% to 8% of pregnancies and is diagnosed principally when hypertension appears in the second-d half of pregnancy. WHO estimates the incidence of PE to be seven times higher in developing countries than in developed countries. Severe preeclampsia/eclampsia is one of the most important causes of maternal mortality, associated with 50,000 to 100,000 annual deaths globally as well as serious fetal and neonatal morbidity and mortality, especially in developing countries. Even though evidence from family-based studies suggest PE has a heritable component, its etiology, and specific genetic contributions remain unclear. Many studies examining the genetic factors contributing to PE have been conducted, most of them are focused on single nucleotide polymorphisms (SNPs). Given that PE has a very important inflammatory component, is mandatory to examine cytokine-SNPs for elucidating all mechanisms involved in this pathology. In this review, we describe the most important cytokine-polymorphisms associated with the onset and development of PE. We aim to provide current and relevant evidence in this regard.

METHODS

We searched English databases such as PubMed and the National Center for Biotechnology Information. The publication time of the papers was set from the establishment of the databases to February 2022. All studies about Th1/Th2/Th17 cytokines polymorphisms were included in our study.

RESULTS

SNPs in IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, and IL-22 are associated with the development, early-onset and severity of PE, being the Th1/Th2/Th17 responses affected by the presence of these SNPs.

CONCLUSIONS

The changes in Th1/Th2/Th17 response modify processes such as placentation, control of inflammation, and vascular function. Nonetheless, association studies have shown different results depending on sample size, diagnostic, and population.

Contribution of -1031T/C and -376G/A tumor necrosis factor alpha polymorphisms and haplotypes to preeclampsia risk in Tunisia (North Africa)

Preeclampsia is a gestational disorder characterized by hypertension and proteinuria. Excessive release of pro-inflammatory cytokines, particularly tumour necrosis factor-alpha, has been demonstrated to contribute to endothelial activation and poor trophoblast invasion in placental development, resulting in preeclampsia's clinical symptoms. Genetic polymorphisms of tumour necrosis factor-alpha can regulate its production and may play an important role in the pathogenesis of this disease. This study aimed to evaluate the association of five tumour necrosis factor-alpha gene promoter single nucleotide polymorphisms, or their haplotype combinations, with preeclampsia prevalence. This case-control study was conducted on 300 women with preeclampsia and 300 age-matched women with normal pregnancy from Tunisian hospitals. Genotyping of tumour necrosis factor-alpha -1031 T/C, -376 G/A, -308 G/A, -238 G/A, and +489 G/A SNPs was performed on DNA extracted from blood samples using PCR-restriction fragment-length polymorphism analysis. Statistical analysis was performed using the chi-square test. P < 0.01 were considered statistically significant to take into consideration the multiple comparisons. A significantly higher frequency of the minor allele -1031C (p < 0.001) was observed in preeclampsia cases compared to controls. Notably, the -1031C and -376A (CA) haplotype, which correlates with a higher production of TNF-α protein, had a higher incidence in women with preeclampsia (p = 0.0005). Conversely, the TG haplotype had a low frequency in preeclampsia cases compared to controls (p = 0.002) which suggests that it is associated with a reduced incidence of preeclampsia. These results suggest that tumour necrosis factor-alpha polymorphisms, in particular the -1031C/A, and the haplotype CA, contribute to an increased risk of preeclampsia in Tunisian women.

Association of IL-10 -819C/T, -592A/C polymorphisms with the risk of preeclampsia: An updated meta-analysis

OBJECTIVE

The purpose of our study was to investigate whether IL-10 -819C/T, -592A/C polymorphisms were associated with preeclampsia (PE) susceptibility.

METHODS

A comprehensive and systematic literature search was performed through online databases, including Web of Science, PubMed, EMBASE, and Chinese databases. Then eligible literatures were included according to inclusion criteria and exclusion criteria. Statistical data analysis was performed using Stata 10.0 software. Odds ratios (OR) and 95% confidence interval were applied to evaluated the association between IL-10 -819C/T, -592A/C polymorphisms and PE susceptibility.

RESULTS

According to inclusion and exclusion criteria, 9 case-control studies, including 1423 cases and 2031 controls, were included in this meta-analysis. Our meta-analysis revealed that no association was found between IL-10 -819C/T, -592A/C polymorphisms and the risk of PE in our study.

CONCLUSION

Our meta-analysis suggested that IL-10 -819C/T and -592A/C polymorphisms had no association with PE susceptibility, but had a significant association with PE susceptibility in Asian and Caucasian.

Long-Term Cardiovascular Disease Risk in Women After Hypertensive Disorders of Pregnancy: Recent Advances in Hypertension

Patients with a history of hypertensive disorders of pregnancy (HDP) suffer higher rates of long-term cardiovascular events including heart failure, coronary artery disease, and stroke. Cardiovascular changes during pregnancy can act as a natural stress test, subsequently unmasking latent cardiovascular disease in the form of HDP. Because HDP now affect 10% of pregnancies in the United States, the American Heart Association has called for physicians who provide peripartum care to promote early identification and cardiovascular risk reduction. In this review, we discuss the epidemiology, pathophysiology, and outcomes of HDP-associated cardiovascular disease. In addition, we propose a multi-pronged approach to support cardiovascular risk reduction for women with a history of HDP. Additional research is warranted to define appropriate blood pressure targets in the postpartum period, optimize the use of pregnancy history in risk stratification tools, and clarify the effectiveness of preventive interventions. The highest rates of HDP are in populations with poor access to resources and quality health care, making it a major risk for inequity of care. Interventions to decrease long-term cardiovascular disease risk in women following HDP must also target disparity reduction.

Tumour necrosis factor-α (TNF-α) serum levels in preeclampsia pregnant women and pregnant women at risk with preeclampsia

OBJECTIVE

This study aimed to determine serum tumour necrosis factor-α (TNF-α) levels in pregnant women with the risk of preeclampsia and those who have preeclampsia.

METHOD

This research was a cross-sectional study and conducted in two maternal and child hospitals in Makassar, South Sulawesi, Indonesia, that is Pertiwi and Fatimah hospitals. As many as 86 pregnant women; 31 normal blood pressure, 26 high-risk preeclampsia and 29 preeclampsia pregnant women checked their blood pressure and then gave informed consent. TNF-α level was examined used enzyme-linked immunosorbent assay (ELISA) in Hasanuddin University laboratorium. Pregnant women with antiplatelet therapy, infectious, and inflammatory diseases were excluded from the study. Data presented in the form of tables and narratives. The bivariate analysis presented in the form of a cross table between variables TNF-α levels with pregnant women at risk for preeclampsia and preeclampsia and analyzed used Kruskal Wallis Test.

RESULTS

TNF-α levels in normal patients are 24.47pg/ml, whereas those at the risk of preeclampsia appear two times higher than preeclampsia (57.052pg/ml), pregnant women with preeclampsia have approximately five times higher levels than normal pregnant women (327.330pg/ml).

CONCLUSION

Increased levels of TNF have begun to occur during the high-risk phase and have increased very high during preeclampsia.

Association between tumor necrosis factor-α-308G/A gene polymorphism and susceptibility to pre-eclampsia: An updated meta-analysis

AIMS

Although two meta-analysis have reported no association between the tumor necrosis factor-α (TNF-α)-308G/A polymorphism and susceptibility to pre-eclampsia (PE), recent studies showed the association was still controversial. Thus, we conduct an updated meta-analysis to elucidate this association.

METHODS

Studies related to TNF-α-308G/A and PE risk were retrieved from PubMed, the Web of Science, Embase, Cochrane Library, CNKI, Wanfang, CBM, VIP Database. The odds ratios (OR) and 95% confidence intervals (CIs) were calculated to estimate the association between the TNF-α-308G/A polymorphism and susceptibility to PE under the models of allelic contrast (A vs. G), recessive (AA vs. AG+GG), dominant (AA+AG vs. GG), and co-dominant (AA vs. GG).

RESULTS

22 studies (including 2459 cases and 4246 controls) were included in the meta-analysis. The overall analysis indicated that the significant association between TNF-α-308G/A polymorphism and susceptibility to pre-eclampsia existed in allele model (A vs. G: OR = 1.37, 95%CI: 1.06-1.77), but not in dominant model, recessive model, and co-dominant model. In subgroup analysis by ethnicity, pre-pregnancy BMI and pregnancy parity, the results showed the significant association between TNF-α-308G/A polymorphism and the risk of PE was obvious in Caucasian (A vs. G: OR = 1.36, 95%CI: 1.13-1.64; AA vs. GG: OR = 1.71, 95%CI: 1.03-2.86; AA+AG vs. GG: OR = 1.32, 95%CI: 1.03-1.71), Iranian (A vs. G: OR = 4.28, 95%CI: 2.01-9.11), and primipara (A vs. G: OR = 1.49, 95%CI: 1.15-1.92; AA vs. GG: OR = 2.15, 95%CI: 1.10-4.21).

CONCLUSION

Current evidence demonstrates that carriers of TNF-α (308A) allele would increase the susceptibility to PE, especially among Caucasian, Iranian and primipara.

Combination of Genetic Markers and Age Effectively Facilitates the Identification of People with High Risk of Preeclampsia in the Han Chinese Population

Objective

This study aimed to analyze the possible association between known genetic risks and preeclampsia in a Han Chinese population.

Methods

A total of 156 patients with preeclampsia and 286 healthy Han Chinese women were enrolled and genotyped for 27 genetic alleles associated with preeclampsia in different populations. The association between the genotypes of the individual alleles and preeclampsia and the possible interaction among the alleles were analyzed. Finally logistic models were trained with the genotypes of possible alleles contributing to preeclampsia.

Results

Seven alleles were significantly or marginally significantly associated with preeclampsia, which involved six genes (rs4762 in AGT, rs1800896 in IL-10, rs1800629 and rs1799724 in TNFα, rs2070744 in NOS3, rs7412 in APOE, and rs2549782 in ERAP2). A multilocus interaction analysis further disclosed an interaction among seven alleles. A logistic model showing individual or synergetic contribution to preeclampsia could reach ~0.67 preeclampsia prediction accuracy in the Han Chinese population, while integration of age information could improve the performance to ~0.75 accuracy using a fivefold training-testing evaluation strategy.

Conclusions

The genetic factors were closely associated with preeclampsia in the Han Chinese population despite large ethnicity heterogeneity. The genotypes of different alleles also had synergetic interactions.

Effects of anti-lipid peroxidation of Punica granatum fruit extract in endothelial cells induced by plasma of severe pre-eclamptic patients

Preeclampsia is a pregnancy disorder characterized by hypertension and proteinuria. This disorder involves oxidative stress and changes in endothelial homeostasis. This study was aimed to seek whether an ethanolic extract of Punica granatum fruit inhibits 8-iso-PGFα formation and modulates nitric oxide (NO) in endothelial cells induced by plasma from pre-eclamptic patients. Endothelial cells were cultured from human umbilical vein endothelial cells. At confluence, endothelial cells were divided into five groups, which included endothelial cells exposed to 2% plasma from normal pregnancy (NP), endothelial cells exposed to 2% plasma from pre-eclamptic patients (PP), endothelial cells exposed to PP in the presence of ethanolic extract of P. granatum (PP + PG) at the following three doses: 14; 28; and 56 ppm. Analysis of 8-iso-PGFα was done by immunoassay technique. Analysis of NO level was done by colorimetric technique. Plasma from PP significantly increased 8-iso-PGFα level compared to cells treated by normal pregnancy plasma. This increase in 8-iso-PGFα was significantly (p < 0.05) attenuated by all doses treatments of P. granatum extract. The level of NO was insignificant (p > 0.05) between groups. P. granatum fruit extract protects endothelial cells from oxidative stress induced by plasma from pre-eclamptic patients.

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Endothelial cells induce by preeclamptic plasma.

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8-iso-PGFα level significantly increased.

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NO level insignificantly changed.

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All doses of Theobroma cacao attenuated this 8-iso-PGFα increase.

Association Between Gene Polymorphisms on Chromosome 1 and Susceptibility to Pre-Eclampsia: An Updated Meta-Analysis

Background

This meta-analysis enabled us to obtain a precise estimation of the association between gene polymorphisms on chromosome 1 (MTHFR, AGT, F5, IL-10, LEPR) and the susceptibility to pre-eclampsia (PE) in order to reach a uniform conclusion.

Material/Methods

Web of Science, PubMed, EMBASE, Cochran Library (CENTRAL), and Chinese databases (Chinese National Knowledge Infrastructure-CNKI and Wan Fang) were electronically searched to select relevant studies for this meta-analysis. We selected 95 case-control studies investigating 5 genes (MTHFR, AGT, F5, IL-10, and LEPR) with 8 SNPs. Odds ratios (OR) with their 95% confidence intervals (CI) were used for estimating the association.

Results

A total of 16 646 PE patients and 28 901 normal-pregnancy patients were included in this meta-analysis. The overall results suggested that rs1801133 of MTHFR (OR=1.17, 95% CI: 1.05–1.13) and rs6025 of F5 (OR=1.53, 95%CI: 1.07–2.20) are significantly associated with PE, whereas rs1801131 of MTHFR, rs699 and rs4762 of AGT, rs1800896 and rs1800871 of IL-10, and rs1137101 of LEPR have no significant association with PE. Subgroup analysis by ethnicity revealed that, except for MTHFR rs1801133 and F5 rs6025 in Caucasians, which were significantly associated with an increased risk of PE, none of these SNPs were significantly associated with PE. As suggested by a symmetric funnel plot in conjunction with the Egger’s test, there was no significant publication bias in MTHFR rs1801133 (P=0.318) and rs1801131 (P=0.204), F5 rs6025 (P=0.511), LEPR rs1137101 (P=0.511), AGT rs4762 (P=0.215) and rs699 (P=0.482), IL-10 rs1800871 (P=0.955), and rs1800896 (P=0.144).

Conclusions

This meta-analysis provides evidence that MTHFR rs1801133 and F5 rs6025 are associated with an increased risk of PE, especially in Caucasians. However, we do not have sufficient evidence to conclude there is a significant association between other gene polymorphisms and PE.

Inhibitory Effect of the Punica granatum Fruit Extract on Angiotensin-II Type I Receptor and Thromboxane B2 in Endothelial Cells Induced by Plasma from Preeclamptic Patients

This study aims to evaluate whether the Punica granatum fruit extract modulates the Angiotensin-II Type I receptor (AT1-R) and thromboxane B2 level in endothelial cells induced by plasma from preeclamptic patients. Endothelial cells were obtained from human umbilical vascular endothelial cells. At confluence, endothelial cells were divided into five groups, which included endothelial cells exposed to 2% plasma from normal pregnancy (NP), endothelial cells exposed to 2% plasma from preeclamptic patients (PP), and endothelial cells exposed to PP in the presence of ethanolic extract of Punica granatum (PP + PG) at the following three doses: 14; 28; and 56 ppm. The expression of AT1-R was observed by immunohistochemistry technique, and thromboxane B2 level was done by immunoassay technique. Plasma from PP significantly increased AT1-R expression and thromboxane B2 levels compared to cells treated by normal pregnancy plasma. The increasing of AT1-R expression significantly (P < 0.05) attenuated by high dose treatments of Punica granatum extract. Moreover, the increasing of thromboxane B2 levels significantly (P < 0.05) attenuated by lowest dose treatments of Punica granatum extract. We further concluded that Punica granatum fruit protects and inhibits the sensitivity of endothelial cells to plasma from preeclamptic patients due to inhibition of AT1-R expression (56 ppm) and reduced thromboxane B2 levels (14 ppm).

Increased circulating interleukin-17 levels in preeclampsia

Increasing evidence suggests that an exaggerated maternal systemic inflammatory response and an angiogenic imbalance might play a central role in the pathogenesis of preeclampsia. We determined circulating levels of interleukin-17 (IL-17) along with those of angiogenic factors in healthy nonpregnant and pregnant women and preeclamptic patients, and examined whether serum IL-17 levels of preeclamptic patients were related to their clinical features and angiogenic factor concentrations. Fifty-nine preeclamptic patients, 60 healthy pregnant women and 56 healthy nonpregnant women were involved in this case-control study. Serum levels of IL-17A were measured using a high-sensitivity ELISA. Serum total soluble fms-like tyrosine kinase-1 (sFlt-1) and biologically active placental growth factor (PlGF) levels were determined by electrochemiluminescence immunoassay. For statistical analyses, nonparametric methods were applied. Serum IL-17 levels were significantly higher in preeclamptic patients than in healthy nonpregnant and pregnant women. We did not find any relationship between serum IL-17 concentrations of preeclamptic patients and their clinical features and serum sFlt-1 and PlGF levels or sFlt-1/PlGF ratios. However, elevated serum IL-17 level and sFlt-1/PlGF ratio were found to have an additive effect on the risk of preeclampsia, as shown by the substantially higher odds ratios of a combination of the two than of either alone. In conclusion, serum IL-17 levels are increased in preeclampsia, which may contribute to the development of the excessive systemic inflammatory response characteristic of the maternal syndrome of the disease. In addition, elevated serum IL-17 level and sFlt-1/PlGF ratio had an additive (joint) effect on the risk of preeclampsia.

Decreased circulating anandamide levels in preeclampsia

The endocannabinoid system has a key role in female reproduction, including implantation, decidualization and placentation. A growing number of studies indicate that placental and peripheral blood anandamide levels correlate closely with both spontaneous miscarriage and ectopic pregnancy. Anandamide has also been implicated in blood pressure regulation. In this study, we aimed to determine circulating anandamide levels in preeclampsia for the first time in the literature. Forty-three preeclamptic patients and 71 healthy pregnant women were involved in this case-control study. Serum anandamide concentrations were determined by high-performance liquid chromatography-mass spectrometry technique. Serum total soluble fms-like tyrosine kinase-1 (sFlt-1) and biologically active placental growth factor (PlGF) levels were measured by electrochemiluminescence immunoassay. For statistical analyses, nonparametric methods were applied. Serum levels of anandamide were significantly lower in preeclamptic patients than in healthy pregnant women (0.75 (0.44-1.03) ng ml(-1) vs. 1.30 (0.76-2.0) ng ml(-1), P<0.001). Preeclamptic patients had significantly higher sFlt-1 levels (12,121 (7963-18,316) pg ml(-1) vs. 2299 (1393-3179) pg ml(-1), P<0.001) and significantly lower PlGF concentrations (71.2 (39.2-86.4) pg ml(-1) vs. 256.8 (181.1-421.0) pg ml(-1), P<0.001) as compared with healthy pregnant women. Serum anandamide concentrations did not correlate with serum levels of sFlt-1 and PlGF in our healthy pregnant and preeclamptic groups. In conclusion, we demonstrated for the first time in the literature that serum anandamide concentrations are decreased in women with preeclampsia. However, the cause and consequence of this observation remain to be determined.

Increased serum levels of inflammatory mediators and low frequency of regulatory T cells in the peripheral blood of preeclamptic Mexican women

Regulatory T cells (T_regs; CD4+CD25^highFoxp3+) are critical in maintaining immune tolerance during pregnancy and uterine vascularization. In this study, we show that, in Mexican women with different preeclamptic severity levels, the number of T_regs and the subset of CD4+CD25^highFoxp3+ are decreased compared with those of normotensive pregnant women (NP). Moreover, a systemic inflammatory state is a pivotal feature in the pathogenesis of this disorder and could be related to hypertension and endothelial dysfunction. Likewise, we observed elevated levels of IL-6, TNF-α, and IL-8 in the serum of severe preeclamptic patients (SPE); no differences were found in the IL-1β and IL-10 levels compared with those of NP patients. An analysis of chemokines in the preeclamptic serum samples showed high levels of CXCL10, CCL2, and CXCL9. Our findings suggest that the preeclamptic state is linked with systemic inflammation and reduced numbers of T_regs.

Maternal genotype and severe preeclampsia: a HuGE review

Severe preeclampsia is a common cause of maternal and perinatal morbidity worldwide. The disease clusters in families; however, individual genetic studies have produced inconsistent results. We conducted a review to examine relationships between maternal genotype and severe preeclampsia. We searched the MEDLINE and Embase databases for prospective and retrospective cohort and case-control studies reporting associations between genes and severe preeclampsia. Four reviewers independently undertook study selection, quality assessment, and data extraction. We performed random-effects meta-analyses by genotype and predefined functional gene group (thrombophilic, vasoactive, metabolic, immune, and cell signalling). Fifty-seven studies evaluated 50 genotypes in 5,049 cases and 16,989 controls. Meta-analysis showed a higher risk of severe preeclampsia with coagulation factor V gene (proaccelerin, labile factor) (F5) polymorphism rs6025 (odds ratio = 1.90, 95% confidence interval: 1.42, 2.54; 23 studies, I(2) = 29%), coagulation factor II (thrombin) gene (F2) mutation G20210A (rs1799963) (odds ratio = 2.01, 95% confidence interval: 1.14, 3.55, 9 studies, I(2) = 0%), leptin receptor gene (LEPR) polymorphism rs1137100 (odds ratio = 1.75, 95% confidence interval: 1.15, 2.65; 2 studies, I(2) = 0%), and the thrombophilic gene group (odds ratio = 1.87, 95% confidence interval: 1.43, 2.45, I(2) = 27%). There were no associations with other gene groups. There was moderate heterogeneity between studies and potential for bias from poor-quality genotyping and inconsistent definition of phenotype. Further studies with robust methods should investigate genetic factors that might potentially be used to stratify pregnancies according to risk of complications.

TNF α G308A gene polymorphism has an impact on renal function, microvascular permeability, organ involvement and severity of preeclampsia

BACKGROUND/AIMS

Preeclampsia (PE) is a life-threatening complication of pregnancy that is associated with a high rate of maternal and perinatal morbidity and/or mortality worldwide. If untreated, it can progress to eclampsia, which can result in the death of the mother, the fetus or both. The etiology of PE is still uncertain; however, recently the role of the immune system has gained in importance. The role of tumor necrosis factor-α (TNF-α), a cytokine involved in inflammation processes, has been widely investigated in obstetric disorders. The aims of the present study were to investigate the effect of TNF-α gene G308A (rs1800629) polymorphism on disease risk, renal function, microvascular permeability, endothelial cell dysfunction and organ involvement in women with PE.

METHODS

Initially, 102 3rd-trimester pregnant women (preeclamptic cases and healthy controls) with singleton pregnancy were invited for participation, of which 76 were genotyped for TNF-α G308A polymorphism and evaluated for plasma levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), fibronectin and TNF-α, which were tested for correlations with the profile of PE. The odds ratio (OR) and 95% confidence intervals obtained from unconditional logistic regression were used to test the association between the TNF-α polymorphism and PE risk. For continuous variables, we applied Student's t test and, for categorical variables, the Pearson χ(2) or Fisher's exact test. The two-way ANOVA test with Bonferroni correction was used in multivariate analyses.

RESULTS

The A allele was more frequent in cases than controls (22.4 vs. 13.2%), which increased disease risk (OR = 2.73). Maternal serum levels of TNF-α, sVCAM-1 and fibronectin were significantly increased in cases (855.8 ± 385.1 pg/ml, 1,243 ± 671 ng/ml, 0.308 ± 0.231 g/l, respectively) compared to controls (301.1 ± 156.1 pg/ml, 651 ± 250 ng/ml, 0.218 ± 0.101 g/l, respectively; p < 0.0001, p < 0.0001 and p = 0.031, respectively), and these levels showed an increasing trend with the mutant allele genotype. Moderate and severe proteinuria was higher in rs1800629 allele A subjects compared to G/G carriers (53.8 vs. 14.3% (p < 0.05) and 13.0 vs. 4.7% (p < 0.01), respectively). The adverse effect of rs1800629 allele A on renal function was confirmed by increased plasma creatine levels, urinary protein excretion and lower tubular resorption rate in preeclamptic patients. Moreover, rs1800629 allele A preeclamptic carriers showed higher serum levels of fibronectin and sVCAM-1 compared to G/G homozygotes.

CONCLUSION

This study reveals a possible association between clinical and laboratory manifestations of PE and the TNF-α gene G308A (rs1800629) polymorphism.

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.

Single-nucleotide polymorphisms in genes involved in placental function and unexplained stillbirth

OBJECTIVE

The purpose of this study was to evaluate the association between unexplained stillbirth (SB) and single-nucleotide polymorphisms (SNPs) in genes involved in placental function using a well-characterized cohort.

STUDY DESIGN

Placentas were obtained from 50 unexplained SB and 46 live birth controls. Classification of stillbirth was by Wigglesworth criteria. SBs were stratified by weight: appropriate (AGA-SB) and small for gestational age (SGA-SB, less than the 10th percentile) and gestational age: before 32 and after 32 weeks. Placental DNA was extracted and various SNPs in the endothelial nitric oxide synthase (eNOS), Klotho, hypoxic inducible factor-1α, and and tumor necrosis factor-α genes were evaluated.

RESULTS

None of the SNPs were associated with SB overall. Significantly different genotype distribution emerged for eNOS-SNP rs1800783 when comparing AGA-SB with SGA-SB and control (P = .004). Its allele-A was more frequent in AGA-SB compared with both controls (P = .03) and SGA-SB (P = .001). No differences were seen accordingly to gestational age.

CONCLUSION

Unexplained stillbirth in the setting of adequate growth is associated with carrier of allele A of rs1800783 eNOS gene in the placenta.

Circulating ficolin-2 and ficolin-3 in normal pregnancy and pre-eclampsia

Ficolins are soluble molecules of the innate immune system that recognize carbohydrate molecules on microbial pathogens, apoptotic and necrotic cells. They act through two distinct routes: initiating the lectin pathway of complement activation and mediating a primitive opsonophagocytosis. In this study, we measured plasma levels of ficolin-2 and ficolin-3 in 60 pre-eclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women by enzyme-linked immunosorbent assay (ELISA). Circulating levels of complement activation products (C4d, C3a, SC5b9), angiogenic factors (soluble fms-like tyrosine kinase-1, placental growth factor) and markers of endothelial activation (von Willebrand factor antigen), endothelial injury (fibronectin) and trophoblast debris (cell-free fetal DNA) were also determined. Plasma levels of ficolin-2 were significantly lower in healthy pregnant than in healthy non-pregnant women, while ficolin-3 levels did not differ significantly between the two groups. Furthermore, pre-eclamptic patients had significantly lower ficolin-2 and ficolin-3 concentrations than healthy non-pregnant and pregnant women. In the pre-eclamptic group, plasma ficolin-2 levels showed a significant positive correlation with serum placental growth factor (PlGF) concentrations and significant inverse correlations with serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1), blood urea nitrogen and creatinine, serum lactate dehydrogenase activities, as well as with plasma VWF:antigen, fibronectin and cell-free fetal DNA concentrations. In conclusion, circulating levels of ficolin-2 are decreased in the third trimester of normal pregnancy. There is a further decrease in plasma ficolin-2 concentrations in pre-eclampsia, which might contribute to the development of the maternal syndrome of the disease through impaired removal of the trophoblast-derived material released into the maternal circulation by the hypoxic and oxidatively stressed pre-eclamptic placenta.

Promoter region polymorphisms in the transforming growth factor beta-1 (TGFβ1) gene and serum TGFβ1 concentration in preeclamptic and control Iranian women

Preeclampsia (PE) is a pregnancy associated disorder characterized by hypertension and proteinuria, which causes neonatal and maternal morbidity and mortality. The Th1/Th2 cytokine paradigm of the immune adaptation in pregnancy is now expanded to include Th1/Th2/Th17 and regulatory T (Treg) cells. Among cytokines, TGFβ1 has properties that justify evaluation of its role in PE etiopathology. In this investigation the polymorphisms of the TGFβ1 gene at promoter region, positions -800G→A and -509C→T, were studied in 142 PE and 140 normal pregnant female subjects using PCR-RFLP. Additionally, serum TGFβ1 was determined by ELISA. At position -800G→A genotypes and allele frequencies showed no significant differences between PE patients (GG 73.9%; GA 21.1%; AA 4.93%) and normal control (GG 70%; GA 28.6%; AA 1.4%) women. However the AA genotype at this position was more frequent in PE patients than in the control group. At -509C→T position, genotypes and allele frequencies showed no significant differences between PE patients and control individuals. The CC genotype at -509C→T position was more prevalent in PE patients than in the control group. The mean serum TGFβ1 level was significantly higher (62.14 ng/ml) in PE patients compared with pregnant and non-pregnant control groups (and 47.01 and 40.68 ng/ml, respectively). In conclusion, the promoter region polymorphisms of TGFβ1 may not be associated with PE, but serum levels of this cytokine may contribute to the etiopathology of PE.

Serum leptin levels in relation to circulating cytokines, chemokines, adhesion molecules and angiogenic factors in normal pregnancy and preeclampsia

OBJECTIVE

In this study, we determined circulating levels of C-reactive protein, several cytokines, chemokines, adhesion molecules and angiogenic factors along with those of leptin in healthy non-pregnant and pregnant women and preeclamptic patients, and investigated whether serum leptin levels were related to the clinical characteristics and measured laboratory parameters of the study participants.

METHODS

Sixty preeclamptic patients, 60 healthy pregnant women and 59 healthy non-pregnant women were involved in this case-control study. Levels of leptin and transforming growth factor (TGF)-beta1 in maternal sera were assessed by ELISA. 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, interferon-gamma-inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were determined by multiplex suspension array. Serum C-reactive protein (CRP) concentrations were measured by an autoanalyzer. Serum total soluble fms-like tyrosine kinase-1 (sFlt-1) and biologically active placental growth factor (PlGF) levels were determined by electrochemiluminescence immunoassay. For statistical analyses, non-parametric methods were applied.

RESULTS

There were significant differences in most of the measured laboratory parameters among the three study groups except for serum IL-1beta and TGF-beta1 levels. Serum leptin levels were significantly higher in preeclamptic patients and healthy pregnant women than in healthy non-pregnant women. Additionally, preeclamptic patients had significantly higher leptin levels as compared to healthy pregnant women. Serum leptin levels were independently associated with BMI in healthy non-pregnant women. In healthy pregnant women, both BMI and serum CRP concentrations showed significant positive linear association with leptin levels. There were significant positive correlations between serum leptin concentrations of healthy pregnant women and systolic blood pressure, as well as serum levels of IP-10, while their serum leptin levels correlated inversely with fetal birth weight. In preeclamptic patients, a significant positive correlation was observed between serum concentrations of leptin and IP-10. Furthermore, elevated serum leptin level and sFlt-1/PlGF ratio had an additive (joint) effect in the risk of preeclampsia, as shown by the substantially higher odds ratios of their combination than of either alone.

CONCLUSIONS

Simultaneous measurement of leptin with several inflammatory molecules and angiogenic factors in this study enabled us to investigate their relationship, which can help to understand the role of circulating leptin in normal pregnancy and preeclampsia.

Fibroblast growth factor receptor 4 Gly388 Arg polymorphism is not associated with pre-eclampsia in Turkish women

AIM

The aim of this study was to assess the association between human fibroblast growth factor receptor 4 (FGFR4) Gly(388) Arg polymorphism and pre-eclampsia (PE) by carrying out a case-control study in Turkish women.

MATERIALS AND METHODS

In the present study 159 PE patients and 161 controls were included. DNA was extracted from peripheral blood leukocyte and FGFR4 Gly(388) Arg polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism methods.

RESULTS

For Gly388Arg polymorphism of FGFR4 we found no significant association between controls and PE patients. The frequencies of GlyGly, GlyArg and ArgArg genotypes were 56.6%, 36.4% and 7% for the study group and 50.3%, 44.7% and 5% for the control group, respectively. The risk of women with the GlyArg (odds ratio = 0.7, 95% confidence interval: 0.45-1.14) and ArgArg (odds ratio = 1.2, 95% confidence interval: 0.47-3.22) genotypes for PE did not differ significantly from that of GlyGly genotype carriers.

CONCLUSION

As we could not find any association between genetic variability in Gly(388) Arg of FGFR4 and PE, this specific polymorphism of FGFR4 can be eliminated as a risk factor for PE at least for Turkish women.

ADAMTS13, FVIII, von Willebrand factor, ABO blood group assessment in preeclampsia

INTRODUCTION

Preeclampsia (PE) is a multifactorial disease characterized by high blood pressure and proteinuria after the 20th week of pregnancy. PE is associated with fibrin deposition in placental microcirculation and intrauterine fetal growth retardation. We evaluated FVIII activity, VWF and ADAMTS13 plasma levels, according to O and "non O" blood groups, in women with severe PE (sPE).

METHODS

This case-control study included 140 women; 55 pregnant with sPE, 35 normotensive pregnant and 50 non-pregnant women. VWF and ADAMTS13 antigen levels were assessed by ELISA (American Diagnostica). FVIII activity was measured by automated coagulometric method (Dade Behring) and ABO blood groups phenotyping was performed by indirect technique.

RESULTS

FVIII activity and VWF levels were significantly higher comparing either sPE to normotensive pregnant (P=0.01; P=0.05) and to non-pregnant women (P=0.00 in both cases) or normotensive pregnant and non-pregnant women (P=0.00 in both cases). A significant decrease in ADAMTS13 levels was observed comparing either sPE to normotensive pregnant (P=0.02) and non-pregnant women (P=0.00) or normotensive pregnant and non-pregnant women (P=0.00). FVIII activity and VWF levels were associated to O and "non O" blood groups only in non-pregnant women.

CONCLUSIONS

The increase of FVIII activity and VWF levels and the decrease of ADAMTS13 in sPE are not associated to O and "non O" blood groups. These alterations in hemostatic markers in sPE largely surpass those physiologically determined by ABO blood groups influence and may have masked the effect of O and "non O" groups in this disease. A concomitant analysis of VWF levels and ADAMTS13 activity and antigenic levels will be important to clarify the imbalance between these parameters found in sPE in the present study.

Increased prevalence of peripheral blood granulysin-producing cytotoxic T lymphocytes in preeclampsia

Preeclampsia (PE) 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. Granulysin is a cytolytic and pro-inflammatory molecule expressed by activated human cytotoxic T lymphocytes and natural killer (NK) cells. Recent data show that serum granulysin levels are elevated in preeclampsia. The purpose of this study was to determine whether the proportion of peripheral blood cytotoxic T lymphocytes and NK cells that express intracellular granulysin is altered in PE. Twenty-two preeclamptic patients and 29 healthy pregnant women were involved in this case-control study. Intracellular granulysin expression of lymphocytes was determined with flow cytometric examination. In healthy pregnant women, the majority of NK cells and a small fraction of cytotoxic T cells expressed granulysin in their cytoplasma (median (25-75 percentile): 53.5 (45.6-68.0)% and 13.8 (8.5-23.1)%, respectively). In PE, the percentage of granulysin-positive cytotoxic T lymphocytes was markedly increased, while the proportion of granulysin-producing NK cells was unchanged as compared to healthy pregnant women (for cytotoxic T cells: 34.1 (19.3-45.6)%, p<0.001; for NK cells: 57.2 (42.9-74.9)%, p>0.05). Maternal age of healthy pregnant women showed a significant inverse correlation with the frequency of granulysin-expressing NK cells (Spearman R=-0.44, p<0.05), while their BMI correlated positively with the proportions of granulysin-positive cytotoxic T cells and NK cells (Spearman R=0.43, p<0.05 for both). In conclusion, the majority of circulating NK cells but only a small population of cytotoxic T cells shows intracellular granulysin expression in normal pregnancy. In preeclampsia, the proportion of granulysin-producing cytotoxic T cells in the peripheral blood is markedly increased, which might contribute to the development of the pro-inflammatory Th1-type immune responses characteristics of the maternal syndrome of the disease.

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.

Decreased proportion of peripheral blood vascular endothelial growth factor-expressing T and natural killer cells in preeclampsia

OBJECTIVE

The purpose of this study was to determine the proportion of circulating T and natural killer (NK) cells that express intracellular vascular endothelial growth factor (VEGF) in women with preeclampsia compared to those with a normal pregnancy.

STUDY DESIGN

In all, 24 preeclamptic patients and 30 healthy pregnant women were involved in this case-control study. Intracellular VEGF expression of unstimulated lymphocytes was determined with flow cytometric examination.

RESULTS

In healthy pregnant women, the majority of both T and NK cells expressed VEGF in their cytoplasma (median, 79.9%; 25-75 percentile, 73.7-87.0 and median, 78.3%; 25-75 percentile, 64.1-85.3, respectively). Furthermore, CD4(+) helper and CD8(+) cytotoxic T cells showed a similar pattern of VEGF expression in normal pregnancy. However, the proportion of VEGF-expressing peripheral blood T (both helper and cytotoxic) and NK cells was markedly decreased in preeclampsia (for T cells: median, 51.6%; 25-75 percentile, 40.1-60.0; P < .001; for NK cells: median, 45.2%; 25-75 percentile, 27.4-64.0; P < .001).

CONCLUSION

Our results suggest decreased production of VEGF by circulating T and NK cells in preeclampsia, which might contribute to the development of the generalized endothelial dysfunction characteristic of the maternal syndrome of the disease.

Plasma osteopontin concentrations in preeclampsia - is there an association with endothelial injury?

Abstract Background: It has been previously reported that plasma osteopontin (OPN) concentrations are increased in cardiovascular disorders. The goal of the present study was to determine plasma OPN concentrations in healthy pregnant women and preeclamptic patients, and to investigate their relationship to the clinical characteristics of the study subjects and to markers of inflammation [C-reactive protein (CRP)], endothelial activation [von Willebrand factor antigen (VWF:Ag)] or endothelial injury (fibronectin), oxidative stress [malondialdehyde (MDA)] and trophoblast debris (cell-free fetal DNA).

METHODS

Forty-four patients with preeclampsia and 44 healthy pregnant women matched for age and gestational age were involved in this case-control study. Plasma OPN concentrations were measured with ELISA. Serum CRP concentrations were determined with an autoanalyzer using the manufacturer's reagents. Plasma VWF:Ag was quantified by ELISA, while plasma fibronectin concentrations were measured by nephelometry. Plasma MDA concentrations were estimated by the thiobarbituric acid-based colorimetric assay. The amount of cell-free fetal DNA in maternal plasma was determined by quantitative real-time PCR analysis of the sex-determining region Y (SRY) gene. For statistical analyses, non-parametric methods were applied.

RESULTS

Serum levels of CRP, as well as plasma concentrations of VWF:Ag, fibronectin, MDA and cell-free fetal DNA were significantly higher in preeclamptic patients than in healthy pregnant women. There was no significant difference in plasma OPN concentrations between controls and the preeclamptic group. However, preeclamptic patients with plasma fibronectin concentrations in the upper quartile had significantly higher plasma OPN concentrations than those below the 75th percentile, as well as healthy pregnant women [median (interquartile range): 9.38 (8.10-11.99) vs. 7.54 (6.31-9.40) and 7.40 (6.51-8.80) ng/mL, respectively, p<0.05 for both]. Furthermore, in preeclamptic patients, plasma OPN concentrations showed a significant positive linear association with plasma fibronectin (Spearman R=0.38, standardized regression coefficient (beta)=0.41, p<0.05 for both).

CONCLUSIONS

Plasma OPN concentrations are increased in preeclamptic patients with extensive endothelial injury. However, further studies are warranted to explore the relationship between OPN and endothelial damage. Clin Chem Lab Med 2010;48:181-7.

Lack of association between TNF 238 G/A polymorphism and type 2 diabetes: a meta-analysis

The aim of this meta-analysis was to determine the nature of the association between TNF 238 G/A polymorphism and the risk for T2D. We searched databases updated on January 2009 for all publications on the association between this variation and T2D. Data on genotypes and the numbers of cases and controls were assessed using Review Manager 4.2. Meta-analysis of the overall and specific populations was conducted, and odds ratios (OR) and 95% confidence intervals (95% CI) were calculated in the fixed-effect model. I(2) statistic was calculated to examine heterogeneity, and publication bias was evaluated by Egger test. The overall OR (95% CI) for AA and GA genotypes versus GG genotype for TNF-alpha-238 was 1.15 (0.92-1.44), which in European and Asian populations were 1.18 (0.92-1.51) and 1.13 (0.62-2.04), respectively. This first meta-analysis of data from the current and published studies did not detect any association between the polymorphism of TNF 238 G/A and risk for T2D.

A novel exonic variant (221delT) in the LGALS13 gene encoding placental protein 13 (PP13) is associated with preterm labour in a low risk population

Predicting adverse pregnancy outcome in low risk patients in a community with poor socio-economic circumstances is difficult, yet about 5% of these pregnancies will result in preterm labour or severe pre-eclampsia. In this study we aimed to identify markers in pro- and anti-inflammatory genes that may contribute to disease and possibly disease prediction in a low risk community setting. A prospective study was undertaken on 450 consecutive low risk primigravid patients. Blood obtained at first booking was screened for known immunological gene variants (IL4 -590, IL1B +3953, IL1RN, IL10 -1082; -819; -592 and TNFA -308; -238; +488) as well as for novel variants in the LGALS13 gene coding for placental protein 13 (PP13). The incidence of preterm labour and pre-eclampsia was 7.1% and 6.8% respectively. A novel exonic variant (221delT) in the LGALS13 gene increased the risk for preterm labour in the total study group (relative risk RR 2.27). Maternal carriage of the interleukin-1 RN*2 allele was associated with an increased risk of hypertension in pregnancy in the Coloured subgroup of the study cohort (RR 2.53). There was an increased risk for preterm labour in the same subgroup with carriage of the TNFA -308 A-allele (TNF2) (RR 2.53). No significance was found for the other variants examined. We conclude that single nucleotide polymorphisms (SNPs) in certain genes regulating implantation and inflammation may contribute to the complex etiology of pre-eclampsia and preterm labour. The association between the 221delT deletion and adverse pregnancy outcome needs to be confirmed in different populations.

Tumour necrosis factor (-308A) polymorphism in pre-eclampsia: meta-analysis of 16 case-control studies

BACKGROUND

The guanine to adenine transition at position -308 nucleotides in the tumour necrosis factor promoter region (TNF -308A) is a putative genetic risk factor for pre-eclampsia/eclampsia (PE/E). However, association studies have reported conflicting findings and have generally been underpowered to exclude modest effect sizes.

AIM

To assess and synthesise the available evidence for the association of the TNF (-308A) polymorphism with PE/E.

METHODS

Systematic review and random effects meta-analysis of genetic association studies.

RESULTS

Sixteen eligible case-control studies in which a total of 1919 patients with PE/E and 2374 controls participated were identified. The studies were generally small but of reasonable methodological quality. Random effects meta-analysis improved the precision of the estimate of effect size but did not detect a statistically significant association: pooled relative risk 1.02 (95% confidence interval 0.86 to 1.20).

CONCLUSIONS

The available data are not consistent with more than a very modest association between the TNF (-308A) allele and PE/E. Screening pregnant women for this allele in order to guide antenatal surveillance or treatment is unwarranted. Future research efforts should focus on alternative candidate genes.

Human tumour necrosis factor: physiological and pathological roles in placenta and endometrium

The cytokine tumour necrosis factor alpha (TNF) is a well known member of the TNF superfamily consisting of at least 18 ligands and 29 different receptors involved in numerous cellular processes. TNF signals through two distinct receptors TNFR1 and TNFR2 thereby controlling expression of cytokines, immune receptors, proteases, growth factors and cell cycle genes which in turn regulate inflammation, survival, apoptosis, cell migration, proliferation and differentiation. Since expression of TNF was discovered in amnion and placenta many studies demonstrated the presence of the cytokine and its receptors in the diverse human reproductive tissues. Whereas TNF has been implicated in ovulation, corpus luteum formation and luteolysis, this review focuses on the functions of TNF in human placental, endometrial and decidual cell types of normal tissues and also discusses its role in endometrial and gestational diseases. Physiological levels of the cytokine could be important for balancing cell fusion and apoptotic shedding of villous trophoblasts and to limit trophoblast invasion into maternal decidua. Regulation of the TNF/TNFR system by steroid hormones also suggests a role in uterine function including menstrual cycle-dependent destruction and regeneration of endometrial tissue. Aberrant levels of TNF, however, are associated with diverse reproductive diseases such as amniotic infections, recurrent spontaneous abortions, preeclampsia, preterm labour or endometriosis. Hence, concentrations, receptor distribution and length of stimulation determine whether TNF has beneficial or adverse effects on female reproduction and pregnancy.