Association of the TNF2 Allele with Eclampsia

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.

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.

CD14 Receptor Gene Promoter Polymorphism: Awakening Maternal Immunity during Pregnancy

We investigated whether monocyte CD14 receptor gene promoter polymorphisms were associated with the development and severity of pre-eclampsia. We genotyped the CD14-260 C/T polymorphism in 36 preeclamptic patients and 52 healthy pregnant controls. A total of 30.6% and 69.4% of pre-eclamptic patients had the C and T alleles, respectively, and 48.0% and 52.0% of the controls, respectively. More pre-eclamptic patients were TT homozygotes compared with controls (50.0% versus 13.5%). In pre-eclamptic patients, the TT homozygotes exhibited a significantly higher mean systolic blood pressure compared with the non-TT homozygotes (173 ± 28 mmHg versus 153 ± 22 mmHg). We also noted a tendency towards increased proteinuria and placental abruption in the TT homozygotes compared with the non-TT homozygotes. We conclude that CD14 gene promoter polymorphisms appear to be a risk factor for pre-eclampsia. With further research, these findings might form the basis of a prognostic tool for pre-eclampsia.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Maternal 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.

The implication of aberrant GM-CSF expression in decidual cells in the pathogenesis of preeclampsia

Preeclampsia is characterized by an exaggerated systemic inflammatory state as well as shallow placentation. In the decidual implantation site, preeclampsia is accompanied by an excessive number of both macrophages and dendritic cells as well as their recruiting chemokines, which have been implicated in the impairment of endovascular trophoblast invasion. Granulocyte-macrophage colony-stimulating factor is known to regulate the differentiation of both macrophages and dendritic cells, prompting both in vivo and in vitro evaluation of granulocyte-macrophage colony-stimulating factor expression in human decidua as well as in a mouse model of preeclampsia. This study revealed increased granulocyte-macrophage colony-stimulating factor expression levels in preeclamptic decidua. Moreover, both tumor necrosis factor-α and interleukin-1 β, cytokines that are implicated in the genesis of preeclampsia, markedly up-regulated granulocyte-macrophage colony-stimulating factor production in cultured first-trimester human decidual cells. The conditioned media of these cultures promoted the differentiation of both macrophages and dendritic cells from a monocyte precursor. Evaluation of a murine model of preeclampsia revealed that the decidua of affected animals displayed higher levels of immunoreactive granulocyte-macrophage colony-stimulating factor as well as increased numbers of both macrophages and dendritic cells when compared to control animals. Because granulocyte-macrophage colony-stimulating factor is a potent inducer of differentiation and activation of both macrophages and dendritic cells, these findings suggest that this factor plays a crucial role in the pathogenesis of preeclampsia.

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.

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

PROBLEM

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

METHOD OF STUDY

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

RESULTS

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

CONCLUSION

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

Genes and the preeclampsia syndrome

Preeclampsia is specific to pregnancy and is still a leading cause of maternal and perinatal mortality and morbidity, affecting about 3% of women, but the underlying pathogenetic mechanisms still remain unclear. Immune maladaptation, placental ischemia and increased oxidative stress represent the main components discussed to be of etiologic importance, and they all may have genetic implications. Since the familial nature of preeclampsia is known for many years, extensive research on the genetic contribution to the pathogenesis of this severe pregnancy disorder has been performed. In this review, we will overview the linkage and candidate gene studies carried out so far as well as summarize important historical notes on the genetic hypotheses generated in preeclampsia research. Moreover, the influence of maternal and fetal genes and their interaction as well as the role of genomic imprinting in preeclampsia will be discussed.

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

BACKGROUND

Preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome are multifactorial disorders with genetic and environmental components. Given that the tumor necrosis factor (TNF)-alpha G-308A single nucleotide polymorphism (SNP) affects TNF-alpha gene transcription and that preeclampsia and HELLP syndrome are characterized by a shift towards a Th1-type maternal immune response with increased TNF-alpha production, the aim of the current study was to investigate whether this SNP is associated with preeclampsia and HELLP syndrome in a Caucasian population from Hungary. Additionally, we aimed to examine whether TNF-alpha G-308A polymorphism can influence the risk for fetal growth restriction in preeclamptic patients, which issue none of the earlier studies dealt with.

METHODS

In a case-control study, we analyzed blood samples from 140 preeclamptic patients, 69 patients with HELLP syndrome and 144 normotensive, healthy pregnant women using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. We performed also a meta-analysis with our results and those of 8 previously published studies.

RESULTS

There were no significant differences in the genotype and allele frequencies of the TNF-alpha G-308A polymorphism between preeclamptic patients and normotensive, healthy pregnant women. However, the mutant (TNF2 or A) allele occurred significantly more frequently in preeclamptic patients with IUGR than in those without IUGR (18.5% versus 7.1%, p=0.003). In addition, the frequency of the mutant allele carriers was significantly higher among preeclamptic patients with IUGR compared to those without IUGR (30.6% versus 12.8%, p=0.010). The mutant allele carriers were found to have an increased risk of severe IUGR-complicated preeclampsia, which was independent of maternal age, prepregnancy BMI and primiparity (odds ratio (OR): 2.89, 95% confidence interval (CI): 1.16-7.22, p=0.023; adjusted OR: 2.78, 95% CI: 1.04-7.45, p=0.042). Nevertheless, no significant differences were detected in the genotype and allele frequencies of the TNF-alpha G-308A polymorphism between patients with HELLP syndrome and control subjects. In the meta-analysis, no association was observed between this SNP and preeclampsia (summary OR: 0.956, 95% CI: 0.693-1.319).

CONCLUSIONS

Although the meta-analysis demonstrated a lack of an overall association between TNF-alpha G-308A polymorphism and preeclampsia, our results suggest a role of this SNP in the risk of severe IUGR-complicated preeclampsia. However, further studies are required with a larger sample size to confirm our findings.

Genetic association of preeclampsia to the inflammatory response gene SEPS1

OBJECTIVE

The objective of the study was to test for a genetic association between the G-105A promoter polymorphism of the inflammatory mediator Selenoprotein S (SEPS1) and preeclampsia.

STUDY DESIGN

A retrospective study in a large Norwegian case-control cohort compared maternal genotype and allele frequencies of the SEPS1 g.-105G>A polymorphism genotyped by SNPlex assay in preeclamptic (n = 1139) and control (n = 2269) women. Statistical significance was determined by chi2 and multivariate regression analyses.

RESULTS

Women with preeclampsia were 1.34 times more likely to have the GA or AA genotype (P = .0039; 95% confidence interval [CI] 1.09 to 1.64) and 1.22 times more likely to carry the A allele (P = .023; odds ratio, 1.22; 95% CI, 1.02 to 1.46).

CONCLUSION

The A allele of the SEPS1-105G>A polymorphism is a significant risk factor for preeclampsia in this population.

The -56T HLA-G promoter polymorphism is not associated with pre-eclampsia/eclampsia in Australian and New Zealand women

OBJECTIVE

Decreased HLA-G expression has been linked to a number of pregnancy disorders, including preeclampsia, and a genetic basis for HLA-G regulation has yet to be found. The aim of this study was to determine whether a C-to-T base substitution 56 base pairs (bp) upstream from the HLA-G transcription start site is associated with preeclampsia.

METHODS

277 nulliparous women consisting of 113 normotensive, 118 preeclamptic, and 46 eclamptic patients were typed for the -56T polymorphism using restriction fragment length polymorphism and allelic discrimination analysis.

RESULTS

-56T allele frequencies for eclamptic, preeclamptic, and normotensive women were 0.053, 0.030, and 0.035, respectively. A chi2 test indicated that there was no significant association with the polymorphism in preeclamptic or eclamptic women with p > 0.05.

CONCLUSION

The -56T HLA-G polymorphism is not associated with preeclampsia or eclampsia in our population.

Cytokine genotyping in preeclampsia

PROBLEM

Considering that cytokines are involved in preeclampsia (PE) pathogenesis and that cytokine gene polymorphism may affect cytokine production, our purpose was to investigate the association of PE with tumor necrosis factor (TNF)-alpha (-308), transforming growth factor-beta1 (+10; 25), interleukin (IL)-10 (-1082), IL-6 (-174), and interferon-gamma (+874) polymorphisms.

METHOD OF STUDY

Genotyping was performed in women with PE (56 White and 95 non-White women) and in women without obstetric pathology (92 White and 97 non-White women). Data were analyzed by the chi-square or Fisher exact test. We performed a meta-analysis encompassing these and results from other laboratories on the association of TNF-alpha polymorphisms and PE.

RESULTS

We observed a lower frequency of the IL-10 -1082-G/G genotype in White women with PE (PE: 5%; Control (C): 15%, P = 0.02) and no association for all other polymorphisms, including meta-analysis of TNF-alpha results.

CONCLUSION

Our study suggests that PE is associated with IL-10-(1082) polymorphism but not with TNF-(308) polymorphism. On the basis of meta-analysis, we confirm the need for more studies for the evaluation of cytokine genotype in disease.

Detection of CAG repeats in pre-eclampsia/eclampsia using the repeat expansion detection method

Pre-eclampsia/eclampsia is a serious disorder of human pregnancy that has a worldwide incidence of 2-10% and carries a severe morbidity and mortality risk for both mother and child. Its precise cause remains unknown. However, there is increasing evidence of an underlying complex maternal genetic susceptibility. Its high population incidence in the face of strong negative selection pressure suggests that the gene(s) involved have a selective advantage and/or a high mutation rate. One class of genetic diseases that involve a high mutation rate are the trinucleotide repeat expansion diseases. Thus, the aim of this study was to determine whether there is an association between a trinucleotide (CAG) repeat expansion and pre-eclampsia/eclampsia. We have used the repeat expansion detection (RED) method, which was developed to directly identify clinically significant repeat expansions, to analyse genomic DNA from an Australian and New Zealand population. The maximal CAG repeat length for each individual was recorded and the Mann-Whitney U and Wilcoxon rank sum test for independent samples were used to compare distributions for CAG/CTG repeats between two populations. There were no statistically significant differences between the distribution of CAG repeats in normotensive (n = 59) and severe pre-eclampsia (n = 69) (Mann-Whitney U = 1732; P = 0.14), and normotensive (n = 59) and eclamptic (n = 15) populations (Mann-Whitney U = 417, P = 0.726). Therefore, these RED results do not support a role for a large CAG expansion in pre-eclampsia/eclampsia. However, these data do not preclude the possibility that a small CAG expansion is associated with the disorder nor do they negate the hypothesis that a highly mutable gene contributes to the genetic component of pre-eclampsia/eclampsia.