Association of interleukin-6 gene promoter polymorphism with coronary artery disease in Pakistani families

Genetic Polymorphism in miRNA Genes and Their Association with susceptibility of Coronary Heart Disease: anAn Updated Rreview

Coronary heart disease (CHD) remains a major public health concern worldwide, with a complex interplay of genetic, environmental and lifestyle factors contributing to its pathogenesis. The potential significance of microRNAs (miRNAs) in the onset and progression of CHD has attracted increasing attention in recent years. Small non-coding RNA molecules called miRNAs control gene expression at the post-transcriptional level. Dysregulation of miRNAs has been linked to a variety of biological processes, including cell division, proliferation, apoptosis, and inflammation. Numerous research studies have looked into the relationship between genetic variants in miRNA genes and CHD susceptibility. This review highlights the recent research work carried out to identify the relationship of miRNA genes polymorphism with the progression and susceptibility of CHD. Such studies could pave the way for the development of personalized strategies for CHD prevention and treatment based on an individual's genetic profile.

Serum concentrations of IL-16 and its genetic polymorphism rs4778889 affect the susceptibility and severity of endometriosis in Nigerian women

BACKGROUND

Endometriosis is the presence of active ectopic endometrial glands and stroma at other sites outside the uterine cavity. It is a common cause of chronic pelvic pain which is sometimes debilitating, and inflammation is one of the known triggers of endometriosis. Interleukins 6 and 16 (IL-6 and IL-16) are proinflammatory cytokines which play essential roles in inflammatory diseases. We therefore investigated the relationship between genetic polymorphisms of interleukins 6 and 16, and the development of endometriosis in Nigerian women.

METHOD

One hundred and thirty (130) consenting women were consecutively enrolled, sixty-five (65) of whom had endometriosis and 65 age-matched women as reference group, surgically confirmed as not having endometriosis. Spectrophotometric determination of serum concentrations of Interleukins 6 and 16 was carried out and the genotyping of IL-6 (rs1800795) and IL-16 (rs4778889, rs11556218, rs4072111) genes were performed using TaqMan assays.

RESULTS

Serum IL-16 concentration was significantly higher in women with severe chronic pelvic pain compared to those with mild pain (p = 0.023). The C allele of rs4778889 was associated with endometriosis (OR: 1.80, 95% CI: 1.08 - 3.02, p = 0.024).

CONCLUSION

Serum IL-16 and IL-16 rs4778889 may be important markers for endometriosis in Nigerian, and by extension, African women. Multicentre African studies would clarify this.

The Role of Plasma Interleukin-6 Levels on Atherosclerotic Cardiovascular Disease and Cardiovascular Mortality Risk Scores in Javanese Patients with Chronic Kidney Disease

Interleukin-6 (IL-6) has been identified as an important pro-inflammatory factor involved in mediating the severity of chronic kidney disease (CKD). This study sought to determine the effect of plasma IL-6 levels on atherosclerotic cardiovascular disease (ASCVD) and cardiovascular mortality risk scores in Javanese CKD patients. We also analyzed the frequency of IL-6 G174C single nucleotide polymorphism (SNP) in the population. This study was a cross-sectional study involving seventy-three patients of Javanese ethnic origin with stable chronic kidney disease. We assessed the ASCVD risk score, cardiovascular mortality score, genotyping of IL-6 G174C SNP, and plasma IL-6 levels in these patients. The genotype distribution and allele frequencies of the IL-6 G174C SNP were predominated by the G genotype/allele (GG: 97.26%, GC: 1.37%, CC: 1.37%, G-allele: 97.95%, and C-allele: 2.05%). Despite the fact that plasma IL-6 levels did not directly affect cardiovascular mortality risk, further analysis revealed its direct effect on the ASCVD risk score (path coefficient = 0.184, p = 0.043, 95% CI = 0.018−0.380), which in turn affected cardiovascular mortality risk (path coefficient = 0.851, p = <0.01, 95% CI = 0.714−0.925). In conclusion, plasma IL-6 levels play important roles on ASCVD risk and cardiovascular mortality risk in Javanese patients with CKD.

Premature Coronary Artery Disease and Plasma Levels of Interleukins; a Systematic Scoping Review and Meta-Analysis

Introduction

Interleukins (ILs) can act as a predictive indicator of Premature Coronary Artery Disease (pCAD) and may be useful in screening of high-risk patients. However, there is no consensus on the relationship of serum levels of ILs and pCAD, yet. As a result, this study has been conducted in order to review the literature on the relationship between serum levels of different ILs and pCAD.

Methods

Medline, Scopus, Embase, and Web of Science databases were searched until December 7^th 2020. Two reviewers independently screened and summarized eligible articles. A meta-analysis was performed to assess the relationship of ILs and pCAD.

Results

12 case-control articles were included. IL-6 plasma changes do happen in pCAD patients with a standardized mean difference (SMD) of 0.51 (95% CI: 0.12-0.90; p=0.010) compared with the control group. This difference was also observed when evaluating the plasma levels of IL-1 and IL-17, with an SMD of 1.42 (95% CI: 1.11-1.73; p<0.001) and 0.59 (95% CI: 0.14-1.04; p=0.011), respectively. Meanwhile, no significant difference existed in plasma levels of IL-10 (SMD=0.26; 95% CI: -0.17-0.70; p=0.236), and IL-18 (SMD=1.44; 95% CI: -0.19-3.07; p=0.083) between pCAD patients and those in the control group.

Conclusion

Low level of evidence showed that there may be a significant relationship between increased plasma levels of ILs and the occurrence of pCAD. As a result, prospective cohort studies with serial assessments of serum ILs during follow up period, focusing on controlling classical risk factors of pCAD and increase in level of ILs, should be conducted.

Association of three single nucleotide polymorphisms in interleukin 6 gene with risk of chronic obstructive pulmonary disease

BACKGROUNDS

Experimental studies have implicated the involvement of interleukin 6 (IL6) in chronic obstructive pulmonary disease (COPD), supporting the possible association between genetic alterations in IL6 gene and risk of COPD.

OBJECTIVES

We aimed to examine the association of three polymorphisms in IL6 gene with COPD by integrating the summary results of available reports, and summarize the changes circulating IL6 concentrations across genotypes.

METHODS

Two investigators independently searched medical literature, selected qualified publications, assessed study quality, and abstracted detailed information. STATA software v14.1 was applied for statistical analyses.

RESULTS

Ten articles, including 18 independent studies and 4 815 participants, were comprehensively pooled. When all studies were analyzed together, the association with COPD was not significant for rs1800795 and rs1800797, yet statistical significance was attained for rs1818879 (P < 0.05) across four genetic modes of inheritance. When analyses were restricted to preset subgroups, race, matched condition, and COPD diagnosis were identified as the factors attributed to heterogeneity between studies. Moreover, changes in circulating IL6 concentrations remained nonsignificant across the genotypes of rs1800795 and rs1818879 (P > 0.05). Funnel plots and related tests revealed a low likelihood of publication bias for three studied polymorphisms (P > 0.1).

CONCLUSIONS

Our findings indicated that IL6 gene rs1818879 might be a COPD-susceptibility locus. Further validations in longitudinal studies are necessary.

Association of interleukin 6 -174 G/C polymorphism with coronary artery disease and circulating IL-6 levels: a systematic review and meta-analysis

INTRODUCTION

Circulating IL-6 levels and at least one polymorphic form of IL6 gene (IL6 -174 G/C, rs1800795) have been shown to be independently associated with coronary artery disease (CAD) by several investigators. Despite more than 12 published meta-analyses on this subject, association of -174 G/C with CAD, especially amongst distinct ancestral population groups remain unclear. We, therefore, conducted a systematic review and an updated meta-analysis to comprehensively ascertain the association of IL6 -174 G/C with CAD and circulating IL-6 levels.

MATERIALS AND METHODS

Relevant case-control/cohort studies investigating association of -174 G/C with CAD and circulating IL-6 levels were identified following a comprehensive online search. Association status for CAD was determined for the pooled sample, as well as separately for major ancestral subgroups. Association status for circulating IL-6 levels was assessed for the pooled sample, as well as separately for CAD cases and CAD free controls. Study-level odds ratios (OR) and 95% confidence intervals (CI) were pooled using random/fixed-effects model.

RESULTS

Quantitative synthesis for the CAD endpoint was performed using 55 separate qualifying studies with a collective sample size of 51,213 (19,160 cases/32,053 controls). Pooled association of -174 G/C with CAD was found to be statistically significant through dominant (OR 1.15; 95% CI 1.05-1.25, p = 0.002) as well as allelic genetic model comparisons (OR 1.13, 95% CI 1.06-1.21, p = 0.0003). This effect was largely driven by Asian and Asian Indian ancestral subgroups, which also showed significant association with CAD in both genetic model comparisons (OR range 1.29-1.53, p value range ≤ 0.02). Other ancestral subgroups failed to show any meaningful association. Circulating IL-6 levels were found to be significantly higher amongst the 'C' allele carriers in the pooled sample (Standard mean difference, SMD 0.11, 95% CI 0.01-0.22 pg/ml, p = 0.009) as well as in the CAD free control subgroup (SMD 0.10, 95% CI 0.02-0.17 pg/ml, p = 0.009), though not in the CAD case subgroup (SMD 0.17, 95% CI = - 0.02 to 0.37, p = 0.12).

CONCLUSIONS

The present systematic review and meta-analysis demonstrate an overall association between IL6 -174 G/C polymorphism and CAD, which seems to be mainly driven by Asian and Asian Indian ancestral subgroups. Upregulation of plasma IL-6 levels in the 'C' allele carriers seems to be at least partly responsible for this observed association. This warrants further investigations with large, structured case-control studies especially amongst Asian and Asian Indian ancestral groups.

Multi-biomarker responses to pesticides in an agricultural population from Central Brazil

We evaluated farmworkers exposed to pesticides and individuals with no history of occupational exposure to pesticides. It was performed the comet assay to evaluate DNA damage. The immunophenotyping of TCD4⁺ lymphocyte subpopulations in peripheral blood was performed by flow cytometry. The single nucleotide polymorphisms (SNPs) in PON1, XRCC1, IL6, IL6R, TNF-α, and MIR137 genes were evaluated by real-time PCR. The exposed group was composed mostly by males (69.44%), with direct exposure to pesticides (56%) and with an average age range of 46 ± 13.89 years, being that 58.3% of farmworkers directly exposed to pesticides and reported the full use of personal protective equipment (PPE). DNA damage was greater in the exposed group (p < 0.05), reinforced by the use of PPE to denote a lower degree of DNA damage (p = 0.002). In this context, in the exposed group, we demonstrated that the use of PPE, age, gender and intoxication events were the variables that most contributed to increase DNA damage (p < 0.0001). Besides, the exposed group showed a significant increase in the subpopulations of T lymphocytes CD3⁺CD4⁺ (p < 0.05) and CD3⁺CD4⁺CD25⁺ (p < 0.0001) and a significant decrease in CD3⁺CD4⁺CD25^-FOXP3⁺ (p < 0.05). SNPs in the TNF-α (rs361525) gene presented a difference in the genotype distribution between the groups (p = 0.002). The genotype distribution of TNF-α (rs361525) was also positively correlated with the DNA damage of the exposed group (r = 0.19; p = 0.01), demonstrating a higher risk of DNA damage in the farmworkers presenting the A mutated allele. Our findings demonstrate that pesticides can exert various deleterious effects on human health by damaging the DNA as well as by influencing the immune system in the case of both direct or indirect exposure and these issues are associated to age, gender, intoxication and the nonuse of PPE.

The effect of polymorphisms (174G> C and 572C> G) on the Interleukin-6 gene in coronary artery disease: a systematic review and meta-analysis

Background

Coronary Artery Disease (CAD) is caused by the blockage of the coronary arteries. it is argued that there has an association between the Interleukin-6 gene and the occurrence of atherosclerosis, coronary artery disease, Due to the short half-life and high variability of Interleukin-6 (IL-6), limited studies have been performed on the association of serum levels of interleukin-6 with coronary artery disease. The aim of this study is to investigate the relationship between IL-6 gene polymorphisms and coronary artery disease.

Methods

This study was conducted as a meta-analysis of selected articles with no lower time limit and upto March 2020. Articles related to the subject were obtained by searching several data sources,such as the SID, IranDoc, Scopus, Embase, Web of Science (ISI), PubMed, Science Direct, and Google Scholar databases. The heterogeneity of the studies was assessed using the I² index in the Comprehensive Meta-Analysis software.

Results

The GG genotype of the IL-6174 G> C polymorphism with a 0.8 odds ratio tended to reduce the risk of CAD by 20%. The odds ratio of CAD in CG and GG genotypes were found to be 1.16 and 1.48 times respectively, indicating the increasing effect of these two genotypes. In the IL-6-572 C>G polymorphism, CG and GG genotypes increased the risk of CAD by 1.21 and 1.27 times respectively, and the CC genotype tended to reduce the risk of CAD by 15%, considering the odds ratio of 0.85.

Conclusion

This study showed a relationship between IL-6174G> C and Interleukin-6 (IL-6) 572 C>G genes and coronary artery disease. Moreover, the protective effects of GG genotype in IL-6 gene 174 G> C and CC genotype in IL-6 gene 572 C>G gene were reported. The study also confirmed that the CG and CC genotypes of the G>C IL-6174 gene have an increasing effect on coronary artery disease. Moreover, CG and GG genotypes in the IL-6 gene 572 C>G increased the risk of developing CAD. It should be noted that the increased risk of developing CAD was limited to meta-analytic studies in reported literatures.

Systematic review and meta-analysis of association of polymorphisms in inflammatory cytokine genes with coronary artery disease

BACKGROUND

It has comprehensively been acknowledged that a genetic contribution, especially in immune inflammatory players, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, are critically involved in the pathophysiology of coronary artery disease (CAD). This meta-analysis study aimed to reach a conclusive understanding of the role of genetic polymorphisms, including IL6 gene C572G (rs1800796) and G174C (rs1800795) as well as TNFA gene G238A (rs361525) and G308A (rs1800629) in susceptibility to CAD.

METHODS

Two major databases, namely MEDLINE and Scopus, were searched to find the studies surveying the mentioned polymorphisms and CAD susceptibility up to July 2020. Association comparison between the polymorphisms and CAD susceptibility were assessed using pooled odds ratio (OR) and their corresponding 95% confidence interval (CI).

RESULTS

This meta-analysis study was conducted on 69 papers (73 population studies), comprising 5062 patients and 8446 controls for IL6 gene rs1800796 (17 studies), 13801 patients and 16215 controls for IL6 gene rs1800795 (38 studies), 1439 patients and 2850 controls for TNFA gene rs361525 (5 studies), and 5051 patients and 3958 controls for TNFA gene rs1800629 (13 studies), according to inclusion and exclusion criteria. There were statistically positive association between all genetic comparisons of IL6 gene rs1800795 polymorphism and the CAD risk. Moreover, the recessive model (CC vs. CG + GG) in IL6 gene rs1800796 polymorphism had marginally significant association with decreased risk of CAD. None of the TNFA gene polymorphisms were associated with CAD risk.

CONCLUSIONS

The meta-analysis revealed the positive association of IL6 gene rs1800795 polymorphism in susceptibility to CAD.

The IL-6 rs1800795 and rs1800796 polymorphisms are associated with coronary artery disease risk

Studies examining the associations between the interleukin‐6 (IL‐6) rs1800795 and rs1800796 gene polymorphisms and risk of coronary artery disease (CAD) remain controversial. Our aim was to evaluate the accurately determine role of these two polymorphisms in CAD risk. PubMed, Embase, VIP, Wan fang and China National Knowledge Infrastructure databases were searched. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The trial sequential analysis (TSA) was conducted, and bioinformatics tools were employed. A total of thirty‐seven articles were obtained. For the IL‐6 rs1800795 polymorphism, 9411 CAD patients and 3161 controls were included, 4720 patients with CAD, and 5000 controls were included for the IL‐6 rs1800796 polymorphism. In the pooled analysis, significant associations were only observed for the rs1800796 polymorphism (allelic: OR [95%CI] = 1.28 [1.13, 1.44], dominant: OR [95%CI] = 1.35 [1.17, 1.57], recessive: OR [95%CI] = 1.35 [1.18, 1.55], heterozygote: OR [95%CI] = 1.26 [1.15, 1.37], homozygote: OR [95%CI] = 1.62 [1.23, 2.13]). Significant associations were detected in the Asian and Mongoloid populations and ‘more than 500’ subgroup for the rs1800795 polymorphism. TSA confirmed the true‐positive results for the rs1800796 polymorphism. The bioinformatics analysis showed that the two polymorphisms played important roles in the gene transcription. The IL‐6 rs1800796 polymorphism is associated with an increased susceptibility to CAD and is a risk factor for CAD. The IL‐6 rs1800795 polymorphism is associated with an increased risk of CAD in Asians, particularly in Chinese, and a decreased risk of CAD in an African population is remarkably observed.

Interleukin 6 (rs1800795) gene polymorphism is associated with cardiovascular diseases: a meta-analysis of 74 studies with 86,229 subjects

Cardiovascular diseases (CVD) are group of complex and multifactorial pathologies, in which interleukin-6 (IL-6) gene polymorphisms have been associated with several components of the CVD. Thus, in this study, we thoroughly reviewed and meta-analyzed evidence on the association between the IL-6 (rs1800795) gene polymorphism and CVD. We systematically searched in the PubMed, Web of Sciences, and Scopus databases. The analyses were performed using five study groups based on (1) a combined pool of the overall populations, (2) the country of birth, (3) the continent of birth, (4) the diagnosis and (5) both location (country or continent) and diagnosis. The analysis included the allelic, homozygote, heterozygote, dominant and recessive models. The meta-analysis showed that -174G>C (rs1800795) is a risk factor for CVD (allelic: OR=1.06, CI 95%=1.02-1.10. Z p value <0.0001; homozygous: OR=1.11, CI 95%=1.03-1.19, Z p value= 0.002; heterozygous: OR=1.08, CI 95%=1.03-1.21, Z p value= 0.003; dominant: OR= 1.12, CI 95%= 1.07-1.18, Z p value= 0.001) and that this risk increases in the Chinese population. Additionally, we found that carriers of the C allele of 174G>C (rs1800795) polymorphism have an increase in the risk of coronary artery disease under the hereditary models assessed in the study. Using robust data, we found that IL-6 (rs1800795) -174G>C gene polymorphism is associated with CVD risk.

Association of Chlamydia trachomatis, C. pneumoniae, and IL-6 and IL-8 Gene Alterations With Heart Diseases

Atherosclerosis is a progressive disease characterized by chronic inflammation of the arterial walls, associated with genetic and infectious factors. The present study investigated the involvement of Chlamydia trachomatis and Chlamydia pneumoniae infections and immunological markers (C-reactive protein, CRP, TNF-α, IL-6, IL-8, and IL-10) in the process of atherosclerosis. The evaluation included 159 patients for surgical revascularization (CAD) and 71 patients for surgical heart valve disease (HVD) at three hospitals in Belém, Brazil. The control group (CG) comprised 300 healthy individuals. Blood samples collected before surgery were used for antibodies detection (enzyme immunoassay), CRP (immunoturbidimetry) and IL-6 levels (enzyme immunoassay). Tissue fragments (atheroma plaque, heart valve and ascending aorta) were collected during surgery and subjected to qPCR for detection of bacterial DNA. Promoter region polymorphisms of each marker and relative quantification of TNF-α, IL-8, and IL-10 gene expression were performed. Demography and social information were similar to the general population involved with both diseases. Antibody prevalence to C. trachomatis was 30.6, 20.3, and 36.7% (in the CAD, HVD, and CG, respectively) and to C. pneumoniae was 83.6, 84.5, and 80.3% (in the CAD, HVD, and CG, respectively). C. trachomatis cryptic plasmid DNA was detected in 7.4% of the samples. Frequency of IL6−174G>C polymorphism was higher in CAD and HVD than in CG regardless of previous exposure to Chlamydia. Previous C. trachomatis infection showed involvement in HVD and CAD. Significant association between disease and previous C. pneumoniae infection was found only among HVD. GG genotype of IL6−174G>C is apparently a risk factor for heart disease, whereas AT genotype of IL8−251A>T was mainly involved in valvulopathies, including patients with prior exposure to C. pneumoniae.

Serum profile of cytokines and their genetic variants in metabolic syndrome and healthy subjects: a comparative study

AIM

To identify genetic variants in promoter areas of IL-6 -174 G>C and TNF-α -308 G>A in metabolic syndrome (Met S) and controls and associate them with Met S and serum cytokine levels.It was a cross-sectional study, including 224 cases of Met S and 200 controls. A fasting blood sample was taken and biochemical parameters including serum glucose, insulin, lipid profile, interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were measured. Restriction fragment length polymorphism was used to identify the genetic variants of IL-6 and TNF-α. Serum levels of IL-6 and TNF-α and insulin resistance were significantly higher in cases than the controls. IL-6 showed significant positive correlation with HOMA-IR and TNF-α. CC genotype of IL-6 was associated with the increased risk of Met S (P=0.016, OR for CC vs GC+GG = 2.33, CI: 1.15-4.71). There was no significant difference of TNF-α genotypes between the cases and the controls. Serum TNF-α and IL-6 levels were significantly higher in AA and CC genotypes of TNF-α (-308 G>A) and IL-6 (-174 G>C) as compared with the GG (P=0.00 and P=0.001). Significant correlation of IL-6 with TNF-α and insulin resistance was observed that may provide us a therapeutic target for preventing metabolic derangements from insulin resistance.

Gene polymorphism associated with TNF-α (G308A) IL-6 (C174G) and susceptibility to coronary atherosclerotic heart disease: A meta-analysis

To evaluate the association between gene polymorphisms of TNF-α G308A, IL-6 C174G, and coronary atherosclerotic heart disease (CHD) risk.We used computers to collect related case-control studies. After screening, a meta-analysis was conducted to assess the strength of association by Stata 12.0 software.Thirty-five articles were included. Among them, 17 studies were related to TNF-α (G308A) gene mutation and CHD, and 18 studies examined IL-6 (C174G) gene mutation. According to the results of subgroup analysis of ethnicity, it suggested that TNF-α (G308A) polymorphism was not significantly associated with CHD risk under all models in Asians (P > .05). There were no connected of IL-6 C174G polymorphism with CHD risk under all models in Caucasians after subgroup analysis (P > .05).The present evidence shows that TNF-α (G308A) have no connected with the risk of CHD in Asians; IL-6 (C174G) gene were not associated with the risk of CHD in Caucasians.

Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links

Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.

TP53 single nucleotide polymorphism (rs1042522) in Iranian patients with coronary artery disease

Chronic diseases including coronary artery disease (CAD) impose a high burden in terms of mortality and disability particularly in developing countries. Both genetic and environmental risk factors confer susceptibility to CAD. Meanwhile, a functional polymorphism in the tumor protein p53 (TP53) gene (codon 72, exon 4) has been reported to be associated with a wide range of cancers and inflammatory disorders. There are controversies regarding CAD and involvement of the TP53 codon 72 single nucleotide polymorphism; therefore, the present case-control study was conducted to evaluate the potential association between this TP53 polymorphism and CAD in an Iranian population. A total of 153 subjects (including 70 patients diagnosed with CAD and 83 subjects with normal coronary parameters, determined by angiography) were genotyped for the TP53 (rs1042522) polymorphism by the polymerase chain reaction-restriction fragment length polymorphism technique. Clinical and laboratory findings were also evaluated. The χ² test and unpaired Student's t-test were applied to compare genotype and allele distributions and clinical characteristics between the two groups. Significant associations of the Pro72 allele [odds ratio (OR)=1.66, P=0.027] and Pro/Pro genotype (OR=2.91, P=0.022) with CAD were identified. No associations between patients' clinical findings and genotypes were apparent. Therefore, according to present findings, the TP53 Pro72 allele may be involved in the development of CAD along with conventional risk factors in patients from Northern Iran.

Association of Interleukin-6 Genetic Polymorphisms and Environment Factors Interactions with Coronary Artery Disease in a Chinese Han Population

OBJECTIVES

To investigate the influence of IL-6 single nucleotide polymorphisms (SNPs), additional gene-gene and gene-environment interactions on coronary artery disease (CAD) risk.

METHODS

A total of 751 participants (429 CAD patients and 322 controls) were recruited in this study. Logistic regression analysis was conducted to evaluate the association of IL-6 SNPs with CAD risk and generalized multifactor dimensionality reduction (GMDR) was performed to investigate the best interaction combinations for gene-gene and gene-environment interactions.

RESULTS

CAD risk is significantly higher in carriers of C allele of the rs1800795 polymorphism than those with GG genotype (CC + CG versus GG, adjusted OR (95%CI) = 2.07 (1.56-2.86), p < 0.001). GMDR analysis revealed rs1800795 was significantly interacted with tobacco smoking and alcohol drinking in two-locus model (p < 0.0010). Current smokers with CC or CG of rs1800795 genotype have the highest CAD risk, OR (95%CI) = 3.22 (2.45-3.94) and current drinkers with CC or CG of rs1800795 genotype have the highest CAD risk, OR (95%CI) = 3.17 (2.20-4.24).

CONCLUSION

The C allele of rs1800795 within IL-6 gene promoter, rs1800795-tobacco smoking and rs1800795-alcohol drinking interaction were all associated with increased CAD risk.

Acute coronary syndrome: Relationship between genetic variants and TIMI risk

Acute Coronary Syndrome (ACS) is a multifactorial disease, including the genetic factor, caused by coronary artery obstruction by atheroma. Some genetic variants have been described as risk factors for this disease. Its early diagnosis and stratification of risk of death by Thrombolysis in Myocardial Infarction (TIMI) are important. Therefore, we evaluated variants in the IL6R (c950-1722C>T), TNFa (c.-488G>A), LEPR (c.2673+1118C>T) and IL1b (c.-598T>C) genes in relation to TIMI risk, cytokine serum levels, and risk factors for ACS. We selected 200 patients with ACS, 50 without ACS from the Real Hospital Português, Recife - PE, and 295 blood donors at the Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope). Variants were determined by DNA sequencing or enzymatic cleavage. Cytokine levels were measured by ELISA. The most frequent risk factors found in the patients were dyslipidemia and hypertension, this latter associated with high TIMI risk (p = 0.003). Genotype frequencies of IL6R and TNFa differed between patients with ACS and the blood donors (p = 0.0002 and p = 0.01, respectively), and TNF-α levels differed between genotypes. The TT genotype of the IL6R gene is as a possible protective factor for ACS because it was significantly more present in blood donors (32.2%) than in patients with ACS (18.0%), and was more frequent in low TIMI risk (22.9%) than in the intermediate (20.2%) or high (4.9%). In patients with ACS, the TT genotype in IL6R was related to a lower concentration of c-reactive protein (p = 0.03) and troponin (p = 0.02), showing a less inflammatory reaction and tissue damage. The differences in the frequencies of variants in genes of medical interest among the groups show the importance of studies in specific populations groups to establish the relationship between genes and diseases.

Dual Effect of IL-6 -174 G/C Polymorphism and Promoter Methylation in the Risk of Coronary Artery Disease Among South Indians

Inflammation plays an important role in the pathogenesis of atherosclerosis and coronary syndromes; moreover, various lines of evidence suggest that genetic factors do contribute to the risk of coronary artery disease (CAD). The proinflammatory cytokine IL-6 is a central mediator of inflammation associated with CAD. The present study is aimed to investigate the association of single nucleotide polymorphism in the promoter region of the IL-6 gene (-174 G > C) and methylation with the susceptibility of CAD. Genotyping of IL-6 -174 G/C polymorphism was performed by PCR-RFLP. Methylation-specific PCR method was used to study the IL-6 gene promoter methylation. Analysis of 470 subjects (265 CAD patients and 205 controls) showed association of the -174 G/C variant with the CAD risk in dominant model (OR 1.58, 95% CI, 1.024-2.23, P = 0.04). Further, the analysis of the distribution of genotypes and alleles of -174 G > C polymorphism according to clinical features of CAD, revealed significant association of genotype and allele (OR 1.86, 95% CI 1.18-2.84 P = 0.01, and OR 1.71, 95% CI 1.09-2.23 P = 0.02 respectively) with diabetes, and we found no association with hypertension (OR 0.95, 95% CI 0.57-1.59, P = 0.8). We also analyzed the methylation status of IL-6 promoter region between cases and controls showed significant hypo methylation in CAD subjects (OR 2.36, 95% CI 1.51-4.259, P = 0.006). Additionally, GC, CC genotypes and C allele carriers show hypomethylation in CAD cases compared to controls (54.58 vs. 76.85%, 29.83 vs. 40% respectively). In conclusion, the promoter polymorphism -174 G/C is associated with CAD risk and further carriers of 'C' allele at -174 locus showed significant hypo methylation which could contribute to increased risk of CAD. The present study highlights the association of allele and genotypes with differential DNA methylation of CpG islands in the IL-6 promoter region which may affect IL-6 gene regulation.

Association between interleukin-6/6R gene polymorphisms and coronary artery disease in Russian population: influence of interleukin-6/6R gene polymorphisms on inflammatory markers

This study determined the genotype effects of interleukin (IL)-6/IL-6R single nucleotide polymorphisms (SNPs) on circulating levels of different cytokines in healthy and coronary artery disease (CAD) patients with different allele frequencies. In the control patients, rs1800795 showed significant differences in IL-18 concentrations between CC and CG and CC and GG genotypes (P=0.003 and 0.004, respectively). Furthermore, circulatory IL-1β was significantly different between GC and GG genotypes from the same SNP (P=0.038). In the diseased patients, significance was determined only for IL-2 (P=0.021) between the C and G homozygote allele carriers of rs1800795. The diseased GC and GG genotype carriers were statistically different for IL-2 (P=0.049) from the rs1800796 and for IL-4 (P=0.049) from the rs2228044. IL-4 was also statistically significant between the GC and CC genotypes from the rs2228043 of the IL-6R gene (P=0.025). The last combination of genotypes in the same gene for the same SNP was statistically significant for IL-10 (P=0.036). According to the logistic regression, only gender (odds ratio [OR] =2.43) and triglycerides (OR =1.98) could be taken as determinants of CAD, while examined SNPs genotypes were not identified as risk factors for CAD. In general, the IL-6 polymorphism genotypes were mainly associated with inflammatory cytokines, while the IL-6R polymorphism genotypes were associated with anti-inflammatory cytokines.

Genetic association of pro-inflammatory cytokine gene polymorphisms with coronary artery disease (CAD) in a North Indian population

BACKGROUND

Cytokines regulate the expression of inflammatory molecules which destabilize the atheromatic plaques. This study focuses on studying the association of inflammatory cytokine polymorphisms like TNF-α -308 (G/A), TNF-β +252 (A/G), IL-6 -174 (G/C) and IL-6 -597 (G/A), and IFN-ɣ +874 (T/A) with coronary artery disease (CAD) among north Indian patients.

MATERIALS AND METHODS

143 CAD and 137 normal healthy controls were recruited in this study. DNA extraction was carried out by high salting out method. TNF-α -308 (G/A) (rs1800797), TNF-β +252 (A/G) (rs909253), IL-6 -174 (G/C) (rs1800795), IL6 -597 (G/A) (rs1800797), and IFN-ɣ +874 (T/A) (rs2430561) SNPs were genotyped by TaqMan®SNP genotyping assays. Different statistical analyses were performed using SPSS v 22.0 and SNPStats. p≤0.05 was considered significant.

RESULTS

Significant risk association with CAD was found for TNF-α -308 (G/A) "A" allele (OR=5.6, CI 1.8-17.4, p=0.001) and TNF-β +252 (A/G) "G" allele (OR=3.4, CI=1.9-6.0, p<0.001). However, no statistical significance was found for IL-6 -174 (G/C) or IL6 -597 (G/A), with CAD. TNF-α -308 (G/A), and TNF-β +252 (A/G) haplotype "GG" "AG" increased CAD risk significantly (GG haplotype, adjusted OR=2.6, CI 1.4-5.0, p=0.003 and AG haplotype OR=8.5, CI 2.2-33.35, p=0.002) after adjustments for age, sex, TC, TG, HDL, APOB, smoking and diet.

DISCUSSION

The present study found significant risk association for TNF-α -308 (G/A), and TNF-β +252 (A/G) genotypes, alleles and haplotypes, with CAD in a North Indian population.

Assessment of genetic diversity in IL-6 and RANTES promoters and their level in Saudi coronary artery disease patients

BACKGROUND

The present study consisted of a total of 200 subjects (100 confirmed coronary artery disease (CAD) patients), both men and women, and 100 healthy control individuals.

METHODS

Serum concentration of IL-6 and RANTES were measured by enzyme-linked immunosorbent assay kit. For SNPs analysis, sanger method of DNA sequencing was followed.

RESULTS

We observed variable numbers of SNP sites at -174 G/C, -572 G/C, and -597 G/A in IL-6 and -28 C/G and -109 C/T in RANTES promoters in CAD patients compared with control individuals. However, the observed changes in the number of SNPs were found to be non-significant compared with control individuals. The IL-6 level was found to be significantly (P<.001) elevated in CAD patients compared with control. Moreover, RANTES serum level did not show any significant change in CAD patients.

CONCLUSION

Based on our result, it is quite clear that inflammation has a role in the pathogenesis of CAD but does not lead to significant changes at the genetic level in our population. As far as our knowledge goes, this is the first report that shows the genetic diversity in IL-6 and RANTES promoters and their respective levels in Saudi CAD patients.

Role of Cytokine Gene Score in Risk Prediction of Premature Coronary Artery Disease

AIMS

Pro- and anti-inflammatory cytokines play a significant role in early atherosclerosis. Linkage disequilibrium patterns differ between ethnic groups pointing toward the need to develop population-specific gene risk scores. Our objective was to investigate the role of a cytokine gene score in the risk prediction of premature coronary artery disease (PCAD).

METHODS

A case-control study was performed at the National University of Sciences and Technology (NUST) in collaboration with the Cardiovascular Genetics Institute, University College London, United Kingdom. Three hundred forty subjects with >70% stenosis in at least one coronary vessel on angiography were labeled as PCAD cases and compared with 310 angio-negative controls. Genotyping of the rs187238 (interleukin [IL]-18), rs1800795 (IL-6), rs1800629 (tumor necrosis factor [TNF]-alpha), rs1800871 (IL-10), and rs1946519 (IL-18) SNPs was performed using KASPar and TaqMan assays.

RESULTS

The odds ratio for cytokine gene score was significantly higher for PCAD (p = 0.025) when adjusted for age, sex, and ethnicity. There was a highly significant difference in gene risk allele frequency between Pakistanis and Caucasians (Northwick Park Heart Study II [NPHSII]) for rs187238 (IL-18), rs1800795 (IL-6), rs1800629 (TNF-alpha), and rs1800871 (IL-10) (p < 0.01).

CONCLUSIONS

A cytokine gene score has significant discriminatory ability and potential in the risk prediction of PCAD. Cytokine gene risk allele frequencies differ significantly between Pakistanis and Caucasians supporting the need to develop population-specific gene scores.

IL6-174 G>C Polymorphism (rs1800795) Association with Late Effects of Low Dose Radiation Exposure in the Portuguese Tinea Capitis Cohort

Head and neck cancers, and cardiovascular disease have been described as late effects of low dose radiation (LDR) exposure, namely in tinea capitis cohorts. In addition to radiation dose, gender and younger age at exposure, the genetic background might be involved in the susceptibility to LDR late effects. The -174 G>C (rs1800795) SNP in IL6 has been associated with cancer and cardiovascular disease, nevertheless this association is still controversial. We assessed the association of the IL6-174 G>C SNP with LDR effects such as thyroid carcinoma, basal cell carcinoma and carotid atherosclerosis in the Portuguese tinea capitis cohort. The IL6-174 G>C SNP was genotyped in 1269 individuals formerly irradiated for tinea capitis. This sampling group included thyroid cancer (n = 36), basal cell carcinoma (n = 113) and cases without thyroid or basal cell carcinoma (1120). A subgroup was assessed for atherosclerosis by ultrasonography (n = 379) and included matched controls (n = 222). Genotypes were discriminated by real-time PCR using a TaqMan SNP genotyping assay. In the irradiated group, we observed that the CC genotype was significantly associated with carotid plaque risk, both in the genotypic (OR = 3.57, CI = 1.60–7.95, p-value = 0.002) and in the recessive (OR = 3.02, CI = 1.42–6.42, p-value = 0.004) models. Irradiation alone was not a risk factor for carotid atherosclerosis. We did not find a significant association of the IL6-174 C allele with thyroid carcinoma or basal cell carcinoma risk. The IL6-174 CC genotype confers a three-fold risk for carotid atherosclerotic disease suggesting it may represent a genetic susceptibility factor in the LDR context.

Relative risk for cardiovascular morbidity in hemodialysis patients regarding gene polymorphism for IL-10, IL-6, and TNF

Uremia-related inflammation is prone to be a key factor to explain high cardiovascular morbidity in hemodialysis patients. Genetic susceptibility may be of importance, including IL-10, IL-6, and TNF. The aim was to analyze IL-10, IL-6, and TNF gene polymorphisms in a group of hemodialysis patients and to correlate the findings with cardiovascular morbidity. This study included 169 patients on regular hemodialysis at Zvezdara University Medical Center. Gene polymorphisms for IL-10, IL-6 and TNF were determined using PCR. These findings were correlated with the cardiovascular morbidity data from patient histories. Heterozygots for IL-10 gene showed significantly lower incidence of cardiovascular events (p = 0.05) and twice lower risk for development of myocardial infarction, but experienced twice higher risk for left ventricular hypertrophy. Regarding TNF gene polymorphism, patients with A allele had 1.5-fold higher risk for cerebrovascular accident and cardiovascular events and 2-fold higher risk for hypertension and peripheral vascular disease. Patients with G allele of IL-6 gene experienced 1.5-fold higher risks for cerebrovascular accident. We need studies with larger number of patients for definitive conclusion about the influence of gene polymorphisms on cardiovascular morbidity in hemodialysis patients and its importance in everyday clinical practice.

Effect of G(-174)C polymorphism in interleukin-6 gene on cardiovascular disease in type 2 diabetes patients

Interleukin-6 (IL-6) is an important pro-inflammatory cytokine of relevance to cardiovascular diseases. The aim of this case-control study was to evaluate the association between the G(-174)C functional polymorphism in the IL-6 gene and risk of cardiovascular disease (CVD) in type 2 diabetes patients. We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the G(-174)C polymorphism by polymerase chain reaction (PCR) and restriction analysis. There were no significant differences in the distribution of genotypes and alleles between T2DM patients and healthy controls. Significantly higher C allele frequency was observed in CVD+ patients compared to CVD- subgroup (53% vs. 32%, p<0.0001). The odds ratio for C allele was 2.4 (95% CI 1.99-2.9, p<0.0001) and for CC genotype 4.55 (95% CI 3.12-6.63, p<0.000). When the distribution of G(-174)C polymorphism was compared in subgroups with different clinical phenotypes of CVD, a significant association of CC genotype with myocardial infarction was observed. Forty eight percent of patients with MI had the CC genotype compared to 22% of patients without MI (p<0.0001). In conclusion, type 2 diabetes patients carrying the C allele of the IL-6 G(-174)C polymorphism have a significantly increased risk of CVD.

Clinical associations of host genetic variations in the genes of cytokines in critically ill patients

Host genetic variations may influence a changing profile of biochemical markers and outcome in patients with trauma/injury. The objective of this study was to assess clinical associations of single nucleotide polymorphisms (SNPs) in the genes of cytokines in critically ill patients. A total of 430 patients were genotyped for SNPs in the genes of pro- (IL1B, IL6, IL8) and anti-inflammatory (IL4, IL10, IL13) cytokines. The main end-points were sepsis, mortality and adult respiratory distress syndrome (ARDS). We evaluated the dynamic levels of bilirubin, blood urea nitrogen, creatine kinase, creatinine and lactate dehydrogenase in five points of measurements (between 1 and 14 days after admission) and correlated them with SNPs. High-producing alleles of proinflammatory cytokines protected patients against sepsis (IL1B -511A and IL8 -251A) and mortality (IL1B -511A). High-producing alleles of anti-inflammatory cytokines IL4 -589T and IL13 431A (144Gln) were less frequent in ARDS patients. The carriers of IL6 -174C/C genotypes were prone to the increased levels of biochemical markers and acute kidney and liver insufficiency. Genotype-dependent differences in the levels of biochemical indicators gradually increased to a maximal value on the 14th day after admission. These findings suggest that genetic variability in pro- and anti-inflammatory cytokines may contribute to different clinical phenotypes in patients at high risk of critical illness.

An association study between genetic polymorphism in the interleukin-6 receptor gene and coronary heart disease

The goal of our study is to test the association of IL6R rs7529229 polymorphism with CHD through a case-control study in Han Chinese population and a meta-analysis. Our result showed there is a lack of association between IL6R rs7529229 polymorphism and CHD on both genotype and allele levels in Han Chinese (P > 0.05). However, a meta-analysis among 11678 cases and 12861 controls showed that rs7529229-C allele was significantly associated with a decreased risk of CHD, especially in Europeans (P < 0.0001, odds ratio = 0.93, 95% confidential interval = 0.89–0.96). Since there is significant difference among different populations, further studies are warranted to test the contribution of rs7529229 to CHD in other ethnic populations.