Association of polymorphisms and allelic combinations in the tumour necrosis factor-alpha-complement MHC region with coronary artery disease

Estimating the role of single-nucleotide polymorphism (rs1800629)-308 G/A of TNF-alpha gene as genetic marker associated with angina pectoris in a sample of Iraqi patients

BACKGROUND

Angina pectoris (AP) occurs when oxygen and other nutrients are insufficient to meet the metabolic needs of the heart muscle. Stable angina is the most common, while the unstable angina is less frequent. Tumor necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine plays a vital function in the immune response regulation. TNF gene cluster contains many polymorphisms; the most commonly investigated polymorphism is the rs1800629 SNP. This SNP, located at - 308 position with regard to the TNF promoter region, replaces guanine (G) with adenine (A), with the allelic types - 308 G/A, and has been linked to a variety of inflammatory condition and autoimmune diseases. The - 308 G/A SNP was investigated in AP and interconnected to the TNF level to figure out the responsibilities of TNF-alpha gene polymorphism in the pathogenesis of AP.

METHOD

The current work design as a case-control study that involves 300 participant divided to 200 patients evaluated as (stable angina n = 100 and unstable angina n = 100) compared with 100 apparently healthy control subjects. The serum level of TNF-alpha was assessed via enzyme-linked immunosorbent assay (ELISA)/sandwich method. The genotype and allele frequency distribution of TNF-alpha rs1800629 gene polymorphism were investigated by TaqMan probe of allelic discrimination method.

RESULTS

The levels of TNF-alpha were significantly higher in patients with stable and unstable angina pectoris in comparison with controls. The deviation from Hardy-Weinberg equilibrium (HWE) of TNF-alpha genotypes was obvious in control and unstable angina pectoris groups. Moreover, the significant differences between patients with AP and controls under the five genetic models consider the association between TNF-alpha (rs1800629) - 308 G/A and AP with OR > 1. However, data analysis of allelic and genotypic of (rs1800629) - 308 G/A revealed higher significantly differences of GG homozygous and GA heterozygous proportions between stable angina patients and control. The A allele was more represented as etiological allele, and G allele was represented as protective allele. The serum levels of TNF-alpha were significantly higher in subjects with genetically mutated AA genotypes than in subjects with wild GG genotypes in the study groups. ROC curve analysis found the best cutoff value of TNF-alpha level was 77.25 pg/ml.

CONCLUSION

As the results, our data observed a linked of TNF-alpha (rs1800629) - 308 G/A genetic variant with angina pectoris patients, and the A allele has been linked to the production or expression of TNF-alpha serum level and represented an etiological factor of angina pectoris.

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.

Clinical features of patients with homozygous complement C4A or C4B deficiency

INTRODUCTION

Homozygous deficiencies of complement C4A or C4B are detected in 1-10% of populations. In genome-wide association studies C4 deficiencies are missed because the genetic variation of C4 is complex. There are no studies where the clinical presentation of these patients is analyzed. This study was aimed to characterize the clinical features of patients with homozygous C4A or C4B deficiency.

MATERIAL AND METHODS

Thirty-two patients with no functional C4A, 87 patients with no C4B and 120 with normal amount of C4 genes were included. C4A and C4B numbers were assessed with genomic quantitative real-time PCR. Medical history was studied retrospectively from patients' files.

RESULTS

Novel associations between homozygous C4A deficiency and lymphoma, coeliac disease and sarcoidosis were detected. These conditions were present in 12.5%, (4/32 in patients vs. 0.8%, 1/120, in controls, OR = 17.00, 95%CI = 1.83-158.04, p = 0.007), 12.5% (4/32 in patients vs. 0%, 0/120 in controls, OR = 1.14, 95%CI = 1.00-1.30, p = 0.002) and 12.5%, respectively (4/32 in patients vs. 2.5%, 3/120 in controls, OR = 5.571, 95%CI = 1.79-2.32, p = 0.036). In addition, C4A and C4B deficiencies were both associated with adverse drug reactions leading to drug discontinuation (34.4%, 11/32 in C4A-deficient patients vs. 14.2%, 17/120 in controls, OR = 3.174, 95%CI = 1.30-7.74, p = 0.009 and 28.7%, 25/87 in C4B-deficient patients, OR = 2.44, 95%CI = 1.22-4.88, p = 0.010).

CONCLUSION

This reported cohort of homozygous deficiencies of C4A or C4B suggests that C4 deficiencies may have various unrecorded disease associations. C4 gene should be considered as a candidate gene in studying these selected disease associations.

Tumor necrosis factor-alpha gene polymorphisms and susceptibility to ischemic heart disease: A systematic review and meta-analysis

BACKGROUND

A number of studies had reported the association between tumor necrosis factor-alpha (TNF-α) gene polymorphisms and ischemic heart disease (IHD) risk. However, the results remained controversial. Therefore, we performed a systematic review with multiple meta-analyses to provide the more precise estimations of the relationship.

METHODS

We systematically searched electronic databases (PubMed, the Web of Science, EMBASE, Medline, Chinese National Knowledge Infrastructure, WanFang and ChongQing VIP Database) for relevant studies published up to February 2017. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for assessing the association. The present meta-analysis was performed using STATA 12.0 software.

RESULTS

In total, 45 articles with 17,375 cases and 15,375 controls involved were included. Pooled ORs revealed a significant association between TNF-α -308G/A gene polymorphism and IHD (A vs. G: OR = 1.22, 95% CI = 1.10-1.35; (AA + GA) vs. GG: OR = 1.18, 95% CI = 1.03-1.36; (AA vs. (GA+GG): OR = 1.37, 95% CI = 1.08-1.75)), indicating that the TNF-α -308A allele might be an important risk factor for IHD. No association between other TNF-α gene polymorphisms and susceptibility to IHD were observed. No publication bias were found. Sensitivity analyses indicated that our results were stable.

CONCLUSION

The present study indicated a possible association between the TNF-α -308G/A gene polymorphism and IHD risk. However, evidence was limited to confirm the role of TNF-α -238G/A, -857C/T, -863C/A, -1031T/C and other TNF-α gene polymorphisms in the risk of IHD.

Association between CRP and TNF-α genes Variants and Cardiovascular Heart Disease in a Mexican Population: Protocol for a Case-Control Study

BACKGROUND

The C-reactive protein (CRP) and the tumor necrosis factor-alpha (TNF-α) are considered markers of inflammation and have been shown to predict the risk of incident cardiovascular events. However, few studies have undertaken a comprehensive examination of SNPs (single nucleotide polymorphisms) of the CRP and TNF-α genes; due to this, we will present a protocol study to evaluate the role of the CRP and TNF-α genes in Mexican individuals.

METHODS/DESIGN

we will perform a case-control study to explore the CRP and TNF-α genotype distribution as well as the serum influence of rs1800947, rs1130864, rs2794521 and rs1205 (polymorphisms of the CRP gene) and rs361525, rs1800629, rs1799724, rs1800630, rs1799964 (of the TNF-α gene) in Mexican individuals who present coronary artery disease.

ETHICS AND DISSEMINATION

a written informed consent will be obtained from all the participating subjects. An article detailing the results of the study will be submitted for publication in an international peer-reviewed journal, in accordance with STROBE criteria.

Integrated probability of coronary heart disease subject to the -308 tumor necrosis factor-alpha SNP: a Bayesian meta-analysis

We present a meta-analysis of independent studies on the potential implication in the occurrence of coronary heart disease (CHD) of the single-nucleotide polymorphism (SNP) at the −308 position of the tumor necrosis factor alpha (TNF-alpha) gene. We use Bayesian analysis to integrate independent data sets and to infer statistically robust measurements of correlation. Bayesian hypothesis testing indicates that there is no preference for the hypothesis that the −308 TNF-alpha SNP is related to the occurrence of CHD, in the Caucasian or in the Asian population, over the null hypothesis. As a measure of correlation, we use the probability of occurrence of CHD conditional on the presence of the SNP, derived as the posterior probability of the Bayesian meta-analysis. The conditional probability indicates that CHD is not more likely to occur when the SNP is present, which suggests that the −308 TNF-alpha SNP is not implicated in the occurrence of CHD.

Tumor necrosis factor-alpha G-238A polymorphism and coronary artery disease risk: a meta-analysis of 4,222 patients and 4,832 controls

BACKGROUND

The aim of the present study was to investigate the association between tumor necrosis factor-alpha (TNF-α) gene G-238A polymorphism and risk of coronary artery disease (CAD) using a meta-analytical approach.

METHODS

The PubMed and Embase databases were searched for relevant publications up to January 13, 2015. Four authors (XPH, XDZ, XTZ, and ZJZ) independently selected the studies, extracted, and analyzed the data using the Comprehensive Meta-Analysis software. The sensitivity and subgroups analyses were also performed. Either a fixed effects or a random effects model was used to estimate pooled odds ratios (ORs) and their 95% confidence intervals (CIs).

RESULTS

Finally, ten articles including eleven case-control studies involving 4,222 patients and 4,832 controls were yielded. The results indicated no significant association between G-238A polymorphism and CAD risk (A vs G: OR =1.08, 95% CI =0.89-1.30; AA vs GG: OR =1.15, 95% CI =0.59-2.25; GA vs GG: OR =1.14, 95% CI =0.88-1.48; AA vs [GG + GA]: OR =1.09, 95% CI =0.56-2.14; (GA + AA) vs GG: OR =1.11, 95% CI =0.90-1.38). In the subgroup analyses, similar results were obtained with overall populations. The sensitivity analyses showed that the overall results were robust. No publication bias was detected.

CONCLUSION

Based on current evidence, we can conclude that TNF-α G-238A polymorphism might not be associated with CAD risk.

Association between the TNF-α G-308A polymorphism and risk of ischemic heart disease: a meta-analysis

BACKGROUND

The role of the tumor necrosis factor-α (TNF-α) G-308A polymorphism in the risk of ischemic heart disease (IHD) has been controversial in recent decades. A substantial number of newly-published studies concerning the association between the TNF-α polymorphism and IHD risk have emerged after the publication of the latest meta-analysis. Therefore, we conducted an updated meta-analysis to further investigate the influence of this polymorphism on IHD.

METHODS

Electronic databases (PubMed, Embase, CNKI, and Wanfang) were systematically searched to identify all relevant papers published before September 25(th), 2014. The quality of all eligible studies was assessed. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) of all studies and high-quality studies were assessed by the fixed/random-effects model in Review Manager 5.0.25 and STATA 10.0. Heterogeneity and publication bias were detected; sensitivity analysis was conducted.

RESULTS

Data from 36 studies were recorded after study selection and exclusion. Under the dominant model, the results of pooled analysis of high-quality studies suggested that the G-308A polymorphism was associated with an increased risk of IHD in total population (P = 0.02, OR = 1.13, 95% CI = 1.02-1.24, P heterogeneity = 0.009, I(2) = 45%). No significant result was obtained in Asians, Caucasians, or Indians.

CONCLUSION

The TNF-α -308A allele is probably associated with an increased risk of IHD in total population, but to further identify this association, more high quality studies in Indians and Africans are merited.

Tumor necrosis factor-α and its role as a mediator in myocardial infarction: A brief review

Tumor necrosis factor-α (TNF-α) contributes to myocardial infarction (MI) injury. Polymorphism of TNF-α gene promoter region and secretion and release of TNF-α and its transformation by a series of signaling pathways are all changed at different points of pathophysiological process in MI. Researches also investigated TNF-α antagonists and their potential therapeutic role in the setting of MI and heart failure at both molecular and clinical level. This article briefly reviews TNF-α and its mechanism as a mediator in MI.

Investigation of complement component C4 copy number variation in human longevity

Genetic factors have been estimated to account for about 25% of the variation in an adult's life span. The complement component C4 with the isotypes C4A and C4B is an effector protein of the immune system, and differences in the overall C4 copy number or gene size (long C4L; short C4S) may influence the strength of the immune response and disease susceptibilities. Previously, an association between C4B copy number and life span was reported for Hungarians and Icelanders, where the C4B*Q0 genotype, which is defined by C4B gene deficiency, showed a decrease in frequency with age. Additionally, one of the studies indicated that a low C4B copy number might be a genetic trait that is manifested only in the presence of the environmental risk factor "smoking". These observations prompted us to investigate the role of the C4 alleles in our large German longevity sample (∼ 700 cases; 94-110 years and ∼ 900 younger controls). No significant differences in the number of C4A, C4B and C4S were detected. Besides, the C4B*Q0 carrier state did not decrease with age, irrespective of smoking as an interacting variable. However, for C4L*Q0 a significantly different carrier frequency was observed in the cases compared with controls (cases: 5.08%; controls: 9.12%; p = 0.003). In a replication sample of 714 German cases (91-108 years) and 890 controls this result was not replicated (p = 0.14) although a similar trend of decreased C4L*Q0 carrier frequency in cases was visible (cases: 7.84%; controls: 10.00%).

Tumor necrosis factor-alpha G-308 A polymorphism and risk of coronary heart disease and myocardial infarction: A case-control study and meta-analysis

Objectives:

The tumor necrosis factor-alpha (TNF-α) gene may play an important role in coronary heart disease (CHD) and myocardial infarction (MI) risk. Recently, controversial results regarding the association of the G-308 A (rs1800629)polymorphism of the TNF-α gene with CHD/MI have been reported. We herein examine a possible association between the G-308 A (rs1800629)polymorphism of the TNF-α gene and CHD/MI in a sample of the Chinese Han population.

Materials and Methods:

We determined the genotypes of TNF-α G-308 A (rs1800629) in 535 unrelated Chinese patients with CHD, 420 patients with MI, and 1020 coronary artery disease-free controls. Additionally, a meta-analysis of all previous studies on the TNF-α G-308 A polymorphism and the risk of CHD and MI was performed.

Results:

AA genotypes in the G-308 A (rs1800629)polymorphism of the TNF-α gene did not occur more frequently in CHD/MI patients than in controls; odds ratios (95% confidence intervals) were 1.743 (0.325 to 1.423) for CHD and 1.731 (0.442 to 1.526) for MI, after adjusting for conventional risk factors. Further stratification for age, gender, and other cardiovascular risk factors did not alter the prior negative findings. Pooled meta-analysis of 23 studies also found no statistically significant associations between the TNF-α polymorphism and CHD/MI risk in the genetic additive, dominant, and recessive models. Subgroup analyses showed no association between the TNF-α polymorphism and CHD/MI in Asian and Caucasian populations.

Conclusion:

Our study showed no association between the G-308 A (rs1800629) polymorphism of the TNF-α gene (presence of A allele) and CHD/MI in the Chinese Han population. There was no evidence of a difference in risk effects of rs1800629 between Caucasians and Asians.

ACTH-induced cortisol release is related to the copy number of the C4B gene encoding the fourth component of complement in patients with non-functional adrenal incidentaloma

OBJECTIVE

According to our previous findings, carriers of the C4B*Q0 genotype, which means zero or one copy of the C4B gene, which is located in the RCCX copy number variation region on chromosome 6, have a significantly shorter life-expectancy and higher risk of cardiovascular disease than non-carriers. We have postulated that the C4B*Q0 genotype is linked to variant(s) of the neighboring CYP21A2 gene encoding a steroid 21-hydroxylase with altered function.

DESIGN

Single-center, observational, retrospective study.

PATIENTS

Seventy-six patients with non-functional, benign adrenal incidentaloma.

MEASUREMENTS

Serum cortisol, aldosterone, 17-hydroxyprogesterone, corticosterone and ACTH levels basally and after ACTH-stimulation, metyrapone or dexamethasone tests were determined. C4B gene copy number was quantified.

RESULTS

The ratio of ACTH-stimulated and baseline cortisol concentrations was significantly higher (P = 0·001) in the group of patients carrying the C4B*Q0 genotype compared to the rest of the patients. This difference remained significant (P = 0·004) after adjustment for sex and age, as well as for tumor size. A significant (P = 0·018), adjusted difference between carriers and non-carriers was found also for ACTH-induced/basal aldosterone ratio. In C4B*Q0 carriers, metyrapone hardly reduced the serum cortisol level, while in non-carriers it induced a highly significant (P = 0·002) decrease.

CONCLUSIONS

The C4B*Q0 genotype may be associated with hyperreactivity of the HPA axis (manifested as an increased responsiveness to ACTH-stimulation), probably through enhanced function of steroid 21-hydroxylase. Since hyperreactivity of the HPA axis is known to be associated with an increased risk of cardiovascular disease, our present findings may explain the increased cardiovascular morbidity and mortality of C4B*Q0 carriers.

Tumor necrosis factor-alpha G-308A gene polymorphism and coronary heart disease susceptibility: an updated meta-analysis

PURPOSE

Several studies have reported apparently conflicting findings for the effects of tumor necrosis factor-alpha (TNF-α) G-308A polymorphism on coronary heart disease (CHD) susceptibility. We undertook a systematic review and meta-analysis to investigate the association between this gene variant and CHD predisposition.

METHODS

We systematically searched electronic databases (Medline, EMbase, Chinese BioMedical, BIOSIS, Global Health, PsycINFO, Allied and Complementary Medicine Database, Cochrane Library, HuGE Navigator, and British Nursing) for relevant studies published between 1947 and October, 2010. Summarized estimation of odds ratio (OR) and 95% confidence interval (CI) were calculated. Publication bias and heterogeneity among studies were explored.

RESULTS

We identified 24 studies providing data for 9 921 cases and 7 944 controls. Pooled analysis based on ORs adjusted by CHD risk factors showed that carrying the TNF-α gene A variant conferred a 1.5-fold increased risk of developing CHD (AG+AA vs. GG, OR = 1.50, 95% CI: 1.23-1.77) in Caucasian population. No significant association between the gene polymorphism and CHD risk could be found in other ethnic groups.

CONCLUSIONS

It is probable that carrying the A variant is associated with CHD risk in Caucasians but not in Asians, Indians, or Africans. Further studies are merited to assess the association in greater details, especially in Asians, Indians and Africans.

Single nucleotide polymorphism in the tumor necrosis factor-alpha gene affects inflammatory bowel diseases risk

AIM: To investigate the role that single nucleotide polymorphisms (SNPs) in the promoter of the tumour necrosis factor-alpha (TNF-α) gene play in the risk of inflammatory bowel diseases (IBDs) in a New Zealand population, in the context of international studies.

METHODS: DNA samples from 388 patients with Crohn’s disease (CD), 405 ulcerative colitis (UC), 27 indeterminate colitis (IC) and 201 randomly selected controls, from Canterbury, New Zealand were screened for 3 common polymorphisms in the TNF-α receptor: -238 G→A, -308 G→A and -857C→T, using a Taqman^R assay. A meta-analysis was performed on the data obtained on these polymorphisms combined with that from other published studies.

RESULTS: Individuals carrying the -308 G/A allele had a significantly (OR = 1.91, χ² = 17.36, P < 0.0001) increased risk of pancolitis, and a 1.57-fold increased risk (OR = 1.57, χ² = 4.34, P = 0.037) of requiring a bowel resection in UC. Carrying the -857 C/T variant decreased the risk of ileocolonic CD (OR = 0.56, χ² = 4.32, P = 0.037), and the need for a bowel resection (OR = 0.59, χ² = 4.85, P = 0.028). The risk of UC was reduced in individuals who were smokers at diagnosis, (OR = 0.48, χ² = 4.86, P = 0.028).

CONCLUSION: TNF-α is a key cytokine known to play a role in inflammatory response, and the locus for the gene is found in the IBD3 region on chromosome 6p21, known to be associated with an increased risk for IBD. The -308 G/A SNP in the TNF-α promoter is functional, and may account in part for the increased UC risk associated with the IBD3 genomic region. The -857 C/T SNP may decrease IBD risk in certain groups. Pharmaco- or nutrigenomic approaches may be desirable for individuals with such affected genotypes.

Polymorphisms of the TNF-alpha gene and risk of celiac disease in T1DM children

BACKGROUND

Type 1 diabetes mellitus (T1DM) and celiac disease (CD) frequently occur together. Previous reports suggested that the (-308)A variant of the tumor necrosis factor-alpha (TNF-alpha) gene is associated either with T1DM or with CD. The aim of our study was to determine whether (-308)A and (-238)A allelic variants of the TNF-alpha gene might have any impact on the risk of CD in T1DM children.

METHODS

Three hundred and one T1DM children were enrolled to the study. The presence of CD was screened with IgA endomysial antibodies (EMA) test. Jejunal biopsy was performed to confirm CD. TNF-alpha-308 and -238 genetic variants were tested using the method of restriction fragment length polymorphism.

RESULTS

The prevalence of CD in the enrolled diabetic children was 6.3% (19 out of 301 children). The frequency of the (-308)A TNF-alpha variant was similar in the CD and the non-CD groups, exceeding the Hungarian healthy reference value. The number of (-238)A allele carriers was higher in the CD (4/19) than in the non-CD group (17/277) (p < 0.05).

CONCLUSIONS

Our study is limited by the small number of CD patients. On the basis of our findings, carriers of TNF (-308)A allele do not seem to have an increased risk for CD in T1DM. The association between TNF-alpha(-238)A allele carrier state and CD requires further investigation.

Effect of the G-308A polymorphism of the tumor necrosis factor alpha gene on the risk of ischemic heart disease and ischemic stroke: a meta-analysis

BACKGROUND

Under the hypothesis that the G-308A polymorphism in the promoter region of the tumor necrosis factor alpha gene might increase tumor necrosis factor alpha expression, several investigations have been performed to examine the influence of the -308A allele on the risk of cardiovascular events. The results of these studies, however, have been conflicting. To provide a more robust estimate of the putative effect of the G-308A polymorphism on the risk of cerebrocardiovascular events, we did 2 meta-analyses that examined the role of the -308A variant in both ischemic heart disease (IHD) and ischemic stroke.

METHODS

We applied both fixed- and random-effects models to combine odds ratios (OR) and 95% CIs, and publication bias and heterogeneity were explored.

RESULTS

Data of 17,030 subjects from 23 studies were used. Overall, in populations predominantly of European ancestry, no association between the G-308A polymorphism and IHD under a dominant model (AA + GA vs GG) was observed: OR, 1.07; 95% CI, 0.94-1.21; P = .32. Similarly, the -308A allele was not associated with ischemic stroke considering all studies: OR, 0.99; 95% CI, 0.70-1.41, P = .96. However, analysis by ancestry revealed that Asian subjects harboring the -308A variant were approximately 40% less likely to have stroke compared to the GG genotype: OR, 0.62; 95% CI, 0.44-0.86; P = .004.

CONCLUSIONS

These results suggest that the G-308A polymorphism is unlikely to be associated with the development of IHD, whereas it might be a protective factor for ischemic stroke in Asians only.

Serum complement C3/C4 ratio, a novel marker for recurrent cardiovascular events

Acute coronary syndrome is an inflammatory disease, during which the complement cascade is activated. We assessed the complement C3 and C4 concentration ratio (C3/C4 ratio) in serum as a potential measurement to predict cardiovascular attacks. Patients with acute coronary syndrome (n=148) were followed after an initial attack for subsequent ischemic cardiovascular events (composite end point of death, myocardial infarction, recurrent unstable angina, or stroke). During the follow-up period (average 555 days), 44 patients met an end point. Blood samples were taken at hospitalization, 1 week, 3 months, and 1 year after hospital admission. Serum complement C3 and C4 concentrations and the C3/C4 ratio were analyzed. Patients with an end point had, throughout the follow-up period, a higher C3/C4 ratio than patients without these end points (repeated measures analysis of variance, p=0.007). When all traditional cardiovascular risk factors and other potential confounding factors were included in a Cox multivariate logistic regression survival analysis, the C3/C4 ratio emerged as the novel risk factor for any new cardiovascular event (odds ratio 1.33, 95% confidence interval 1.08 to 1.63, p=0.007). When the C3/C4 ratio was divided into 4 quartiles, 24% in quartiles 1 and 2 (lowest) and 48% in quartile 4 (highest) had end points during follow-up (odds ratio 3.04, 95% confidence interval 1.27 to 7.29, p=0.01). In conclusion, increased serum C3/C4 ratio is a readily available and novel marker for recurrent cardiovascular events in acute coronary syndrome. The relative increase in serum C3 protein and decrease in C4 protein could explain changes in the C3/C4 ratio.

Complement and c4 null alleles in severe chronic adult periodontitis

Severe forms of chronic periodontitis affect up to 10% of adults. Tumour necrosis factor and lymphotoxin-alpha genes in the major histocompatibility complex are associated with severe periodontitis. Complement factor C4 is a nearby, polymorphic, functionally relevant gene region. Although associated with chronic mucosal infections, C4 deficiencies have not been assessed in adult periodontitis patients. We tested whether complement levels are systemically altered and C4 deficiencies associated with severe chronic periodontitis. In a case-control study, we analysed levels of plasma C3, and C4, serum classical pathway haemolytic activity, C4 allotypes and C4 gene numbers in 37 patients with severe chronic periodontitis and in 150 voluntary controls. Plasma levels of C3 were higher, and classical pathway haemolytic activity was lower in patients than in controls. Partial C4 gene deficiencies were more frequent in patients than in controls (odds ratio 2.4, 95% confidence interval 1.1-5.5, P = 0.032). Changes in complement levels may reflect chronic, recurring inflammation. C4 gene deficiencies are associated with predisposition to chronic periodontitis.

Human MHC region harbors both susceptibility and protective haplotypes for coronary artery disease

Aiming to study the role of human major histocompatibility complex (MHC) region on coronary artery disease (CAD), we enrolled two separate patient materials and controls. First, heart transplantation recipients (n = 276) were divided into three subgroups according to the severity of atherosclerosis. The human leukocyte antigen (HLA)-A-B-DR haplotype and gene frequencies were compared between groups. Second, patients with acute coronary syndrome (ACS) (n = 100) and healthy controls (n = 74) were assessed by nine genetic MHC markers (HLA-A, HLA-B, HLA-DRB1, LTA+253(a/g), LTA+496(C/T), LTA+633(c/g), LTA+724(C/A), C4A and C4B), and the frequencies were compared. In the heart transplantation recipients, HLA-DR1 was strongly associated with CAD [severe vs no evidence, odds ratio (OR) 2.37; 95% confidence interval (CI) 1.33-4.25; P = 0.003]. Similarly, in the patients with ACS, HLA-DRB1*01 was associated with CAD (patients vs controls, OR 2.36; 95% CI 1.25-4.44; P = 0.007). HLA-DRB1*01 was associated with low-density-lipoprotein cholesterol (OR 5.32; 95% CI 1.64-17.26; P = 0.005) and smoking habit (OR 3.13; 95% CI 1.09-9.03; P = 0.035) as risk factors. The strongest protective gene was HLA-B*07 alone (OR 0.46; 95% CI 0.24-0.88; P = 0.02) or together with the haplotype LTA+253a-LTA+633g-C4A3-C4B1 (OR 0.36; 95% CI 0.22-0.57; P = 0.00001). In conclusion, human MHC region harbors genes that protect from and predispose to CAD.

Involvement of TNFalpha -308A promoter polymorphism in the development of asthma in children infected with Chlamydophila pneumoniae

Several data indicate a connection between Chlamydophila pneumoniae infection and asthma. Although C. pneumoniae is a common cause of infection, not all infected patients develop asthma. This suggests that certain individuals may be genetically predisposed to the chronic effects of C. pneumoniae infection on airway functions. We investigated the possible modifying effect of different polymorphisms on C. pneumoniae infection and on the susceptibility to asthma in 318 children, among those 144 had asthma and 174 had no asthmatic symptoms. C. pneumoniae-specific antibodies were measured by ELISA. Tumor necrosis factor-alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), and RANTES (regulated on activation normal T cell expressed and secreted) genotypes were determined by PCR-restriction fragment length polymorphism (RFLP). There were no significant differences in the percentage of children positive for C. pneumoniae-specific antibodies between cases and controls. None of the genotypes was associated with altered susceptibility to C. pneumoniae infection. Among asthmatic children carrying the TNFalpha -308A allele, there were significantly more patients positive for C. pneumoniae-specific IgG, than among control children carrying the same allele (20.1% versus 9.2% of asthmatic versus control children, respectively; p = 0.002; odds ratio = 3.52 (1.52-7.53); p = 0.005). This study indicates the possible roles of polymorphisms in the immune system in the susceptibility to asthma in children infected with C. pneumoniae.

Gene polymorphisms in patients below 35 years of age who underwent coronary artery bypass surgery

OBJECTIVE

Genetic bases for novel prothrombotic, inflammatory risk factors may play a role in the early onset of coronary artery disease.

METHODS

Twenty-one patients below 35 years of age who underwent coronary bypass grafting between 2002 and 2004 constituted the study group and were compared with 50 healthy, age and sex-matched controls. Gene analysis for genetic polymorphisms of angiotensin-converting enzyme, prothrombin G20210A, tumour necrosis factor-alpha G308A, factor V Leiden and interleukin-6 genes was carried out.

RESULTS

The control group was 98% homozygous for the factor V Leiden GG allele and 2% heterozygous for the GA allele. On the other hand, the study group was 76.2% homozygous for the GG allele, and 23.8% heterozygous for the GA allele (P<0.05). Homozygosity for factor V Leiden mutation (AA) was not encountered in either group. With regard to interleukin-6, 70.0% of the control group demonstrated homozygosity for the GG allele and 30.0% showed heterozygosity (GC). The study group was 52.4% homozygous for the GG allele and heterogenicity was similar in this group (28.6% GC). On the other hand, 19.0% of this group demonstrated CC homogenicity (P<0.05). No difference was observed with regard to gene polymorphisms.

CONCLUSIONS

Gene polymorphisms with regard to prothrombotic factor V Leiden mutation and inflammatory marker interleukin-6 may play a role in the pathogenesis of early-onset coronary artery stenosis in patients below 35 years of age.

Association between TNF-α −308G>A polymorphism and the development of acute coronary syndromes in Greek subjects: The CARDIO2000-GENE Study

PURPOSE

We investigated the association of a polymorphism within the promoter of TauNuF-alpha locus at the position -308 on the likelihood of having acute coronary syndromes (ACS) in Greek adults.

METHODS

We studied demographic, lifestyle, and clinical information in 237 hospitalized patients (185 males) with a first event of an ACS and 237 matched by age and sex (controls) without any clinical evidence of coronary heart disease. Genotyping was performed by PCR-RFLP analysis.

RESULTS

The genotype frequencies were in patients, 87% (n = 206), 12% (n = 29), and 1% (n = 2) for G/G, G/A, and A/A, and in controls, 96% (n = 227), 4% (n = 10), and 0% (n = 0) for G/G, G/A, and A/A, respectively (P = 0.04). After adjusting for age and sex, as well as various potential confounders, we observed that G/A or A/A genotypes were associated with 1.94-fold higher odds (95% CI 1.06 to 3.68) of ACS compared to G/G homozygotes. No gene to-gender or to-clinical syndrome interactions were observed. Further subgroup analysis showed that the distribution of TNF-alpha -308G>A polymorphism was associated with the presence of family history of CHD in patients, but not in controls. In particular, in G/A and A/A patients 17.2% reported family history of CHD, whereas in G/G patients, 34.5% reported family history (P = 0.036).

CONCLUSIONS

Our findings may state a hypothesis of an association between the -308G>A TNF-alpha polymorphism the development of ACS and the presence of family history of CHD, in Greece.

Association of TNF-α gene promoter polymorphisms with outcome of hepatitis B virus infection

AIM: To investigate the polymorphism of tumor necrosis factor-a(TNF-α) gene promoters in Chinese Han people, and to clarify whether such polymorphism was associated with the outcome of hepatitis B virus infection.

METHODS: After the process of extracting genomic DNA from blood in 165 subjects who spontaneously recovered(SR) and 131 patients with chronic hepatitis B (CHB), four single nucleotide polymorphism (SNP) sites in TNF-α gene promoter marked as -238G/A, -308G/A, -857C/T and -863C/A were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis.

RESULTS: Twelve different promoter genotypes were detected from all of 296 research subjects, and GG.GG.CC.CC, GG.GG.CC.CA, GG.GG.CT.CC, GG.GA.CC.CC genotypes accounted for about 85% of genotypes in these subjects. By analyzing the four promoter genotypes of TNF-α, the results showed that there were significant differences in the frequencies of GG.GG.CC.CC, GG.GG.CC.CA and GG.GA.CC·CC genotypes in TNF-α gene promoter between CHB and SR, GG.GG.CC.CC genotype carriers were at increased risk of CHB with an odds ratio of 2.15 (95% CI 1.34-3.45); While GG.GG.CC.CA and GG.GA.CC.CC genotypes carriers were at increased risk of CHB with an odds ratio of 0.48(95% CI 0.27-0.86) and 0.35 (95% CI 0.14-0.89), respectively. GG.GG.CC.CA and GG.GA.CC.CC genotypes were strongly associated with the resolution of HBV infection(χ² = 6.14, P = 0.013<0.05; χ² = 5.18, P = 0.023<0.05, respectively). Single site analysis also revealed that TNF-α gene -308G/A and -863C/A SNP sites were associated with persistent HBV infection in Chinese Han people (-308G/A site, χ² = 6.53, P = 0.011<0.05, OR=3.21; -863C/A site, χ² = 4.33, P = 0.037<0.05, OR=1.69, respectively).

CONCLUSION: There is an association between polymorphisms of the promoter region -308G/A and -863C/A of TNF-α and the resolution of HBV infection. The presence of the -308A allele (TNF-α-308GA) and /or -863A allele(TNF-α-863CA or AA) may be resistant to HBV infection, which gives some new clues to the study of pathogenesis of chronic hepatitis B.

Relationship between complement components C4A and C4B diversities and two TNFA promoter polymorphisms in two healthy Caucasian populations

The RP-C4-CYP21-TNX (RCCX) modules and the tumor necrosis factor (TNF) gene cluster are probably the most polymorphic genomic regions in the human central major histocompatibility complex (MHC). Using definitive methods for genotypic and phenotypic analyses of complement components C4A and C4B, determination of the RCCX length variants, and SSP-PCR/RFLP analyses of TNFA promoter polymorphisms at positions -308 and -238, we studied the complex relationships between the C4 and TNFA polymorphisms in two normal Caucasian populations. The patterns of the RCCX modular structures and the allelic frequency of -308A TNFA (TNF2) were similar between the Budapest (n = 125) and the Ohio (n = 80) Caucasians. However, the frequency of the -238A allele was significantly higher in the Ohio (11.3%) than in the Budapest (1.6%) study population (p < 0.0001). Marked features were found in the RCCX length variants in the TNF2 carriers and noncarriers. Strong associations were found between the C4AQ0 B1 haplotype from the monomodular short (mono-S) RCCX structure and the TNF2 allele, and between the C4A6 B1 haplotype from the bimodular long-short (LS) structure of the RCCX and the TNFA -238A allele. However, 36%-46% of the TNF2 carriers did not associate with a mono-S in both study cohorts, and 57.1% of the TNFA -238A carriers in Ohio did not associate with C4A6, which has a defective complement C5 convertase activity. The carriers of TNF2 allele had significantly lower C4A serum concentration (0.17 +/- 0.08 g/l) than noncarriers (0.23 +/- 0.09 g/l) (p < 0.001). The lowest C4A serum levels were found in TNF2 carriers with mono-S structures (0.14 +/- 0.06 g/l). In essence, our results demonstrated the heterogeneities of the TNFA promoter polymorphisms, and the linkage disequilibrium of TNFA -308A and -238A alleles with complement C4A deficiency and impaired C4A protein function, respectively.

Association between G-308A polymorphism of the tumor necrosis factor-alpha gene and 24-hour ambulatory blood pressure values in type 1 diabetic adolescents

Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine, which also influences blood pressure (BP). The G-308A polymorphism of the TNF-alpha gene is associated with altered TNF-alpha production. The prevalence of the TNF-alpha-308A allele is reportedly higher among patients with type 1 diabetes mellitus (T1DM) than in the healthy population. In this study we investigated whether this genetic polymorphism might correlate with BP values in diabetic adolescents. Ambulatory BP monitoring (ABPM) was performed in 126 adolescents with T1DM (mean age: 14 +/- 2.4 years). The TNF-alpha G-308A genotype was determined by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methodologies. ABPM results were related to healthy reference values and are given as standard deviation score (SDS). The prevalence of the -308A allele was higher in diabetic adolescents than the Hungarian reference population (0.26 vs 0.14, p < 0.01). TNF-alpha genotype was associated both with systolic and diastolic BP values (p < 0.01 and p < 0.01, respectively). In patients with TNF-alpha-308GG and -308GA/AA genotypes, the 24-h systolic BP average values were 0.37 +/- 1.33 and -0.38 +/- 1.28 SDS, while 24-h diastolic BP average values were 0.09 +/- 1.30 and -0.67 +/- 1.31 SDS. Hence, the TNF-alpha-308A allele carrier state appears to be associated with lower systolic and diastolic BP values.