Functional analysis of a new polymorphism in the human TNF alpha gene promoter

The TNF-α (-238 G/A) polymorphism could protect against development of severe sepsis

Primary responses in sepsis-mediated inflammation are regulated by pro-inflammatory cytokines. Variations in the cytokine genes might modify their transcription or expression, plasma cytokines levels and response to sepsis. Activation protein-1 (AP-1) and NF-κB regulate cytokines gene expression in sepsis. A total of 90 severely septic and 91 non-infected patients were prospectively studied. IL-1α (-889 C/T), IL-1β (+3954 C/T), IL-6 (-174 G/C), TNF-α (-238 G/A), TNF-α (-308G/A), IL-8 (-251A/T) and IL-10 (-1082 G/A) SNPs, plasma IL-1β, IL-4, IL-6, IL-8, IL-10, IL-13, IFN-γ, TNF-α and monocyte chemoattractant protein 1 (MCP-1) levels, and AP-1 and NF-κB gene expression by neutrophils were assessed. A allele carriers of TNF-α (-238 G/A) SNP were less frequent among septic patients. IL-6, IL-8, IL-10, TNF-α and MCP-1 levels were higher, and AP-1 and NF-κB gene expressions lower in septic patients. Sepsis was independently associated with higher fibrinogen, neutrophils counts and IL-8 levels, lower prothrombin, absence of the variant A allele of the TNF-α (-238 G/A) SNP, and haemodynamic failure. Death was independently associated with a higher APACHE II score, higher IL-8 levels, and the diagnosis of sepsis. TNF-a (-238 G/A) SNP could protect against sepsis development. Higher IL-8 levels are predictive of sepsis and mortality.

Association of NFκβ, TNFα, IL-6, IL-1β, and LPL Polymorphisms with Type 2 Diabetes Mellitus and Biochemical Parameters in a Mexican Population

Chronic low-grade inflammation is strongly related to the etiology of diabetes mellitus type 2 (T2DM), and the expression of inflammatory cytokines may be modulated by polymorphisms located in the regulatory regions of the NFκβ, IL-1β, IL-6, TNFα, and LPL genes. We considered it particularly important to investigate the relationship of gene polymorphisms involved in chronic inflammation with the risk of T2DM or uncontrolled biochemical parameters.

METHODS

We included 199 individuals with a T2DM diagnosis and 213 individuals without a T2DM diagnosis. Restriction fragment length polymorphism (RFLP) analyses were used to assess polymorphisms.

RESULTS

We found a risk association between T2DM and uncontrolled biochemical parameters in a Mexican population for the genotypes del/del of NFκβ, -174 and -572 of IL-6, C/C of IL-1β, -308 and -238 of TNFα, and T/T of LPL. In subjects without diabetes (controls), we found an association between the G/C genotype of the -572 polymorphism and the G/C and C/C genotypes of the -597 polymorphism of IL-6 with the risk of glucose levels > 131 mg/dL. Genotype C/C of polymorphism -174 of the IL-6 gene was associated with high triglyceride levels, and levels > 5.8% of HbA1c were associated with the G/A genotype of TNFα -308.

CONCLUSION

Here, we describe for the first time the relationship of T2DM risk and uncontrolled biochemical parameters with polymorphisms in the NFκβ, IL-6, TNFα, IL-1β, and LPL genes in a Mexican population. We also showed that for the population included in this study, there is an additive effect of the polymorphisms of the studied genes that considerably increases the risk of developing T2DM.We also showed that there are interactions between genes related to chronic inflammation that affect the risk of T2DM.

Association between tumor necrosis factor alpha gene polymorphisms and multiple myeloma risk: an updated meta-analysis

OBJECTIVE

This study aimed to investigate the relationship between tumor necrosis factor alpha (TNFα) polymorphisms and multiple myeloma (MM) risk.

METHODS

Eligible studies were retrieved from PubMed, the Cochrane Library, Embase, CNKI and the Wanfang database. Polymorphisms of TNFα-308 G/A, TNFα-857 C/T, and TNFα-238 G/A were analyzed based on the allele, recessive, dominant, and additive-dominant models. The meta-analysis was conducted using R 3.12 software. Odds ratio (OR) and 95% confidence intervals (CI) were used as evaluation indicators. Heterogeneity among studies was detected. Publication bias was evaluated. Sensitivity and power analyses were also conducted.

RESULTS

Significant associations existed between 'TT vs. CC' (OR = 2.3752, 95% CI = 1.1342-4.9740) and 'TT vs. CC + TC' (OR = 2.0802, 95% CI = 1.0250-4.2218) models of the TNFα-857 C/T gene and MM risk. There were no significant differences in other genetic models of TNFα-857 C/T or any genetic models of TNFα-308 G/A and TNFα-238 G/A. No significant publication bias existed among the studies. In addition, sensitivity analyses showed that meta-analysis results of all genetic models of the TNFα-238 G/A gene did not change after omitting one of these studies, but most models of TNFα-857 C/T and TNFα-308 G/A exhibited significant changes.

CONCLUSION

Our findings indicate that the 'TT vs. CC' and 'TT vs. CC + TC' of TNFα-857 C/T are correlated with MM risk. TNFα-857 C/T may be a risk factor for MM development. There is no association between TNFα-238/-308 polymorphisms and MM risk.

Association between tumor necrosis factor polymorphisms and rheumatoid arthritis as well as systemic lupus erythematosus: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) plays an important role in autoimmune diseases. Previous studies have investigated the association of TNF-α-238G/A (rs361525) and -308G/A (rs1800629) polymorphisms with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, no agreed conclusion had been made. Therefore, this meta-analysis was conducted to assess the associations of TNF-α-238G/A and -308G/A polymorphisms with RA and SLE risk. A systematic search was conducted in commonly used databases. Meta-analysis was performed by STATA12.0. A total of 43 studies were included. In the overall population, the TNF-α-238A allele was observed to be a protective factor for RA (A vs G: OR=0.75, 95%CI=0.57–0.99, P=0.040) and the TNF-α-308A allele was found to be a risk factor for SLE (A vs G: OR=1.78, 95%CI=1.45–2.19, P<0.001). However, no evidence of association was found between TNF-α-238 G/A polymorphism and SLE nor between -308G/A and RA. In the subgroup analysis, TNF-α-308A allele played a pathogenic role for RA in Latin Americans (A vs G: OR=1.46, 95%CI=1.15–1.84, P=0.002) and for SLE in Latin Americans (A vs G: OR=2.12, 95%CI=1.32–3.41, P=0.002) and Europeans (A vs G: OR=2.03, 95%CI=1.56–2.63, P<0.001), while it played a protective role for RA in Asians (A vs G: OR=0.54, 95%CI=0.32–0.90, P=0.017). No significant association was found between TNF-α-308G/A and SLE susceptibility in Africans and Asians. This meta-analysis demonstrated that TNF-α-238A was associated with decreased risk of RA rather than SLE, while -308G/A polymorphism was associated with SLE rather than RA. Stratification analysis indicated that different ethnicities would have different risk alleles.

Tumor necrosis factor alpha gene polymorphisms and haplotypes in Egyptian children with nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS) characterized by complex pathogenesis and clinical course with relapses; and needs novel breakthroughs for decades. Polymorphisms of cytokines genes including tumor necrosis factor alpha (TNF-α)may influence susceptibility to NS as well as different patients' steroid responses. In the current study, we demonstrated the potential roles of TNF-α promoter gene polymorphisms [-238, -308, -863] and haplotypes in susceptibility to childhood NS. Also, elucidating their possible influence on patients' steroid response and serum TNF-α level.

METHODS

This case-control study included 150 children suffering from NS and 150 healthy children. Polymerase chain reaction- restriction-fragment length polymorphism (PCR-RFLP) was performed to evaluate different TNF-α gene polymorphism. TNF-α serum levels were assessed by ELISA.

RESULTS

Serum TNF-α levels were significantly higher in NS patients than in controls and in steroid resistant NS (SRNS) than in steroid sensitive NS (SSNS) (P<0.001 for each). The risk of NS in patients carrying TNF-α-238GA genotype, and TNF-α-308GA or AA genotypes and allele A was significantly increased compared to healthy children. While no significant association was detected between TNF-α-863 and NS. The risk of resistance to steroid therapy was significantly high in NS carrying TNF-α-238GA genotype and A allele, TNF-α-308, AA genotypes and A allele, and TNF-α-863CA, AA genotypes and A allele. The TNF-α GCG (-308/-863/-238) haplotype has protective roles against NS and steroid resistance. However, the risk of NS was significantly high in TNF-α AAG and AAA haplotype's carriers compared to healthy children. Additionally the risk of steroid resistance was significantly high in TNF-α AAA haplotype's NS carrier (OR (95%CI): 2.2 (1.19-4.36), P=0.01). Moreover, we found significant higher serum TNF-α levels NS patients including SSNS and SRNS carrying mutant allele TNF-α-238GA genotype, -308GA and AA and -863CA and AA wild genotype's carriers than in those GG, GG and CC respectively. Interstingely, TNF-α levels were significantly higher in healthy children carrying TNF-α(-308/-863/-238) [AAG and AAA haplotypes], NS cases carrying [ACA, AAG, AAA haplotypes], and in SSNS carrying [ACA and AAA haplotypes] than in those carrying GCG, haplotype of wild alleles.

CONCLUSION

This study reported, for the first time, that TNF-α promoter gene polymorphisms and/or haplotypes are risk factors of NS and resistance to steroid among Egyptian children.

Tumour necrosis factor alpha promoter polymorphism, TNF-238 is associated with severe clinical outcome of falciparum malaria in Ibadan southwest Nigeria

Tumour necrosis factor (TNF) - α has been shown to play an important role in the pathogenesis of falciparum malaria. Two TNF promoter polymorphisms, TNF-308 and TNF-238 have been associated with differential activity and production of TNF. In order to investigate the association between TNF-308 and TNF-238 and the clinical outcome of malaria in a Nigerian population, the two TNF polymorphisms were analysed using Sequenom iPLEX Platform. A total of 782 children; 283 children with uncomplicated malaria, 255 children with severe malaria and 244 children with asymptomatic infection (controls) were studied. The distribution of TNF-308 and TNF-238 genotypes were consistent with the Hardy-Weinberg equilibrium. Distribution of both TNF polymorphisms differed significantly across all clinical groups (TNF-308: p=0.007; TNF-238: p=0.001). Further tests for association with severe malaria using genotype models controlling for age, parasitaemia and HbAS showed a significant association of the TNF-238 polymorphism with susceptibility to severe malaria (95% CI=1.43-6.02, OR=2.94, p=0.003237) The GG genotype of TNF-238 significantly increased the risk of developing cerebral malaria from asymptomatic malaria and uncomplicated malaria (95% CI=1.99-18.17, OR=6.02, p<0.001 and 95% CI=1.78-8.23, OR=3.84, p<0.001 respectively). No significant association was found between TNF-308 and malaria outcome. These results show thegenetic association of TNF-238 in the clinical outcome of malaria in Ibadan, southwest Nigeria. These findings add support to the role of TNF in the outcome of malaria infection. Further large scale studies across multiple malaria endemic populations will be required to determine the specific roles of TNF-308 and TNF-238 in the outcome of falciparum malaria infection.

Influence of cytokine and cytokine receptor gene polymorphisms on the degree of liver damage in patients with chronic hepatitis C

Hepatic fibrosis may be the result of repetitive injury to hepatocytes caused by HCV infection and the immune response to it. Cytokines regulate the inflammatory response to injury and modulate hepatic fibrogenesis. Single nucleotide polymorphisms (SNPs) located in cytokine genes may influence the cytokine expression and secretion that may contribute to hepatic fibrogenesis in HCV infection. The aim of this study was to determine the genotype of 22 SNPs found in the genes of 13 cytokines/cytokine receptors to assess the influence of polymorphic variants on the stage of liver damage in Brazilian patients chronically infected with HCV genotype 1 only. 141 unrelated patients were grouped according to their stage of fibrosis: absence of fibrosis or patients in the initial stages of fibrosis (F0-F2, n = 84), patients with advanced stages of fibrosis or cirrhosis (F3-F4, n = 57), without cirrhosis (F0-F3, n = 103), and with cirrhosis (F4, n = 38). The comparison of frequencies in each sub-sample was performed by 2 × 2 contingency tables using the chi-square or Fisher's exact test. Stepwise logistic regression was also used to assess independent associations between cirrhosis or fibrosis with polymorphic variants. The TNFA-308G:A genotype conferred increased risk of fibrosis and cirrhosis. The TNFA-238G:G genotype was associated with protection from cirrhosis. The IL10-819C:T genotype conferred protection from fibrosis and the IL1B-511C:T genotype conferred increased risk of cirrhosis. Some of these genotypes showed results on the borderline of statistical significance in the bivariate analysis. We conclude that gene variants of cytokines/receptors may influence liver damage in patients chronically infected by HCV genotype 1.

The rs361525 polymorphism does not increase production of tumor necrosis factor alpha by monocytes from alpha-1 antitrypsin deficient subjects with chronic obstructive pulmonary disease - a pilot study

Background

Polymorphisms in the TNF-A gene have been associated with chronic obstructive pulmonary disease (COPD) in some case-control studies. Previous work has shown that COPD/chronic bronchitis subjects with alpha-1 antitrypsin deficiency with the rs361525 TNF-α single nucleotide polymorphism have 100 times more TNF-in spontaneous sputum than disease matched controls. Our objective was to determine if the presence of this polymorphism increased TNF-α production by blood monocytes from COPD subjects.

Findings

Monocytes from 18 COPD/alpha-1 antitrypsin deficient subjects, with and without the rs361525 polymorphism, were cultured in the presence or absence of lipopolysaccharide. Cell-free supernatants were analyzed by ELISA and real-time PCR performed using cDNA from extracted RNA. Baseline expression of TNF-α messenger RNA was no different between the groups. No difference in messenger RNA or secreted protein was observed over time in un-stimulated cells. TNF-α messenger RNA expression and protein was not higher in lipopolysaccharide-stimulated monocytes from subjects with the polymorphism compared to cells from patients with the wild-type allele.

Conclusions

This small pilot study did not provide an explanation for the findings of earlier observations of the association of the rs361525 polymorphism with TNF-α in airways secretions. Possible reasons for the lack of concordance include the study of blood rather than tissue cells, the use of a single stimulant rather than biological secretions and the need for far greater subject numbers to overcome intra-subject variation in monocyte TNF-α production.

Influence of Genetic Polymorphisms of Tumor Necrosis Factor Alpha and Interleukin 10 Genes on the Risk of Liver Cirrhosis in HIV-HCV Coinfected Patients

OBJECTIVE

Analysis of the contribution of genetic (single nucleotide polymorphisms (SNP) at position -238 and -308 of the tumor necrosis factor alpha (TNF-α) and -592 of the interleukin-10 (IL-10) promotor genes) and of classical factors (age, alcohol, immunodepression, antirretroviral therapy) on the risk of liver cirrhosis in human immunodeficiency (HIV)-hepatitis C (HCV) virus coinfected patients.

PATIENTS AND METHODS

Ninety one HIV-HCV coinfected patients (50 of them with chronic hepatitis and 41 with liver cirrhosis) and 55 healthy controls were studied. Demographic, risk factors for the HIV-HCV infection, HIV-related (CD4+ T cell count, antiretroviral therapy, HIV viral load) and HCV-related (serum ALT concentration, HCV viral load, HCV genotype) characteristics and polymorphisms at position -238 and -308 of the tumor necrosis factor alfa (TNF- α) and -592 of the interleukin-10 (IL-10) promotor genes were studied.

RESULTS

Evolution time of the infection was 21 years in both patients' groups (chronic hepatitis and liver cirrhosis). The group of patients with liver cirrhosis shows a lower CD4+ T cell count at the inclusion in the study (but not at diagnosis of HIV infection), a higher percentage of individuals with previous alcohol abuse, and a higher proportion of patients with the genotype GG at position -238 of the TNF-α promotor gene; polymorphism at -592 of the IL-10 promotor gene approaches to statistical significance. Serum concentrations of profibrogenic transforming growth factor beta1 were significantly higher in healthy controls with genotype GG at -238 TNF-α promotor gene. The linear regression analysis demonstrates that the genotype GG at -238 TNF-α promotor gene was the independent factor associated to liver cirrhosis.

CONCLUSION

It is stressed the importance of immunogenetic factors (TNF-α polymorphism at -238 position), above other factors previously accepted (age, gender, alcohol, immunodepression), on the evolution to liver cirrhosis among HIV-infected patients with established chronic HCV infections.

Novel genetic association of TNF-α-238 and PDCD1-7209 polymorphisms with long-term non-progressive HIV-1 infection

OBJECTIVES

About 2-5% of HIV-1-infected subjects, defined as long-term non-progressors (LTNPs), remain immunologically stable for a long time without treatment. The factors governing this condition are known only in part, and include genetic factors. Thus, we studied 20 polymorphisms of 15 genes encoding proinflammatory and immunoregulatory cytokines, chemokines and their receptors, genes involved in apoptosis, and the gene HCP5.

METHODS

We analyzed 47 Caucasian LTNPs infected for >9 years, compared with 131 HIV-1-infected Caucasian patients defined as 'usual progressors'. The genotypes were determined by methods based upon PCR, and the statistical analysis was performed by univariate logistic regression.

RESULTS

The well-known CCR5Δ32 del32 allele, the cell death-related TNF-α-238 A and PDCD1-7209 T alleles, and HCP5 rs2395029 G, a non-coding protein associated with the HLA-B*5701, were found positively associated with the LTNP condition. No association was observed for other single nucleotide polymorphisms (SDF-1-801, IL-10-592, MCP-1-2518, CX3CR1 V249I, CCR2V64I, RANTES-403, IL-2-330, IL-1β-511, IL-4-590, FASL IVS3nt-169, FAS-670, FAS-1377, FASL IVS2nt-124, PDCD1-7146, MMP-7-181, and MMP7-153).

CONCLUSIONS

The novel genetic associations between allelic variants of genes TNF-α-238 and PDCD1-7209 with the LTNP condition underline the importance of host genetic factors in the progression of HIV-1 infection and in immunological preservation.

Analysis ofCOCHandTNFAVariants in East Indian Primary Open-Angle Glaucoma Patients

Glaucoma represents a heterogeneous group of optic neuropathies with a complex genetic basis. It is the second-largest cause of blindness in the world that reduces vision without warning and often without symptoms. Among 3 major subtypes of glaucoma, primary open-angle glaucoma (POAG) is the most common form. The focus of this study is to understand the molecular basis of the disease among Indian patients with respect to two genes, Cochlin (COCH) and tumor necrosis factor alpha (TNFA), selected based on reports of possible association with POAG. The genes were screened in patients and controls by PCR and direct sequencing. Although two novel changes (–450 C/T and –79 G/G) were identified in the 5′upstream region of COCH, no causal variant could be identified in either gene. –450 C/T was detected in 3 patients and 2 controls and –79 G/C in a single patient. Further, we did not observe significant association with the promoter SNPs of TNFA that had been previously reported to be associated with POAG pathogenesis. Thus, our study suggests lack of association of both COCH and TNFA with POAG pathogenesis.

TNF-α Polymorphisms in Juvenile Idiopathic Arthritis: Which Potential Clinical Implications?

Whether tumor necrosis factor alpha (TNF-α) gene polymorphisms (SNPs) influence disease susceptibility and treatment of patients with juvenile idiopathic arthritis (JIA) is presently uncertain. TNF-α is one of the most important cytokine involved in JIA pathogenesis. Several single nucleotide polymorphisms (SNPs) have been identified within the region of the TNF-α gene but only a very small minority have proven functional consequences and have been associated with susceptibility to JIA. An association between some TNF-α SNPs and adult rheumatoid arthritis (RA) susceptibility, severity and clinical response to anti-TNF-α treatment has been reported. The most frenquetly studied TNF-α SNP is located at -308 position, where a substitution of the G allele with the rare A allele has been found. The presence of the allele -308A is associated to JIA and to a poor prognosis. Besides, the -308G genotype has been associated with a better response to anti-TNF-α therapy in JIA patients, confirming adult data. Psoriatic and oligoarticular arthritis are significantly associated to the -238 SNP only in some works. Studies considering other SNPs are conflicting and inconclusive. Large scale studies are required to define the contribution of TNF-α gene products to disease pathogenesis and anti-TNF-α therapeutic efficacy in JIA.

Tumor necrosis factor gene variation predicts hippocampus volume in healthy individuals

BACKGROUND

Cytokines such as tumor necrosis factor (TNF) α have been implicated in neurodegeneration relevant to various neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative properties of cytokine genes on brain function and on hippocampus (HC) function in particular. In this study we investigate the neurodegenerative role of TNF polymorphisms on brain morphology in healthy individuals.

METHODS

Voxel-based morphometry was used in a large sample of healthy individuals (n = 303) to analyze the associations between genetic variants of TNF (rs1800629; rs361525) and brain morphology (gray matter concentration).

RESULTS

In a region of interest analysis of the HC, for rs1800629, we observed a strong genotype effect on bilateral HC gray matter concentration. Carriers of one or two A-alleles had significantly smaller volumes compared with GG-homozygotes. For rs361525, a similar effect was observed at almost the same location, with the A-allele resulting in smaller HC volumes compared with GG homozygotes.

CONCLUSIONS

The findings suggest a neurodegenerative role of the A-alleles of the TNF single nucleotide polymorphisms rs1800629 (-308G/A) and rs361525 (-238G/A) on hippocampal volumes in healthy individuals. Future imaging studies on the role of these single nucleotide polymorphisms in psychiatric populations of diseases with neurodegenerative components are warranted.

Association study between functional polymorphisms in the TNF-alpha gene and obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a prevalent psychiatric disorder of unknown etiology. However, there is some evidence that the immune system may play an important role in its pathogenesis. In the present study, two polymorphisms (rs1800795 and rs361525) in the promoter region of the cytokine tumor necrosis factor-alpha (TNFA) gene were genotyped in 183 OCD patients and in 249 healthy controls. The statistical tests were performed using the PLINK(®) software. We found that the A allele of the TNFA rs361525 polymorphism was significantly associated with OCD subjects, according to the allelic χ(2) association test (p=0.007). The presence of genetic markers, such as inflammatory cytokines genes linked to OCD, may represent additional evidence supporting the role of the immune system in its pathogenesis.

Lack of association between TNF-α promoter polymorphisms and multiple myeloma: a meta-analysis

Results of available literatures, which concerned the association between TNF-α promoter -238/-308 gene polymorphisms and multiple myeloma (MM), are of great controversy. A review was performed in studies reporting on the association between them. Odds ratios (ORs) with 95% confidence interval (CI) were used to evaluate the association. The pooled ORs indicated that there was no association between TNF-α -238/-308 polymorphisms and MM susceptibility in overall population. Sub-group analysis also confirmed that no evidence supported the relevance of TNF-α promoter -238/-308 gene polymorphisms with MM. Studies with large sample size and multi-ethnics may be needed to further explore the association between them.

Functional differences exist between TNFα promoters encoding the common -237G SNP and the rarer HLA-B*5701-linked A variant

A large body of functional and epidemiological evidence have previously illustrated the impact of specific MHC class I subtypes on clinical outcome during HIV-1 infection, and these observations have recently been re-iterated in genome wide association studies (GWAS). Yet because of the complexities surrounding GWAS-based approaches and the lack of knowledge relating to the identity of rarer single nucleotide polymorphism (SNP) variants, it has proved difficult to discover independent causal variants associated with favourable immune control. This is especially true of the candidate variants within the HLA region where many of the recently proposed disease influencing SNPs appear to reflect linkage with ‘protective’ MHC class I alleles. Yet causal MHC-linked SNPs may exist but remain overlooked owing to the complexities associated with their identification. Here we focus on the ancestral TNFα promoter −237A variant (rs361525), shown historically to be in complete linkage disequilibrium with the ‘protective’ HLA-B*5701 allele. Many of the ancestral SNPs within the extended TNFα promoter have been associated with both autoimmune conditions and disease outcomes, however, the direct role of these variants on TNFα expression remains controversial. Yet, because of the important role played by TNFα in HIV-1 infection, and given the proximity of the −237 SNP to the core promoter, its location within a putative repressor region previously characterized in mice, and its disruption of a methylation-susceptible CpG dinucleotide motif, we chose to carefully evaluate its impact on TNFα production. Using a variety of approaches we now demonstrate that carriage of the A SNP is associated with lower TNFα production, via a mechanism not readily explained by promoter methylation nor the binding of transcription factors or repressors. We propose that the −237A variant could represent a minor causal SNP that additionally contributes to the HLA-B*5701-mediated ‘protective’ effect during HIV-1 infection.

The relationship between tumor necrosis factor-α polymorphisms and hepatitis C virus infection: a systematic review and meta-analysis

BACKGROUND AND AIMS

Hepatitis C virus (HCV) is now recognized as one of the major causes of chronic liver disease. It is also one of the most common complications in maintenance hemodialysis (HD) patients. Tumor necrosis factor (TNF)-α promoter polymorphisms are observed to modulate TNF-α levels and thought to have an effect on susceptibility to HCV infection and the virus clearance, but the results are inconsistent. In this study, a systematic review and meta-analysis of the published data was performed to evaluate the relationship between the TNF-α-238, -308 polymorphisms and HCV infection.

METHODS

A total of 15 studies published were analyzed, which were indexed from PubMed, Embase, and CNKI databases (up to December 2010). All the data were analyzed using RevMan 4.2 software. Odds ratios (OR) and confidence intervals (95% CI) were calculated by fixed or random-effects models. Heterogeneity and publication bias across the studies were also explored.

RESULTS

The data showed no significant association between TNF-α-308, -238 gene polymorphisms and the susceptibility to HCV infection in the global group (p = 0.28, p = 0.38, respectively) and the sub-groups (European, American, African, and Asian). Besides, the distributions of TNF-α-308, -238 A/G alleles were also not significantly different between the persistent infection group and the spontaneous clearance group (p = 0.64, p = 0.75, respectively).

CONCLUSION

TNF-α-238, -308 gene polymorphisms might have no effect on susceptibility to HCV infection and the virus clearance. The findings of this meta-analysis have implications in the optimal prevention of HCV in HD patients and in the guidance of future research.

A study of TNF-alpha-238 and -308 polymorphisms with different outcomes of persistent hepatitis B virus infection in China

BACKGROUND

Two common functional polymorphisms in the promoter region of TNF-α located at nucleotides -238 (rs361525) and -308 (rs1800629) have been reported to regulate the expression of tumour necrosis factor alpha (TNF-α) and to be associated with hepatitis B virus (HBV) infection related diseases. However, their frequencies and associations with outcomes of HBV infection are not clear.

METHODS

We performed a genetic analysis of 956 Chinese Han subjects, who were divided into a HBV clearance group, an asymptomatic persistent infection group, a chronic hepatitis B group, two stages of liver cirrhosis (LC) groups, and three stages of hepatocellular carcinoma (HCC) groups to examine the relationship among HBV infection related diseases and these two single nucleotide polymorphisms (SNPs).

RESULTS

The phenotype of polymorphism -238 in all study samples displayed no significant differences among the eight subgroups. The distribution of -308 phenotypes among the eight groups differed significantly. For females, compared with persistent infection, LC patients had a significantly higher A allele frequency, and the association with cirrhosis progression was significant. For males, there were statistically significant differences in allele distributions between the persistent infection group and the HCC group. The AG haplotype (-A308, -G238) was associated significantly with HCC development.

CONCLUSIONS

The results of the present study indicate an association between rs1800629 and HBV related disease progression in the Chinese Han population. The association was different between genders, with the rs1800629 A allele being a risk factor for female carriers to develop LC, and the allele being a risk factor for male carriers to develop HCC, especially in subjects with an alcohol abuse or cigarette smoking history.

IL-10 and TNFalpha genotypes in SLE

The production of two regulators of the inflammatory response, interleukin 10 (IL-10) and tumor necrosis factor α (TNFα), has been found to be deeply deregulated in SLE patients, suggesting that these cytokines may be involved in the pathogenesis of the disease. Genetic polymorphisms at the promoter regions of IL-10 and TNFα genes have been associated with different constitutive and induced cytokine production. Given that individual steady-state levels of these molecules may deviate an initial immune response towards different forms of lymphocyte activation, functional genetic variants in their promoters could influence the development of SLE. The present review summarizes the information previously reported about the involvement of IL-10 and TNFα genetic variants on SLE appearance, clinical phenotype, and outcome. We show that, in spite of the heterogeneity of the populations studied, the existing knowledge points towards a relevant role of IL-10 and TNFα genotypes in SLE.

Tumor necrosis factor-alpha promoter variants and iron phenotypes in 785 hemochromatosis and iron overload screening (HEIRS) study participants

We sought to determine if TNF promoter variants could explain iron phenotype heterogeneity in adults with previous HFE genotyping. HEIRS Study participants genotyped for C282Y and H63D were designated as high transferrin saturation (TS) and/or serum ferritin (SF) (high TS/SF), low TS/SF, or controls. We grouped 191 C282Y homozygotes as high TS/SF, low TS/SF, or controls, and 594 other participants by race/ethnicity as high TS/SF or controls. Using denaturing high-performance liquid chromatography (DHPLC), we screened the TNF promoter region in each participant. We performed multiple regression analyses in C282Y homozygotes using age, sex, HEIRS Study Field Center, and positivity for TNF -308G-->A and -238G-->A to determine if these attributes predicted ln TS or ln SF. DHPLC analyses were successful in 99.3% of 791 participants and detected 9 different variants; TNF -308G-->A and -238G-->A were the most prevalent. Most subjects positive for variants were heterozygous. The phenotype frequencies of each variant did not differ significantly (p<0.05) across subgroups of C282Y homozygotes, or across white, black, Hispanic, and Asian non-C282Y homozygotes subgrouped as high TS/SF phenotypes and controls. TNF -308G-->A positivity was a significant predictor of initial screening ln TS but not ln SF; TNF -238G-->A predicted neither ln TS nor ln SF. We conclude that TNF promoter variants have little, if any, effect on initial screening SF values in adults with or without C282Y homozygosity. We cannot exclude a possible association of homozygosity for TNF promoter variants on TS and SF values.

Cytokine gene polymorphisms and sudden infant death syndrome

AIM

Several studies indicate that the mucosal immune system is stimulated in cases of sudden infant death syndrome (SIDS), and our hypothesis is that this immune reaction is because of an unfavourable combination of functional polymorphisms in the cytokine genes.

METHODS

Thus, in this study, single nucleotide polymorphisms (SNPs) in the genes encoding IL-6, IL-8, IL-12, IL-13, IL-16, IL-18 and IFNgamma were investigated in 148 SIDS cases, 56 borderline SIDS cases, 41 cases of infectious death and 131 controls.

RESULTS

Regarding genotype distribution, no differences between the investigated groups were found. However, in the SIDS group, the genotypes IL-8 -251AA/AT and IL-8 -781CT/TT were significantly more frequent in the SIDS cases found dead in a prone sleeping position, compared with SIDS cases found dead in other sleeping positions. In addition, there was an association between fever prior to death and the genotype IL-13 +4464GG in the cases of infectious death.

CONCLUSION

This study indicates that specific interleukin genotypes are a part of a genetic make up that make infants sleeping prone at risk for SIDS.

Role of the TNF-α promoter polymorphisms for development of multiple myeloma and clinical outcome in thalidomide plus dexamethasone

The role of TNF-α promoter polymorphisms in the development of multiple myeloma (MM) were tested in 210 patients and 218 healthy individuals and their impact on the clinical outcome were evaluated in 98 patients treated with thalidomide and dexamethasone (Thal+Dex) regimen. MM patients carrying the GA genotype (P=0.01) or GA+AA genotypes (P=0.02) at the TNF-α -308 polymorphism were associated with a reduced risk for MM. The TNF-α -238 GA+AA genotypes were associated with a significant enhancement in the progression-free survival (PFS) (P=0.009) and a better overall survival (OS) (P=0.088).

Does the simultaneous tumor necrosis factor receptor 2, tumor necrosis factor promoter gene polymorphism represent a higher risk for alcoholic liver disease?

BACKGROUND AND AIM

Tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine that seems to play a crucial role in the pathogenesis of alcoholic liver disease (ALD). TNF-alpha exerts its effects by binding to specific receptors (TNFR); the polymorphism of TNFRII T587G has been associated with increased TNF apoptotic response and its presence may increase the risk to develop liver disease. The aim of this study was to evaluate the prevalence of the TNF-alpha G238A promoter and TNFRII polymorphisms, individually or simultaneously, in ALD.

METHODS

TNF-alpha G238A and TNFRII T587G polymorphisms were studied in 103 unrelated patients with ALD (biopsy confirmed or clinical evidence) and in 76 heavy drinkers without liver disease (NLD). Single nucleotide polymorphism gene was detected by a polymerase chain reaction-restriction fragment length polymorphisms method. All patients had, at least, a 5 year history of alcohol consumption greater than 80 g/day.

RESULTS

TNF-alpha G238A allele frequency was similar in both groups. TNFRII T587G allele frequency was slightly higher in the ALD group than in the NLD group (21 vs. 18%, P=NS). TNF-alpha G238A and TNFRII T587G were simultaneously present in six ALD patients and in none of NLD patients (P=0.04).

CONCLUSION

Although individually there was no association between TNFRII T587G or TNF-alpha G238A polymorphisms and ALD, this study suggests that the presence of both polymorphisms may enhance the susceptibility for ALD. TNF-alpha G238A may increase TNF-alpha production, which when associated with TNFRII T587G, can further exacerbate TNF-alpha response leading to a greater risk of ALD.

Cytokine and cytokine receptor gene polymorphisms and their functionality

Cytokines, signaling proteins produced by a variety of cell types, are essential for the development and functioning of both innate and adaptive immune response. Cytokine gene expression is tightly regulated, and aberrant expression from environmental and genetic polymorphism has been implicated in a range of diseases, susceptibility to infections, and responses to treatment. This review concentrates on the functionality of cytokine and cytokine receptor gene polymorphisms; it is through these variants that genuine disease-associations are based. Several mechanisms for single nucleotide polymorphism (SNP) functionality are present within cytokine genes including: amino acid changes (IL-6R, IL-13, IL-1alpha), exon skipping (IL-7Ralpha), proximal promoter variants (IL-1beta, IL-Ra, IL-2, IL-6, IL-10, IL-12, IL-13, IL-16, TNF, IFN-gamma, TGF-beta), distal promoter variants (IL-6, IL-18) and intronic enhancer variants (IL-8).

Tumor necrosis factor SNP haplotypes are associated with iron deficiency anemia in West African children

Plasma levels of tumor necrosis factor-alpha (TNF-alpha) are significantly raised in malaria infection and TNF-alpha is thought to inhibit intestinal iron absorption and macrophage iron release. This study investigated putative functional single nucleotide polymorphisms (SNPs) and haplotypes across the major histocompatibility complex (MHC) class III region, including TNF and its immediate neighbors nuclear factor of kappa light polypeptide gene enhancer in B cells (lkappaBL), inhibitor-like 1 and lymphotoxin alpha (LTA), in relation to nutritional iron status and anemia, in a cohort of 780 children across a malaria season. The prevalence of iron deficiency anemia (IDA) increased over the malaria season (P < .001). The TNF(-308) AA genotype was associated with an increased risk of iron deficiency (adjusted OR 8.1; P = .001) and IDA (adjusted OR 5.1; P = .01) at the end of the malaria season. No genotypes were associated with IDA before the malaria season. Thus, TNF appears to be a risk factor for iron deficiency and IDA in children in a malaria-endemic environment and this is likely to be due to a TNF-alpha-induced block in iron absorption.

Rapid genotyping of tumor necrosis factor alpha with fluorogenic hybridization probes on the LightCycler

Genotyping of tumor necrosis factor alpha (TNF-alpha) has become an important procedure in the selection of high-risk population of septic shock and prevention from death due to septic shock. We present a single-tube method for TNF-alpha genotyping that performed on the LightCycler by melting curve analysis with allele-specific fluorescent probe. A fragment covering the polymorphic site is amplified in the presence of two fluorescently labeled hybridization probes. During amplification, probe hybridization is observed as fluorescence increases every cycle as the product accumulates during amplification. A single base mismatch resulted in a melting temperature (Tm) shift of 7-8 degrees C, allowing for the easy distinction of a common type allele from the polymorphic allele. Using this method, genotyping of 104 samples was completed within 1 h without the need for any post-PCR sample manipulation, thereby eliminating the risks of end-product contamination and sample tracking errors. The genotypes determined with the LightCycler were identical when compared with a conventional sequencing. The simplicity, speed, and accuracy of real-time PCR analysis using FRET probes make it the method of choice in the clinical laboratory for genotyping of a variety of human DNA polymorphisms and mutations.

Serum TNF-alpha levels in relation to alcohol consumption and common TNF gene polymorphisms

Tumor necrosis factor-alpha (TNF-alpha) mediates alcohol-induced organ dysfunction, including alcoholic hepatitis. Variations in the TNF-alpha gene may underlie the individual predisposition to alcoholic liver disease. Measurement of serum TNF-alpha levels has become a routine in clinical practice. The study was aimed at investigating the level of serum TNF-alpha levels in adults and analyzing its relationship with different levels of alcohol consumption, as well as the potential interaction between alcohol consumption and common TNF-alpha gene polymorphisms in relation to TNF-alpha levels and liver disease. Serum TNF-alpha was measured in a random sample of 459 individuals from a general adult population and in 137 hospital-admitted alcoholics. Three common TNF-alpha gene polymorphisms (-238G> A, -308G> A, and -857C> T) were investigated in 419 of these individuals. In the general adult population, the TNF-alpha levels were similar in alcohol abstainers and alcohol drinkers. Alcoholics admitted to the hospital showed the highest TNF-alpha levels, which were correlated with liver dysfunction. We found no evidence of an interaction between alcohol consumption and TNF-alpha gene polymorphisms in relation to TNF-alpha levels. Carriers of the TNF -238A allele tended to have a higher prevalence of advanced liver disease than -238G homozygotes, confirming previous reports. In conclusion, light-to-moderate drinking had no significant effect on the levels of serum TNF-alpha levels. Serum TNF-alpha levels are elevated in alcoholics independently of common TNF gene polymorphisms.

TNF-alpha polymorphisms are associated with obsessive-compulsive disorder

INTRODUCTION

Several lines of evidence support an immunologic involvement in obsessive-compulsive disorder (OCD): the increased prevalence of OCD in patients with rheumatic fever (RF), and the aggregation of obsessive-compulsive spectrum disorders among relatives of RF probands. Tumor necrosis factor alpha is a proinflammatory cytokine involved in RF and other autoimmune diseases. Polymorphisms in the promoter region of the TNFA gene have been associated with RF. Given the association between OCD and RF, the goal of the present study was to investigate a possible association between polymorphisms within the promoter region of TNFA and OCD.

MATERIALS AND METHODS

Two polymorphisms were investigated: -308 G/A and -238 G/A. The allelic and genotypic frequencies of these polymorphisms were examined in 111 patients who fulfilled DSM-IV criteria for OCD and compared with the frequencies in 250 controls.

RESULTS

Significant associations were observed between both polymorphisms and OCD. For -238 G/A, an association between the A allele and OCD was observed (chi(2)=12.05, p=0.0005). A significant association was also observed between the A allele of the -308 G/A polymorphism and OCD (chi(2)=7.09, p=0.007). Finally, a haplotype consisting of genotypes of these two markers was also examined. Significant association was observed for the A-A haplotype (p=0.0099 after correcting for multiple testing).

DISCUSSION

There is association between the -308 G/A and -238 G/A TNFA polymorphisms and OCD in our Brazilian sample. However, these results need to be replicated in larger samples collected from different populations.

Pharmacogenetics of anti-TNF treatment in patients with rheumatoid arthritis

TNF-blocking strategies are widely used in the treatment of rheumatoid arthritis (RA). Three anti-TNF agents are registered for use in RA: etanercept, infliximab and adalimumab. Although anti-TNF therapy is very effective in controlling disease activity and slowing down radiological damage, prolonged response is only seen in approximately 70% of the patients. The causes for nonresponse in the remaining patients have not yet been elucidated. Pharmacogenetic studies focusing on genes involved in RA etiology (and/or progression) and in the pharmacokinetics of TNF-blocking agents have identified markers associated with anti-TNF treatment outcome. In the future, more exhaustive, less hypothesis-driven search strategies are expected to discover additional markers. Identification of these markers might be viewed as the first step towards tailored TNF-blocking therapy for patients with RA. Nevertheless, replication and large prospective studies will be needed to demonstrate the validity of the identified genetic markers before implementation into daily clinical practice.

TNF-α Gene Promoter -238G>A and -308G>A Polymorphisms Alter Risk of Psoriasis Vulgaris: A Meta-Analysis

Tumor necrosis factor-alpha (TNF-alpha) is a major proinflammatory cytokine and involved in the etiology of psoriasis. The -238G>A and -308G>A polymorphisms influence the transcription of the TNF-alpha gene and have been implicated in psoriasis risk. However, the results from the published studies on the association between TNF-alpha polymorphisms and psoriasis risk are conflicting. Our meta-analysis of a total of 997 psoriasis cases and 943 control subjects from eight published case-control studies for the -238G>A polymorphism and of 1,156 psoriasis cases and 1,083 control subjects from 10 published case-control studies for the -308G>A polymorphism showed that a significantly increased risk was associated with the variant GA+AA genotypes of -238G>A, compared with the GG genotype (odds ratio (OR) 2.60, 95% confidence interval (95% CI) 1.48-4.56), whereas a significantly reduced psoriasis risk was associated with the variant GA+AA genotypes of the -308G>A compared with the GG genotype (OR 0.57, 95% CI 0.45-0.71). Our findings suggest that TNF-alpha -238G>A and -308G>A polymorphisms might be used as biomarkers for psoriasis risk prediction. A single larger study with thousands of subjects and biochemical and biological characterization is warranted to evaluate further the role of -238G>A and -308G>A polymorphisms and psoriasis risk in a population of various ethnicities.

Investigation of functional gene polymorphisms interleukin-1β, interleukin-6, interleukin-10 and tumor necrosis factor in individuals with oral lichen planus

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease. There are some studies in the literature demonstrating association between cytokines genes polymorphisms and susceptibility to develop some immune-mediate conditions. The purpose of this study was to investigate cytokine gene polymorphisms in a sample of Brazilian patients with OLP. Fifty-three patients with OLP (mean age = 43.1 years; range 20-68 years) and 53 healthy volunteers (mean age = 42.9 years; range 21-67) were genotyped for IL-1beta +3954 (C/T), IL-6-174 (G/C), IL-10-1082 (G/A) and TNFA-308 (G/A) gene polymorphisms. Statistical analysis was based on the use of logistic regression (P-values below 0.05 were considered as significant). IL-6 and TNFA homozygous genotypes were significantly more often detected in OLP patients. These genotypes were associated with an increased risk of OLP development (OR 6.89 and 13.04, respectively). IL-1beta and IL-10 gene polymorphisms were not related to OLP development. Our findings clearly demonstrate an association between inheritance of IL-6 and TNFA gene polymorphisms and OLP occurrence, thus giving additional support for genetic basis of this disease.

TNF alpha promoter polymorphisms analysis in benign and malignant breast lesions

Polymorphisms in genes involved in the complex mechanisms of carcinogenesis may affect the susceptibility to cancer. The multifunctional cytokine tumor necrosis factor alpha (TNF alpha) has an important role in the pathogenesis of inflammatory, autoimmune and malignant diseases. It has a large spectrum of activities, including both antitumorigenic and protumorigenic. In recent years, several TNF alpha promoter polymorphisms have been identified and related to the expression level of cytokine and to the susceptibility to solid tumors. The aim of our study was to investigate the frequency of three TNF alpha promoter polymorphisms (-1031, -308 and -238) in benign (fibrocystic changes) and malignant (invasive carcinoma) breast lesions. Using "real-time" PCR SNP analysis these polymorphisms were determined in 76 patients with benign and 158 patients with malignant breast lesions. The high expression genotypes at any of the three SNP polymorphisms were more frequent in invasive breast carcinoma (in 81 of 158 examined, 51.3%) than in fibrocystic changes (in 33 of 76 examined, 43.4%). The combined frequency of high production genotypes (-1031 T/C and C/C, -308 G/A and A/A and -238 G/A and A/A) was higher in patients with invasive breast carcinoma than in those with fibrocystic changes. However, these results were not statistically significant. Further studies on a larger group of patients are needed to evaluate the significance of potential differences in TNF alpha genotypes in different breast lesions.

T helper 1 type cytokines polymorphisms: association with susceptibility to Behçet’s disease

The pathogenesis of Behçet's disease (BD) is not fully understood and immunological abnormalities and genetic factors have been investigated. Because serum concentrations of mainly T helper 1 (Th1) type cells have been reported to be increased in BD, we aimed to investigate whether certain cytokine polymorphisms might represent a risk factor for developing BD. We genotyped 80 patients with BD and 105 healthy controls for interleukin (IL)-1 alpha (T/C -889), IL-1 beta (C/T -511, T/C +3962), IL-1R (C/T pst11970), IL-1RA (T/C mspa111100), IL-2 (T/G -330), IL-12 (C/A -1188), interferon (IFN)-gamma (A/T UTR 5644), and TNF-alpha (G/A -238) polymorphisms. Analyses of cytokine polymorphisms were performed with PCR-SSP. The genotype and allele frequencies of the patients and controls were compared and the association between the polymorphisms of the cytokines with the clinical findings was investigated. Genotype distribution showed significant differences between the patients and the controls for the IL-1 alpha -889, IL-1 beta -511, IL-1 beta +3962, IL-1R, IL-12, IFN- gamma, and TNF-alpha cytokines. We didn't observe significant difference in genotypic frequencies of IL-1RA and IL-2 in our study. Comparison of the IL-1 alpha -889, IL 1 beta -511, and IL 1 beta +3962 genotype frequencies showed significant increase in CC genotype between the patients and the controls. The individuals with IL-1R TT polymorphism had a higher risk for BD compared to patients with CT/CC polymorphism. Comparison of IL-12, IFN- gamma, and TNF-alpha, genotype frequencies showed significant increase in CA, AA, and AA genotypes between the patients and controls, respectively. The frequencies of genotypes according to the clinical features of the patients with BD did not show a significant difference (p>0.05). Our study suggests that development of BD might be determined by various cytokine gene polymorphisms. However, further studies on larger numbers of cases are needed before definite conclusions can be drawn.

Contribution for new genetic markers of rheumatoid arthritis activity and severity: sequencing of the tumor necrosis factor-alpha gene promoter

The objective of this study was to assess whether clinical measures of rheumatoid arthritis activity and severity were influenced by tumor necrosis factor-alpha (TNF-alpha) promoter genotype/haplotype markers. Each patient's disease activity was assessed by the disease activity score using 28 joint counts (DAS28) and functional capacity by the Health Assessment Questionnaire (HAQ) score. Systemic manifestations, radiological damage evaluated by the Sharp/van der Heijde (SvdH) score, disease-modifying anti-rheumatic drug use, joint surgeries, and work disability were also assessed. The promoter region of the TNF-alpha gene, between nucleotides -1,318 and +49, was sequenced using an automated platform. Five hundred fifty-four patients were evaluated and genotyped for 10 single-nucleotide polymorphism (SNP) markers, but 5 of these markers were excluded due to failure to fall within Hardy-Weinberg equilibrium or to monomorphism. Patients with more than 10 years of disease duration (DD) presented significant associations between the -857 SNP and systemic manifestations, as well as joint surgeries. Associations were also found between the -308 SNP and work disability in patients with more than 2 years of DD and radiological damage in patients with less than 10 years of DD. A borderline effect was found between the -238 SNP and HAQ score and radiological damage in patients with 2 to 10 years of DD. An association was also found between haplotypes and the SvdH score for those with more than 10 years of DD. An association was found between some TNF-alpha promoter SNPs and systemic manifestations, radiological progression, HAQ score, work disability, and joint surgeries, particularly in some classes of DD and between haplotypes and radiological progression for those with more than 10 years of DD.

Association of TNF-.ALPHA. Gene Promoter C-857T Polymorphism with Higher Serum LDL Cholesterol Levels and Carotid Plaque Formation in Japanese Patients with Type 2 Diabetes

Little has been known about the role of tumor necrosis factor-alpha (TNF-alpha) gene polymorphisms in metabolic syndrome and atherosclerosis in type 2 diabetes, although TNF-alpha was reported to be involved in these conditions. We examined the association of TNF-alpha gene promoter polymorphisms, G-238A, G-308A, C-857T, C-863A, and T-1031C, with metabolic syndrome and surrogate markers of atherosclerosis in Japanese patients with type 2 diabetes. DNA was obtained from 162 patients and TNF-alpha gene promoter polymorphisms determined by direct sequencing. Allelic frequency of -238A, -308A, -857T, -863A, and -1031C was 0.6%, 2.2%, 11.1%, 16.7%, and 15.7%, respectively. Association of the gene polymorphisms with a number of variables, because of their high frequency, was analyzed in the latter 3 polymorphisms. There were no significant differences in components of metabolic syndrome and variables affecting atherosclerosis, except in case of serum low-density-lipoprotein cholesterol (LDL-C) (111+/-33 vs 125+/-39 mg/dl, p<0.05) between -857C/C and -857(C/T+T/T). In contrast, no significant differences were found in these markers between -863C/C and -863(C/A+A/A) and between -1031T/T and -1031(T/C+C/C). Furthermore, 87% of the patients with -857(C/T+T/T) and 64% with -857C/C had carotid plaques (p<0.05). There was no difference in proportion of patients treated with medications such as statins, fibrates, oral hypoglycemic agents, insulin, or antihypertensive drugs between -857C/C and -857(C/T+T/T). These data imply that TNF-alpha gene polymorphism (C-857T) is likely associated with higher serum LDL-C levels and carotid plaque formation in Japanese patients with type 2 diabetes.

Associations of tumour necrosis factor alpha promoter polymorphisms at position -308 and -238 with clinical characteristics of chronic hepatitis C

The aim of this study was to investigate the association between G vs A transitions in the promoter region of the tumour necrosis factor (TNF) alpha at positions -308 (TNF308.2) and -238 (TNF238.2) and clinical features of chronic hepatitis C (CHC). These two promoter TNF-alpha variants were determined in 250 biopsy-proven CHC patients by polymerase chain reaction amplification, followed by the Restriction Fragment Length Polymorphism (RFLP) method. The distribution of -308 and -238 TNF-alpha promoter genotypes were TNF308.1/TNF308.1: 187 (74.8%), TNF308.1/TNF308.2: 57 (22.8%) and TNF308.2/TNF308.2: 6 (2.4%), respectively, and TNF238.1/TNF238.1: 247 (98.8%) and TNF238.1/TNF238.2: 3 (1.2%). The frequencies of the TNF308.2 and TNF238.2 promoter alleles were 13.8% and 0.6%. Increased TNF308.2 allele copy numbers were significantly associated with increased frequency of lower pretreatment hepatitis C virus (HCV) RNA levels (<800 000 IU/mL; P = 0.031) and severe fibrosis stage (F3-F4; P = 0.006) and higher mean fibrosis score (P = 0.007). The higher cytokine production (with one or two TNF308.2 alleles) was correlated significantly with lower pretreatment HCV RNA levels with a lower mean HCV RNA level (P = 0.024) and increased frequency of lower pretreatment HCV RNA levels (<800 000 IU/mL; P = 0.017). Stepwise logistic regression showed that higher fibrosis score and low HCV RNA levels were independently related to the TNF308.2 allele [odds ratio (95% CI): 1.385 (1.127-1.702) and 0.698 (0.488-0.990)]. We conclude that inheritance of the TNF-alpha promoter genotype at the position -308 appears to be associated with variability in severity of fibrosis and viral load in chronic HCV infection.

Association of polymorphisms within the promoter region of the tumor necrosis factor-alpha with clinical outcomes of rheumatic fever

Rheumatic fever (RF)/rheumatic heart disease (RHD) is an inflammatory disease with a complex etiology in which Group A streptococci within a genetically susceptible host untreated for strep-throat may deviate the innate and adaptive arms of the immune system towards recognition of autoantigens. The TNFA gene has been associated with a number of autoimmune diseases, including RF. We investigated whether the G-308A and G-238A polymorphisms of the TNFA gene are associated with clinical outcomes of RF in a cohort of 318 patients and 281 healthy controls (HC). Both polymorphisms showed borderline associations with RF (TNFA -308G/A, OR=1.4 [1-2.2], P=0.026; TNFA -238G/A, OR=1.9 [1-3.3], P=0.015). The presence of either one of the minor alleles (-308A and -238A) was more common among patients with RF/RHD than controls (P=0.0006). Stratification of patients according to clinical phenotype also showed significant associations between presence of either one of the minor alleles and RHD (Pc=0.0006) when compared with controls. This association was stronger with the development of aortic valve lesions. In contrast, there was no association between genotype and Sydenham's chorea or RF patients with mild carditis. In conclusion, we show that the TNFA is a susceptibility locus for RF. The ability to predict which RF patients will develop valve lesion may have therapeutic, economic and social implications.

-238 G>A polymorphism of tumor necrosis factor alpha gene (TNFA) is associated with alcoholic liver cirrhosis in alcoholic Spanish men

BACKGROUND

The tumor necrosis factor alpha gene (TNFA) has been recently associated to alcoholic steatohepatitis. We have analyzed the distribution of genotypes and alleles of two polymorphisms at positions -238 and -308 in the promoter region of the TNFA gene in a Spanish male population of alcoholics with and without alcoholic liver cirrhosis.

METHODS

149 male alcoholics (84 without alcoholic liver disease, and 65 with alcoholic liver cirrhosis) and 90 control subjects were included. Genotyping was done by polymerase chain reaction and digestion with restriction enzymes.

RESULTS

No significant differences in the distribution of genotypes and alleles of the -308 TNFA gene polymorphism were observed between alcoholics and non-alcoholics, or between alcoholics with liver cirrhosis and those without liver disease. However, we found an association between the -238 TNFA polymorphism and alcoholic liver cirrhosis; the frequency of the heterozygous genotype being significantly higher in alcoholics with cirrhosis than in those without liver damage.

CONCLUSION

The -238 TNFA-A allele is associated with a higher risk to develop alcoholic liver cirrhosis. This polymorphism could be considered as a genetic factors that confer predisposition to suffer liver cirrhosis in the alcoholic population of Castile and León.

TNF polymorphisms in Alzheimer disease and functional implications on CSF beta-amyloid levels

Alzheimer disease (AD), vascular dementia, and stroke are all associated with inflammation though their respective initiating factors differ. Recently a polymorphism in the proinflammatory cytokine tumor necrosis factor (TNF), in association with apolipoprotein E (APOE), was reported to increase AD risk. Two SNPs, rs1799724 (-850C>T; NT_007592.14:g.22400733C>T) and rs1800629 (-308G>A; [NT_007592.14:g.22401282G>A]), and the APOE polymorphism were genotyped in 506 patients with sporadic AD and in 277 cognitively healthy controls. In a subset of 90 individuals we also investigated whether these SNPs exerted any functional effects on cerebrospinal fluid (CSF) beta-amyloid (Abeta) levels. The frequency of the rs1799724 genotypes and the rs1799724-T allele were significantly different in AD individuals (P=0.009; odds ratio [OR], 1.63; 95% confidence interval [CI], 1.13-2.34), while the rs1800629 SNP was not associated with AD. Significant interaction was observed between the rs1799724-T and APOE epsilon4 alleles in that the rs1799724-T allele significantly modified risk associated with possession of the epsilon4 allele only (epsilon4 in absence of rs1799724-T: OR, 2.92; 95% CI, 2.00-4.27; epsilon4 in presence of rs1799724-T: OR, 6.65; 95% CI, 3.26-13.55; P=0.03). Haplotyping analysis revealed a significant overrepresentation of an rs1799724-T/rs1800629-G haplotype in AD (P=0.012; OR, 1.60; 95% CI, 1.11-2.29), although to a lesser degree than rs1799724-T alone. Further, the rs1799724-T allele was found to be associated with lower levels of CSF Abeta42 (P=0.023), thus corroborating the genetic findings. Inheritance of the rs1799724-T allele appears to synergistically increase the risk of AD in APOEepsilon4 carriers and is associated with altered CSF Abeta42 levels. Further investigations are warranted to assess the significance of these novel findings.

Association of TNF-α polymorphism with susceptibility to and severity of non-small cell lung cancer

BACKGROUND

Genetic polymorphisms in the promoter region of the tumor necrosis factor-alpha (TNF-alpha) gene are involved in the regulation of expression levels and have been associated with various inflammatory and malignant conditions. We have investigated two polymorphisms in the promoter region of the TNF-alpha gene (-308 G/A and -238 G/A) for their role in the susceptibility to and severity of non-small cell lung cancer (NSCLC), by means of an allelic association study.

METHODS

Using a case-control study design, lung cancer patients (n = 202) and appropriate age- and sex-matched controls recruited from the health check-up unit (n = 205) were subjected to genotype analysis for these polymorphisms, using a high-throughput allelic discrimination method.

RESULTS

Genotype was analyzed using the polymerase chain reaction-restriction fragment length polymorphism technique with genomic DNA isolated from peripheral blood lymphocytes. Overall, the distribution of the genotype frequencies of TNF-alpha-308 A/G and -238 A/G were significantly different between the lung cancer patients and the healthy controls, and also different between patients with lung cancers of various stages (p < 0.0001). Logistic regression analysis revealed that higher odds ratios (ORs) for lung cancer were seen for individuals with TNF-alpha-308 AA/GA genotypes against GG genotype (an OR of 3.75, 95% CI 2.38-5.92, p < 0.0001), and lower ORs were seen for individuals with TNF-alpha-238 AA/GA genotypes against GG genotype (an OR of 0.26, 95% CI 0.13-0.50, p < 0.0001). The patients carrying a homologous AA or heterologous GA genotype at TNF-308 (p = 0.017), or a homologous GG genotype at TNF-238 (p = 0.001), had a tendency to advanced disease.

CONCLUSIONS

A significant association between the 308 G/A and 238 G/A polymorphisms in the promoter region of TNF-alpha and the susceptibility to lung cancer was demonstrated. Also, these two polymorphisms were associated with the severity of lung cancer. The -308 A allele has a promotive effect for lung cancer development and progression, whereas the -238 A allele has a protective function against lung cancers.

No allelic variant associations of the IL-1 and TNF gene polymorphisms in the susceptibility to duodenal ulcer disease

Recent studies have reported the association of a pro-inflammatory profile of genetic polymorphisms in IL-1B, IL-1RN, TNF-A, and IL-10 genes with an increased risk of non-cardia gastric cancer. Because gastric cancer and duodenal ulcer are mutually exclusive outcomes of Helicobacter pylori infection, we aimed to investigate possible allelic variant associations of several functional polymorphisms in the IL-1B, IL-1RN, TNFA, and LTA genes in the susceptibility to duodenal ulcer. Genomic DNA from 118 patients with duodenal ulcer and 97 healthy controls was typed for the IL-1B polymorphisms at positions -511, -31, and +3954, the VNTR polymorphism in intron 2 of the IL-1RN gene, the TNFA-308, TNFA -238, and the NcoI and BsI LTA polymorphisms by PCR, SSCP and TaqMan assays. H. pylori infection and non-steroidal anti-inflammatory drugs (NSAIDs) use was investigated in patients and controls. Logistic regression analysis identified H. pylori infection (OR: 12.86; 95%CI: 3.85-43), NSAID use (OR: 11.95; 95%CI: 4.19-34.05), and family history-ulcer (OR: 3.79; 95%CI: 1.68-8.54) as independent risk factors for duodenal ulcer. When the effect of the combinations of IL-1 and TNF genotypes was studied we found that the distribution of all possible combinations of these eight polymorphisms was similar in duodenal ulcer patients and controls. The simultaneous carriage of alleles IL-1RN*2/IL-1B -31T/IL-1B -511C/IL-IB +3954C/TNF-HaplotypeE negative (termed in some studies as 'low-producing' alleles) was increased in H. pylori-positive duodenal ulcer patients compared to H. pylori-infected healthy controls (10.5% vs. 5.9%) although the difference did not reach statistical significance (OR: 1.85; 95%CI: 0.57-5.99, P = 0.41). Moreover, no differences were found with respect to H. pylori status, NSAID use, age, gender, smoking habit, type of complication, recurrence of the ulcer, and need for surgical treatment. Our data show no association between allelic variants of IL-1 and TNF gene polymorphisms in the susceptibility to and final outcome of duodenal ulcer.