TNF-308 gene polymorphism and tuberculosis susceptibility: a meta-analysis involving 18 studies

Low levels of TNFA gene expression seem to favor the development of pulmonary tuberculosis in a population from the Brazilian Amazon

TNF-α is a Th1 cytokine profile active in the control of Mycobacterium tuberculosis infection, IL-10 is associated with persistence of bacterial infection. The aim of the study was to investigate the association of TNFA -308G/A and IL10 -819C/T polymorphisms and TNFA and IL10 gene expression levels with pulmonary and extrapulmonary tuberculosis (n = 200) and control (n = 200). The individuals were submitted to genotyping and quantification of gene expression performed by real-time quantitative polymerase chain reaction (qPCR). No association was observed between the frequencies of polymorphisms evaluated and pulmonary tuberculosis. The frequency of polymorphic genotypes for TNFA -308G/A were associated with the extrapulmonary tuberculosis (p = 0.0445). The levels of TNFA expression were lower in the pulmonary tuberculosis group than in the control (p = 0.0009). There was a positive correlation between the levels of TNFA and IL10 in patients with pulmonary tuberculosis (r = 0.560; p = 0.0103). Reduced levels of TNFA expression may promote the formation of an anti-inflammatory microenvironment, favoring the persistence of the bacillus in the host, contributing to the establishment of pulmonary tuberculosis.

Exposure to biomass smoke, cigarettes, and alcohol modifies the association between tumour necrosis factor (-308G/A, -238G/A) polymorphisms and tuberculosis in Mexican carriers

INTRODUCTION

Exposure to biomass smoke, cigarettes, alcohol, and the impairment of immunoregulation are considered to be risk factors for tuberculosis. Tumour necrosis factor (TNF) -308G/A and -238G/A gene polymorphisms have been associated with tuberculosis. However, the results remain inconsistent. The aim of this study was to determine the association between TNF polymorphisms and tuberculosis in the presence of biomass smoke, cigarettes, and alcohol in a Mexican population.

MATERIAL AND METHODS

TNF polymorphisms were determined in 118 tuberculosis patients and 223 controls. We performed a univariate, bivariate, stratified analysis. Odds ratios, confidence intervals, and p-values were calculated.

RESULTS

Occupational biomass smoke exposure was associated with tuberculosis between the patients and controls (OR = 1.70, 95% CI: 1.08-2.70, p = 0.02). We also found an association of the -308A allele carriers between the patients and controls without exposure to occupational (p = 0.04, OR = 0.16, 95% CI: 0.01-0.92) and in-home (p = 0.02, OR = 0.14, 95% CI: 0.01-0.81) biomass smoke, as well as an association with alcohol (p = 0.01, OR = 0.24, 95% CI: 0.05-0.75). The haplotype analysis revealed an association of the -308A/-238G haplotype between patients and nonconsanguineous controls without exposure to occupational (p = 0.02, OR = 0.12, 95% CI: 0.01-0.99) and in-home (p = 0.01, OR = 0.1, 95% CI: 0.01-0.9) biomass smoke, cigarette use (p = 0.04, OR = 0.28, 95% CI: 0.08-0.98), and alcohol (p = 0.02, OR = 0.22, 95% CI: 0.05-0.88) intake.

CONCLUSIONS

The TNF -308A allele and the -308A/-238G haplotype are associated with tuberculosis, as are exposure to biomass smoke, cigarettes, and alcohol. No association for the -238G/A polymorphism was found. Our results provide insight into a possible protective role of TNF polymorphisms in tuberculosis in our population.

Interleukin 1α and 1β gene variations are associated with tuberculosis in silica exposed subjects

INTRODUCTION

Silicosis is a fibrotic lung disease resulting from the inhalation of crystalline silica and can be classified as simple or complicated according to the International Labour Organization criteria. Furthermore, individuals exposed to crystalline silica also have a higher risk for the development of tuberculosis (Tb). The contribution of inflammatory cytokines to the risk of silicosis and Tb in different populations has previously been reported. Since genetic background might be related to susceptibility to silicosis and Tb, the study of polymorphisms within IL-1α, IL-1β, and tumor necrosis factor protein-coding genes may contribute to elucidating the genetic basis of these diseases.

METHODS

Single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction using restriction fragment length polymorphism or by Taqman methodology, in a sample of 102 silica-exposed patients from Brazil.

RESULTS

No significant associations were observed between the SNPs studied and the severity of silicosis. However, significant associations were found between Tb and the C allele (odds ratio [OR] = 1.93, 95% confidence interval [CI], 1.01-3.73) and the CC genotype (OR = 2.34, 95% CI, 1.04-5.31) of IL1A -899C>T. The IL1B +3954C>T polymorphism also showed an association with Tb (T allele dominant model OR = 2.38, 95% CI, 1.04-5.41).

CONCLUSION

These preliminary results demonstrate that the IL1A and IL1B gene variations may contribute to some extent to susceptibility to Tb, but not silicosis. However, additional studies are still needed to confirm these results.

Polymorphisms of cytokine genes and tuberculosis in two independent studies

Cytokine gene single nucleotide polymorphisms (SNPs) can influence cytokine levels, which may be associated with tuberculosis (TB) susceptibility. There is evidence that interleukin 1B (IL1B), tumor necrosis factor-alpha (TNF-alpha), and IL6 may be involved in the progression of TB. Using a self-validating case-control design, we selected eleven functional SNPs in IL1B, TNF and IL6 to detect their association with TB in Chinese Han and Tibetan populations. The associations between SNPs and TB were estimated by computing the odds ratios (ORs) and 95% confidence intervals (95% CI) using logistic regression analyses. We found that the IL1B rs16944 polymorphism was associated with decreased risk of TB in the two studies. The G allele at rs2069837 of IL6 was significantly more common in controls than in TB patients in the Han population. Moreover, TNF rs1799964 and rs1800630 were risk factors for susceptibility to TB, which were validated in the Chinese Tibetan population. In addition, TNF rs1799724 and rs1800629 were associated with TB, but only in the Tibetan population. In conclusion, SNPs of the IL1B and TNF gene were associated with TB susceptibility in Chinese Han and Tibetan populations. IL6 polymorphism may be considered as a protective factor for TB in the Chinese Han population, but not the Tibetan population.

Single nucleotide polymorphisms of cytokine-related genes and association with clinical outcome in a Chagas disease case-control study from Brazil

BACKGROUND

The severity of chronic chagasic cardiomyopathy (CCC), the most frequent clinical outcome of Chagas disease (CD), has been associated with cytokine-enriched heart tissue inflammation, and high serum levels of transforming growth factor (TGFβ), interferon-gamma (IFNγ), and tumour necrosis factor (TNF). Conversely, increased interleukin (IL)-10 serum concentrations have been associated with asymptomatic CD. Cytokines and cytokine-related gene polymorphisms may control cytokine expression and have been proposed to contribute to CCC outcomes.

OBJECTIVES

We evaluated the association of 13 cytokine-related genes (TGFB: rs8179181, rs8105161, rs1800469; IL10: rs1800890, rs1800871, rs1800896; IFNG: rs2430561; TNF: rs1800629; BAT1: rs3853601; LTA: rs909253, rs2239704; TNFR1: rs767455; TNFR2: rs1061624) with risk and progression of CCC.

FINDINGS

Four hundred and six seropositive patients from CD endemic areas in the state of Pernambuco, north-eastern Brazil, were classified as non-cardiopathic (A, 110) or cardiopathic (mild, B1, 163; severe, C, 133). We found no evidence of TGFB, IL10, TNF, or TNFR1/2 gene polymorphisms associated with CCC risk or progression. Only BAT1 rs3853601 −22G carriers (B1 vs. C: OR = 0.5; p-value = 0.03) and IFNG rs2430561 +874AT (A vs. C: OR = 0.7; p-value = 0.03; A vs. B1+C: OR = 0.8; p-value = 0.02) showed a significant association with protection from cardiopathy in a logistic regression analysis with adjustment for gender and ethnicity; however, the association disappeared after performing adjustment for multiple testing. A systematic review of TNF rs1800629 −308G>A publications included five studies for meta-analysis (534 CCC and 472 asymptomatic patients) and showed no consensus in pooled odds ratio (OR) estimates for A allele or A carriers (OR = 1.4 and 1.5; p-values = 0.14 and 0.15, respectively). In CD patients, TNF serum levels were increased, but not affected by the TNF rs1800629 −308A allele.

MAIN CONCLUSIONS

Our data suggest no significant contribution of the analysed gene variants of cytokine-related molecules to development/severity of Chagas' heart disease, reinforcing the idea that parasite/host interplay is critical to CD outcomes.

Polymorphisms in the SP110 and TNF-α Gene and Susceptibility to Pulmonary and Spinal Tuberculosis among Southern Chinese Population

Objective

To investigate the association of single-nucleotide polymorphisms (SNPs) in SP110 gene and TNF-α gene among pulmonary TB (PTB) and spinal TB (STB) patients.

Methods

In a total of 190 PTB patients, 183 STB patients were enrolled as the case group and 362 healthy individuals at the same geographical region as the control group. The SP110 SNPs (rs722555 and rs1135791) and the promoter -308G>A (rs1800629) and -238G>A (rs361525) polymorphisms in TNF-α were genotyped. Results. TNF-α -238G>A polymorphism was involved in susceptibility to STB, but not to PTB. The TNF-α -238 A allele was a protective factor against STB (A versus G: OR [95% CI] = 0.331 [0.113–0.972], P = 0.044). Furthermore, the presence of the -238 A allele was considered a trend to decrease the risk of STB (AG versus GG: P = 0.062, OR [95% CI] = 0.352 [0.118–1.053]; AA + AG versus GG: P = 0.050, OR [95CI%] = 0.335 [0.113–0.999]). However, SP110 SNPs (rs722555 and rs1135791) and TNF-α -308G>A (rs1800629) showed no association with PTB and STB in all genetic models.

Conclusion

The TNF-α -238 A allele appeared a protective effect against STB, whereas the SP110 SNPs (rs722555 and rs1135791) and TNF-α -308G>A (rs1800629) showed no association with susceptibility to PTB and STB patients in southern China.

The Role of Host Genetics (and Genomics) in Tuberculosis

Familial risk of tuberculosis (TB) has been recognized for centuries. Largely through studies of mono- and dizygotic twin concordance rates, studies of families with Mendelian susceptibility to mycobacterial disease, and candidate gene studies performed in the 20th century, it was recognized that susceptibility to TB disease has a substantial host genetic component. Limitations in candidate gene studies and early linkage studies made the robust identification of specific loci associated with disease challenging, and few loci have been convincingly associated across multiple populations. Genome-wide and transcriptome-wide association studies, based on microarray (commonly known as genechip) technologies, conducted in the past decade have helped shed some light on pathogenesis but only a handful of new pathways have been identified. This apparent paradox, of high heritability but few replicable associations, has spurred a new wave of collaborative global studies. This review aims to comprehensively review the heritability of TB, critically review the host genetic and transcriptomic correlates of disease, and highlight current studies and future prospects in the study of host genomics in TB. An implicit goal of elucidating host genetic correlates of susceptibility to Mycobacterium tuberculosis infection or TB disease is to identify pathophysiological features amenable to translation to new preventive, diagnostic, or therapeutic interventions. The translation of genomic insights into new clinical tools is therefore also discussed.

High levels of plasma interferon gamma and +874T/A gene polymorphism is associated with HIV-TB co-infection

OBJECTIVE

Tuberculosis (TB) is one of the most frequent opportunistic infections in HIV patients leading to increased morbidity and death rate. This study was carried out to investigate the role of the cytokines IFN-γ and TNF-α level and their single nucleotide polymorphisms (SNPs) in HIV-TB co-infection.

METHODS

247 HIV-TB (124 HIV-pulmonary TB, 123 HIV-extra pulmonary TB), 126 HIV positive individuals without tuberculosis and 129 healthy subjects (HS) were included to measure plasma levels of IFN-γ and TNF-α by sandwich ELISA and One way ANOVA statistical analysis was carried out among the groups. The SNPs of TNF-α-308 G/A, -238 G/A and IFN-γ+874 T/A were also investigated using amplification refractory mutation system polymerase chain reaction (ARMS-PCR). The frequencies between the groups were compared by Pearson's chi square statistical analysis.

RESULTS

Plasma IFN-γ and TNF-α were significantly elevated in HIV-TB and TB (p<0.05) as compared to those in HS group. There was significant association between IFN-γ+874 'A' allele and AA genotype in HIV-TB groups compared to HS and HIV (p<0.05) and no such association was found for TNF-α-308 and -238. The plasma cytokine levels of TNF-α and IFN-γ reveals no significant association with levels of IFN-γ+874 T/A, TNF-α -308 G/Aand-238 G/A genotypes in any of the study groups.

CONCLUSION

In conclusion, the present study revealed elevated plasma IFN-γ and its +874 'A' allele are associated with HIV-TB co-infection indicating 1.6 times increased risk for TB susceptibility. Elevated TNF-α levels in TB and HIV-TB suggest its involvement in TB pathogenesis.

The NRAMP1, VDR, TNF-α, ICAM1, TLR2 and TLR4 gene polymorphisms in Iranian patients with pulmonary tuberculosis: A case-control study

The innate immune response drives early events in Mycobacterium tuberculosis infection. Since human genetic variation is an important determinant in the outcome of infection with M. tuberculosis, we typed polymorphisms in the innate immune molecules, such as natural-resistance-associated macrophage protein 1 (NRAMP1), Vitamin D receptor (VDR), Tumor necrosis factor alpha (TNF-α), intercellular adhesion molecule1 (ICAM-1), Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in a case-control study of pulmonary tuberculosis in Iranian population. We conducted an association study and included 96 patients and 122 matched healthy individuals. We used single ARMS-PCR technique to simultaneously genotype fourteen polymorphisms in this survey. Among all fourteen polymorphisms that were examined, three polymorphisms were significantly different between case and control groups. The TNF -308A polymorphism showed significant increase in allele and genotype frequencies among patients compared to control individuals [-308A allele: 19.3 vs. 9.4%, GA genotype: 28.1 vs. 17.2%, AA genotype: 5.2 vs. 0.8%; Corrected P (Pc)<0.05], and the TLR4 variant allele and genotypes prevalence (D299G and T399I) were significantly higher among patients compared to controls [DG genotype: 14.6 vs. 5.7%, Pc<0.05 and I399 allele: 4.2 vs. 0.8%, TI genotype: 8.3 vs. 1.6%; Pc<0.05], respectively. In conclusion, our data suggest that TLR4 (D299G and T399I) and TNF (-308G/A) genetic polymorphisms may influence the risk of developing tuberculosis after exposure to Mycobacterium.

TNF-α -238, -308, -863 polymorphisms, and brucellosis infection

BACKGROUND

Brucella abortus is an intracellular bacterium that affects humans and domestic animals. Tumor necrosis factor-alpha (TNF-α) has been shown as a key player in the induction of cell-mediated resistance against Brucella infection. We aimed to evaluate the possible influence of the TNF-α promoter polymorphisms (-308 G/A, -238 G/A, and -863 C/A) on the susceptibility of human brucellosis.

METHODOLOGY

A total of 153 patients with active brucellosis and 128 healthy individuals were recruited. All subjects were genotyped for the polymorphisms in the TNF-α gene by Allele-Specific polymerase chain reaction analysis.

RESULTS

Our results showed that the TNF-α -308 GG genotype was significantly more frequently present in controls than in brucellosis patients (91% vs. 75%), thus was a protective factor against developing brucellosis (OR=0.313, p=0.001). In contrast, the -308 GA genotype (OR=3.026, p=0.002) and minor allele (A) (OR=3.058, p=0.001) as well as AAG haplotype (OR=4.014, p=0.001) conferred an increased risk of brucellosis. However, the -238 G/A and -863 C/A polymorphisms were not associated with the risk of brucellosis at both allelic and genotypic levels (p>0.05).

CONCLUSION

Our study revealed that the TNF-α -308 A allele or GA heterozygosity or AAG haplotype were associated with an increased risk of brucellosis in our population.

Inflammatory and immunogenetic markers in correlation with pulmonary tuberculosis

OBJECTIVE:

To describe serum levels of the cytokines IL-10, TNF-α, and IFN-γ, as well as polymorphisms in the genes involved in their transcription, and their association with markers of the acute inflammatory response in patients with pulmonary tuberculosis.

METHODS:

This was a descriptive, longitudinal study involving 81 patients with pulmonary tuberculosis treated at two referral hospitals. We collected data on sociodemographic variables and evaluated bacteriological conversion at the eighth week of antituberculosis treatment, gene polymorphisms related to the cytokines studied, and serum levels of those cytokines, as well as those of C-reactive protein (CRP). We also determined the ESR and CD4+ counts.

RESULTS:

The median age of the patients was 43 years; 67 patients (82.7%) were male; and 8 patients (9.9%) were infected with HIV. The ESR was highest in the patients with high IFN-γ levels and low IL-10 levels. IFN-γ and TNF-α gene polymorphisms at positions +874 and −238, respectively, showed no correlations with the corresponding cytokine serum levels. Low IL-10 levels were associated with IL-10 gene polymorphisms at positions −592 and −819 (but not −1082). There was a negative association between bacteriological conversion at the eighth week of treatment and CRP levels.

CONCLUSIONS:

Our results suggest that genetic markers and markers of acute inflammatory response are useful in predicting the response to antituberculosis treatment.

Gene polymorphisms in patients with pulmonary tuberculosis from Mozambique

Several host and environmental factors contribute to tuberculosis outcome, interestingly single nucleotide polymorphisms (SNPs) in candidate genes have been evaluated in populations with different ethnicities and TB infection. In the present study we focused on SNPs in cytokine and inflammatory mediator genes: tumor necrosis factor (TNF) -308G>A (rs1800629), interleukin-10 (IL10) -819C>T (rs1800871), interferon-gamma (IFNG) +874T>A (rs2430561), and leukotriene A4 hydrolase (LTA4H) rs1978331, rs17525495 and rs2660898 in a case-control study involving 102 pulmonary tuberculosis patients and 456 controls from Mozambique. LTA4H, IL10 and IFNG SNPs showed no associations with pulmonary tuberculosis. However, distribution of the TNF -308A allele, genotype and carrier frequencies showed a significant risk association with tuberculosis that was maintained after adjustment for non-genetic variables and Bonferroni correction (AA genotype, OR = 1.9, p Bonf < 0.001; A allele OR = 2.9, p Bonf = 0.005 and GA/AA carrier OR = 2.6, p Bonf = 0.035). Interestingly, this association has not been reported in a sub-Saharan African population before. Our results suggest a role of -308 TNF polymorphism and tuberculosis susceptibility.

Single nucleotide polymorphic macrophage cytokine regulation by Mycobacterium tuberculosis and drug treatment

Aim: To investigate the survival of Mycobacterium tuberculosis in primary macrophages with SNPs affecting cytokine secretion under treatment with drugs in solution or microparticles. Materials & methods: Volunteers were typed for TNF (-308G/A), IL-10 (-1082A/G) and IL-4 (-590C/T). Monocyte-derived macrophages (MDMs) were infected in vitro. Cytokine secretion and survival of intracellular bacilli were estimated. Results: IL-10 AG associated with high secretion in uninfected and infected MDMs (p < 0.05) and was reduced more effectively by microparticles than drugs, irrespective of genotype (p < 0.05). Differences were observed between IL-4 secretion by MDMs of CC and TT genotypes (p = 0.1). Bacteria proliferated more in MDMs from volunteers with higher IL-4 levels (p = 0.05). Microparticles showed higher efficacy (p = 0.05) than drugs. Conclusion: IL-4 and IL-10 SNPs affect the ability of macrophages to counter infection with M. tuberculosis. Microparticles elicit favorable macrophage cytokines regardless of SNPs.

Original submitted 5 August 2013; Revision submitted 27 November 2013

Association of Mycobacterium Tuberculosis Lineages with IFN-γ and TNF-α Gene Polymorphisms among Pulmonary Tuberculosis Patient

The six major lineages of Mycobacterium tuberculosis [MTB] are found to be strongly associated with specific geographical outbreaks. But whether these bacterial lineages influence the host genetic polymorphism is uncertain. The present study was designed to evaluate the relevance of strain diversity and host genetic polymorphisms in susceptibility to pulmonary tuberculosis [PTB]. For this reason, single –nucleotide polymorphisms [SNPs] in interferon- γ [IFN-γ] receptor-1[G-611A], IFNG [G+ 2109A] and tumor necrosis factors [TNF-α] genes [at −238, 308,−857position] in patients [n=151] were analyzed and compared with controls [n=83]. The genetic diversity of M. tuberculosis isolates was performed using spacer oligonucleotide typing. Thereafter, the profile of IFN-γ and TNF-α allele frequency were investigated in each subtype of M.tuberculosis. The results showed C allele of TNF 857 and A allele of TNF 238 were more frequent in PTB cases [[TNF 857 C allele OR [CI95%] 0.6[0.4–0.9], p= 0.02] for TNF 238 A allele OR [CI95%] 5.5[3.4–9.0], p= 0.00]]. Similarly, G allele in IFNG+ 2109 A/G polymorphism were significantly more in patients than control subject[OR[CI95%] 0.3; p< 0.05]. The major identified clinical isolates of M. tuberculosis were EAI[42; 27.8% ], Haarlem[ 31; 20.5% ], CAS [ 23;15.2% ], Beijing[14; 9.2%], and T [11; 7.2% ] lineages. No correction was observed between strains diversity and frequency of SNPs in studied PTB cases. In conclusions, we exclude the possibility of genetic mutation in IFN-γ and TNF-α gene by different subtypes of M. tuberculosis. Although, our results supports a positive correlation between host SNPs and susceptibility to PTB.

Four tumor necrosis factor alpha genes polymorphisms and periodontitis risk in a Chinese population

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of generalized aggressive periodontitis (AgP) and chronic periodontitis (CP). The objective of the present study was to evaluate the association of four TNF-alpha gene polymorphisms (-1031T/C, -857C/T, -308G/A and -238G/A) with susceptibility to AgP and CP in a Chinese population.

METHODS

A hospital-based case-control study was conducted in in patients with CP (n = 180), AgP (n = 180) and healthy controls (n = 180). Gene promoter polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Genotype and allele frequencies were analyzed using the chi-square test and logistic regression analysis.

RESULTS

TNF-alpha -1031CC genotype was significantly higher [odds ratio (OR) = 2.36, 95% confidence interval (CI) = 1.03, 5.43; P = 0.04] in patients with CP compared with healthy controls. TNF-alpha -308AA genotype was significantly higher (OR = 2.71, 95% CI = 1.09, 6.73; P = 0.03) in patients with AgP compared with healthy controls. No association was found of TNF-alpha -857C/T and -238G/A polymorphisms with susceptibility to AgP or CP.

CONCLUSIONS

Our data demonstrated that TNF-alpha -1031CC genotype was a risk factor for CP, and that TNF-alpha -308AA genotype was a risk factor for AgP. But there is a lack of association of TNF-alpha -857C/T and -238G/A polymorphisms with susceptibility to AgP or CP in a Chinese population.

Candidate gene analysis of arteriovenous fistula failure in hemodialysis patients

BACKGROUND AND OBJECTIVES

Arteriovenous fistula (AVF) failure remains an important cause of morbidity in hemodialysis patients. The exact underlying mechanisms responsible for AVF failure are unknown but processes like proliferation, inflammation, vascular remodeling, and thrombosis are thought to be involved. The current objective was to investigate the association between AVF failure and single nucleotide polymorphisms (SNPs) in genes related to these pathophysiologic processes in a large population of incident hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 479 incident hemodialysis patients were included between January 1997 and April 2004. Follow-up lasted 2 years or until AVF failure, defined as surgery, percutaneous endovascular intervention, or abandonment of the vascular access. Forty-three SNPs in 26 genes, related to proliferation, inflammation, endothelial function, vascular remodeling, coagulation, and calcium/phosphate metabolism, were genotyped. Relations were analyzed using Cox regression analysis.

RESULTS

In total, 207 (43.2%) patients developed AVF failure. After adjustment, two SNPs were significantly associated with an increased risk of AVF failure. The hazard ratio (95% confidence interval) of LRP1 rs1466535 was 1.75 (1.15 to 2.66) and patients with factor V Leiden had a hazard ratio of 2.54 (1.41 to 4.56) to develop AVF failure. The other SNPs were not associated with AVF failure.

CONCLUSIONS

In this large cohort of hemodialysis patients, only 2 of the 43 candidate SNPs were associated with an increased risk of AVF failure. Whether other factors, like local hemodynamic circumstances, are more important or other SNPs play a role in AVF failure remains to be elucidated.

Association between tumor necrosis factor alpha-238G/a polymorphism and tuberculosis susceptibility: a meta-analysis study

Background

Tumor necrosis factor alpha (TNF-α) plays a key role in the containment of tuberculosis. The relationship between the TNF -238G/A polymorphism and tuberculosis susceptibility remains inconclusive. A comprehensive meta-analysis was made to provide a more precise estimate of the relationship between them.

Methods

Multiple search strategies were used. A fixed effect model was takentook to estimate pooled OR with 95% confidence interval (CI) for the association between the TNF -238G/A polymorphism and tuberculosis susceptibility. The Chi-squared-based Q-test and I-squaredI² statistic were calculated to examine heterogeneity. Begg’s funnel plot and Egger’s test were used to assess publication bias.

Results

9 case-control studies were included in this meta-analysis. No significant heterogeneity was demonstrated, and no obvious publication bias was detected among the included studies. The meta-analysis indicated that there was no significant association between the TNF -238G/A polymorphism and tuberculosis susceptibility (GA+AA versus GG model: OR=1.005, 95% CI: 0.765-1.319; A versus G model: OR=1.000, 95% CI: 0.769-1.300). In the subgroup analyses by ethnicity, types of TB and human immunodeficiency virus (HIV) status, no significant association were identified.

Conclusions

The meta-analysis involving 2723 subjects did not detect any association between the TNF -238G/A polymorphism and tuberculosis susceptibility.

The TNF-α -308 Promoter Gene Polymorphism and Chronic HBV Infection

Background and Aims. TNF-α -308 allele promoter polymorphism has been known to be a potential prognostic factor in patients with chronic HBV infection. We tried to determine how TNF-α -308 allele promoter polymorphism would affect the prognosis in patients with chronic HBV infection. Methods. We searched MEDLINE, EMBASE, and reference lists of relevant review articles related to the association between “TNF-α G-308A promoter polymorphism” with “chronic HBV infection”. We only focused on searching -308 locus in published studies. We reviewed 21 original articles about TNF-α -308 allele polymorphism and its effect on prognosis in patients with chronic HBV infection and discussed the results. Results. conflicting results were observed. The results were divided into 3 groups including neutral, negative, and positive associations between TNF-α -308 allele polymorphism and prognosis in patients with chronic HBV infection. We summarized the primary data as a table. Conclusions. Authors concluded that although there is an upward trend in evidence to claim that there is a positive relation between TNF-α G-308A promoter polymorphisms and resolution of chronic HBV infection, due to many biases and limitations observed in reviewed studies, an organized well-designed study is needed for clarifying the real association.

Innate immune gene polymorphisms in tuberculosis

Tuberculosis (TB) is a leading cause worldwide of human mortality attributable to a single infectious agent. Recent studies targeting candidate genes and "case-control" association have revealed numerous polymorphisms implicated in host susceptibility to TB. Here, we review current progress in the understanding of causative polymorphisms in host innate immune genes associated with TB pathogenesis. We discuss genes encoding several types of proteins: macrophage receptors, such as the mannose receptor (MR, CD206), dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN, CD209), Dectin-1, Toll-like receptors (TLRs), complement receptor 3 (CR3, CD11b/CD18), nucleotide oligomerization domain 1 (NOD1) and NOD2, CD14, P2X7, and the vitamin D nuclear receptor (VDR); soluble C-type lectins, such as surfactant protein-A (SP-A), SP-D, and mannose-binding lectin (MBL); phagocyte cytokines, such as tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6, IL-10, IL-12, and IL-18; chemokines, such as IL-8, monocyte chemoattractant protein 1 (MCP-1), RANTES, and CXCL10; and other important innate immune molecules, such as inducible nitric oxide synthase (iNOS) and solute carrier protein 11A1 (SLC11A1). Polymorphisms in these genes have been variably associated with susceptibility to TB among different populations. This apparent variability is probably accounted for by evolutionary selection pressure as a result of long-term host-pathogen interactions in certain regions or populations and, in part, by lack of proper study design and limited knowledge of molecular and functional effects of the implicated genetic variants. Finally, we discuss genomic technologies that hold promise for resolving questions regarding the evolutionary paths of the human genome, functional effects of polymorphisms, and corollary impacts of adaptation on human health, ultimately leading to novel approaches to controlling TB.

Tumor necrosis factor alpha -308G>A, -863C>A, -857C>T gene polymorphisms and tuberculosis susceptibility: a meta-analysis

BACKGROUND/AIMS

A large number of studies have shown that polymorphisms in the tumor necrosis factor-α (TNF-α, TNFA) gene are implicated in susceptibility to tuberculosis (TB). However, the results are inconsistent. We performed this meta-analysis to estimate the association between polymorphisms in the TNFA gene and TB susceptibility.

METHODS

Relevant studies published before March 2012 were identified by searching PubMed, ISI web of knowledge, EBSCO and CNKI. The strength of relationship between the TNFA gene and TB susceptibility was assessed using odds ratios (ORs).

RESULTS

A total number of twenty-three case-control studies including 3630 cases and 4055 controls were identified referring to three previously chosen single-nucleotide polymorphisms (SNPs): -308G>A, -863C>A and -857C>T. No association was found between -308G>A, -863C>A and TB susceptibility: -308G>A (GG+GA vs. AA): OR 0.85, 95%CI: 0.55-1.30, P=0.44; -863C>A (CC+CA vs. AA): OR 0.93, 95%CI: 0.84-1.81, P=0.83. Increased risk of TB was associated with -857C>T in the dominant genetic model (CC+CT vs. TT: OR 2.13, 95%CI: 1.25-3.63, P=0.01), the heterozygote comparison (CT vs. TT: OR 2.69, 95%CI: 1.44-5.02, P=0.00) and the homozygote comparison (CC vs. TT: OR 2.08, 95%CI: 1.22-3.53, P=0.01) in Asian subjects.

CONCLUSION

There is an increased association between TNFA -857C>T polymorphism and TB risk among Asian subjects. No association was found between -308G>A and -863C>A with TB risk. Due to several limitations in the present study, well-designed epidemiological studies with large sample size among different ethnicities should be performed in the future.

Association between CD209 -336A/G and -871A/G polymorphisms and susceptibility of tuberculosis: a meta-analysis

Background

The association between CD209 promoter polymorphisms (-336A/G, -871A/G) and tuberculosis (TB) risk has been widely reported, but results of previous studies remain controversial and ambiguous. To assess the association between CD209 polymorphisms and TB risk, a meta-analysis was performed.

Methods

Based on comprehensive searches of the PubMed, Embase, Web of Science, Weipu, and CBM databases, we identified outcome data from all articles estimating the association between CD209 polymorphisms and TB risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated.

Results

A total of 14 studies with 3,610 cases and 3,539 controls were identified. There was no significant association between CD209 -336A/G polymorphism and TB risk (OR = 1.04, 95% CI = 0.91–1.19 for G vs. A; OR = 1.13, 95% CI = 0.84–1.53 for GG vs. AA; OR = 1.04, 95% CI = 0.87–1.24 for GG+AG vs. AA; OR = 1.11, 95% CI = 0.88–1.39 for GG vs. AG+AA). However, the significant association was revealed for Asians in GG vs. AA (OR = 2.48, 95% CI = 1.46–4.22, P = 0.0008) and GG vs. AG+AA (OR = 2.10, 95% CI = 1.33–3.32, P = 0.001). For the CD209 -871A/G polymorphism, lack of an association was also found (OR = 0.81, 95% CI = 0.70–0.95 for G vs. A; OR = 1.00, 95% CI = 0.52–1.93 for GG vs. AA; OR = 0.73, 95% CI = 0.60–0.89 for GG+AG vs. AA; OR = 1.09, 95% CI = 0.57–2.10 for GG vs. AG+AA).

Conclusion

The present meta-analysis suggested that CD209 promoter polymorphisms (-336A/G, -871A/G) were unlikely to substantially contribute to TB susceptibility. However, the GG genotype of CD209 -336A/G polymorphism might be a genetic risk factor that increases TB susceptibility for Asians in GG vs. AA and GG vs. AG+AA.