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

TNF-α polymorphisms might influence predisposition to periodontitis: A meta-analysis

BACKGROUND

Tumor necrosis factor-α (TNF-α) polymorphisms might influence predisposition to periodontitis, but the results of already published studies were still controversial and ambiguous. So the authors designed this meta-analysis to more precisely estimate relationship between TNF-α polymorphisms and periodontitis by pooling the results of already published related studies.

METHODS

The authors searched Pubmed, Embase, Web of Science and CNKI for already published studies. Forty-five already published studies were pooled analyzed in this meta-analysis.

RESULTS

The crude pooled meta-analyses results showed that distributions of TNF-α rs361525, rs1800629, rs1800630 and rs1799964 polymorphisms among patients and controls differed significantly, which suggested that these polymorphisms might influence predisposition to periodontitis in the general population. We also got similar significant results for rs361525, rs1800629, rs1800630 and rs1799964 polymorphisms in subgroup analyses in Asians. The crude findings were further subjected to Bonferroni correction to account for multiple comparisons. For rs361525, rs1800629 and rs1799964 polymorphisms, basically no changes of results were detected. But for rs1800630 polymorphism, the results were no longer significant after adjustment for multiple comparisons.

CONCLUSIONS

This meta-analysis suggested that TNF-α rs361525, rs1800629 and rs1799964 polymorphisms might influence predisposition to periodontitis, particularly in Asians.

A Meta-Analysis of the Relationship between Tumor Necrosis Factor-α Polymorphisms and Psoriasis

BACKGROUND

Some previous studies already explored associations between tumor necrosis factor-α (TNF-α) polymorphisms and psoriasis, with conflicting findings. Here, we aimed to better analyze the relationship between TNF-α polymorphisms and psoriasis in a larger pooled population by performing a meta-analysis.

METHODS

We searched Pubmed, Embase, Web of Science and CNKI for related articles. We calculated OR and 95% CI to estimate whether there are genetic associations between TNF-α polymorphisms and psoriasis.

RESULTS

Twenty-nine studies were included for this meta-analysis. TNF-α-238 G/A (dominant comparison: OR 0.44, 95% CI 0.34-0.59; recessive comparison: OR 1.63, 95% CI 1.03-2.57; overdominant comparison: OR 2.21, 95% CI 1.71-2.85; allele comparison: OR 0.48, 95% CI 0.36-0.62) and -857 C/T (dominant comparison: OR 0.58, 95% CI 0.41-0.80; overdominant comparison: OR 1.58, 95% CI 1.12-2.23; allele comparison: OR 0.62, 95% CI 0. 0.47-0.82) polymorphisms were found to be significantly associated with psoriasis in the general population. Subgroup analyses indicated that the -238 G/A polymorphism was significantly associated with psoriasis in Caucasians and East Asians, the -308 G/A polymorphism was significantly associated with psoriasis in East Asians, and the -857 C/T polymorphism was significantly associated with psoriasis in Caucasians.

CONCLUSIONS

TNF-α -238 G/A, -308 G/A and -857 C/T polymorphisms could be used to identity individuals with elevated susceptibility to psoriasis in certain populations.

Associations of P2X7 Polymorphisms with the Odds of Tuberculosis: A Meta-Analysis

BACKGROUND

Recently, the roles of purinergic receptor P2X ligand-gated ion channel 7 (P2X7) polymorphisms in tuberculosis (TB) were analyzed by some pilot studies, but the results of these studies were inconsistent. We performed this study to better assess the relationship between P2X7 polymorphisms and the odds of TB.

METHODS

Eligible studies were searched in PubMed, MEDLINE, and Embase. Odds ratios and 95% confidence intervals were calculated.

RESULTS

A total of 21 studies were included for analyses. Significant associations with the odds of TB were detected for rs3751143 polymorphism in dominant (p = 0.01), recessive (p < 0.0001), additive (p = 0.0002), and allele models (p < 0.0001) in overall analyses. Further subgroup analyses based on the ethnicity of participants revealed that the rs1718119 polymorphism is significantly associated with the odds of TB in Asians and the rs3751143 polymorphism with the odds of TB in Caucasians.

CONCLUSION

Our findings indicate that rs1718119 polymorphism may serve as a potential biological marker of TB in Asians and the rs3751143 polymorphism as a potential biological marker of TB in Caucasians.

Screening of TNF-α gene polymorphisms in patients with extremity chronic osteomyelitis in China

AIM

This study aims to investigate the link between TNF-α gene SNPs and patients with extremity chronic osteomyelitis in China.

METHODOLOGY

Our study included 433 subjects, composed of 233 extremity chronic osteomyelitis patients and 200 controls. Six single-nucleotide polymorphisms (rs1799964, rs1800630, rs1799724, rs1800750, rs1800629 and rs361525) in TNF-α gene were detected by the SNaPshot genotyping method.

RESULTS

Significant genotype distribution of rs1799964 was identified between patients and healthy controls (p = 0.045). In addition, statistical difference was found between rs1799964 SNP and the susceptibility to extremity chronic osteomyelitis (p = 0.044).

CONCLUSION

We reported for the first time that TNF-α gene SNP rs1799964 contributes to the elevated venture of extremity chronic osteomyelitis in China.

Associations between tumor necrosis factor-α gene polymorphisms and the risk of Guillain-Barré syndrome and its subtypes: A systematic review and meta-analysis

This meta-analysis aimed to assess the relationship between tumor necrosis factor-α (TNF-α) polymorphisms and Guillain-Barré syndrome (GBS) or its subtypes of acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor-sensory axonal neuropathy (AMSAN). A total of six studies with 1013 cases and 1029 controls were included. Our pooled data indicated that TNF-α 308G/A polymorphism was significantly associated with GBS, AMAN, and AMSAN but not with AIDP; TNF-α 857C/T polymorphism was significantly associated with AMAN but not with GBS or AIDP. Besides, no association was found between TNF-α 238G/A and 863C/A polymorphisms and GBS or its subtypes.

Immune-related gene polymorphisms in pulmonary diseases

Between the DNA sequences of two randomly-selected human genomes, which consist of over 3 billion base pairs and twenty five thousand genes, there exists only 0.1% variation and 99.9% sequence identity. During the last couple of decades, extensive genome-wide studies have investigated the association between single-nucleotide polymorphisms (SNPs), the most common DNA variations, and susceptibility to various diseases. Because the immune system's primary function is to defend against myriad infectious agents and diseases, the large number of people who escape serious infectious diseases underscores the tremendous success of this system at this task. In fact, out of the third of the global human population infected with Mycobacterium tuberculosis during their lifetime, only a few people develop active disease, and a heavy chain smoker may inexplicably escape all symptoms of chronic obstructive pulmonary disease (COPD), lung cancer, and other smoke-associated lung diseases. This may be attributable to the genetic makeup of the individual(s), including their SNPs, which provide some resistance to the disease. Pattern recognition receptors (PRRs), transcription factors, cytokines and chemokines all play critical roles in orchestrating immune responses and their expression/activation is directly linked to human disease tolerance. Moreover, genetic variations present in the immune-response genes of various ethnicities may explain the huge differences in individual outcomes to various diseases and following exposure to infectious agents. The current review focuses on recent advances in our understanding of pulmonary diseases and the relationship of genetic variations in immune response genes to these conditions.

Polymorphisms in Beta-2 Adrenergic Receptor Gene and Association with Tuberculosis

PURPOSE

Genetic susceptibility for tuberculosis in human has been previously demonstrated. Polymorphisms in genes involved in immune responses may alter the susceptibility of individuals to tuberculosis. Polymorphisms of beta-2 adrenergic receptor (ADRB2) gene can be possibly an important risk factor in tuberculosis. In this study, the association between rs1042713 (Arg16Gly +46A>G) and rs1042714 (Gln27Glu +79C>G) polymorphisms in ADRB2 gene and tuberculosis was evaluated.

METHODS

Genotype distributions of the rs1042713 (Arg16Gly +46A>G) and rs1042714 (Gln27Glu +79C>G) polymorphisms in ADRB2 gene in 106 patients with pulmonary tuberculosis and 88 healthy subjects were studied by PCR-RFLP method in an Iranian population.

RESULTS

The frequency of rs1042713*G and rs1042714*G alleles in ADRB2 gene in tuberculosis patients was significantly different from healthy controls [odds ratio (OR) 0.176, 95% confidence interval (CI) 0.065-0.48, P value <0.001 and OR 0.45, 95% CI 0.247-0.825, P value = 0.009, respectively]. There were no significant differences in haplotype analysis between the patients and control subjects.

CONCLUSION

The association was reported between rs1042713 and rs1042714 polymorphisms in ADRB2 gene and tuberculosis for the first time. rs1042713*G and rs1042714*G polymorphisms in ADRB2 gene makes people more susceptible to develop the disease.

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.

Single Nucleotide Polymorphisms in P2X7 Gene Are Associated with Serum Immunoglobulin G Responses to Mycobacterium tuberculosis in Tuberculosis Patients

Objective. Our study investigated the association between single nucleotide polymorphisms (SNPs) in P2X7 gene and serum immunoglobulin G (IgG) responses to mycobacterium tuberculosis (MTB) in TB patients. Methods. A total of 103 TB patients were enrolled as case group and 87 healthy individuals at same geographical region as control group. The SNP detection of 1513A>C and -762T>C was performed using PCR-RFLP, and the levels of serum IgG responses to MTB in all subjects were determined. Results. AC and CC of 1513A>C and TC and CC of -762T>C had higher frequencies in case group than in control group. TB patients carrying TC and CC of -762T>C had higher positive rate of IgG responses to MTB than those carrying TT. Additionally, patients carrying TC and CC of -762T>C had more MTB in sputum than those carrying TT. Conclusion. P2X7 SNPs, 1513A>C and -762T>C, may be associated with the susceptibility to tuberculosis, and -762T>C SNP may contribute to the development of MTB. The mutant genotype of -762T>C (TC and CC) may lower human capability of phagocytosis to MTB, leading to an increased morbidity of TB.

Arg753Gln Polymorphisms in Toll-Like Receptor 2 Gene are Associated with Tuberculosis Risk: A Meta-Analysis

Background

Numerous epidemiological studies have reported the association between polymorphisms of Toll-like receptor 2 (TLR2) and susceptibility to tuberculosis (TB). However, the results remain inconclusive. Therefore, we performed a quantitative meta-analysis to evaluate associations between the polymorphism of Arg753Gln of the TLR2 gene and susceptibility to TB.

Material/Methods

Three databases (PubMed, CNKI and Embase) were systematically searched for eligible studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) as our index were used to assess the relation between the TLR2 gene Arg753Gln polymorphism and risk of TB. Overall and subgroup analyses were conducted according to the available information.

Results

With a detailed selection, 7 eligible studies with 1486 cases and 1322 controls were identified in our meta-analysis. There was a significant difference between TLR2 gene Arg753Gln polymorphism and the risk of TB (additive model: P<0.01, OR=2.89, 95% CI: 2.13–3.91; GA vs. GG: P<0.01, OR=2.92, 95% CI: 2.09–4.08). Interestingly, subgroup analysis based on ethnicity indicated that TB risk was significantly increased in Asians (additive model: P<0.01, OR=3.17, 95% CI: 2.31–4.35; GA vs. GG: P<0.01, OR=3.29, 95% CI: 2.32–4.68); by contrast, there was no association found in whites (additive model: P=0.40, OR=0.57, 95% CI: 0.15–2.13; GA vs. GG: P=0.40, OR=0.57, 95% CI: 0.15–2.13).

Conclusions

Our meta-analysis provides evidence that the TLR2 gene Arg753Gln polymorphism is a risk factor to TB, especially in Asian populations.

Association of TNF -1031 C/C as a potential protection marker for leprosy development in Amazonas state patients, Brazil

Polymorphisms present in the TNF promoter region has shown to influence the gene transcription. Leprosy displays different clinical manifestations according to the immune responses of the individual infected with Mycobacterium leprae. In this study, we evaluated the single nucleotide polymorphisms (SNPs) -238 G/A (rs361525), -308 G/A (rs1800629), -857 C/T (rs1799724), -863 A/C (rs1800630) and -1031 T/C (rs1799964) in the promoter region of the TNF to see whether these SNPs influence host-susceptibility to leprosy and the different clinical manifestation. Nucleotide sequencing was performed with DNA samples from 108 leprosy patients and 253 control subjects. An association between -1031 C/C genotype and protection from leprosy was observed when leprosy patients were compared to controls (OR 0.11; 95% CI=0.01-0.82; p=0.012). The -857 C/T genotype may be associated with susceptibility to leprosy (OR=1.81; 95% CI=1.09-3.00; p=0.028). Similar genotype and allele frequencies for the SNPs -308 G/A and -238 G/A were observed between leprosy patients and control subjects. Altogether, TNF polymorphisms in the promoter region may be predictive of leprosy outcome.

A meta-analysis of P2X7 gene-762T/C polymorphism and pulmonary tuberculosis susceptibility

AIM

We performed a comprehensive meta-analysis to determine the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis susceptibility.

METHODOLOGY

Based on comprehensive searches of the PubMed, SCI, Elsevier, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis risk. Pooled odds ratio (ORs) and 95% confidence intervals (95%CIs) were calculated in random-effects model.

RESULTS

A total of 2207 tuberculosis cases and 2220 controls in 8 case-control studies were included in this meta-analysis. Allele model (C vs. T: p = 0.15; OR = 0.83, 95% CI = 0.65-1.07), homozygous model (CC vs. TT: p = 0.23; OR = 0.73, 95% CI = 0.44 to 1.22), and heterozygous model (CT vs. TT: p = 0.57; OR = 0.92, 95% CI = 0.68 to 1.24) did not show increased risk of developing pulmonary tuberculosis. Similarly, dominant model (CC+CT vs. TT: p = 0.32; OR = 0.84, 95% CI = 0.59 to 1.19) and recessive model (CC vs. CT+TT: p = 0.08; OR = 0.77, 95% CI = 0.57 to 1.04) failed to show increased risk of developing pulmonary tuberculosis. Subgroup analysis by ethnicity did not detect any significant association between P2X7-762T/C polymorphism and pulmonary tuberculosis susceptibility.

CONCLUSIONS

P2X7 -762T/C gene polymorphism is not associated with pulmonary 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

Comprehensive assessment of the association between tumor necrosis factor alpha G238A polymorphism and liver cancer risk

Tumor necrosis factor alpha (TNF-α) has been suggested to play an important role in the development and liver cancer. TNF-α 238 G/A polymorphism was hypothesized to increase the risk of liver cancer, but findings from previous studies were controversial. To explore a more precise estimation of the relationship between TNF-α 238 G/A polymorphism and liver cancer, we performed a meta-analysis. PubMed, Embase, and China Biology Medicine databases were searched for all publications on this association through March 12, 2013. Odds ratios (ORs) with its 95% confidence intervals (CIs) were used to assess the strength of this association. Eleven studies with 1,406 liver cancer cases and 2,386 noncancer controls were included into this meta-analysis. Overall, there was a significant association between TNF-α 238 G/A polymorphism and increased risk of liver cancer under all three genetic models (A vs. G, OR 1.51, 95% CI 1.20-1.89, P < 0.001, I(2) = 37.7%; AG vs. GG, OR 1.49, 95% CI 1.01-2.21, P = 0.045, I(2) = 53.2%; AA/AG vs. GG, OR 1.76, 95% CI 1.35-2.30, P < 0.001, I(2) = 36.5%). The sensitivity analysis further strengthened the validity of the positive association. Subgroup analysis of nine studies from Asian countries showed that there was a significant association between TNF-α 238 G/A polymorphism and increased risk of liver cancer in Asians (A vs. G, OR 1.35, 95% CI 1.03-1.76, P = 0.027, I(2) = 40.2%; AA/AG vs. GG, OR 1.56, 95% CI 1.14-2.15, P = 0.006, I(2) = 41.9%). In conclusion, TNF-α 238 G/A polymorphism is significantly associated with increased risk of liver cancer, especially in Asians.