NRAMP1 and TNF-alpha polymorphisms and susceptibility to tuberculosis in Thais

Polymorphisms of SLC11A1(NRAMP1) rs17235409 associated with and susceptibility to spinal tuberculosis in a southern Han Chinese population

OBJECTIVE

To investigate the association between SLC11A1 (NRAMP1) rs17235409 (D543N) polymorphisms and susceptibility to spinal tuberculosis (STB) in the Han population in southern China.

METHODS

This study included 227 STB patients and 516 controls. Polymorphisms of SLC11A1 rs17235409 were genotyped using a SNPscan™ kit, and the protein was detected by western blotting.

RESULTS

The genotype and allele frequency distributions of SLC11A1 rs17235409 differed significantly between the STB group and the control group(χ² = 17.650, P = 0.000). The distribution of GA genotype(GA vs. GG: P = 0.000, OR [95% CI] = 2.203[1.520-3.192] was significantly different between STB group and control group, but there was no significant difference in the distribution of AA genotypes(AA vs. GG: P = 0.889, OR [95%CI] = 0.674[0.142-3.208]). The A allele was more common in the STB group than in the control group (A vs. G: P = 0.001, OR [95%CI] = 1.767[1.273-2.452]). Under the dominant model, the GA + AA genotype was more common in the STB group than in the control group (GA + AA vs. GG: P = 0.000, OR [95%CI] = 2.067[1.438-2.971]). However, under the recessive model, there was no difference in GA + GG genotype between the STB and control groups(GA + GG vs. AA: P = 0.701, OR [95%CI] =1.772[0.373-8.409]). NRAMP1 protein expression in the STB group(n = 9) was significantly higher than that in the control group(n = 9) (t = 5.292,P = 0.001).

CONCLUSIONS

Variant genotypes at the rs17235409 locus of the SLC11A1 gene are associated with STB in the southern Han Chinese population. NRAMP1 protein expression is increased in patients with spinal tuberculosis, and the presence of the A allele increases the risk of developing STB.

3'UTR polymorphisms in NRAMP1 are associated with the susceptibility to pulmonary tuberculosis: A MOOSE-compliant meta-analysis

Many studies have investigated the association between the 3'UTR polymorphism in natural resistance-associated macrophage protein 1 (NRAMP1) and the risk of pulmonary tuberculosis (PTB), Revealing inconclusive results. This study aimed to investigate the correlation between the NRAMP1 3'UTR polymorphism and the risk of PTB.This meta-analysis included 29 case-control studies to better and comprehensively assess this correlation. Pooled odds ratios (ORs) and 95% confidence interval (95% CIs) were calculated to assess the strength of the association.These 29 case-control studies included 4672 cases and 6177 controls. The NRAMP1 3'UTR polymorphism displayed a significant positive correlation with the risk of PTB in 3 models (for del/del vs ins/ins: OR = 1.22, 95% CI = 1.01-1.47; for Ins/del vs ins/ins: OR = 1.19, 95% CI 1.08-1.30; for Ins/del + del/del vs ins/ins: OR = 1.25, 95% CI = 1.08-1.45). A stratified analysis by ethnicity revealed that the NRAMP1 3'UTR polymorphism was associated with an increased risk of PTB in the Asian population, but not in Caucasian, African, and South American populations.The present results indicate that the NRAMP1 3'UTR polymorphism may be considered a risk factor for PTB in the Asian population.

Association of the TNF-α-308, TNF-α-238 gene polymorphisms with risk of bone-joint and spinal tuberculosis: a meta-analysis

The aim of the present study was to investigate the association of TNF-α-308 and TNF-α-238 gene polymorphisms with the risk of bone-joint and spinal tuberculosis (TB) by meta-analysis. By searching PubMed, Web of Science, Wanfang databases, CNKI, Medline, and Cochrane Library, the published articles about studies of the association of the TNF-α-308, TNF-α-238 gene polymorphisms with risk of bone-joint and spinal tuberculosis were collected by two reviewers. Begg’s and Egger’s tests were performed to assess publication bias. Stata 12.0 software was used for data analysis. The symmetry of the funnel plot indicated no significant publication bias in the Begg’s test (A: P=1.00, B: P=0.764), and the results of the Egger’s test showed no evidence of publication bias (A: P=0.954, B: P=0.626). Seven studies assessed the relationship between TNF-α-308 gene polymorphisms and risk of bone-joint and spinal tuberculosis risk. The heterogeneity (I²) of GG vs. AA or AG was 0% and there was no heterogeneity (χ² = 0.06 and P=0.944) in a fixed-effects model. There was also a lack of association between TNF-α-308 polymorphism and bone-joint and spinal tuberculosis risk under the recessive model. The remaining models of the TNF-α-308 genotype and further studies of TNF-α-238 did not show a noteworthy association. Overall, there was no significant association between TNF-α-308, TNF-α-238 gene polymorphisms and bone-joint and spinal tuberculosis risk. Our study suggests that tumor necrosis factor α (TNF-α) gene polymorphisms may not contribute to bone-joint and spinal tuberculosis based on the current evidence.

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.

Current immunogenetic predisposition to tuberculosis in the Moroccan population

Tuberculosis (TB) is a serious infectious disease that kills approximately two million people per year, particularly in low- and middle-income countries. Numerous genetic epidemiology studies have been conducted of many ethnic groups worldwide and have highlighted the critical impact of the genetic environment on TB distribution. Many candidate genes associated with resistance or susceptibility to TB have been identified. In Morocco, where TB is still a major public health problem, various observations of clinical, microbiological and incidence distribution are heavily affected by genetic background and external environment. Morocco has almost the same clinical profile as do other North African countries, mainly the increase in more extrapulmonary than pulmonary forms of the diseases, when compared to European, Asian or American populations. In addition, a linkage analysis study that examined Moroccan TB patients identified a unique chromosome region that had a strong association with the risk of contracting TB. Other genes in the Moroccan population that were found to be associated seem to be involved predominantly in modulating the innate immunity. In this review, we appraise the major candidate genes that have been reported in Moroccan immunogenetic studies and discuss their updated role in TB, particularly during the first phase of the immune response to Mycobacterium tuberculosis (Mtb) infection.

NRAMP1 and VDR gene polymorphisms in susceptibility to pulmonary tuberculosis among Andhra Pradesh population in India: a case-control study

Background

The aim of the present study was to evaluate the association of NRAMP1 -3′UTR, 274-CT,VDR- Fok1 VDR-Taq1 Polymorphisms with the risk of pulmonary tuberculosis.

Method

A case –control study was conducted on Andhra Pradesh Population of India. Analysis of gene polymorphisms of NRAMP1 gene (3′UTR, 274CT) and VDR gene (Fok1 and Taq1) was done by using Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in Tuberculosis (TB) patients and healthy controls. The obtained results were observed using 2% Agarose Gel electrophoresis and analysed statistically using Chi-square test and Odds Ratio.

Results

Statistical significance was observed between the patients and the controls in the NRAMP1-3′UTR (P = 0.005; OR = 2.997; 95% CI = 1.019–8.813) and VDR-Taq1 (P < 0.001; OR = 0.140;95% C.I = 0.050–0.386) polymorphisms in Andhra Pradesh population. No statistical significance was observed between patients and controls of the same population in NRAMP1-274CT and VDR-Fok1 polymorphisms (p > 0.05).

Conclusion

3′UTR-NRAMP1 gene and VDR-Taq1 gene Polymorphisms are statistically associated with the susceptibility of TB in Andhra Pradesh Population in India.

Mannose-Binding Lectin (MBL) gene polymorphisms in susceptibility to pulmonary tuberculosis among the Lur population of Lorestan Province of Iran

OBJECTIVE

Tuberculosis (TB) is caused by infection of Mycobacterium tuberculosis. Host genetic variability is an important determinant of the risk of developing TB in humans. Although the association between MBL polymorphisms and TB has been studied in various populations, the results are controversial. The aim of this study was to investigate mannose-binding lectin (MBL) gene polymorphisms with susceptibility to pulmonary tuberculosis (PTB) in a Lur population of Iran.

METHODS

In this case-control study, four functional MBL gene polymorphisms (HL, XY, PQ and AB) were genotyped by using PCR Single Strand Conformation Polymorphism (SSCP) technique in a Lur population living in Lorestan Province, consisting of 100 patients with pulmonary tuberculosis (PTB) age and sex matched 100 healthy controls (HCs). Association analyses were performed with the SPSS 21 statistical software.

RESULTS

We found that MBL (HH) genotype polymorphism significantly was associated with increased susceptibility to TB (35% in patients vs. 22% in controls, P = 0.0417, OR = 1.909, %95 CI = 1.020-3.573). Additionally, H allele showed a significant association with increased risk of TB (56.5% in patients vs. 46% in controls, P = 0.0357, OR = 1.525, %95 CI = 1.028-2.262). Also, the distribution of L allele in patients was significantly lower frequency in TB patients compared to controls (43.5% vs. 54%, P = 0.0357, OR = 0.656, %95 CI = 0.442-0.973). However, the allelic and genotypic frequencies of AB, XY and PQ polymorphisms were not significantly different between the patients and the controls. We couldn't detect any significant differences between haplotypes among TB patients and healthy controls.

CONCLUSIONS

Our findings demonstrated that HH genotype and H allele may increase the susceptibility to pulmonary TB in the Lur population of Iran, although L allele may decrease the susceptibility to pulmonary TB in this population. We suggest that it is necessary to further more studies with larger sample size and other ethnic population.

Association between SLC11A1 (NRAMP1) polymorphisms and susceptibility to tuberculosis in Chinese Holstein cattle

We investigated the associations between SLC11A1 polymorphisms and susceptibility to tuberculosis (TB) in Chinese Holstein cattle, using a case-control study of 136 animals that had positive reactions to TB tests and showed symptoms and 96 animals that had negative reactions to tests and showed no symptoms. Polymerase chain reaction (PCR) sequencing and the restriction fragment length polymorphism (RFLP) technique were used to detect and determine SLC11A1 polymorphisms. Association analysis identified significant correlations between SLC11A1 polymorphisms and susceptibility/resistance to TB, and two genetic markers for SLC11A1 were established using PCR-RFLP. Sequence alignment of SLC11A1 revealed seven single-nucleotide polymorphisms (SNPs). This is the first report of MaeII PCR-RFLP markers for the SLC11A1-SNP3 site and PstI PCR-RFLP markers for the SLC11A1-SNP5 and SLC11A1-SNP6 sites in Chinese Holstein cattle. Logistic regression analysis indicated that SLC11A1-SNP1, SLC11A1-SNP3, and SLC11A1-SNP5 were significantly associated with susceptibility/resistance to TB. Two genotypes of SLC11A1-SNP3 were susceptible to TB, whereas one genotype of SLC11A1-SNP1 and two genotypes of SLC11A1-SNP5 were resistant. Haplotype analysis showed that nine haplotypes were potentially resistant to TB. After Bonferroni correction, three of the haplotypes remained significantly associated with TB resistance. SLC11A1 is a useful candidate gene related to TB in Chinese Holstein cattle.

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.

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.

NRAMP1 and VDR Gene Polymorphisms in Susceptibility to Tuberculosis in Venezuelan Population

Natural resistance-associated macrophage protein (Nramp1) and the vitamin D receptor (VDR) are central components of the innate and adaptive immunity against Mycobacterium tuberculosis, and associations between susceptibility to tuberculosis and polymorphisms in the genes NRAMP and VDR have been sought in geographically diverse populations. We investigated associations of NRAMP1 and VDR gene polymorphisms with susceptibility to TB in the Venezuelan population. The results suggest the absence of any association between VDR variants FokI, ApaI, and TaqI and susceptibility to tuberculosis. In contrast, the NRAMP1 3'UTR variants were associated with susceptibility to M. tuberculosis infection, as seen in the comparisons between TST+ and TST- controls, and also with progression to TB disease, as shown in the comparisons between TB patients and TST+ controls. This study confirms the previously described association of the NRAMP1 3'UTR polymorphism with M. tuberculosis infection and disease progression.

An association study of NRAMP1, VDR, MBL and their interaction with the susceptibility to tuberculosis in a Chinese population

OBJECTIVES

To investigate natural-resistance-associated macrophage protein 1 (NRAMP1), mannose-binding lectin (MBL), vitamin D receptor (VDR) gene polymorphisms and their interaction with susceptibility to pulmonary tuberculosis (PTB) in a Chinese population.

METHODS

A case-control study was conducted in PTB (n=151), age- and sex- matched healthy controls (HCs) (n=453). Genetic polymorphisms of NRAMP1 (INT4, D543NA and 3'UTR), MBL (HL, PQ, XY and AB) and VDR (FokI and Taq) were analyzed by using PCR-restriction fragment length polymorphism (RFLP) and PCR- single- strand conformation polymorphism (SSCP) techniques. Multifactor dimensionality reduction (MDR) analysis was carried out to assess the effects of the interaction between SNPs.

RESULTS

The distribution of NRAMP1- 3'UTR (TGTG/del), MBL- HL (H/L) and FokI (F/f) were significantly different between PTB patients and HCs (p<0.05). HPYA (OR: 1.88; 95% CI: 1.22-2.91), LPXA (OR: 3.17; 95% CI: 1.69- 5.96), LQYA (OR: 3.52; 95%CI: 1.50-8.23) and LPYB (OR: 12.37; 95%CI: 3.75- 40.85) of MBL were risk haplotypes for PTB. The TGTG- H- f (OR: 1.70; 95%CI: 1.10-2.62) and del- H-f (OR: 3.48; 95% CI: 1.45-8.37) of 3'UTR- HL- FokI were also high-risk haplotypes associated with tuberculosis.

CONCLUSIONS

Our study suggests that genotypes of many polymorphic genes are associated with TB, it is necessary to further explore the mechanism of genotypes and gene-gene interaction in susceptibility to tuberculosis.

Association of leishmaniasis with TNF alpha promoter and SLC11A1 gene polymorphisms in patients of two endemic areas in Mexico

Some Single Nucleotide Polymorphisms (SNPs) of interleukins and other modulatory molecules of the immune response play an important role in susceptibility to infectious diseases, particularly those involving intracellular parasites. In this study, we evaluated allele, genotype and haplotype associations of two SNPs of the TNF-α promoter and seven of the SLC11A1 gene in 79 patients with localized cutaneous leishmaniasis (CL) and 15 with visceral leishmaniasis (VL), compared with 127 and 89 locality paired controls, respectively, from two endemic areas of Chiapas State, Mexico. None of the TNF-α alleles and genotypes was associated either to CL or to VL. Alleles rs2276631-C (P = 0.02; OR [95%CI] = 2.11 [1.16-3.86]) and rs2279015-G (P = 0.005; OR [95%CI] = 2.42 [1.33-4.41]) of SLC11A1, were associated with susceptibility to VL, whereas genotypes rs2276631 C/C (P = 0.003; OR [95%CI] = 2.65 [1.41-5.00]) and rs2279015 G/G (P = 0.018; OR [95%CI] = 2.05 [1.15-3.64]) were significantly increased in CL and VL patients, respectively. Complete haplotypes involved in susceptibility were CGCCGDins with VL and CGCCADins with CL. CGCCA was the minimal susceptibility haplotype for CL and CCG for VL. Our data suggest that SLC11A1 gene polymorphisms might have a relevant role in the pathology of leishmaniasis, directing towards susceptibility outcome of this disease in residents of an endemic area.

SLC11A1 polymorphisms and susceptibility to visceral leishmaniasis in Moroccan patients

Human visceral leishmaniasis is endemic in the Mediterranean basin. Since most infections are sub-clinical or asymptomatic, host genetics can provide concrete evidence in determining disease outcome. SLC11A1/NRAMP1 is a candidate gene that may be related to host susceptibility versus resistance to intracellular pathogens. This study aimed to determine possible association of SLC11A1 polymorphisms with visceral leishmaniasis among Moroccan children. A total of 106 children who developed visceral leishmaniasis due to Leishmania infantum were enrolled in this study. The control group was composed of 137 unrelated children, 97 asymptomatic subjects (DTH+) and 42 healthy individuals (DTH) who had no evidence of present or past infection. Four polymorphisms were studied by PCR-RFLP and sequencing: (GT)n microsatellite in the 5' exon 1; silent substitutions 469+14G/C in intron 4; amino acid substitution D543N in exon 15 and 823C/T polymorphism in exon 8. Thereafter, the frequencies of genotypes, alleles and haplotypes were estimated. Two polymorphisms were each significantly associated in the genotypes with visceral leishmaniasis: 823C/T in exon 8 and D543N in exon 15 when comparing visceral leishmaniasis and DTH+ groups. The results of haplotype frequencies suggested an evidence of association with resistance to visceral leishmaniasis for the "286GTG" and "288GCA" haplotypes, whereas, the "286GCG" haplotype appears to increase the risk to visceral leishmaniasis susceptibility.Our data provide insights into the possible role of SLC11A1 variation in visceral leishmaniasis susceptibility. These results must be regarded as preliminary but suggestive that further study with larger populations is worthwhile.

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.

NRAMP1, VDR, HLA-DRB1, and HLA-DQB1 gene polymorphisms in susceptibility to tuberculosis among the Chinese Kazakh population: a case-control study

Background. To explore the potential role of natural-resistance-associated macrophage protein 1 (NRAMP1) gene, vitamin D receptor (VDR) gene, (human leukocyte antigen, (HLA-DRB1) HLA) -DRB1 gene, and HLA-DQB1 gene polymorphisms in susceptibility to tuberculosis (TB) in the Chinese Kazakh population. Methods. A case-control study was performed on the Chinese Kazak population. Genetic polymorphisms of NRAMP1 gene (3′UTR) and VDR gene (TaqI and FokI) were analysed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analysis in TB patients and healthy controls. Genetic polymorphisms of HLA-DRB1 gene and HLA-DQB1 gene in the two groups were detected with polymerase chain reaction-sequence-specific primers (PCR-SSPs) technique and sequencing analysis. Results. There was statistically significant difference in the 3′UTR polymorphism between the TB patients and healthy controls in the Chinese Kazak population (P = 0.002; OR = 1.859; 95% CI = 1.182–2.926). Significant difference was observed in the FokI polymorphism between the TB patients and healthy controls (P = 0.001; OR = 1.530; 95% CI = 1.007–2.325). It does not disclose any significant association between the disease and TaqI (P > 0.05). Alleles HLA-DRB1∗04 and HLA-DQB1∗0201 occurred more frequently in patients than in controls (P = 0.011 and 0.002; OR = 1.889 and 1.802; 95% CI = 1.153–3.095 and 1.230–2.639, resp.). Conclusions. Polymorphisms in the NRAMP1 gene, VDR gene, HLA-DRB1 gene, and HLA-DQB1 gene are statistically associated with susceptibility to TB in the Chinese Kazakh population.

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.

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.

Tumour necrosis factor gene polymorphism and disease prevalence

Tumour necrosis factor (TNF), an important proinflammatory cytokine, plays a role in the regulation of cell differentiation, proliferation and death, as well as in inflammation, innate and adaptive immune responses, and also implicated in a wide variety of human diseases. The presence of DNA sequence variations in regulatory region might interfere with transcription of TNF gene, influencing the circulating level of TNF and thus increases the susceptibility to human diseases (infectious, cancer, autoimmune, neurodegenerative and other diseases). In this review, we have comprehensively analysed various published case-control studies of different types of human diseases, in which TNF gene polymorphism played a role, and computationally predicted several single nucleotide polymorphisms (SNPs) lie in transcription factor-binding sites (TFBS) of transcription factors (TFs). It has been observed that TNF enhancer polymorphism is implicated in several diseases, and TNF rs1800629 and rs361525 SNPs are the most important in human disease susceptibility as these might influence the transcription of TNF gene. Thirty-two SNPs lies in TFBS of 20 TFs have been detected in the TNF upstream region. It has been found that TNF enhancer polymorphism influences the serum level of TNF in different human diseases and thus affects the susceptibility to diseases. The presence of DNA sequence variation in TNF gene causes the modification of transcriptional regulation and thus responsible for association of susceptibility/resistance with human diseases.

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

A number of studies have investigated the association between TNF-308 (rs1800629 G/A) polymorphisms and the susceptibility towards tuberculosis (TB) in different populations. However, many of these studies provided inconsistent results. In this study, a systematic review and meta-analysis of the published studies was performed to gain a clearer understanding of this association. The PubMed, Embase, Web of Science and CNKI databases were searched for case-control studies published up to Jan 2011, we used no lower date limit. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. A total of 18 publications from 2001 to 2010, involving 2584 TB cases and 3817 controls were included. Overall, for the A allele carriers (G/A + A/A) vs. homozygote GG, the pooled OR was 1.03 (95% CI = 0.89-1.19; P = 0.912 for heterogeneity). For the allele A vs. allele G, the pooled OR was 1.07 (95% CI = 0.93-1.22; P = 0.013 for heterogeneity). In the stratified analysis by ethnicity, among Asians significant risk was found for allele A vs. allele G (OR = 1.22, 95% CI = 1.02-1.47; P = 0.152 for heterogeneity), no significant risks were found among Caucasians. This meta-analysis indicated that the TNF-308 polymorphism was not associated with the risk of TB in the total population, however the significant risk for TNF-308 A allele was found among Asians not Caucasians.

Association between TNF-Alpha (-857) Gene Polymorphism and Susceptibility to Tuberculosis

BACKGROUND

TNF-α as a pro-inflammatory cytokine plays a key role in host defense against tuberculosis (TB). Presence of mutation in TNF-α gene can influence the effectiveness, performance and capability of immune responses against this infection. The Aim of this study was to investigate the frequency of TNF-α alleles and its relationship with susceptibility to TB and TNF-α gene variations.

METHODS

A case-control study was conducted and 103 healthy controls and 93 TB patients were enrolled. Genotype of TNF-238, TNF -244, TNF-308, TNF -857 and TNF-863 were distinguished using PCR-RFLP method.

RESULTS

TNF-857 and TNF-863 were in high frequency mutation regions in a population level, and a significant difference at TNF-857 was noticed between the two groups of case and control.

CONCLUSION

Presence of mutation in TNF-857 region probably increases the host susceptibility to mycobacterial infection. Genotyping of these regions in combination with other factors can be used for screening of high risk persons. According to high distribution of mutations in TNF-857 and TNF-863 regions, further studies on association of these regions is suggested.

SLC11A1 (NRAMP1) polymorphisms and tuberculosis susceptibility: updated systematic review and meta-analysis

BACKGROUND

Natural resistance associated macrophage protein 1 (NRAMP1), encoded by the SLC11A1 gene, has been described to regulate macrophage activation and be associated with infectious and autoimmune diseases. The relation between SLC11A1 polymorphisms and tuberculosis susceptibility has been studied in different populations.

METHODS

We systematically reviewed published studies on SLC11A1 polymorphisms and tuberculosis susceptibility until September 15, 2010 and quantitatively summarized associations of the most widely studied polymorphisms using meta-analysis.

RESULTS

In total, 36 eligible articles were included in this review. In Meta-analysis, significant associations were observed between tuberculosis risk and widely studied SLC11A1 polymorphisms with summarized odds ratio of 1.35 (95%CI, 1.17-1.54), 1.25 (95% CI, 1.04-1.50), 1.23 (95% CI, 1.04-1.44), 1.31 (95%CI, 1.08-1.59) for 3' UTR, D543N, INT4, and 5' (GT)n, respectively. Heterogeneity between studies was not pronounced, and the associations did not remarkably vary in the stratified analysis with respect to study population and study base.

CONCLUSIONS

The association between SLC11A1 polymorphisms and tuberculosis susceptibility observed in our analyses supports the hypothesis that NRAMP1 might play an important role in the host defense to the development of tuberculosis.

Genetic epidemiology of tuberculosis susceptibility: impact of study design

Several candidate gene studies have provided evidence for a role of host genetics in susceptibility to tuberculosis (TB). However, the results of these studies have been very inconsistent, even within a study population. Here, we review the design of these studies from a genetic epidemiological perspective, illustrating important differences in phenotype definition in both cases and controls, consideration of latent M. tuberculosis infection versus active TB disease, population genetic factors such as population substructure and linkage disequilibrium, polymorphism selection, and potential global differences in M. tuberculosis strain. These considerable differences between studies should be accounted for when examining the current literature. Recommendations are made for future studies to further clarify the host genetics of TB.

Tuberculosis as a complex trait: impact of genetic epidemiological study design

Several studies have suggested a role for human genetic risk factors in the susceptibility to developing tuberculosis (TB). However, results of these studies have been inconsistent, and one potential reason for these inconsistencies is variation in aspects of study design. Specifically, phenotype definitions and population genetic factors have varied dramatically. Since TB is a complex trait, there are many challenges in designing studies to assess appropriately human genetic risk factors for the development of TB as opposed to the acquisition of latent M. tuberculosis infection. In this review we summarize these important study design differences, with illustrations from the TB genetics literature. We cite specific examples of studies of the NRAMP1 (SLC11A1) gene and present Fisher's combined p values for different stratifications of these studies to further illustrate the impact of study design differences. Finally, we provide suggestions for the design of future genetic epidemiological studies of TB.

Can immunogenetics illuminate the diverse manifestations of respiratory infections?

Improved technologies for high-throughput genotyping and the establishment of well-defined cohorts prompted hope that polymorphisms would be discovered that define a patients' risk of respiratory disease or aid in diagnosis. Genetic pitfalls encountered in this quest include genotyping errors, ethnic differences and linkage dysequilibrium. Differences in the definition of the disease phenotype also create discrepancies, so immunogenetic testing has not yet reached the clinic. However, associations between a polymorphism and a disease phenotype place the gene or one in linkage dysequilibrium on the path to the disease. Here we review studies of immune-related genes that are illuminating the immunopathogenesis of community-acquired pneumonia and mycobacterial infections.

Genetic polymorphisms in TNF genes and tuberculosis in North Indians

BACKGROUND

Pulmonary tuberculosis, the most common clinical form of mycobacterial diseases, is a granulomatous disease of the lungs caused by Mycobaterium tuberculosis. A number of genes have been identified in studies of diverse origins to be important in tuberculosis. Of these, both tumor necrosis factor alpha (TNF-alpha) and lymphotoxin alpha (LT-alpha) play important immunoregulatory roles.

METHODS

To investigate the association of TNF polymorphisms with tuberculosis in the Asian Indians, we genotyped five potentially functional promoter polymorphisms in the TNFA gene and a LTA_NcoI polymorphism (+252 position) of the LTA gene in a clinically well-defined cohort of North-Indian patients with tuberculosis (N = 185) and their regional controls (N = 155). Serum TNF-alpha (sTNF-alpha) levels were measured and correlated with genotypes and haplotypes.

RESULTS

The comparison of the allele frequencies for the various loci investigated revealed no significant differences between the tuberculosis patients and controls. Also, when the patients were sub-grouped into minimal, moderately advanced and far advanced disease on the basis of chest radiographs, TST and the presence/absence of cavitary lesions, none of the polymorphisms showed a significant association with any of the patient sub-groups. Although a significant difference was observed in the serum TNF-alpha levels in the patients and the controls, none of the investigated polymorphisms were found to affect the sTNF-alpha levels. Interestingly, it was observed that patients with minimal severity were associated with lower log sTNF-alpha levels when compared to the patients with moderately advanced and far advanced severity. However, none of these differences were found to be statistically significant. Furthermore, when haplotypes were analyzed, no significant difference was observed.

CONCLUSIONS

Thus, our findings exclude the TNF genes as major risk factor for tuberculosis in the North Indians.

TNF and LTA gene, allele, and extended HLA haplotype associations with severe dengue virus infection in ethnic Thais

Severe dengue virus (DENV) infection is characterized by a cascade of cytokine production, including the production of tumor necrosis factor-alpha (TNF-alpha) and lymphotoxin-alpha (LT-alpha). We have analyzed a variety of polymorphisms in the TNF and LTA genes of 435 ethnic Thais who had subclinical DENV infection, primary or secondary dengue fever (DF), or primary or secondary dengue hemorrhagic fever (DHF). The TNF -238A polymorphism marking the TNF-4,LTA-3 haplotype occurred in a significantly greater number of patients with secondary DHF (20 [15.2%] of 132) than patients with secondary DF (7 [4.1%] of 169) (P < .001; P corrected by use of Bonferroni adjustment, .022; odds ratio, 4.13 [95% confidence interval, 1.59-11.17]). In a subset of patients, the LTA-3 haplotype was associated with in vivo intracellular production of LT-alpha and TNF-alpha during the acute viremic phase of infection. Two extended human major histocompatibility complex (MHC) haplotypes containing TNF-4 and LTA-3, together with HLA-B48, HLA-B57, and HLA-DPB1*0501, were detected only in patients with secondary DHF. These observations indicate that polymorphism in functionally distinct MHC-encoded proteins contributes to the risk of developing severe secondary DENV infection and warrants further investigation.

NRAMP1 (SLC11A1) gene polymorphisms that correlate with autoimmune versus infectious disease susceptibility in tuberculosis and rheumatoid arthritis

NRAMP1 gene has multiple pleiotropic effects on macrophage activation pathways. These pleiotropic effects may increase resistance to infections such as tuberculosis (TB), but may also lead to susceptibility of autoimmune diseases such as rheumatoid arthritis (RA). It has been hypothesized that allele 3 would be associated with autoimmune diseases, whereas allele 2 would be associated with infectious diseases, and genetic factors that enhanced survival in the epidemics of TB might have led to susceptibility for the development of RA. We analysed four NRAMP1 gene polymorphisms including 5' promoter (GT)(n) (rs34448891), INT4 (469 + 14G/C) (rs3731865), 3'UTR (1729 + 55del4) (rs17235416) and D543N (codon 543, Asp to Asn) (rs17235409) in 112 patients with TB, 98 patients with RA, 80 healthy controls for TB and 122 healthy controls for RA using ARMS-PCR and PCR-RFLP. We found a significant association between INT4 and RA (P = 0.004, odds ratio: 2.06, 95% CI: 1.24-3.41), but no significant differences between 5' promoter, D543N, 3'UTR polymorphisms and RA. There were no associations between NRAMP1 gene polymorphisms and TB. Similarly, no significant differences were observed between NRAMP1 polymorphisms and rheumatoid factor positivity and erosive disease in RA and localization of TB. INT4 polymorphism may be associated with RA in Turkish patients.

IFNG +874T/A, IL10 -1082G/A and TNF -308G/A polymorphisms in association with tuberculosis susceptibility: a meta-analysis study

Susceptibility to infectious diseases is influenced by genetic background and efficient cellular immune activation is responsible for protection. In tuberculosis (TB), interferon-gamma (IFNgamma) is crucial to control intracellular growth of Mycobacterium tuberculosis while interleukin-10 (IL-10) has an antagonistic role. Tumor necrosis factor (TNF) is a central mediator of granuloma formation and control of bacilli spread synergizing with IFNgamma to hamper M. tuberculosis infection. Single nucleotide polymorphisms (SNPs) located at these genes could influence cytokine levels and regulate resistance and susceptibility to TB. The aim of this study was to determine the association of the interferon-gamma gene (IFNG) +874T/A, interleukin-10 gene (IL10) -1082G/A and tumor necrosis factor gene (TNF) -308G/A SNPs with TB in several populations using meta-analysis. We searched for association studies correlating these polymorphisms and TB using pre-established keywords in Medline. Meta-analysis was conducted with random effects models to account for heterogeneity between studies. Eleven studies were included in the IFNG +874T/A meta-analysis, while eight were used for the IL10 -1082G/A, and 10 were employed for TNF -308G/A. Data were analyzed in respect to associations between alleles, genotypes and minor allele carriers. Statistically significant results were found only for IFNG. The +874T allele of IFNG showed a protective significant association (OR = 0.75; 95% CI, 0.634-0.887; P = 0.0008). Though not significant, IL10 presented a trend towards protection when only studies with pulmonary TB patients were considered. This data reinforces the critical importance of IFNG +874T/A as a genetic marker for TB resistance and this information can be used for better design of a TB vaccine.