Association of IL-1β +3954 C/T and IL-10-1082 G/A cytokine gene polymorphisms with susceptibility to tuberculosis

Influence of Cytokine-Related genetic variants in TNF, IL6, IL1β, and IFNγ genes in the thalidomide treatment for Erythema nodosum leprosum in a Brazilian population sample

Erythema nodosum leprosum (ENL), an inflammatory reaction in leprosy, causes painful nodules, fever, and malaise due to immune system activation. Thalidomide is an effective treatment, although associated with important adverse effects. We aimed to evaluate the association of genetic variants in genes encoding tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) with the response to treatment of ENL with thalidomide. 148 patients from the South and Northeast regions of Brazil were included. Genomic DNA was isolated from blood and/or saliva samples using commercial kits, and genetic variants in TNF, IL6, IL1β, and IFNγ genes were genotyped by TaqMan system. We identified an association between polymorphisms in TNF (rs1799964C, rs1800630A, rs1799724T and rs1800629A) IL1β (rs4848306G, rs1143623G, rs16944A, and rs1143627A), IL6 (rs2069840C and rs2069845G) and IFNγ (rs2430561T) with thalidomide dose variation in a time-dependent manner. Associations of IL6 and TNF haplotypes with thalidomide dosage variation over the time of treatment were also observed. Polymorphisms in TNF, IL6, IL1β, and IFNγ genes may modulate their expression levels, potentially impacting the required dosage of thalidomide in the treatment of ENL. Our findings should be confirmed in further studies to estimate the size effect of these polymorphisms on ENL treatment with thalidomide.

Association of TOLLIP mRNA Expression and TOLLIP rs5743899A/G, TOLLIP rs3750920C/T, and IL-10 -1082G/A Single-Nucleotide Polymorphisms with Susceptibility to Tuberculosis

The early innate host immune response is crucial in the susceptibility to tuberculosis (TB). This study aimed to investigate the potential role of Toll-interacting protein (TOLLIP), a negative regulator of the human innate immune response, and interleukin-10 (IL-10), an anti-inflammatory cytokine, in susceptibility to TB. The peripheral blood mononuclear cells of 30 active pulmonary TB patients and 30 healthy volunteers were included. TOLLIP mRNA expression levels, single nucleotide polymorphisms (SNPs) of the TOLLIP gene, such as rs5743899A/G and rs3750920C/T, and IL-10 -1082G/A SNP were detected using real-time PCR, PCR-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system-PCR (ARMS-PCR), respectively. TOLLIP mRNA expression levels were significantly higher in TB patients than in healthy controls (expression fold difference = 2.72, the delta-delta Ct method, also known as the 2-∆∆Ct method). The heterozygous (GA) genotype of the IL-10 -1080G/A polymorphism was significantly predominant among the patient group (p = 0.02, Hardy-Weinberg equilibrium). However, the Kruskal‒Wallis analysis found no significant relationship between TOLLIP mRNA expression levels and SNPs. TOLLIP mRNA and IL-10 -1082G/A SNP were assessed as potential biomarkers to predict TB susceptibility. For more significant results, they should be examined with other negative regulators of innate immunity and other immune factors associated with susceptibility to TB. Our study is the first to investigate the association of TOLLIP polymorphisms and expression levels with TB susceptibility in Turkey.

The Impact of IL1B rs1143634 and DEFB1 rs11362 Variants on Periodontitis Risk in Phenylketonuria and Type 1 Diabetes Mellitus Patients in a Latvian Population

OBJECTIVES

Periodontitis is a multifactorial disease that affects approximately 11% of the global population. The objective of this study was to examine whether, among individuals with phenylketonuria and type 1 diabetes mellitus, those with the IL1B rs1143634 and/or DEFB1 rs11362 genetic variants exhibit a higher periodontitis risk compared to healthy controls.

MATERIALS AND METHODS

In all, 43 phenylketonuria patients (aged 12-53), 28 type 1 diabetes mellitus patients (aged 11-40), and 63 healthy controls (aged 12-53) were included. The evaluation of periodontitis risk was conducted using the Silness-Löe plaque index, the Greene-Vermillion index, and an assessment for the necessity of calculus removal. Genetic variants rs1143634 and rs11362 were genotyped from salivary samples using restriction length polymorphism analysis.

RESULTS

The DEFB1 rs11362 variant was associated with higher Silness-Löe and Greene-Vermillion index scores in phenylketonuria patients (p = 0.011 and p = 0.043, respectively). The IL1B rs1143634 variant was associated with lower calculus removal necessity in type 1 diabetes mellitus patients (p = 0.030). Clinical examination showed the worst oral hygiene index scores for PKU patients. PKU patients also reported the least consistent tooth brushing and flossing habits.

CONCLUSIONS

Genetic associations between DEFB1 rs11362 and IL1B rs1143634 variants and oral hygiene indices were observed in the PKU and T1DM groups, suggesting that genetic factors may contribute to periodontal health differences in these populations. Further research with a larger sample size is needed to confirm these findings and develop targeted oral health interventions.

Association of IL-1β, NLRP3, and COX-2 Gene Polymorphisms with Autoimmune Thyroid Disease Risk and Clinical Features in the Iranian Population

Background

Grave's disease (GD) and Hashimoto's thyroiditis (HT) are autoimmune diseases of the thyroid gland in which genetic predisposition plays a major role in their development. Currently, the role of NLRP3 inflammasome and COX-2 has been documented in many autoimmune diseases. The purpose of the study is to delineate the impact of IL-1β (rs1143634), NLRP3 (rs3806265), and COX-2 (rs2745557) gene polymorphisms in the development of GD and HT.

Methods

A total of 256 newly diagnosed patients with autoimmune thyroid disease (135 patients with HT and 121 GD patients) as case groups and 145 controls were included in the study.

Results

Recessive and overdominant models showed a significant association between IL-1β rs1143634 SNP and HT development risk. The frequency of TT genotype and T allele of IL-1β rs1143634 SNP in the control group was significantly higher than the GD group. There was no significant association between NLRP3 rs3806265 polymorphism and HT and GD development. The frequency of GA genotype of COX-2 (rs2745557) in the control group was significantly higher than that in the HT group. There was no significant association between COX-2 rs2745557 genotypic and allelic distribution and GD development risk. The results revealed a significant relationship between some clinical features of HT and GD groups and SNPs studied.

Conclusion

The results manifest the significant impact of IL-1β rs1143634 and COX-2 (rs2745557) SNPs and HT development and IL-1β rs1143634 SNP on GD occurrence risk. Furthermore, a significant relationship was observed between some clinical features of HT and GD groups and studied SNPs.

TNFA -308G>A and IL10 -1082A>G polymorphisms seem to be predictive biomarkers of chronic HCV infection

Background

Genetic changes may induce dysregulated cytokine production and affect the progression of the chronic disease caused by the hepacivirus C (HCV) because the balance of pro- and anti-inflammatory cytokines determines the outcome of infection. This study evaluated the TNFA -308G>A and IL10 -1082A>G polymorphisms in the susceptibility and progress of chronic hepatitis C.

Method

The study included 101 samples from patients with chronic hepatitis C and 300 samples from healthy donors. Polymorphisms were typed by real-time PCR and were analyzed for associations with histopathological parameters (according to METAVIR classification) and HCV viral load.

Results

The polymorphic genotype for the TNFA -308G>A variant was not present in the group of patients with chronic hepatitis C and its absence could be associated with protection against HCV infection (p = 0.0477). Patients with the polymorphic genotype of the IL10 -1082A>G polymorphism had higher HCV viral load than wild-type patients (p = 0.0428). Neither polymorphism was associated with different levels of necroinflammatory activity or fibrosis scores.

Conclusion

Our results suggest the polymorphic genotype at TNFA -308G>A as protective against chronic HCV infection, and the polymorphic genotype at the IL10 -1082A>G variant associated with higher HCV viral load. Further studies must be performed in order to confirm these associations.

Interleukin-18 and interferon-γ single nucleotide polymorphisms in Egyptian patients with tuberculosis

BACKGROUND

Interleukin-18 (IL-18) and interferon-γ (IFN-γ) are cytokines of crucial role in inflammation and immune reactions. There is a growing evidence supporting important roles for IL-18 and IFN γ in tuberculosis (TB) infection and anti-tuberculosis immunity.

OBJECTIVE

To evaluate the role of polymorphisms in IL-18-607 and -137 and INF-γ +874 in susceptibility to TB infection among Egyptian patients.

METHODS

A case control study was conducted to investigate the polymorphism at IL-18-607, -137 and INF-γ+874 by sequence specific primer-polymerase chain reaction (SSP- PCR) in 105 patients with pulmonary and extra pulmonary tuberculosis and 106 controls.

RESULTS

A significant protective effect against TB was found in homozygous CC genotype at IL-18 -137G/C, in addition to a 7-fold risk with GG and GC genotypes in the recessive model. Apart from a decreased risk with the AC genotype, no association was detected between the susceptibility to TB and different genotypes or alleles at the IL-18 -607A/C site. The homozygous AA genotype in INF-γ+874 showed a significant higher risk to TB than the homozygous TT or heterozygous AT genotypes with nearly a 2-fold risk of TB infection with the A allele. Regarding haplotype association, the GC haplotype was strongly associated with TB infection compared to other haplotypes.

CONCLUSION

These findings suggest; for the first time in Egypt; a significant risk to TB infection with SNP at the IL-18-137G/C with no LD with SNP at the IL-18-607 site. The homozygous AA genotype in INF-γ+874 showed a significant higher risk to TB than the homozygous TT or heterozygous AT genotypes.

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.

Influence of Genetic Polymorphism Towards Pulmonary Tuberculosis Susceptibility

Tuberculosis (TB) is still remains the major threat for human health worldwide. Several case-control, candidate-gene, family studies and genome-wide association studies (GWAS) suggested the association of host genetic factors to TB susceptibility or resistance in various ethnic populations. Moreover, these factors modulate the host immune responses to tuberculosis. Studies have reported genetic markers to predict TB development in human leukocyte antigen (HLA) and non-HLA genes like killer immunoglobulin-like receptor (KIR), toll-like receptors (TLRs), cytokine/chemokines and their receptors, vitamin D receptor (VDR) and SLC11A1 etc. Highly polymorphic HLA loci may influence antigen presentation specificities by modifying peptide binding motifs. The recent meta-analysis studies revealed the association of several HLA alleles in particular class II HLA-DRB1 with TB susceptibility and valuable marker for disease development especially in Asian populations. Case-control studies have found the association of HLA-DR2 in some populations, but not in other populations, this could be due to an ethnic specific association of gene variants. Recently, GWAS conducted in case-control and family based studies in Russia, Chinese Han, Morocco, Uganda and Tanzania revealed the association of genes such as ASAP1, Alkylglycerol monooxygenase (AGMO), Forkhead BoxP1 (FOXP1), C-terminal domain phosphatase 1 (UBLCP1) and intergenic SNP rs932347C/T with TB. Whereas, SNP rs10956514A/G were not associated with TB in western Chinese Han and Tibetan population. In this review, we summarize the recent findings of genetic variants with susceptibility/resistance to TB.

Genetic Polymorphisms in Cytokine Genes in Colombian Patients with Ocular Toxoplasmosis

Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii, which has the capacity to infect all warm-blooded animals worldwide. Toxoplasmosis is a major cause of visual defects in the Colombian population; however, the association between genetic polymorphisms in cytokine genes and susceptibility to ocular toxoplasmosis has not been studied in this population. This work evaluates the associations between polymorphisms in genes coding for the cytokines tumor necrosis factor alpha (TNF-α) (rs1799964, rs1800629, rs1799724, rs1800630, and rs361525), interleukin 1β (IL-1β) (rs16944, rs1143634, and rs1143627), IL-1α (rs1800587), gamma interferon (IFN-γ) (rs2430561), and IL-10 (rs1800896 and rs1800871) and the presence of ocular toxoplasmosis (OT) in a sample of a Colombian population (61 patients with OT and 116 healthy controls). Genotyping was performed with the "dideoxynucleotide (ddNTP) primer extension" technique. Functional-effect predictions of single nucleotide polymorphisms (SNPs) were done by using FuncPred. A polymorphism in the IL-10 gene promoter (-1082G/A) was significantly more prevalent in OT patients than in controls (P = 1.93e-08; odds ratio [OR] = 5.27e+03; 95% confidence interval [CI] = 3.18 to 8.739; Bonferroni correction [BONF] = 3.48e-07). In contrast, haplotype "AG" of the IL-10 gene promoter polymorphisms (rs1800896 and rs1800871) was present at a lower frequency in OT patients (P = 7e-04; OR = 0.10; 95% CI = 0.03 to 0.35). The +874A/T polymorphism of IFN-γ was associated with OT (P = 3.37e-05; OR = 4.2; 95% CI = 2.478 to 7.12; BONF = 6.07e-04). Haplotype "GAG" of the IL-1β gene promoter polymorphisms (rs1143634, rs1143627, and rs16944) appeared to be significantly associated with OT (P = 0.0494). The IL-10, IFN-γ, and IL-1β polymorphisms influence the development of OT in the Colombian population.

Association of IL-37 gene polymorphisms with susceptibility to tuberculosis in Saudi subjects

Tuberculosis (TB) is one of the most common infectious diseases worldwide. IL-37, a novel member of the IL-1 family, has anti-inflammatory activity. Various cytokine genes polymorphisms are reportedly associated with susceptibility to TB infection. However, an association between genetic variations in the IL-37 gene and susceptibility to TB infection has not been investigated. The aim of this case-control study was therefore to identify such an association in Saudi subjects, in which five single-nucleotide polymorphisms (SNPs) in the IL-37 gene were assessed. Serum concentrations of IL-37 were evaluated using ELISA, and genetic variants genotyped by multiplex PCR and ligase detection reaction. It was found that the C/C genotype of rs2723176 (-6962 A/C) occurs significantly more frequently in patients with active TB and that the C allele of this SNP is associated with TB. In addition, the C allele of rs2723176 SNP was associated with high circulating concentrations of IL-37. However, the genotype and allele frequency of the other four SNPs (rs3811046, rs3811047, rs2723186 and rs2723187) were not significantly associated with TB infection. In conclusion, the present data suggest that rs2723176 SNP of IL-37 is involved in the development of TB infection. Furthermore, high circulating concentrations of IL-37 may have a negative effect on protective immunity against TB infection.

The role of single nucleotide polymorphisms, contained in proinflammatory cytokine genes, in the development of congenital infection with human cytomegalovirus in fetuses and neonates

PURPOSE

The research project targeted the distribution of genotypes, alleles and haplotypes in single nucleotide polymorphisms (SNPs) within the interleukin (IL) 1A, IL1B, IL6, IL12B and TNFA genes, in fetuses and neonates, congenitally infected with human cytomegalovirus (HCMV), and among uninfected controls.

METHODS

The study included 20 fetuses and neonates with congenital HCMV infection and 31 control individuals. The genotypes in SNPs of the studied cytokine genes were identified by a self-designed nested PCR-RFLP assays. Selected genotypes, representing distinct variants in analyzed polymorphisms, were confirmed by sequencing. The relationship between the genetic status of the studied polymorphisms and congenital infection development was estimated, using a logistic regression model.

RESULTS

The CT haplotype, composed of C allele determined in IL1A -889 C > T and T allele in IL1B +3954 C > T SNP, increased the risk of congenital HCMV infection, as well as the onset of disease related symptoms (P ≤ 0.0001). Considering disease outcome, the risk of development of symptoms, was increased among the CT heterozygotes in IL1A -889 C > T polymorphism (OR 2.86, 95% CI 0.24-33.90; P = 0.045). Moreover, multiple-SNP variants CCGAG in the range of all the SNPs, analyzed in the study, increased the risk of congenital infection with HCMV (OR 7.94, 95% CI 1.38-45.69; P = 0.026).

CONCLUSIONS

Polymorphisms within the proinflammatory cytokine genes may contribute to the development of congenital infection with HCMV.

Association of SNPs from IL1A, IL1B, and IL6 Genes with Human Cytomegalovirus Infection Among Pregnant Women

The study was aimed to estimate the role and prevalence rates of genotypes, haplotypes, and alleles, located within the single-nucleotide polymorphisms (SNPs) of interleukin (IL) 1A, IL1B, and IL6 genes, in the occurrence and development of human cytomegalovirus (HCMV) infection among pregnant women. A research was conducted in 129 pregnant women, out of whom, 65 were HCMV infected and 64 were age-matched control uninfected individuals. HCMV DNA was quantitated for UL55 gene by the real-time Q PCR in the body fluids. The genotypic statuses within the SNPs were determined by nested PCR-RFLP assays and confirmed, by sequencing for randomly selected representative PCR products. A relationship between the genotypes and alleles, as well as haplotypes and multiple variants in the studied polymorphisms, and the occurrence of HCMV infection in pregnant women, was determined using a logistic regression model. TT genotype within IL1A polymorphism significantly decreased the risk of HCMV infection (OR 0.32, 95% CI 0.09-1.05; p ≤ 0.050). Considering IL6 SNP, the prevalence rate of GC genotype was significantly decreased among the HCMV infected, compared to the uninfected control individuals (OR 0.45, 95% CI 0.21-0.99; p ≤ 0.050). Moreover, CC homozygotic status in IL6 SNP, found in pregnant women, significantly decreased the risk of congenital infection with HCMV in their offsprings (OR 0.12; p ≤ 0.050). In multiple SNP analysis, TC haplotype within the IL1 polymorphisms significantly decreased the risk of the infection in pregnant women (OR 0.38 95% CI 0.15-0.96; p ≤ 0.050). In addition, TTG complex variants for all the studied polymorphisms and TG variants for IL1B and IL6 SNPs were significantly more prevalent among the infected offsprings with symptomatic congenital cytomegaly than among the asymptomatic cases (p ≤ 0.050). In conclusion, the analyzed IL1A -889 C>T, IL1B +3954 C>T, and IL6 -174 G>C polymorphisms may be associated with the occurrence and development of HCMV infection among studied patients.

The immunological response to syphilis differs by HIV status; a prospective observational cohort study

Background

It is not known if there is a difference in the immune response to syphilis between HIV-infected and uninfected individuals.

Methods

We prospectively recruited all patients with a new diagnosis of syphilis and tested their plasma for IFNα, IFNγ, IL-1β, IL-12p40, IL-12p70, IP-10, MCP-1, MIP-1α, MIP-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10 and IL-17A at baseline pre-treatment and 6 months following therapy.

Results

A total of 79 HIV-infected [44 primary/secondary syphilis (PSS) and 35 latent syphilis (LS)] and 12 HIV-uninfected (10 PSS and 2 LS) cases of syphilis and 30 HIV-infected controls were included in the study. At the baseline visit, compared to the control group, concentrations of IL-10 were significantly elevated in the HIV-infected and uninfected groups. The level of IL-10 was significantly higher in the HIV-infected compared to the HIV-uninfected PSS group (25.3 pg/mL (IQR, 4.56–41.76) vs 2.73 pg/mL (IQR, 1.55–9.02), P = 0.0192). In the HIV-infected PSS group (but not the HIV-infected LS or HIV-uninfected PSS groups) the IP-10, MIP-1b, IL-6 and IL-8 were raised compared to the controls. IL-10 levels decreased but did not return to control baseline values by 6 months in HIV infected PSS and LS and HIV uninfected PSS.

Conclusion

PSS and LS in HIV-infected individuals is characterized by an increase in inflammatory and anti-inflammatory cytokines such as IL-10. The increase of IL-10 is greater in HIV-infected than uninfected individuals. Further work is required to ascertain if this is part of an immunological profile that correlates with adverse outcomes such as serofast syphilis and neurosyphilis, in HIV-infected individuals.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2201-7) contains supplementary material, which is available to authorized users.

The association of interleukin-10 -1082, -819, -592 polymorphisms and tuberculosis risk

Objectives:

To assess the association between interleukin (IL)-10 -1082, -819, -592 polymorphisms and tuberculosis (TB) risk.

Methods:

This study was conducted between July and October 2014 in West China Hospital, Chengdu, Sichuan, China. We searched and collected data from PUBMED, EMBASE, Web of Science, China National Knowledge Infrastructure, VIP, and WANGFANG up to October 2014.

Results:

A total of 37 studies were enrolled, including 8625 TB cases, and 9928 healthy controls. The IL-10-1082G/A polymorphism was found to be associated with TB susceptibility in Caucasian (GG versus GA+AA, odds ratio [OR] - 1.83, 95% confidence interval [CI] - 1.03-3.24). The IL-10-819C/T polymorphism was related to TB susceptibility among Asians (C versus T, OR - 0.88, 95% CI - 0.81-0.97; CC versus TT: OR - 0.79, 95% CI - 0.64-0.97; CC+CT versus TT: OR - 0.87, 95% CI - 0.77-0.98; CC versus CT+TT: OR - 0.82, 95% CI - 0.68-0.98). The IL-10-592C/A polymorphism was in association with TB susceptibility in Asians (C versus A: OR - 0.74, 95% CI - 0.65-0.85; CC versus AA: OR - 0.55, 95% CI - 0.41-0.75; CA versus AA: OR - 0.73, 95% CI - 0.60-0.89; CC+CA versus AA: OR - 0.69, 95% CI 0.58-0.83; CA versus AA: OR - 0.66, 95% CI 0.51-0.86), Caucasian (C versus A: OR - 1.25, 95% CI - 1.08-1.45; CC versus CA+AA: OR-1.48, 95% CI - 1.16-1.89), and Europeans (C versus A: OR - 1.31, 95% CI - 1.02-1.67; CC versus AA: OR - 1.88, 95% CI - 1.05-3.37).

Conclusion:

This meta-analysis suggests that IL-10-1082G/A, IL-819C/T, and IL-592C/A polymorphisms might be associated with TB susceptibility in certain ethnicities.

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.

Polymorphisms of IFN-γ (+874A/T) and IL-12 (+1188A/C) in tuberculosis patients and their household contacts in Hyderabad, India

Several cytokine gene variants have shown to be associated with host susceptibility to infectious diseases including tuberculosis (TB). High rates of transmission were identified within household members of TB patients. In this study, we examined whether single nucleotide polymorphisms of IFN-γ +874A/T and IL-12 +1188A/C affect susceptibility to TB. Genomic DNA from patients with active disease, their household contacts HHC and healthy controls HC was genotyped for IFN-γ +874A/T and IL-12 +1188A/C SNPs by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). IFN-γ +874 AA and AT genotypes were significantly with different frequencies in patients and total HHC as compared to HC (p<0.0001). In patients IL-12 +1188 AC and CC genotypes were associated with TB (p<0.003, p<0.008). In total HHC AC, CC genotypes and both alleles (A&C) were significantly different as compared to HC (p<0.004, p<0.001, p<0.034) and the same result was obtained when HHC were stratified into related (p<0.02, p<0.001) and unrelated (p<0.009, p<0.017) individuals. Allelic frequencies, however, were significant only in related contacts (p<0.021). Generalized multifactor dimensionality reduction method (GMDR) testing revealed high risk combinations of several genotypes in IFN-γ & IL-12 genes. Our findings suggest an important role of genetic variations of IFN-γ and IL-12 for susceptibility to TB.

Lack of Association Between the IL1B (-511 and +3954), IL1RN VNTR Polymorphisms and Tuberculosis Risk: A Meta-analysis

BACKGROUND

Several recent studies have provided evidence that polymorphisms in the interleukin-1 (IL1) gene are implicated in tuberculosis (TB). However, results of different studies are inconsistent. The aim of this study was to perform a meta-analysis investigating the association of the IL1B (-511 and +3954) and IL1RN VNTR polymorphisms with TB risk.

METHODS

A systematic review of the English literature was conducted by searching Pubmed, Scopus, and ISI Web of Knowledge databases for relevant studies. Pooled odds ratios (OR) with 95 % confidence intervals (CI) were calculated using fixed effects models. Between-study heterogeneity and publication bias were also evaluated.

RESULTS

Nine case-control studies including 3327 participants were reviewed and analyzed. Our results did not indicate any association of the IL1B (-511 and +3954) and IL1RN VNTR polymorphisms with TB risk in the overall populations. The pooled OR of the IL1B -511 polymorphism was 1.09 (95 % CI 0.87-1.36) for the dominant model, 1.11 (0.89-1.38) for the recessive model, 1.15 (0.87-1.50) for the homozygote model, and 1.07 (0.94-1.23) for the allelic comparison model. ORs for the IL1B +3954 and IL1RN VNTR polymorphisms were similar. In subgroup analysis stratified by ethnicity, the results revealed no association between these polymorphisms and TB risk in black people, Asians, and Caucasians, respectively. We did not identify significant between-study heterogeneity across all studies, and there was no evidence of publication bias.

CONCLUSIONS

Our results indicate there is a lack of association between the IL1B (-511 and +3954), IL1RN VNTR polymorphisms and TB risk.

IL-10 Polymorphisms and Tuberculosis Susceptibility: An Updated Meta-Analysis

PURPOSE

The association of interleukin-10 (IL-10) polymorphisms (-1082G/A, -819C/T, -592A/C) and interleukin-6 (IL-6) poly-morphisms (-174G/C) with tuberculosis (TB) risk has been widely reported. However, the results are controversial. To clarify the role of these polymorphisms in TB, we performed a meta-analysis of all available and relevant published studies.

MATERIALS AND METHODS

Based on comprehensive searches of the PubMed, Medline, Embase, Web of Science, Elsevier Science Direct and Cochrane Library database, we identified outcome data from all articles estimating the association between IL-10 and IL-6 polymorphisms and TB risk.

RESULTS

The results indicated significant association of the allele model, heterozygous model and dominant model of IL-6 -174G/C polymorphism with decreased risk of TB. In the stratified analysis by ethnicity, significantly increased risk was observed for IL-10 -1082G/A polymorphism in Europeans under recessive model, for IL-10 -819C/T polymorphism in Asians under heterozygous model and dominant model and IL-10 -592A/C polymorphism in Asians under Allele model, homozygous model and recessive model. Moreover, significantly decreased risk of TB was associated with Asians for IL-6 -174C/G polymorphism in allele model, heterozygous model and dominant model. We also performed the analyses by sample types in IL-10 -1082G/A polymorphism, and observed significantly increased TB risk in mixed group under homozygous model.

CONCLUSION

The results suggested that the IL-10 -1082G/A polymorphism is associated with increased TB risk in Europeans, while IL-10 -819C/T and IL-10 -592A/C polymorphisms in Asians. However, IL-6 -174G/C polymorphism might be a genetic risk factor that decreases TB susceptibility in Asians.

IL-1β+3953C/T, -511T/C and IL-6 -174C/G polymorphisms in association with tuberculosis susceptibility: A meta-analysis

BACKGROUND

Studies of the association between the interleukin-1β gene (IL-1β) (+3953C/T, -511T/C) and interleukin-6 gene (IL-6) (-174G/C) polymorphisms and susceptibility to tuberculosis (TB) have yielded inconsistent results. The aim of this study was to investigate the relationship between these polymorphisms and TB risk by this meta-analysis.

METHODS

We systematically searched published literatures on IL-1β gene and IL-6 gene polymorphisms and tuberculosis risk by the PubMed, Medline, Embase, Web of Science, Elsevier Science Direct and Cochrane Library databases, and identified outcome data from all articles. Statistical analysis was performed using Stata 12.0. A total of 15 studies comprising 3983TB patients and 3996 controls were included in the present study.

RESULTS

We found that the IL-6 -174C/G polymorphism might be associated with decreased risk of TB (C vs. G: OR=0.77, 95% CI=0.64-0.91; CG vs. GG: OR=0.72, 95% CI=0.57-0.90; CC+CG vs. GG: OR=0.71, 95% CI=0.57-0.88). In the stratified analysis by ethnicity, significantly decreased risk were observed for IL-1β -511T/C polymorphism in Africans (C allele vs. T allele: OR=0.86, 95% CI=0.74-0.99; CC vs. TT: OR=0.74, 95% CI=0.55-0.99). Moreover, the IL-6 -174 C/G polymorphism was also associated with decreased risk of TB in Asians (C vs. G: OR=0.71, 95% CI=0.54-0.93; CG vs. GG: OR=0.61, 95% CI=0.44-0.85; CC+CG vs. GG: OR=0.63, 95% CI=0.46-0.86). We also performed the analyses by sample types in IL-6 -174 C/G polymorphism, and significant decreased TB risk was observed in pulmonary tuberculosis group (C allele vs. G allele: OR=0.69, 95% CI=0.52-0.93; CG vs. GG: OR=0.69, 95% CI=0.52-0.91; CC+CG vs. GG: OR=0.71, 95% CI=0.55-0.93), and pulmonary tuberculosis plus extra-pulmonary tuberculosis mixed group (CC vs. GG: OR=0.44, 95% CI=0.22-0.88; CC vs. CG+GG: OR=0.48, 95% CI=0.25-0.94).

CONCLUSIONS

This meta-analysis indicates that the IL-1β -511T/C polymorphism is associated with TB decreased risk in Africans, and IL-6 -174C/G polymorphism in Asians. Further well-designed, large scale studies are required to confirm this conclusion.

Association of Interleukin-10 promoter polymorphisms with neurosyphilis

Interleukin 10 (IL-10) is a potent anti-inflammatory cytokine. Increased production of IL-10 has been found in late syphilis, presumably creating favorable conditions for bacteria persistence. Single-nucleotide polymorphisms (SNPs) within the promoter of IL-10 gene have been found to influence IL-10 production. We investigated whether SNPs in the IL-10 gene promoter are associated with cerebrospinal fluid (CSF) levels of IL-10 and neurosyphilis. Polymorphisms in the gene for IL-10 (G→A mutation at the position -1084 and C→A mutation at the position -592) were sought in 35 patients with syphilis and 24 healthy volunteers. CSF examination (i.e. routine laboratory tests and IL-10 levels) was performed in all syphilis patients. Neurosyphilis was defined as reactive CSF VDRL test or CSF white blood cells⩾5/μL and CSF protein concentration⩾45mg/dL. Overall, 31% of patients with syphilis had neurosyphilis. CSF IL-10 levels were significantly higher in patients with neurosyphilis when compared to those with syphilis but not neurosyphilis. -1082 GG and -592 CC genotypes were significantly associated with higher CSF IL-10 levels. Moreover, these genotypes were found to be more frequent in individuals with neurosyphilis in comparison to those without neurosyphilis. Anti-inflammatory immune response seems to be important in pathogenesis of neurosyphilis. Our data suggest that host-related factors, such as SNPs of immune regulatory genes may influence the susceptibility to neurosyphilis.

Interleukin-10 promoter gene polymorphisms and susceptibility to tuberculosis: a meta-analysis

Objective

As an update to other recent meta-analyses, the purpose of this study was to explore whether interleukin-10 (IL-10) polymorphisms and their haplotypes contribute to tuberculosis (TB) susceptibility.

Methods

We searched for published case-control studies examining IL-10 polymorphisms and TB in PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Wanfang databases and the Chinese National Knowledge Infrastructure (CNKI). Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the strengths of the associations.

Results

A total of 28 studies comprising 8,242 TB patients and 9,666 controls were included in the present study. There were no significant associations between the -1082G/A, -819C/T, and -592A/C polymorphisms and TB in the pooled samples. Subgroup analyses revealed that the -819T allele was associated with an increased TB risk in Asians in all genetic models (T vs. C: OR=1.17, 95% CI=1.05-1.29, P=0.003; TT vs. CC: OR=1.37, 95% CI=1.09-1.72, P=0.006; CT+TT vs. CC: OR=1.33, 95% CI=1.09-1.63, P=0.006; TT vs. CT+CC: OR=1.17, 95% CI=1.02-1.35, P=0.03) and that the -592A/C polymorphism was significantly associated with TB in Europeans under two genetic models (A vs. C: OR=0.77, 95% CI=0.60-0.98, P=0.03; AA vs. CC: OR=0.53, 95% CI=0.30-0.95, P=0.03). Furthermore, the GCC IL-10 promoter haplotype was associated with an increased risk of TB (GCC vs. others: P=1.42, 95% CI=1.02-1.97, P=0.04). Subgroup analyses based on ethnicity revealed that the GCC haplotype was associated with a higher risk of TB in Europeans, whereas the ACC haplotype was associated with a lower TB risk in both Asians and Europeans.

Conclusions

This meta-analysis suggests that the IL-10-819T/C polymorphism is associated with the risk of TB in Asians and that the IL-10-592A/C polymorphism may be a risk factor for TB in Europeans. Furthermore, these data indicate that IL-10 promoter haplotypes play a vital role in the susceptibility to or protection against the development of TB.

Association of CYBB polymorphisms with tuberculosis susceptibility in the Chinese Han population

OBJECTIVE

Reactive oxygen species (ROS) play a major role in the nonspecific innate immune response to invading microorganisms, such as Mycobacterium tuberculosis (MTB). Gp91phox, encoded by CYBB, serves as a key functional subunit of the Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase complex, which is pivotal to ROS generation. Therefore, the aim of the study was to investigate the association of CYBB polymorphisms with tuberculosis (TB) susceptibility.

METHODS

In total, 636 TB patients and 608 healthy, age and gender matched controls were enrolled in this study. All subjects were unrelated ethnic Han Chinese. Two tagSNPs were selected from the HapMap database and genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry.

RESULTS

After adjusting for confounders including age, gender and smoking, rs5917471 allele T showed significant association with decreased risk of TB (OR 0.745, 95% CI 0.556-0.999) and pulmonary TB (OR 0.618, 95% CI 0.410-0.931). However, no difference in allelic distribution was observed for the rs6610650 G/A polymorphism with respect to TB or different clinical types of TB. Further stratified analyses demonstrated the protective effect of allele T of rs5917471 was stronger among males (OR 0.500, 95% CI 0.295-0.846), smokers (OR 0.462, 95% CI 0.239-0.896), and male smokers (OR 0.372, 95% CI 0.182-0.761); the individuals carrying the A allele of rs6610650 exhibited an decreased risk of TB among males, smokers and male smokers, with OR (95% CI) of 0.535 (0.290-0.984), 0.442 (0.198-0.988), and 0.350 (0.145-0.845), respectively. There were no statistically significant differences in haplotype distribution between TB and control groups. Smoking and rs5917471 formed the best gene-environment interaction model with the testing balanced accuracy of 53.29% and cross-validation consistency of 9/10.

CONCLUSIONS

This is the first study of the association of CYBB polymorphisms with TB. Our findings suggest that the CYBB polymorphisms are significantly correlated with reduced risk of TB, especially among male smokers. Further studies are needed to verify this association.

Role of cytokines and other factors involved in the Mycobacterium tuberculosis infection

Mycobacterium tuberculosis (Mtb) is a pathogen that is widely distributed geographically and continues to be a major threat to world health. Bacterial virulence factors, nutritional state, host genetic condition and immune response play an important role in the evolution of the infection. The genetically diverse Mtb strains from different lineages have been shown to induce variable immune system response. The modern and ancient lineages strains induce different cytokines patterns. The immunity to Mtb depends on Th1-cell activity [interferon-γ (IFN-γ), interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α)]. IL-1β directly kills Mtb in murine and human macrophages. IL-6 is a requirement in host resistance to Mtb infection. IFN-γ, TNF-α, IL-12 and IL-17 are participants in Mycobacterium-induced granuloma formation. Other regulating proteins as IL-27 and IL-10 can prevent extensive immunopathology. CXCL 8 enhances the capacity of the neutrophil to kill Mtb. CXCL13 and CCL19 have been identified as participants in the formation of granuloma and control the Mtb infection. Treg cells are increased in patients with active tuberculosis (TB) but decrease with anti-TB treatment. The increment of these cells causes down- regulation of adaptive immune response facilitating the persistence of the bacterial infection. Predominance of Th2 phenotype cytokines increases the severity of TB. The evolution of the Mtb infection will depend of the cytokines network and of the influence of other factors aforementioned.

Pathologic patterns of interleukin 10 expression--a review

Interleukin 10 (IL-10) is important pleiotropic immunoregulatory cytokine which gene is located on chromosome 1 at 1q31-32. There are many genetic variants of IL-10 gene. However, the most studied are two dinucleotide repeats (microsatellites), IL10.G and IL10.R, located 1.2 kb and 4 kb upstream of the transcription start site and three single nucleotide polymorphisms (SNPs) -1082(G/A), -819(C/T) and -592(C/A). A large number of studies have shown that IL-10 gene polymorphisms are associated with different diseases and play an important role in pathophysiology and clinical course of these diseases. This review summarizes published literature knowledge about the association of IL-10 polymorphisms and expression patterns with asthma, systemic lupus erythematosus, psoriasis, inflammatory bowel disease, rheumatoid arthritis, tuberculosis and some neoplasms.

Genetics of upper and lower airway diseases in the horse

Genetic predispositions for guttural pouch tympany, recurrent laryngeal neuropathy and recurrent airway obstruction (RAO) are well documented. There is also evidence that exercise-induced pulmonary haemorrhage and infectious diseases of the respiratory tract in horses have a genetic component. The clinical expression of equine respiratory diseases with a genetic basis results from complex interactions between the environment and the genetic make-up of each individual horse. The genetic effects are likely to be due to variations in several genes, i.e. they are polygenic. It is therefore unlikely that single gene tests will be diagnostically useful in these disorders. Genetic profiling panels, combining several genetic factors with an assessment of environmental risk factors, may have greater value, but much work is still needed to uncover diagnostically useful genetic markers or even causative variants for equine respiratory diseases. Nonetheless, chromosomal regions associated with guttural pouch tympany, recurrent laryngeal neuropathy and RAO have been identified. The association of RAO with other hypersensitivities and with resistance to intestinal parasites requires further study. This review aims to provide an overview of the available data and current thoughts on the genetics of equine airway diseases.

Genetic contribution of CISH promoter polymorphisms to susceptibility to tuberculosis in Chinese children

Tuberculosis (TB) is the leading cause of death due to an infectious disease worldwide, particularly in developing countries. A series of candidate genes have been suggested to be associated with development of TB disease. Among them, the human Cytokine-inducible Src homology 2(SH2) domain protein (CISH) gene has been very recently reported to be involved in T cell activation and differentiation in response to Mycobacterium tuberculosis infection. Here, we studied the association between CISH promoter polymorphisms and pediatric TB. A case-control study enrolled 352 TB patients and 527 healthy controls, who were of Han Chinese ethnicity and aged from 0.2 to 18 years. CISH gene promoter SNPs rs414171, rs622502 and rs809451 were genotyped in all subjects and transcriptional activity, mRNA level, and plasma cytokine level of subjects with different genotypes were further examined. Carriers with rs414171TT homozygotes and rs809451GC heterozygotes had a 1.78-fold (95% CI,1.16–2.74) and 1.86-fold (95% CI, 1.26–2.74) excess risk of developing TB compared to those with wild-type genotypes. A greater risk of TB disease was observed in population carrying C_−809451-T_−414171-C_−622502 haplotype (OR 3.66, 95% CI:2.12–6.32). The G_−809451-A_−414171-C_−622502-containing CISH promoter drove a 5.43-fold increased reporter expression compared to the C_−809451-T_−414171-C_−622502-containing counterpart in Hela cell lines (P = 0.0009). PBMCs carrying rs414171TT homozygotes and rs809451GC heterozygotes showed a reduced CISH mRNA level compared to cells carrying wild type genotypes. Individuals with the rs414171TT genotype had significantly increased IL-12p40 and IL-10 production. In conclusion, CISH promoter rs414171 and rs809451 polymorphisms may play a vital role in mediating individual susceptibility to tuberculosis.

Association between IL-10 gene polymorphisms and susceptibility of tuberculosis: evidence based on a meta-analysis

Background

A number of observational studies have been conducted to investigate the association of IL-10 gene polymorphisms with tuberculosis (TB) susceptibility. However, the results of different studies were inconsistent. The aim of this study was to investigate the relationship between IL-10 -1082G/A, -819T/C, and -592A/C polymorphisms and TB risk by meta-analysis.

Methods

A literature search was conducted among six English databases (PubMed, Embase, Web of Science, Science Direct, SpringerLink and EBSCO) and two Chinese databases (Wanfang and Chinese National Knowledge Infrastructure databases) to identify studies involving association between IL-10 −1082G/A, −819T/C, and −592A/C polymorphisms and TB susceptibility before May. 2013. Statistical analysis was performed using Revman 5.0 and Stata 12.0.

Results

A total of 31 studies with 6,559 cases and 7,768 controls were included in this meta-analysis. The results showed that three polymorphisms (-1082G/A, -819T/C, and -592A/C) in the IL-10 gene were not associated with the risk of TB in general population. In the subgroup analysis by ethnicity, IL-10 -1082G/A polymorphism was associated with TB risk in Europeans (AA+AG vs. GG: OR =  0.57, 95% CI = 0. 0.37–0.89, P = 0.01) and Americans (AA+AG vs. GG: OR =  0.39, 95% CI = 0.27–0.57, P<0.01), and IL-10 -819T/C (C allele vs. T allele: OR = 0.83, 95% CI = 0.72–0.96, P = 0.01) and -592A/C (CC+AC vs. AA: OR =  0.65, 95% CI = 0.49–0.85, P = 0.002) polymorphisms were significantly associated with TB risk in Asians.

Conclusion

This meta-analysis provides strong evidence that IL-10-1082G/A polymorphism was associated with TB risk in Europeans and Americans, and IL-10 -819T/C and -592A/C polymorphisms could be risk factors for TB in Asians. Additional well designed large studies were required for the validation of our results.