IFNG +874T/A polymorphism and cytokine plasma levels are associated with susceptibility to Mycobacterium tuberculosis infection and clinical manifestation of tuberculosis

Extrapulmonary Tuberculosis Leading to Abdominal Wall Mass in Young Patient

Background

Tuberculosis is a bacterial infection that is caused by Mycobacterium tuberculosis. Tuberculosis has arguably been the largest killer of humans historically, and it remains one of the most important infectious causes of death in the world. Tuberculosis can be classified into different forms and it manifests as pulmonary and out pulmonary, respectively, in 85% and 15% of cases. Only a few cases of tuberculosis with abdominal wall involvement have been reported. Case Presentation. Herein, we present a 27-year-old Persian woman, presented with asymmetric abdominal bulging in the right side of the periumbilical area since 6 months before admission that has no pain or secretion. The patient was oriented and not ill or toxic in general appearance. Vital signs were within normal ranges. An abdominal physical examination revealed a mobile, well-bordered, nontender mass 3 × 3 centimeter (cm) in diameter palpated in the right periumbilical area. The patient underwent surgery which revealed a cystic lesion that was carefully resected. In histopathology examination of the specimen resection, tuberculosis was confirmed.

Conclusion

We report a rare case of extrapulmonary tuberculosis that was identified at the abdominal wall. Due to the high number of cases of TB and the development of extrapulmonary forms that can present in an unusual location as an abdominal wall which are difficult to diagnose, it is very important to keep in mind the differential diagnosis of tuberculosis.

Association of Cytokine Gene Polymorphisms and Their Impact on Active and Latent Tuberculosis in Brazil's Amazon Region

Some genetic variations in cytokine genes can alter their expression and influence the evolution of Mycobacterium tuberculosis (Mtb) infection. This study aimed to investigate the association of polymorphisms in cytokine genes and variability in plasma levels of cytokines with the development of tuberculosis (TB) and latent tuberculosis infection (LTBI). Blood samples from 245 patients with TB, 80 with LTBI, and healthy controls (n = 100) were included. Genotyping of the IFNG +874A/T, IL6 -174G/C, IL4 -590C/T, and IL10 -1082A/G polymorphisms was performed by real-time PCR, and cytokine levels were determined by flow cytometry. Higher frequencies of genotypes AA (IFNG +874A/T), GG (IL6 -174G/C), TT (IL4 -590C/T), and GG (IL10 -1082A/G) were associated with an increased risk of TB compared to that of LTBI (p = 0.0027; p = 0.0557; p = 0.0286; p = 0.0361, respectively) and the control (p = <0.0001, p = 0.0021; p = 0.01655; p = 0.0132, respectively). In combination, the A allele for IFNG +874A/T and the T allele for IL4 -590C/T were associated with a higher chance of TB (p = 0.0080; OR = 2.753 and p < 0.0001; OR = 3.273, respectively). The TB group had lower levels of IFN-γ and higher concentrations of IL-6, IL-4, and IL-10. Cytokine levels were different between the genotypes based on the polymorphisms investigated (p < 0.05). The genotype and wild-type allele for IFNG +874A/T and the genotype and polymorphic allele for IL4 -590C/T appear to be more relevant in the context of Mtb infection, which has been associated with the development of TB among individuals infected by the bacillus and with susceptibility to active infection but not with susceptibility to latent infection.

Unique Profile of Proinflammatory Cytokines in Plasma of Drug-Naïve Individuals with Advanced HIV/TB Co-Infection

HIV-1 infection is characterized by aberrant immune activation, and infection with M. tuberculosis by an unbalanced production of proinflammatory cytokines. The expression of these cytokines in HIV-1/TB coinfection is still understudied. Here, we aimed to compare the production of proinflammatory cytokines in drug-naive patients coinfected with HIV-1 and M. tuberculosis (HIV/TB) compared to patients with respective monoinfections. Plasma samples of patients with HIV/TB coinfection (n = 36), HIV-1 monoinfection (n = 36), and TB monoinfection (n = 35) and healthy donors (n = 36) were examined for the levels of eight proinflammatory cytokines. Their levels were significantly increased in all patient groups compared to healthy donors. At the same time, a drastic decrease in the plasma levels of IFN-γ, TNF-α, Il-1β, IL-15, and IL-17 was detected in patients with HIV/TB coinfection compared to patients with HIV-1 or TB monoinfections. The plasma levels of IL-17 characterized the TB severity: in HIV/TB-coinfected patients with disseminated TB, plasma levels of IL-17 were eight times lower than in patients with less severe TB forms (infiltrative TB or TB of intrathoracic lymph nodes; p < 0.0001). At the same time, HIV/TB-coinfected patients had increased plasma levels of IL-8, IL-12, and IL-18, with the levels of IL-8 correlating with mortality (p < 0.0001). Thus, on the contrary to the patients with HIV-1 or TB monoinfections, HIV/TB-coinfected patients had suppressed production of most of the proinflammatory cytokines associated with antimicrobial immune response, specifically of T-cells involved in the containment of both infections. At the same time, they demonstrated an expansion of proinflammatory cytokines known to originate from both hematopoietic and nonhematopoietic cells, and manifest tissue inflammation. In HIV-1/TB coinfection, this leads to the disruption of granuloma formation, contributing to bacterial dissemination and enhancing morbidity and mortality.

Epidemiological and Cytokine Profile of Patients with Pulmonary and Extrapulmonary Tuberculosis in a Population of the Brazilian Amazon

Several factors are associated with the development of different clinical forms of tuberculosis (TB). The present study evaluated epidemiological variables and cytokine levels in samples from 89 patients with TB (75 with pulmonary TB and 14 with extrapulmonary TB) and 45 controls. Cytokines were measured by flow cytometry (Human Th1/Th2/Th17 Cytometric Bead Array kit). The TB group had a higher frequency of individuals who were 39 years of age or older, married, with primary education or illiterate and had a lower family income (p < 0.05). All individuals with extrapulmonary TB reported that they were not working, and the main reasons were related to disease symptoms or treatment. The levels of IFN-γ (OR = 4.06) and IL-4 (OR = 2.62) were more likely to be elevated in the TB group (p = 0.05), and IFN-γ levels were lower in patients with extrapulmonary TB compared to those with pulmonary TB (OR = 0.11; p = 0.0050). The ROC curve was applied to investigate the diagnostic accuracy of IFN-γ levels between the different clinical forms of tuberculosis, resulting in high AUC (0.8661; p < 0.0001), sensitivity (93.85%) and specificity median (65.90%), suggesting that IFN-γ levels are useful to differentiate pulmonary TB from extrapulmonary TB. The dysregulation of pro- and anti-inflammatory cytokine levels represent a risk for the development of TB and contribute to the pathogenesis of the disease, especially variation in IFN-γ levels, which may determine protection or risk for extrapulmonary TB.

Th1 cytokine gene polymorphism and the corresponding plasma cytokine levels: A comparative study in HIV-1 positive and exposed uninfected infants

The pro-inflammatory (Th1) cytokines namely interleukin (IL)-2, IL-6, IL-12, interferon (IFN)-γ, tumor necrosis factor-α (TNF-α) are vital in the clearance of HIV infection. This prospective cohort study aimed to evaluate the polymorphisms of Th1 cytokine genes and their corresponding plasma cytokine levels in HIV-1 positive and exposed uninfected (EU) infants born to HIV-1 positive mothers. CD4 count, viral load of HIV-1 positive mothers was done using commercially available reagents. Cytokine genotyping analysis and levels were done in 20 HIV-1 positive and 54 EU infants. The polymorphisms of Th1 cytokines were done using the PCR-SSP method. Plasma cytokine levels were estimated using Bio-Plex-Pro cytokine assay (BIO-RAD; USA). Results revealed treatment status of the mothers and viral load were the two confounding factors having a significant effect on HIV status of the infant. TNF-α GG genotype is significantly higher in EU infants as compared with HIV-1 positive infants. GG genotype was associated with high TNF- α levels in HIV-1 positive infants but the difference was not statistically significant. HIV-1 positive infants with -IFN-γ (+874) TT genotype was significantly associated with high IFN-γ levels. To the best of our knowledge, this is the first study reporting the role of Th1 cytokine gene polymorphisms and their corresponding plasma cytokine levels in HIV-1 positive and EU infants from India.

Association of Polymorphism +874 T/A Interferon Gamma Gene with Susceptibility to Pulmonary Tuberculosis in Medan, Indonesia

BACKGROUND: Pulmonary tuberculosis (TB) is still a disease that concerns in the world due to its high incidence, especially in developing countries, including Indonesia. Polymorphism +874 T/A interferon-gamma (IFN-γ) is one of the host genetic factors that have been widely studied and has been shown to be associated with susceptibility to pulmonary TB. AIM: This study aims to determine the association polymorphism +874 T/A IFN-γ gene with susceptibility to pulmonary TB in Medan population. METHODS: A total of 82 pulmonary TB patients and 85 healthy controls were examined in this case–control study. SPSS 25 is used to process and analyze all data where the Pearson Chi-square is used to analyze the association between genotype and susceptibility to pulmonary TB. RESULTS: The polymorphism +874 T/A IFN-γ gene was not significantly associated with susceptibility to pulmonary TB in patients compared to controls (p = 0.395) and there was no association between allele frequency and susceptibility to pulmonary TB (p = 0.158). CONCLUSION: Our study suggests no association of polymorphism +874 T/A IFN-γ gene with pulmonary TB in Medan, Sumatera Utara, Indonesia.

Surface-enhanced Raman spectroscopy for comparison of serum samples of typhoid and tuberculosis patients of different stages

BACKGROUND

Surface-enhanced Raman spectroscopy (SERS) is a reliable tool for the identification and differentiation of two different human pathological conditions sharing the same symptomology, typhoid and tuberculosis (TB).

OBJECTIVES

To explore the potential of surface-enhanced Raman spectroscopy for differentiation of two different diseases showing the same symptoms and analysis by principal component analysis (PCA) and partial least square discriminate analysis (PLS-DA).

METHODS

Serum samples of clinically diagnosed typhoid and tuberculosis infected individuals were analyzed and differentiated by SERS using silver nanoparticles (Ag NPs) as a SERS substrate. For this purpose, the collected serum samples were analyzed under the SERS instrument and unique SERS spectra of typhoid and tuberculosis were compared showing notable spectral differences in protein, lipid and carbohydrates features. Different stages of the diseased class of typhoid (Early acute and late acute stage) and tuberculosis (Pulmonary and extra-pulmonary stage) were compared with each other and with healthy human serum samples, which were significantly separated. Moreover, SERS data was analyzed using multivariate data analysis techniques including principal component analysis (PCA) and partial least square discriminate analysis (PLS-DA) and differences were so prominent to observe.

RESULTS

SERS Spectral data of typhoid and tuberculosis showed clear differences and were significantly separated using PCA. SERS spectral data of both stages of typhoid and tuberculosis were separated according to 1st principle component. Moreover, by analyzing data using partial least square discriminate analysis, differentiation of two disease classes were considered more valid with a 100% value of sensitivity, specificity and accuracy.

CONCLUSION

SERS can be employed for identification and comparison of two different human pathological conditions sharing same symptomology.

Association of an IFN-γ variant with susceptibility to chronic hepatitis B by the enhancement of HBV DNA replication

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874T^high → A^low)] may alter the outcomes of chronic HBV infection in Tunisian population. The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls. We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10^-4; 24 vs. 13%, P < 10^-4; 52 vs. 38%, P < 10^-4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively]. The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively]. Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.

Interferon-γ (+874 T/A) and interleukin-10 (-1082 G/A) genes polymorphisms are associated with active tuberculosis in the Algerian population of Oran's city

BACKGROUND AND AIMS

Polymorphisms within genes encoding the cytokines involved in anti-tuberculosis immunity have been widely studied and sometimes associated with an increased risk of developing the active form of tuberculosis (TB). This study analyzes for the first time the impact of two polymorphisms, namely IFNG+874 T/A and IL10-1082 G/A, in the Algerian population where tuberculosis is moderately endemic.

METHODS

This case-control study included 104 healthy controls and 141 active TB patients: 75 extrapulmonary (EPTB) and 66 pulmonary (PTB). They were all genotyped by refractory mutational system-PCR amplification. In order to measure the functional impact of IFNG+874 T/A on the production rate of IFN-γ, 43 patients performed a QuantiFERON®Gold In-tube test.

RESULTS

The IFNG+874 AA genotype was associated with a higher risk of developing EPTB (OR = 2.52; 95%CI = 1.23-5.18; p = 0.012) while the IFNG+874 TA genotype was associated with a greater protection (OR = 0.34, 95%CI = 0.16-0.74; p = 0.006) which was further characterized by a high production of IFN-γ (p = 0.001). Similarly, the allele A of SNP IL10-1082 G/A, especially in its homozygous form (AA), were overrepresented in PTB patients (p = 0.010 and 0.019, respectively). The combination of both susceptibility genotypes (AA/AA) was strongly associated with risk of development of active TB (OR = 8.58; 95% C.I = 1.95-37.70, p = 0.004). This susceptibility combination was only significant in men regarding PTB (OR = 11.05; 95% C.I = 1.32-92.72, p = 0.027). Additionally, IFNG+874 TA and IL10-1082G∗ genotypes combination was mostly encountered in men controls and conferred the highest protection rate against EPTB (OR = 0.25; 95% C.I = 0.08-0.76, p = 0.015).

CONCLUSION

These two cytokines genes polymorphisms are associated with active TB susceptibility in the Algerian population. They act synergistically in terms of protection and susceptibility regarding the two forms of the disease. Moreover, these associations were more marked among males suggesting a potential role of gender.

IFN-γ +874 A>T (rs2430561) gene polymorphism and risk of pulmonary tuberculosis: a meta-analysis

INTRODUCTION

The role of interferon gamma (IFN-γ) +874 A>T (rs2430561) gene polymorphism has been evaluated in different ethnicities with pulmonary tuberculosis (PTB) infection, and inconsistent results have been reported. In this study, a meta-analysis was performed to determine the precise association between IFN-γ +874 A>T gene polymorphism and PTB susceptibility.

MATERIAL AND METHODS

A total of 21 studies comprising 4281 confirmed PTB cases and 5186 healthy controls were included in this meta-analysis by searching the PubMed (Medline), EMBASE, and Google Scholar web-databases.

RESULTS

We observed reduced risk of PTB in allelic contrast (T vs. A: p = 0.001; OR = 0.818, 95% CI: 0.723-0.926), homozygous (TT vs. AA: p = 0.017; OR = 0.715, 95% CI: 0.543-0.941), heterozygous (AT vs. AA: p = 0.002; OR = 0.782, 95% CI: 0.667-0.917), dominant (TT+AT vs. AA: p = 0.002; OR = 0.768, 95% CI: 0.652-0.906), and recessive (TT vs. AA+AT: p = 0.042; OR = 0.802, 95% CI: 0.649-0.992) genetic models. In ethnicity-wise subgroup analysis, reduced risk of PTB was found in the Caucasian population. However, we did not find an association with any of the genetic models in the Asian population.

CONCLUSIONS

In conclusion, the IFN-γ +874 A>T gene polymorphism is significantly associated with reduced risk of PTB, showing a protective effect in the overall and in the Caucasian population. However, this polymorphism is not associated with PTB risk in the Asian population.

A Network-Based Analysis Reveals the Mechanism Underlying Vitamin D in Suppressing Cytokine Storm and Virus in SARS-CoV-2 Infection

Background

SARS-CoV-2 causes ongoing pandemic coronavirus disease of 2019 (COVID-19), infects the cells of the lower respiratory tract that leads to a cytokine storm in a significant number of patients resulting in severe pneumonia, shortness of breathing, respiratory and organ failure. Extensive studies suggested the role of Vitamin D in suppressing cytokine storm in COVID-19 and reducing viral infection; however, the precise molecular mechanism is not clearly known. In this work, bioinformatics and systems biology approaches were used to understand SARS-CoV-2 induced cytokine pathways and the potential mechanism of Vitamin D in suppressing cytokine storm and enhancing antiviral response.

Results

This study used transcriptome data and identified 108 differentially expressed host genes (DEHGs) in SARS-CoV-2 infected normal human bronchial epithelial (NHBE) cells compared to control. Then, the DEHGs was integrated with the human protein-protein interaction data to generate a SARS-CoV-2 induced host gene regulatory network (SiHgrn). Analysis of SiHgrn identified a sub-network "Cluster 1" with the highest MCODE score, 31 up-regulated genes, and predominantly associated immune and inflammatory response. Interestingly, the iRegulone tool identified that "Cluster 1" is under the regulation of transcription factors STAT1, STAT2, STAT3, POU2F2, and NFkB1, collectively referred to as "host response signature network". Functional enrichment analysis with NDEx revealed that the "host response signature network" is predominantly associated with critical pathways, including "cytokines and inflammatory response", "non-genomic action of Vitamin D", "the human immune response to tuberculosis", and "lung fibrosis". Finally, in-depth analysis and literature mining revealed that Vitamin D binds with its receptor and could work through two different pathways: (i) it inhibits the expression of pro-inflammatory cytokines through blocking the TNF induced NFkB1 signaling pathway; and (ii) it initiates the expression of interferon-stimulating genes (ISGs) for antiviral defense program through activating the IFN-α induced Jak-STAT signaling pathway.

Conclusion

This comprehensive study identified the pathways associated with cytokine storm in SARS-CoV-2 infection. The proposed underlying mechanism of Vitamin D could be promising in suppressing the cytokine storm and inducing a robust antiviral response in severe COVID-19 patients. The finding in this study urgently needs further experimental validations for the suitability of Vitamin D in combination with IFN-α to control severe COVID-19.

Is mapping the BCG vaccine-induced immune responses the key to improving the efficacy against tuberculosis?

In recent years, the century-old Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) has been re-evaluated for its capacity to stem the global tide of TB. There is increasing evidence that the efficacy of BCG can be improved by the modified administration methods and schedules. Here, we first discuss recent approaches of vaccine administration, revaccination or boosting that have been used to try to improve the efficacy of BCG against TB. We then dive deeper into studies investigating the immune correlates of protection and describe studies that have investigated BCG-specific T-cell responses and the influence of environmental exposures. These studies all highlight that there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity, which has been surprisingly understudied. We argue that several critical gaps in knowledge exist and must be addressed by future research to rationally improve the efficacy of BCG, including comprehensive, proteome-wide understanding of the epitopes derived from BCG recognized by BCG-vaccinated individuals, the phenotype of responding antigen-specific T cells and how previous exposure to environmental mycobacteria affect these parameters and thus influence vaccine efficacy. The development of modern techniques allows us to answer some of these questions to better understand how BCG works in terms of both protection against TB and the immune response that it triggers.

Association of NOD2 and IFNG single nucleotide polymorphisms with leprosy in the Amazon ethnic admixed population

Leprosy is a chronic infectious disease, caused by Mycobacterium leprae, which affects skin and peripheral nerves. Polymorphisms in genes associated with autophagy, metabolism, innate and adaptive immunity confer susceptibility to leprosy. However, these associations need to be confirmed through independent replication studies in different ethnicities. The population from Amazon state (northern Brazil) is admixed and it contains the highest proportion of Native American genetic ancestry in Brazil. We conducted a case-control study for leprosy in which we tested fourteen previously associated SNPs in key immune response regulating genes: TLR1 (rs4833095), NOD2 (rs751271, rs8057341), TNF (rs1800629), IL10 (rs1800871), CCDC122/LACC1 (rs4942254), PACRG/PRKN (rs9356058, rs1040079), IFNG (rs2430561), IL6 (rs2069845), LRRK2 (rs7298930, rs3761863), IL23R (rs76418789) and TYK2 (rs55882956). Genotyping was carried out by allelic discrimination in 967 controls and 412 leprosy patients. Association with susceptibility was assessed by logistic regression analyses adjusted for the following covariates: gender, age and ancestry. Genetic ancestry was similar in case and control groups. Statistically significant results were only found for IFNG and NOD2. The rs8057341 polymorphism within NOD2 was identified as significant for the AA genotype (OR = 0.56; 95% CI, 0.37-0.84; P = 0.005) and borderline for the A allele (OR = 0.76; 95% CI, 0.58-1.00; P = 0.053) and carrier (OR = 0.76; 95% CI, 0.58-1.00; P = 0.051). The rs2430561 SNP in IFNG was associated with disease susceptibility for the AT genotype (OR = 1.40; 95% CI, 1.06-1.85; P = 0.018) and carrier (OR = 1.44; 95% CI, 1.10-1.88; P = 0.008). We confirmed that NOD2 and IFNG are major players in immunity against M.leprae in the Amazon ethnic admixed population.

Impact of Historic Migrations and Evolutionary Processes on Human Immunity

The evolution of mankind has constantly been influenced by the pathogens encountered. The various populations of modern humans that ventured out of Africa adapted to different environments and faced a large variety of infectious agents, resulting in local adaptations of the immune system for these populations. The functional variation of immune genes as a result of evolution is relevant in the responses against infection, as well as in the emergence of autoimmune and inflammatory diseases observed in modern populations. Understanding how host-pathogen interactions have influenced the human immune system from an evolutionary perspective might contribute to unveiling the causes behind different immune-mediated disorders and promote the development of new strategies to detect and control such diseases.

Influence of single-nucleotide polymorphisms in the IFNG towards susceptibility to tuberculosis in a Pakistani population

Tuberculosis (TB) is a global issue as one-third of the population worldwide is considered to be infected. TB has become a critical public health problem as a result of increasing drug resistance, which poses a challenge to current control strategies. Similar to environmental factors, genetic makeup of the host equally contributes to disease onset. We performed genotypic analysis to examine the relationship between IFNG and TB onset and drug resistance in a Pakistani population comprising 689 subjects. Notable differences were observed in the IFNG polymorphism (+874T/A) between the case and control groups. The frequency of the wild-type genotype (TT) in the controls (43.2%) was significantly higher than in the cases (25.3%) (odds ratio [OR] = 0.77, p < 0.0001), while the mutant genotype frequency (AA) (38.57%) in the cases was significantly higher than in the controls (22.6%) (OR = 1.46, p < 0.0001). The heterozygous genotype frequency (TA) did not significantly differ between the control and case groups. Compared with the controls, the variant allele (A) was approximately twice as frequent in the cases. Females and older people have a higher chance of disease development. Finally, the IFNG (+874T/A) polymorphism was not associated with drug sensitivity or resistance. However, a genotypic polymorphism of IFNG (+874T/A) was significantly associated with susceptibility to TB, and the T allele conferred protection against TB. Additional studies involving larger cohorts are needed to further explore this relationship between genetics and disease vulnerability.

A trial sequential meta-analysis of IFN-γ +874 A>T (rs2430561) gene polymorphism and extrapulmonary tuberculosis risk

Interferon-γ (IFN-γ) plays a crucial role in immunological responses against Mycobacterium tuberculosis (M.tb) infection. The polymorphism at +874 A > T (rs2430561) influences the levels of IFN-γ, which may further influence the susceptibility to extrapulmonary tuberculosis (EPTB). This polymorphism has been investigated with respect to EPTB occurrence in different populations and provided contradictory and conflicting results. This study was performed to meta-statistically analyze the data and draw a more accurate conclusion regarding the association of IFN-γ +874 A > T gene polymorphism and EPTB susceptibility. A quantitative synthesis was executed for the pertinent studies retrieved from online web-databases viz. Google Scholar, PubMed/Medline and EMBASE. The pooled odds ratios (ORs) and confidence intervals (95% CIs) were estimated for all the genetic models by meta-analysis. A total of eight studies were retrieved which included 762 confirmed EPTB cases and 1341 controls. The meta-analysis results revealed reduced association of EPTB in allelic contrast (T vs. A: p = 0.001; OR = 0.668, 95% CI = 0.524 to 0.850), homozygous (TT vs. AA: p = 0.017; OR = 0.450, 95% CI = 0.234 to 0.868), heterozygous (AT vs. AA: p = 0.004; OR = 0.574, 95% CI = 0.395 to 0.835), dominant (TT + AT vs. AA: p = 0.003; OR = 0.536, 95% CI = 0.354 to 0.810) and recessive (TT vs. AA + AT: p = 0.039; OR = 0.662, 95% CI = 0.448 to 0.980) genetic models. Furthermore, re-sampling statistics also revealed reduced risk of EPTB in overall population and Asian subgroup. This meta-analysis concluded that IFN-γ +874 A > T gene polymorphism is meaningfully related with the reduced EPTB risk in overall and Asian population, and further necessitates larger studies to be conducted on this topic in other races.

Lack of evidence of association between IFNG and IL28B polymorphisms and QuantiFERON-CMV test results in seropositive transplant patients

The aim of this study was to analyze the relationship between the IFNG +874 T/A and IL28B (rs12979860) C/T polymorphisms and the secretion of IFNG by CD8+ T cells after stimulation with cytomegalovirus (CMV) peptides, measured using QuantiFERON-CMV (QF-CMV) assay. A total of 184 CMV-seropositive solid organ transplant patients (108 kidney, 68 liver and 8 lung) were recruited. Of them, 151 patients were QF-CMV Reactive (IFNG ≥ 0.2 UI/mL) and 33 were Non-reactive. Genotype frequencies in the study population were TT (26.6%), AT (50.0%) and AA (23.4%) for IFNG +874 and CC (52.7%), CT (39.1%) and TT (8.2%) for IL28B (rs12979860). These frequencies did not significantly differ between QF-CMV Reactive and Non-reactive patients. Nor were any significant differences observed in the quantitative IFNG level among the genotypes in either the IFNG or the IL28 genes. When we analyzed whether these polymorphisms had any impact on the risk of CMV replication after transplantation, the adjusted analysis showed no association. In summary, our results showed that IFNG +874 T/A and IL28B (rs12979860) C/T polymorphisms are not associated with the IFNG response to CMV measured by the QuantiFERON-CMV assay, although these results should be confirmed with a higher number of patients.

CD14-159C/T polymorphism in the development of delayed skin hypersensitivity to tuberculin

The skin tuberculin test (TST), an example of a delayed-type hypersensitivity (DTH) reaction, is based on measuring the extent of skin induration to mycobacterial tuberculin (PPD). Little is known about the genetic basis of TST reactivity, widely used for diagnosing TB infection. The study investigated the relationship of the single base change polymorphic variants in CD14 gene (CD14(-159C/T)) with the development of DTH to PPD in BCG-vaccinated Polish Caucasian individuals. We found persistent lack of TST reactivity in about 40% of healthy subjects despite receiving more than one dose of BCG. The TST size was negatively correlated with the number of BCG inoculations. The distribution of C/T genotype was significantly more frequent among TST-negative compared with TST-positive individuals. The concentration of serum sCD14 was positively associated with mCD14 expression, but not with the TST status or CD14(-159C/T) polymorphism. A significant increase in mCD14 expression and serum sCD14 levels was found in TB group. We hypothesize that CD14(-159C/T) polymorphic variants might be one of genetic components in the response to attenuated M. bovis BCG bacilli.

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.

A single nucleotide polymorphism in the interferon-γ gene (IFNG +874 T/A) is associated with susceptibility to tuberculosis

Interferon-γ (Interferon gamma, IFNG) is an important cytokine involved in providing resistance to mycobacterial diseases. Common variants of IFNG, such as IFNG +874 T/A(rs2430561), may be related to tuberculosis susceptibility, but this association has not been consistently observed. We performed an updated meta-analysis to evaluate the association between the IFNG +874 T/A (rs2430561) polymorphism and tuberculosis susceptibility. PubMed and SinoMed databases were searched up to October 2016, and odds ratios (OR) and 95% confidence intervals (CI) were used to assess the association strength. Based on search criteria for manuscripts reporting tuberculosis susceptibility and its relationship with the IFNG +874 T/A(rs2430561)polymorphism, 42 case-control studies from 39 different articles were retrieved. Significantly positive, decreased, and protective associations were found between the IFNG +874 T/A(rs2430561)polymorphism and tuberculosis risk in five genetic models. Moreover, in the stratified subgroup analysis, a protective relationship was detected in four different ethnicities and sources of the control groups. Furthermore, the IFNG +874 T/A(rs2430561)polymorphism played an important role in protecting individuals from both pulmonary tuberculosis and extra-pulmonary tuberculosis. Our meta-analysis suggests that the IFNG +874 T/A(rs2430561)polymorphism is potentially associated with tuberculosis susceptibility and may be used as a predictive biomarker. Further studies with larger sample sizes and consideration of gene-environment interactions should be conducted to elucidate the role of IFNG +874 T/A(rs2430561) polymorphism in tuberculosis susceptibility.

An integrated method for the identification of novel genes related to oral cancer

Cancer is a significant public health problem worldwide. Complete identification of genes related to one type of cancer facilitates earlier diagnosis and effective treatments. In this study, two widely used algorithms, the random walk with restart algorithm and the shortest path algorithm, were adopted to construct two parameterized computational methods, namely, an RWR-based method and an SP-based method; based on these methods, an integrated method was constructed for identifying novel disease genes. To validate the utility of the integrated method, data for oral cancer were used, on which the RWR-based and SP-based methods were trained, thereby building two optimal methods. The integrated method combining these optimal methods was further adopted to identify the novel genes of oral cancer. As a result, 85 novel genes were inferred, among which eleven genes (e.g., MYD88, FGFR2, NF-κBIA) were identified by both the RWR-based and SP-based methods, 70 genes (e.g., BMP4, IFNG, KITLG) were discovered only by the RWR-based method and four genes (L1R1, MCM6, NOG and CXCR3) were predicted only by the SP-based method. Extensive analyses indicate that several novel genes have strong associations with cancers, indicating the effectiveness of the integrated method for identifying disease genes.

Single nucleotide polymorphisms of IFNγ (+874 A/T) and IFNγR1 (-56 C/T) in Iranian patients with TB

BACKGROUND

Two important genes for controlling TB are IFNγ and IFNγR1. However, little information exists regarding genetic susceptibility of the Iranian TB population.

METHODS

We investigated the single nucleotide polymorphisms (SNPs) in genes of IFNγ (+874 A/T) and IFNγR1 (-56 C/T) and serum level of IFNγ and their influence on TB in patients; 300 patients with TB and 300 healthy controls were enrolled in this study. PCR-restriction fragment length polymorphism was used to identify SNPs and serum level of IFNγ was measured by ELISA.

RESULTS

The allelic and the genotypic form of IFNγ+874 A/T SNP of the studied population were not significant (p>0.05). Allele T frequencies of IFNγR1 -56 C/T promoter region in patients with pulmonary TB (PTB) or extrapulmonary TB (EPTB) were significantly greater than allele C. The -56 TT motif of IFNγR1 is associated with both forms of TB (p<0.05). The serum level of IFNγ was significantly higher in patients with TB than in controls, but there was no significant difference between serum level of IFNγ and the studied genotypes (p>0.05).

CONCLUSIONS

The cause of active TB in the patients seems to be due to the lack of effective IFNγ function or the lack of effective signaling connection between IFNγ and its receptor in presence of -56 C/T polymorphism in promoter region of IFNγR1 gene.

The Role of Host Genetics (and Genomics) in Tuberculosis

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Gene Polymorphisms and Serum Levels of Pro- and Anti-Inflammatory Markers in Dengue Viral Infections

Pro- and anti-inflammatory markers (tumor necrosis factor [TNF]-α, TNF-β, interferon [IFN]-γ, interleukin [IL]-6, IL-8, IL-10, and C-reactive protein [CRP]) were investigated in 80 patients infected with dengue viruses, 100 patients presenting with febrile illness but negative for dengue, and 99 healthy subjects. Immunoenzyme methods were used for quantitative assays in the plasma. Polymorphisms of TNF-α, TNF-β, IL-6, IL-8, and IL-10 genes were assessed by polymerase chain reaction (PCR)-restriction fragment length polymorphism and allele-specific oligonucleotide (ASO)-PCR for the IFN-γ. The highest mean serum levels of TNF-α, IFN-γ, IL-8, and CRP were observed in dengue-positive individuals. TNF-β, IL-6, and IL-10 levels were significantly higher in the dengue-negative individuals. No cytokine expression pattern was evidenced according to virus serotype. Genotypic frequency distributions were statistically significant for the polymorphisms of TNF-α and IFN-γ among positive, negative, and control dengue groups and IFN-γ among groups DENV-1, DENV-2, DENV-3, and controls. Modulation of cytokine expression and polymorphisms is a complex matter and needs further explanation considering the ethnic origins of the Brazilian population.

Polymorphisms on IFNG, IL12B and IL12RB1 genes and paracoccidioidomycosis in the Brazilian population

Paracoccidioidomycosis (PCM) is a systemic chronic mycosis, endemic in Latin America, especially Brazil, and is the eighth leading cause of death among chronic and recurrent infectious diseases. PCM infection is characterized by the presence of Th1 immune response; the acute form, by a mixed Th2/Th9, while the chronic form is characterized by Th17/Th22 profiles. The occurrence and severity of human PCM may also be associated with genetic factors such as single nucleotide polymorphisms (SNP) on cytokines encoding genes. We investigated the association between these polymorphisms and the different clinical forms of PCM. We included 156 patients with PCM (40 with the acute form, 99 with the chronic multifocal and 17 with the chronic unifocal form) and assayed their DNA samples for IFNG +874 T/A SNP by PCR-ARMS (Amplification Refractory Mutational System), IL12B +1188 A/C SNP on 3' UTR and IL12RB1 641 A/G SNP on exon 7 by PCR-RFLP (Restriction Fragment Length Polymorphism). We found similar genotypic and allelic frequencies of the investigated SNPs among the clinical forms of PCM. Considering male patients, the IL12RB1 641 AA genotype was more frequent in the chronic multifocal form while heterozygosis was in the chronic unifocal form of PCM (p=0.048). Although our data suggest that the AA genotype (IL12RB1) may be associated with the more disseminated chronic disease, more patients of the chronic unifocal PCM group need to be analyzed as well as the secretion patterns of IFN-γ combined with the IL-12Rβ1 expression for a better comprehension of this association.

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.

Network Analysis of Human Genes Influencing Susceptibility to Mycobacterial Infections

Tuberculosis and nontuberculous mycobacterial infections constitute a high burden of pulmonary disease in humans, resulting in over 1.5 million deaths per year. Building on the premise that genetic factors influence the instance, progression, and defense of infectious disease, we undertook a systems biology approach to investigate relationships among genetic factors that may play a role in increased susceptibility or control of mycobacterial infections. We combined literature and database mining with network analysis and pathway enrichment analysis to examine genes, pathways, and networks, involved in the human response to Mycobacterium tuberculosis and nontuberculous mycobacterial infections. This approach allowed us to examine functional relationships among reported genes, and to identify novel genes and enriched pathways that may play a role in mycobacterial susceptibility or control. Our findings suggest that the primary pathways and genes influencing mycobacterial infection control involve an interplay between innate and adaptive immune proteins and pathways. Signaling pathways involved in autoimmune disease were significantly enriched as revealed in our networks. Mycobacterial disease susceptibility networks were also examined within the context of gene-chemical relationships, in order to identify putative drugs and nutrients with potential beneficial immunomodulatory or anti-mycobacterial effects.

Lack of genetic diversity across diverse immune genes in an endangered mammal, the Tasmanian devil (Sarcophilus harrisii)

The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction due to the spread of devil facial tumour disease. Polymorphisms in immune genes can provide adaptive potential to resist diseases. Previous studies in diversity at immune loci in wild species have almost exclusively focused on genes of the major histocompatibility complex (MHC); however, these genes only account for a fraction of immune gene diversity. Devils lack diversity at functionally important immunity loci, including MHC and Toll-like receptor genes. Whether there are polymorphisms at devil immune genes outside these two families is unknown. Here, we identify polymorphisms in a wide range of key immune genes, and develop assays to type single nucleotide polymorphisms (SNPs) within a subset of these genes. A total of 167 immune genes were examined, including cytokines, chemokines and natural killer cell receptors. Using genome-level data from ten devils, SNPs within coding regions, introns and 10 kb flanking genes of interest were identified. We found low polymorphism across 167 immune genes examined bioinformatically using whole-genome data. From this data, we developed long amplicon assays to target nine genes. These amplicons were sequenced in 29-220 devils and found to contain 78 SNPs, including eight SNPS within exons. Despite the extreme paucity of genetic diversity within these genes, signatures of balancing selection were exhibited by one chemokine gene, suggesting that remaining diversity may hold adaptive potential. The low functional diversity may leave devils highly vulnerable to infectious disease, and therefore, monitoring and preserving remaining diversity will be critical for the long-term management of this species. Examining genetic variation in diverse immune genes should be a priority for threatened wildlife species. This study can act as a model for broad-scale immunogenetic diversity analysis in threatened species.

IL10A genotypic association with decreased IL-10 circulating levels in malaria infected individuals from endemic area of the Brazilian Amazon

Background

Cytokines play an important role in human immune responses to malaria and variation in their production may influence the course of infection and determine the outcome of the disease. The differential production of cytokines has been linked to single nucleotide polymorphisms in gene promoter regions, signal sequences, and gene introns. Although some polymorphisms play significant roles in susceptibility to malaria, gene polymorphism studies in Brazil are scarce.

Methods

A population of 267 individuals from Brazilian Amazon exposed to malaria was genotyped for five single nucleotide polymorphisms (SNPs), IFNG + 874 T/A, IL10A-1082G/A, IL10A-592A/C, IL10A-819 T/C and NOS2A-954G/C. Specific DNA fragments were amplified by polymerase chain reaction, allowing the detection of the polymorphism genotypes. The polymorphisms IL10A-592A/C and IL10A-819 T/C were estimated by a single analysis due to the complete linkage disequilibrium between the two SNPs with D’ = 0.99. Plasma was used to measure the levels of IFN-γ and IL-10 cytokines by Luminex and nitrogen radicals by Griess reaction.

Results

No differences were observed in genotype and allelic frequency of IFNG + 874 T/A and NOS2A-954G/C between positive and negative subjects for malaria infection. Interesting, the genotype NOS2A-954C/C was not identified in the study population. Significant differences were found in IL10A-592A/C and IL10A-819 T/C genotypes distribution, carriers of IL10A -592A/-819 T alleles (genotypes AA/TT + AC/TC) were more frequent among subjects with malaria than in negative subjects that presented a higher frequency of the variant C allele (p < 0.0001). The presence of the allele C was associated with low producer of IL-10 and low parasitaemia. In addition, the GTA haplotypes formed from combinations of investigated polymorphisms in IL10A were significantly associated with malaria (+) and the CCA haplotype with malaria (−) groups. The IL10A-1082G/A polymorphism showed high frequency of heterozygous AG genotype in the population, but it was not possible to infer any association of the polymorphism because their distribution was not in Hardy Weinberg equilibrium.

Conclusion

This study shows that the IL10A-592A/C and IL10A-819 T/C polymorphisms were associated with malaria and decreased IL-10 levels and low parasite density suggesting that this polymorphism influence IL-10 levels and may influence in the susceptibility to clinical malaria.

Single nucleotide polymorphisms in immune response genes in acute Q fever cases with differences in self-reported symptoms

Genes involved in human immune response are well recognized to influence the clinical course of infection. The association of host genetics with susceptibility to and severity of clinical symptoms in acute Q fever was investigated. Single nucleotide polymorphisms (SNPs) in the IFNG (rs2430561/rs1861493), STAT1 (rs1914408), and VDR (rs2228570) genes were determined in 85 patients from the 2007 Dutch acute Q fever outbreak, and a symptom score was calculated. IFNG rs1861493 showed a significant association with the symptom score; IFNG rs2430561 showed a similar trend. These SNPs were then used to reproduce results in a 2009 outbreak population (n = 123). The median symptom score differed significantly in both populations: 2 versus 7. The significant association of IFNG rs1861493 with symptom score in the first population was not reproduced in the second population. We hypothesize that individuals in the second outbreak were exposed to a higher Coxiella burnetii dose compared to the first, which overruled the protection conferred by the A-allele of IFNG rs1861493 in the first population.

Clinical implications of interferon-γ genetic and epigenetic variants

Interferon-γ (IFN-γ) is an integral and critical molecule of the immune system, with multiple functions, mostly related to the T helper type 1 (Th1) response to infection. It is critical for defence against mycobacterial infection and is of increasing interest in defence against fungi. In this article, we review the genetic and epigenetic variants affecting IFN-γ expression and investigate its role in disease, with an emphasis on fungal diseases such as invasive and chronic pulmonary aspergillosis. Over 347 IFN-γ gene variants have been described, in multiple ethnic populations. Many appear to confer a susceptibility to disease, especially tuberculosis (TB) and hepatitis, but also some non-infectious conditions such as aplastic anaemia, cervical cancer and psoriasis. Several epigenetic modifications are also described, increasing IFN-γ expression in Th1 lymphocytes and reducing IFN-γ expression in Th2 lymphocytes. Recombinant IFN-γ administration is licensed for the prophylaxis of infection (bacterial and fungal) in patients with the phagocyte functional deficiency syndrome chronic granulomatous disease, although the benefits appear limited. Interferon-γ therapy is given to patients with profound defects in IFN-γ and interleukin-12 production and appears to be beneficial for patients with invasive aspergillosis and cryptococcal meningitis, but the studies are not definitive. A high proportion of patients with chronic pulmonary aspergillosis are poor producers of IFN-γ in response to multiple stimuli and could also benefit from IFN-γ administration. The investigation and management of patients with possible or demonstrated IFN-γ deficiency in adulthood is poorly studied and could be greatly enhanced with the integration of genetic data.

Could interferon-gamma be a therapeutic target for treating heart failure?

The cytokine interferon-gamma (IFN-γ) is the only known member of the type II family of interferons, and as such, binds to its own distinct receptor. It is important in host defense against infection, as well as adaptive immune responses. While a wide array of cytokines are known to be involved in adverse remodeling of the heart and the progression to heart failure, the role of IFN-γ is unclear. Recent evidence from clinical studies, animal models of myocarditis and hypertension, as well as isolated cell studies, provide conflicting data as to whether IFN-γ is pathological or protective in the heart. Thus, it is important to highlight these discrepant findings so that areas of future investigation can be identified to more clearly determine the precise role of IFN-γ in the heart. Accordingly, this review will (1) discuss the source of IFN-γ in the diseased heart; (2) summarize the data from animal studies; (3) discuss the effects of IFN-γ on isolated cardiac fibroblasts and cardiomyocytes; (4) identify signaling mechanisms that may be invoked by IFN-γ in the heart; and (5) present the clinical evidence supporting a role for IFN-γ in heart failure.

Inflammatory and immunogenetic markers in correlation with pulmonary tuberculosis

OBJECTIVE:

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

METHODS:

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

RESULTS:

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

CONCLUSIONS:

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

The extrapulmonary dissemination of tuberculosis: A meta-analysis

BACKGROUND AND OBJECTIVE

The epidemiology of the forty percent of tuberculosis patients who present with disseminated and/or extrapulmonary disease is in need of further study. Further study of such dissemination using published data from international indices may provide data which assist with control of tuberculosis.

METHODS

For each clinical or epidemiologic factor studied, summary odds ratios and corresponding 95% confidence intervals were calculated showing associations between such factors and documented extrapulmonary dissemination of tuberculosis.

RESULTS

Eighteen studies fulfilled criteria for study of the clinical factors and nine for the cytokine studies. Significant factors associated with a greater risk of extrapulmonary dissemination were female gender (summary odds ratio, 1.92 (95% confidence intervals, 1.72-2.13), I-squared 86.9), age under 45 (1.37, 1.18-1.60, 63.7), and as well the absence of smoking, drinking and diabetes but not HIV infection (1.10, 0.91-1.32, 80.5). Among cytokines, the macrophage receptor protein P2X7 was associated most strongly associated with extrapulmonary dissemination of tuberculosis (2.28, 0.88-5.90, 92.9).

CONCLUSION

Young age, female gender, and the macrophage purinergic receptor protein P2X7 were major factors associated with extrapulmonary dissemination of tuberculosis.

Association between the IFNG +874A/T gene polymorphism and leprosy resistance: a meta-analysis

Previous studies identified the variant IFNG +874A/T (rs2430561) in the first intron of the gene in association with mycobacterial infection, especially tuberculosis and leprosy. The aim of this investigation was to analyze the protective role of the T allele in relation to leprosy using a meta-analysis evaluation. Thus, 1573 patients and 1914 controls were included and analyzed in fixed effects model. The T allele is associated with a protective effect for leprosy under the dominant model (pooled OR=0.83, 95% CI=0.72-0.96, p=0.011) suggesting that carriers of the IFNG +874T allele may be protected from developing leprosy. The T allele has been suggested to correlate with high interferon-γ levels. A phenotype with high IFN-γ producing and an increased inflammatory profile may account for these findings. This meta-analysis suggests that IFNG +874T allele is associated with leprosy resistance.

No association of IFNG+874T/A SNP and NOS2A-954G/C SNP variants with nitric oxide radical serum levels or susceptibility to tuberculosis in a Brazilian population subset

Tuberculosis (TB) is one of the most common infectious diseases in the world. Mycobacterium tuberculosis infection leads to pulmonary active disease in approximately 5-10% of exposed individuals. Both bacteria- and host-related characteristics influence latent infection and disease. Host genetic predisposition to develop TB may involve multiple genes and their polymorphisms. It was reported previously that interferon gamma (IFN-γ) and nitric oxide synthase 2 (NOS2) are expressed on alveolar macrophages from TB patients and are responsible for bacilli control; thus, we aimed this study at genotyping single nucleotide polymorphisms IFNG+874T/A SNP and NOS2A-954G/C SNP to estimate their role on TB susceptibility and determine whether these polymorphisms influence serum nitrite and NOx(-) production. This case-control study enrolled 172 TB patients and 179 healthy controls. Neither polymorphism was associated with susceptibility to TB. NOS2A-954G/C SNP was not associated with serum levels of nitrite and NOx(-). These results indicate that variants of IFNG+874T/A SNP and NOS2A-954G/C SNP do not influence TB susceptibility or the secretion of nitric oxide radicals in the study population.

A functional promoter polymorphism of IFITM3 is associated with susceptibility to pediatric tuberculosis in Han Chinese population

A susceptibility locus for tuberculosis, a re-emerging infectious disease throughout the world, was previously discovered to exist on chromosome 11p15. IFITM3 gene encoding for interferon inducible transmembrane protein 3, is located at 11p15. It acts as an effector molecule for interferon-gamma, which is essential for anti-tuberculosis immune response. In order to investigate the association between susceptibility to TB and genetic polymorphisms of the IFITM3 core promoter, a case-control study including 368 TB patients and 794 healthy controls was performed in Han Chinese children in northern China. The rs3888188 polymorphism showed significant association with susceptibility to TB. The rs3888188 G allele, acting recessively, was more frequent in TB patients (95% confidence interval: 1.08–1.56, Bonferroni P-value: 0.039). We further assessed the effect of rs3888188 polymorphism on IFITM3 transcription in vitro. As based on luciferase promoter assays, the promoter activity of haplotypes with rs3888188 G allele was lower than that of haplotypes with rs3888188 T allele. Moreover, peripheral-blood mononuclear cells carrying rs3888188 GG genotype showed a reduced IFITM3 mRNA level compared to cells carrying TT or GT genotype. In conclusion, rs3888188, a functional promoter polymorphism of IFITM3, was identified to influence the risk for pediatric TB in Han Chinese population.

IFNG polymorphisms are associated with tuberculosis in Han Chinese pediatric female population

Host genetic factors play a major role in determining differential susceptibility to human tuberculosis (TB), a re-emerging infectious disease throughout the world. Genetic variations in the IFNG gene coding for interferon gamma (IFN-γ), have been identified in TB patients. To investigate the association of the IFNG polymorphisms with TB susceptibility in Chinese pediatric population. A case-control study of 189 TB patients and 164 controls was performed using single-nucleotide polymorphism (SNP) analysis. Genomic DNA was extracted from leukocytes in peripheral blood. Three SNPs of IFNG, including -1616C/T (rs2069705), +874A/T (rs2430561), and +3234C/T (rs2069718), were selected for genotyping and analysis. The +874A and +3234C alleles were more frequent among TB patients (P = 0.108 and P = 0.088), especially in females (both P = 0.029), although this difference was not significant since Bonferroni corrected significance threshold was 0.025 (two of three SNPs were found to be in linkage disequilibrium). More pronounced differences for the +874 and +3234 polymorphisms were found under the genotype comparison between TB cases and controls in the total population [P = 0.026 (borderline non-significance) and P = 0.020, respectively], and in the female subgroup (P = 0.020 and P = 0.020). The dominant model of inheritance was shown to be significant for +874A and +3234C alleles (both P = 0.019) in the female subgroup. The +874A and +3234C alleles were more frequently found in extrapulmonary TB patients than in controls (P = 0.039). Haplotype analysis carried out on these three SNPs showed the TTT haplotype to be more frequent in controls than in TB cases, and this difference showed a strong significance (P = 0.005). The +874A and +3234C alleles may be related to TB susceptibility in the female subgroup in the Chinese pediatric population of North China. The higher rate of +874A (known to correlate with lower IFN-γ expression) in the extrapulmonary TB subgroup suggests a sufficient IFN-γ expression to be not only an important factor for the onset of TB disease but also for limiting its dissemination to lungs.

Cytokine Polymorphisms, Their Influence and Levels in Brazilian Patients with Pulmonary Tuberculosis during Antituberculosis Treatment

Cytokines play an essential role during active tuberculosis disease and cytokine genes have been described in association with altered cytokine levels. Therefore, the aim of this study was to verify if IFNG, IL12B, TNF, IL17A, IL10, and TGFB1 gene polymorphisms influence the immune response of Brazilian patients with pulmonary tuberculosis (PTB) at different time points of antituberculosis treatment (T1, T2, and T3). Our results showed the following associations: IFNG +874 T allele and IFNG +2109 A allele with higher IFN-γ levels; IL12B +1188 C allele with higher IL-12 levels; TNF −308 A allele with higher TNF-α plasma levels in controls and mRNA levels in PTB patients at T1; IL17A A allele at rs7747909 with higher IL-17 levels; IL10 −819 T allele with higher IL-10 levels; and TGFB1 +29 CC genotype higher TGF-β plasma levels in PTB patients at T2. The present study suggests that IFNG +874T/A, IFNG +2109A/G, IL12B +1188A/C, IL10 −819C/T, and TGFB1 +21C/T are associated with differential cytokine levels in pulmonary tuberculosis patients and may play a role in the initiation and maintenance of acquired cellular immunity to tuberculosis and in the outcome of the active disease while on antituberculosis treatment.

SP110 gene polymorphisms and tuberculosis susceptibility: a systematic review and meta-analysis based on 10 624 subjects

Tuberculosis (TB), caused by infection of Mycobacterium tuberculosis, is a major challenge to global public health. The SP110 (Speckled 110) gene, which is considered as a host genetic susceptibility to TB, has been widely studied in recent years, yet the results were somewhat contradictory and indeterminate. We systematically searched published literatures on SP110 polymorphisms and tuberculosis risk until January 2012 in relevant databases, selected studies by previously defined criteria, extracted key data and quantitatively summarized associations of the most extensively studied polymorphisms through meta-analysis. A total of 10 624 subjects from seven case-control studies were included in the present study. In overall meta-analysis, pooled odds ratio of polymorphisms rs1135791, rs9061, rs11556887, rs3948464, rs1346311 were 1.01 (95% CI: 0.71-1.44), 0.86 (95% CI: 0.70-1.04), 0.99 (95% CI: 0.67-1.47), 1.29 (CI: 0.89-1.89) and 0.95 (CI: 0.86-1.04) respectively; the summary odds ratio of sensitivity analysis specifically on pulmonary TB were 1.02 (95% CI: 0.65-1.54) for rs1135791, 0.84 (95% CI: 0.68-1.02) for rs9061, 0.88 (95% CI: 0.57-1.36) for rs11556887, 0.94 (95% CI: 0.85-1.04) for rs1346311; and in the ethnicity stratified analysis, the estimated odds ratio were 0.97 (95% CI: 0.54-1.73) for rs1135791 and 0.86 (95% CI: 0.70-1.04) for rs9061 among Asians. None of the target polymorphisms in SP110 gene observed in the present quantitative synthesis was detected to be significantly associated with TB susceptibility. Given the moderate strength of the results, the complexities of pulmonary and extra-pulmonary host genetic polymorphisms, gene-gene and gene-environment interactions, and the cross-species difference between human and mice, it would not be robust to remark that SP110 has no role in TB progress.

Association of polymorphism +874 A/T of interferon-γ and susceptibility to the development of tuberculosis: meta-analysis

The immune defence against Mycobacterium tuberculosis is complex and involves multiple interacting cells. Studies in subjects with polymorphisms in genes for IFN or its receptor gene evaluate their relationship with mycobacterium infections. The purpose of this study was to analyze the evidence of the effect of polymorphism +874 A/T from interferon-γ on the occurrence of tuberculosis. We performed a meta-analysis of studies published between June 2002 and April 2012. The articles analyzed assessed the relationship between the polymorphism +874 A/T and the development of tuberculosis. The meta-analysis was performed with a random effect model, considering the heterogeneity among studies. Genotype TT showed a protective effect (OR, 0.77; 95% CI = 0.67-0.88) while genotype AA may be associated with increased susceptibility to developing tuberculosis (OR, 1.51; 95% CI = 1.38-1.65). In relation to alleles, we can verify that the A allele is related to the development of tuberculosis (OR, 1.56; 95% CI = 1.42-1.71). This information reinforces the importance of host genetics in the development of infectious diseases. Studies in this area can result in the promotion of new and more accurate genetic markers.

IFN-γ +875 microsatellite polymorphism as a potential protection marker for leprosy patients from Amazonas state, Brazil

Polymorphisms present in the first intron of IFN-γ may have an important role in the regulation of the immune response, which could have functional consequences for gene transcription. Leprosy patients are characterized by different immune responses in different clinical forms. We investigated a possible association of the +874 polymorphism and CA repeats present in the first intron of IFN-γ with susceptibility to leprosy and with the manifestation of the different clinical forms. Nucleotide sequencing was performed with samples from 108 leprosy patients and 113 controls subjects, as well as immunophenotyping of CD(4)(+), CD(8)(+) and CD(69)(+) T cells by flow cytometry. The data showed that there were no significant differences between patients and control subjects, as well as according classification of Ridley-Jopling. However, the A/A genotype was significantly increased in paucibacillary patients (p=0.028) and the microsatellite encoding 16 CA repeats were significantly associated with paucibacillary compared to multibacillary patients (p=0.019). Individuals homozygous for the +874 A allele, the mean level of CD(4)(+) and CD(69)(+) T cells was higher. Our data suggest that polymorphisms present in the first intron of IFN-γ are not associated with susceptibility to leprosy, nevertheless, the +874 polymorphism and the CA repeats number encoded in IFN-γ gene may be related to a higher cellular immune response in patients and are consistently more frequently detected in PB patients.