Vitamin D Receptor Gene FOKI Polymorphism Contributes to Increasing the Risk of HIV-Negative Tuberculosis: Evidence from a Meta-Analysis

Association of Toll-like Receptors 1, 2, 4, 6, 8, 9 and 10 Genes Polymorphisms and Susceptibility to Pulmonary Tuberculosis in Sudanese Patients

Background

Genetic factors are important contributors to the development of a wide range of complex disease. Polymorphisms in genes encoding for toll-like receptors (TLRs) usually influence the efficiency of the immune response to infection and are associated with disease susceptibility and progression. Therefore, we aim to describe the first association between TLR1, TLR2, TLR4 TLR6, TLR8, TLR9 and TLR10 genes polymorphisms and susceptibility to pulmonary tuberculosis (PTB) in Sudanese patients.

Methodology

Here we performed a case study which included 160 tuberculosis patients and 220 healthy matched controls from Sudan. In the study population, we evaluated the possible association between 86 markers in TLR1, TLR2, TLR4 TLR6, TLR8, TLR9 and TLR10 genes polymorphisms and susceptibility to PTB disease in Sudanese population using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

Results

From our results it appeared that in the PTB population the TLR1 (rs5743557, rs4833095, rs5743596), TLR2 (rs5743704, rs5743708, rs3804099), TLR4 (rs4986790, rs4986791), TLR6 (rs5743810), TLR8 (rs3764879, rs3764880), TLR9 (rs352165, rs352167, rs187084) and TLR10 (rs4129009) were significantly more often encountered (p<0.0001) than in the control population and were associated with PTB in the Sudanese population. For the other polymorphisms tested, no association with PTB was found in the population tested.

Conclusion

The work describes novel mutations in TLR1, TLR2, TLR4, TLR6, TLR8, TLR9 and TLR10 genes and their association with PTB infection in Sudanese population. These results will enhance our ability to determine the risk of developing the disease by targeting specific TLR pathways to reduce the severity of the disease. Future studies are needed in a larger sample to replicate our findings and understand the mechanism of association of TLR polymorphism in PTB.

Vitamin D Receptor Gene Polymorphism Affecting Vitamin D and Beta Carotene Deficiency in Tuberculosis Patients

BACKGROUND: The working mechanism of Vitamin D in tuberculosis (TB), which is influenced by the work of other vitamins and minerals, remains questionable. This is particularly the case regarding the effect of polymorphism of the Vitamin D receptor (VDR) gene. AIM: The objective of this research was to examine the differences in serum levels of 25(OH)D, retinol, beta-carotene, and calcium in TB patients compared to healthy people who have VDR gene polymorphisms (TaqI, BsmI, and FokI). METHODS: This research was a case–control study involving 176 men and women with a pair of VDR gene polymorphisms, consisting of 94 TB patients (TB group) and 82 healthy people (control group) in North Sumatera, Indonesia. RESULTS: There was a significant difference in Vitamin D levels between the TB and control groups (p = 0.001), with Vitamin D deficiency of 85.1% in the TB group and 100% in the control group. Significant differences were found in retinol levels and beta-carotene, but there were no significant differences in calcium levels (p = 0.619). Based on these results, there was a significant difference between the TBC and normal group in 25(OH)D, retinol, and beta-carotene serum. CONCLUSION: This study showed that 25(OH)D serum was higher in the TBC group than the control group, but lower in retinol and beta-carotene serum. There is no difference in calcium serum level in both groups.

Genetic factors associated with tuberculosis-related clinical outcomes in HIV-infected Black African patients: a systematic review and meta-analysis

Aim: To evaluate the genetic factors influencing tuberculosis (TB) clinical outcomes in HIV-infected Black African patients. Materials & methods: We systematically searched and identified eligible publications from >550 databases indexed through February 2021. Results: Eighteen studies were included in the qualitative synthesis. Only two cohorts from one study were included in quantitative synthesis of which the low expression MIF-794 CATT5,6 (5/5 + 5/6 + 6/6) genotypes were not associated with TB infectivity in HIV-infected patients (OR: 1.31, 95% CI: 0.46-3.79). Other TB clinical outcomes observed in HIV/TB co-infected patients included: drug-induced liver injury, peripheral neuropathy, mortality, lung function and TB cure. Conclusion: This review finds inconclusive evidence that genetic factors are associated with TB clinical outcomes among HIV-infected patients in sub-Saharan Africa.

Association of chemotactic chemokine ligand 5 rs2107538 polymorphism with tuberculosis susceptibility: A meta-analysis

A meta-analysis was carried out in this study by summarizing relevant research to evaluate the relationship between rs2107538 polymorphism in the chemotactic chemokine ligand 5 (CCL5) gene and tuberculosis (TB) susceptibility. Published studies were retrieved from PubMed, Embase, and CNKI databases using the keywords 'CCL5', 'TB', and 'polymorphism'. Nine studies involving 2584 patients with TB and 2265 controls were included in the current meta-analysis. The combined results suggested that the CCL5 rs2107538 polymorphism was correlated with TB susceptibility (recessive model: OR = 1.45, 95% CI = 1.02-2.07). Subgroup analysis according to race indicated that such correlation could be detected in Caucasians (CT versus CC: OR = 1.53, 95% CI = 1.20-1.95; dominant model: OR = 1.58, 95% CI = 1.25-1.99), but not in East Asian, South Asian, and South African populations. In conclusion, the results of our meta-analysis suggest that CCL5 rs2107538 polymorphism might contribute to the risk of TB, especially in Caucasians. Well-designed studies with more subjects will be required for further validation of these results.

VDR polymorphisms influence immunological response in HIV-1+ individuals undergoing antiretroviral therapy

Vitamin D exerts an immuno-modulatory activity on several immune system cells through the vitamin D receptor (VDR). Herein, we verified that age and a therapeutic regimen containing protease inhibitors are associated with failures in antiretroviral therapies (ARVs). In addition, we assessed whether a VDR SNP (rs11568820: C allele and CC genotype) and GC (rs2228570-rs11568820) allelic combinations are associated with immunological failure (p < 0.05). Our findings suggest a possible role of VDR SNPs on immunological failure in HIV-1+ individuals undergoing regular ARVs.

Inter-individual variation in health and disease associated with pulmonary infectious agents

Respiratory infectious diseases resulting from bacterial or viral pathogens such as Mycobacterium tuberculosis, Streptococcus pneumoniae, respiratory syncytial virus (RSV), or influenza, are major global public health concerns. Lower respiratory tract infections are leading causes of morbidity and mortality, only behind ischemic heart disease and stroke (GBD 2015 LRI Collaborators in Lancet Infect Dis 17(11):1133–1161, 2017). Developing countries are particularly impacted by these diseases. However, while many are infected with viruses such as RSV (> 90% of all individuals are infected by age 2), only sub-populations develop severe disease. Many factors may contribute to the inter-individual variation in response to respiratory infections, including gender, age, socioeconomic status, nutrition, and genetic background. Association studies with functional single nucleotide polymorphisms in biologically plausible gene candidates have been performed in human populations to provide insight to the molecular genetic contribution to pulmonary infections and disease severity. In vitro cell models and genome-wide association studies in animal models of genetic susceptibility to respiratory infections have also identified novel candidate susceptibility genes, some of which have also been found to contribute to disease susceptibility in human populations. Genetic background may also contribute to differential efficacy of vaccines against respiratory infections. Development of new genetic mouse models such as the collaborative cross and diversity outbred mice should provide additional insight to the mechanisms of genetic susceptibility to respiratory infections. Continued investigation of susceptibility factors should provide insight to novel strategies to prevent and treat disease that contributes to global morbidity and mortality attributed to respiratory infections.

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.

The role of human host genetics in tuberculosis resistance

INTRODUCTION

Tuberculosis (TB) remains a public health problem: the latest estimate of new incident cases per year is a staggering 10.4 million. Despite this overwhelming number, the majority of the immunocompetent population can control infection with Mycobacterium tuberculosis. The human genome underlies the immune response and contributes to the outcome of TB infection. Areas covered: Investigations of TB resistance in the general population have closely mirrored those of other infectious diseases and initially involved epidemiological observations. Linkage and association studies, including studies of VDR, SLC11A1 and HLA-DRB1 followed. Genome-wide association studies of common variants, not necessarily sufficient for disease, became possible after technological advancements. Other approaches involved the identification of those individuals with rare disease-causing mutations that strongly predispose to TB, epistasis and the role of ethnicity in disease. Despite these efforts, infection outcome, on an individual basis, cannot yet be predicted. Expert commentary: The early identification of future disease progressors is necessary to stem the TB epidemic. Human genetics may contribute to this endeavour and could in future suggest pathways to target for disease prevention. This will however require concerted efforts to establish large, well-phenotyped cohorts from different ethnicities, improved genomic resources and a better understanding of the human genome architecture.

25-Hydroxy Vitamin D, Vitamin D Receptor and Toll-like Receptor 2 Polymorphisms in Spinal Tuberculosis: A Case-Control Study

Vitamin D deficiency and vitamin D receptor (VDR) gene abnormalities confer susceptibility to tuberculosis. Toll-like receptors (TLRs), such asTLR-2, are also important mediators of inflammatory response against Mycobacterium tuberculosis. We evaluated serum vitamin D, and VDR and TLR-2 gene polymorphisms in patients with spinal tuberculosis.This study comprised of 3 groups: spinal tuberculosis, pulmonary tuberculosis, and controls (each with 106 subjects). Enzyme-linked immunosorbent assay was used to measure vitamin D levels, and polymerase chain reaction-sequencing method was used to analyze VDR and TLR-2 gene polymorphisms. Patients were followed up for 6 months.Vitamin D deficiency was significantly more prevalent in patients with spinal tuberculosis (P < 0.001) and pulmonary tuberculosis (P = 0.011), versus controls. The heterozygous and mutant genotypes of VDR TaqI gene were significantly associated with spinal tuberculosis (P < 0.001; odds ratio [OR] 4.74 [2.45-9.18]) and pulmonary tuberculosis (P < 0.001; OR 3.52 [1.80-6.88]) when compared with controls. The heterozygous and mutant variants of VDR ApaI gene were significantly more common in patients with spinal tuberculosis in comparison with patients with pulmonary tuberculosis (P < 0.001; OR 2.90 [1.65-5.10]) and controls (P < 0.001; OR 6.56 [3.41-12.61]). We did not observe any significantly different results for TLR-2 gene polymorphisms. Vitamin D deficiency, VDR, and TLR-2 polymorphisms did not affect the 6-month disability.Vitamin D deficiency and VDR gene polymorphisms are significantly more prevalent in people with pulmonary and spinal tuberculosis. They may, in isolation or collectively, confer susceptibility to pulmonary and spinal tuberculosis.

Association Analysis of Interleukin-17 Gene Polymorphisms with the Risk Susceptibility to Tuberculosis

BACKGROUND

Recently, many institutions have investigated the associations of interleukin-17 (IL17) polymorphisms with tuberculosis (TB) susceptibility, while those results are inconsistent. The purpose of this meta-analysis is to comprehensively assess whether IL17A rs22275913, IL17F rs763780, and IL17A rs3748067 polymorphisms are correlated with TB risk.

METHODS

Electronic bibliographic databases were searched for case-control studies which potentially focused on the relationship between the aforementioned polymorphisms and TB risk on October 15th, 2015. Pooled odds ratios (OR) combined with 95 % confidence intervals (CI) were employed to assess the associations.

RESULTS

There was no significant association of IL-17A rs22275913 polymorphism with susceptibility to TB in Asians or Caucasians. For IL-17A rs3748067 polymorphism, significant associations were observed in Asian (T vs. C: OR 1.461, 95 % CI 1.158-1.844, P = 0.001; TT vs. CC: OR 1.871, 95 % CI 1.140-3.069, P = 0.013; TT/TC vs. CC: OR 1.392 95 % CI 1.062-1.825, P = 0.017; TT vs.

TC/CC

OR 1.820, 95 % CI 1.111-2.981, P = 0.017). For IL-17F rs763780, we detected the significant associations under allele contrast, heterozygote, dominant and recessive models (C vs. T: OR 1.571, 95 % CI 1.352-1.824, P = 0.000; CT vs. TT: OR 1.624, 95 % CI 1.346-1.958, P = 0.000; CT/TT vs. TT: OR 1.639, 95 % CI 1.381-1.946, P = 0.000, respectively). The corresponding results were also detected in Asian populations (C vs. T: OR 1.068, 95 % CI 1.380-1.875, P = 0.000; CT vs. TT: OR 1.689, 95 % CI 1.390-2.053, P = 0.000; CT/TT vs. TT: OR 1.695, 95 % CI 1.420-2.023, P = 0.000), while there were no significant associations in Caucasian.

CONCLUSION

IL-17F rs763780 allele C and IL-17A rs3748067 allele C may be involved in the susceptibility to TB in Asian populations. There were no significant associations between IL-17A rs22275913 polymorphism and risk of TB.

Vitamin D Receptor Gene FokI Polymorphism Contributes to Increasing the Risk of Tuberculosis: An Update Meta-Analysis

The association between vitamin D receptor (VDR) FokI polymorphism and tuberculosis (TB) risk remains a matter of debate. Potential selection bias exists in most studies using HIV-positive TB patients.An update meta-analysis was carried out to derive a more reliable assessment of the association between FokI polymorphisms and TB risk, especially in HIV-negative TB patients. All major databases from inception to June 2015 were searched for all publications that studied the association between FokI polymorphism and TB risk. The odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were calculated according to the frequencies of genotypes.In total, 32 studies with 4894 cases and 5319 controls were included in this meta-analysis. In the overall analysis, the estimated OR was 1.34 (95% CI=1.091-1.646, P = 0.005) in the best genetic model (recessive model, ff vs fF+FF) with moderate heterogeneity (I = 32.2%, P = 0.043). In the subgroup analysis stratified by HIV status, significant associations were found only in the HIV-negative TB group (OR = 1.60, 95% CI = 1.180-2.077, P = 0.002; I = 29.5%, and P = 0.141 for heterogeneity). In the subgroup analysis stratified by ethnicity, significant associations were found in the Asian group (OR = 1.65, 95% CI = 1.205-2.261, P = 0.002; I = 43.9%, and P = 0.024 for heterogeneity), but not in the Caucasian group (OR = 1.09, 95% CI = 0.762-1.547, P = 0.649; I = 0.0%, and P = 0.740 for heterogeneity) and African group (OR = 0.99, 95% CI = 0.726-1.341, P = 0.934; I = 43.9%, and P = 0.024 for heterogeneity).This meta-analysis confirms that VDR FokI polymorphism contributes to the risk of TB, especially in HIV-negative TB patients and in the Asian group. Further studies are required to clarify the role of the FokI polymorphism in HIV-positive TB and in other ethnic groups.