5' regulatory and 3' untranslated region polymorphisms of vitamin D receptor gene in south Indian HIV and HIV-TB patients

The Effect of Genetic Variations in the Vitamin D Receptor Gene on the Course of Depressive Symptoms

BACKGROUND

Evidence on the association between single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and depressive symptoms is inconclusive.

OBJECTIVES

The primary aim of the study was to investigate the association between SNPs in the VDR gene and depressive symptoms.

METHODS

In a sample of older adults from the Longitudinal Ageing Study Amsterdam (n = 922), depressive symptoms were assessed using the Centre for Epidemiological Studies Depression scale (CES-D scale) at baseline and after 3, 6, and 10 y of follow-up. Blood samples for SNP and serum 25-hydroxyvitamin D3 (25(OH)D3) determination were obtained at baseline. The association between 13 SNPs in the VDR gene and the course of depressive symptoms were evaluated using linear mixed models. The interaction between SNPs and serum 25(OH)D3 in relation to depressive symptoms was evaluated using multiple linear regression.

RESULTS

No SNPs were associated with the course of depressive symptoms. Significant interactions between serum 25(OH)D3 and SNPs in the VDR gene were found. Stratified analysis revealed that within the GG genotype strata, 10 nmol/L higher serum 25(OH)D3 was associated with 0.27 (95% CI: -0.50, -0.04) and 0.23 (95% CI: -0.48, 0.02) lower scores on the CES-D scale for Cdx-2 and 1b-G-886A, respectively. This association was not found in persons having the GA or AA genotype.

CONCLUSIONS

No SNPs are associated with the course of depressive symptoms. Stratified analysis shows that the effect of serum 25(OH)D3 concentrations on depressive symptoms is different among genotypes of Cdx-2 and 1b-G-886A. Future research should elucidate on the function of Cdx-2 and 1b-G-886A to describe their effect.

Host Genetic Impact on Infectious Diseases among Different Ethnic Groups

Infectious diseases such as malaria, tuberculosis (TB), human immunodeficiency virus (HIV), and the coronavirus disease of 2019 (COVID-19) are problematic globally, with high prevalence particularly in Africa, attributing to most of the death rates. There have been immense efforts toward developing effective preventative and therapeutic strategies for these pathogens globally, however, some remain uncured. Disease susceptibility and progression for malaria, TB, HIV, and COVID-19 vary among individuals and are attributed to precautionary measures, environment, host, and pathogen genetics. While studying individuals with similar attributes, it is suggested that host genetics contributes to most of an individual's susceptibility to disease. Several host genes are identified to associate with these pathogens. Interestingly, many of these genes and polymorphisms are common across diseases. This paper analyzes genes and genetic variations within host genes associated with HIV, TB, malaria, and COVID-19 among different ethnic groups. The differences in host-pathogen interaction among these groups, particularly of Caucasian and African descent, and which gene polymorphisms are prevalent in an African population that possesses protection or risk to disease are reviewed. The information in this review could potentially help develop personalized treatment that could effectively combat the high disease burden in Africa.

Association of ApaI rs7975232 and BsmI rs1544410 in clinical outcomes of COVID-19 patients according to different SARS-CoV-2 variants

A growing body of research has shown how important vitamin D is in the prognosis of coronavirus disease 19 (COVID-19). The vitamin D receptor is necessary for vitamin D to perform its effects, and its polymorphisms can help in this regard. Therefore, we aimed to evaluate whether the association of ApaI rs7975232 and BsmI rs1544410 polymorphisms in different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants were influential in the outcomes of COVID-19. The polymerase chain reaction-restriction fragment length polymorphism method was utilized to determine the different genotypes of ApaI rs7975232 and BsmI rs1544410 in 1734 and 1450 patients who had recovered and deceased, respectively. Our finding revealed that the ApaI rs7975232 AA genotype in the Delta and Omicron BA.5 and the CA genotype in the Delta and Alpha variants were associated with higher mortality rate. Also, the BsmI rs1544410 GG genotype in the Delta and Omicron BA.5 and the GA genotype in the Delta and Alpha variants were related to a higher mortality rate. The A-G haplotype was linked with COVID-19 mortality in both the Alpha and Delta variants. The A-A haplotype for the Omicron BA.5 variants was statistically significant. In conclusion, our research revealed a connection between SARS-CoV-2 variants and the impacts of ApaI rs7975232 and BsmI rs1544410 polymorphisms. However, more research is still needed to substantiate our findings.

[Vitamin D and polymorphisms of VDR and GC genes in the severity and mortality from COVID-19. A systematic review]

Introduction

Previous studies have pointed to a possible relationship between vitamin D deficiency and the severity of the disease promoted by SARS-CoV-2, reducing respiratory and cardiovascular complications caused by a hyperreaction of the immune system known as "cytokine storm". This vitamin exerts multiple functions that depend on the presence and levels of different proteins, such as the vitamin D receptor (VDR) and the vitamin D binding protein (DBP), and the existence of single nucleotide polymorphisms (SNPs) of the genes that encode these proteins. The objective of this review is to assess whether some VDR and GC SNPs are risk factors for the most severe forms of COVID-19 disease and whether they condition the response to vitamin D supplementation. A search was performed in PubMed, Google Scholar and Scielo, finding that genotypes in patients affected by COVID-19, were rarely performed, although some studies find a relationship between different alleles and the severity of the disease. The ApaI polymorphism of the VDR gene stands out, as the minor allele "a" increases the risk of mortality from COVID-19 (OR = 11.828, CI: 2,493-56,104, p = 0.002). Results divergency in the efficacy of vitamin D supplementation suggest the need for a larger number of studies. In conclusion, the study of VDR and GC polymorphisms seems essential to effectively treat vitamin D deficiency and particularly to protect against COVID-19. Well-designed studies are needed to elucidate whether plasma vitamin D levels play a role of casuality or causality.

DBP rs7041 and DHCR7 rs3829251 are Linked to CD4+ Recovery in HIV Patients on Antiretroviral Therapy

Background: The lack of the recovery of CD4⁺ T-cells (CD4⁺ recovery) among immunodeficiency virus (HIV)-infected patients on antiretroviral therapy (ART) is not well known. We aimed to analyze the association between single nucleotide polymorphisms (SNPs) underlying vitamin D metabolism and the CD4⁺ recovery in naïve HIV-infected patients who started ART with low baseline CD4⁺.

Methods: We conducted a retrospective study in 411 naïve individuals with plasma HIV load >200 copies/mL and CD4⁺ <200 cells/mm³. During 24 months of follow-up, all patients had plasma HIV load <50 copies/mL. DNA genotyping was performed using the Sequenom MassARRAY platform. The outcome variable was the change in CD4⁺ during the study.

Results: CD4⁺ recovery was higher in patients carrying DBP rs7041 AA genotype (AA versus CC/AC) and DHCR7 rs3829251 AA genotype (AA versus GG/AG) (p-value < 0.05). DBP rs7041 AA genotype was linked to increase in CD4⁺ (adjusted arithmetic mean ratio (aAMR) = 1.22; q-value = 0.011), increase in CD4⁺ ≥P75th [adjusted odds ratio (aOR) = 2.31; q-value = 0.005], slope of CD4⁺ recovery (aAMR = 1.25; q-value = 0.008), slope of CD4⁺ recovery ≥ P75th (aOR = 2.55; q-value = 0.005) and achievement of CD4⁺ ≥500 cells/mm³ (aOR = 1.89; q-value = 0.023). Besides, DHCR7 rs3829251 AA genotype was related to increase in CD4⁺ (aAMR = 1.43; q-value = 0.031), increase in CD4⁺ ≥P75th (aOR = 3.92; q-value = 0.030), slope of CD4⁺ recovery (aAMR = 1.40; q-value = 0.036), slope of CD4⁺ recovery ≥ P75th (aOR = 3.42; q-value = 0.031) and achievement of CD4⁺ ≥500 cells/mm³ (aOR = 5.68; q-value = 0.015).

Conclusion: In summary, DHCR7 rs3829251 and DBP rs7041 polymorphisms were associated with CD4⁺ recovery in HIV-infected patients who started cART with low CD4⁺ T-cell counts.

FokI polymorphism of the vitamin D receptor (VDR) gene and susceptibility to tuberculosis: Evidence through a meta-analysis

BACKGROUND

Tuberculosis is one of the top ten causes of deaths worldwide. The deficiency of vitamin D was reported to be associated with the increased susceptibility of tuberculosis. Various previous reports were published to check the association of FokI polymorphism of the vitamin D receptor gene with tuberculosis risk. But their results were inconsistent so, we performed a meta-analysis to know the exact relation of the two.

METHODS

Different databases were screened up to November 2020 with the keywords "Vitamin D receptor", "VDR", and "FokI", along with "Tuberculosis" and "TB" to find the suitable articles. All the statistical analyses were performed by the Open Meta-Analyst program and all p-values were two-tailed with a significance level of 0.05.

RESULTS

No statistically significant association was observed in the allele contrast model (OR_fvs.F = 1.11, 95%CI = 0.99-1.24, p = 0.05, I² = 73.46%), in the dominant model (OR_ff+Ffvs.FF = 1.11, 95%CI = 0.96-1.28, p = 0.14, I² = 71.39%), and in the co-dominant model (OR_Ffvs.FF = 1.05, 95%CI = 0.92-1.21, p = 0.41, I² = 65.97%). However, a significant association was found in the homozygote model (OR_ffvs.FF = 1.32, 95%CI = 1.03-1.69, p = 0.02, I² = 67.02%) and in the recessive model (OR_{FF+Ff vs.ff} = 1.26, 95%CI = 1.03-1.54, p = 0.02, I² = 58.01%). Further analysis was performed on the bases of the ethnicity. In Asian population a significant association was found in the homozygote model (OR_ffvs.FF = 1.57, 95%CI = 1.12-2.21, p = 0.008, I² = 70.37%) and in the recessive model (OR_{FF+Ff vs.ff} = 1.43, 95%CI = 1.08-1.89, p = 0.01, I² = 63.13%).

CONCLUSION

In conclusion, a significant association of FokI with tuberculosis susceptibility was found in the overall analysis and in the Asian population.

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.

Associations between vitamin D receptor genetic variants and tuberculosis: a meta-analysis

We performed a meta-analysis to evaluate potential associations between vitamin D receptor (VDR) genetic variants and tuberculosis (TB). Systematic literature research was conducted in PubMed, Web of Science, and Embase. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) to estimate strength of associations in all possible genetic models, and P values ≤ 0.05 were considered to be statistically significant. In total, 42 studies were enrolled for analyses. Pooled overall analyses suggested that VDR rs1544410 (dominant model: P = 0.02; allele model: P = 0.03) and rs731236 (dominant model: P = 0.04; recessive model: P = 0.02; allele model: P = 0.01) variants were significantly associated with TB. Further subgroup analyses by ethnicity revealed that rs1544410 (dominant and allele models) and rs731236 (dominant, recessive, and allele models) variants were both significantly associated with TB in South Asians. When we stratified data by type of disease, positive results were detected for rs7975232 variant in EPTB (dominant, recessive, over-dominant, and allele models) subgroup, and for rs2228570 variant in PTB (dominant, recessive, and allele models) and EPTB (dominant, recessive, over-dominant, and allele models) subgroups. Our meta-analysis supported that rs7975232, rs1544410, rs2228570, and rs731236 variants might serve as genetic biomarkers of certain types of TB.

VDR rs2228570 Polymorphism Is Related to Non-Progression to AIDS in Antiretroviral Therapy Naïve HIV-Infected Patients

Background: Vitamin D is a fundamental regulator of host defenses by activating genes related to innate and adaptive immunity. In this study, we analyzed the association among single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene, with clinical patterns of AIDS progression in antiretroviral treatment (ART)-naïve HIV-infected patients. Methods: We conducted a retrospective study in 667 HIV-infected patients, who were classified within three groups according to their AIDS progression pattern (183 long-term non-progressors (LTNPs), 334 moderate progressors (MPs), and 150 rapid progressors (RPs)). Five VDR SNPs (rs11568820, rs4516035, rs2228570, rs1544410, and rs7975232) were genotyped using Agena Bioscience’s MassARRAY platform. Results: Significant association results were found for rs2228570. Within all HIV patients, the presence of T allele at VDR rs2228570 SNP was protective against AIDS progression (ordinal outcome) under additive (adjusted odds ratio (aOR) = 0.75; p = 0.009), dominant (aOR = 0.69; p = 0.015), and codominant (aOR = 0.56; p = 0.017) inheritance models. In addition, the same allele was protective under additive and codominant inheritance models when we compared with LTNPs vs. RPs [aOR = 0.64 (p = 0.019) and aOR = 0.37 (p = 0.018), respectively] and when we compared MPs vs. RPs [aOR = 0.72 (p = 0.035) and aOR = 0.45 (p = 0.028), respectively]. Conclusions: The VDR rs2228570 T allele was related to a lower AIDS progression pattern in ART-naïve HIV-infected patients. These findings expand upon the knowledge about HIV pathogenesis in untreated HIV-infected patients with different clinical outcomes.

Vitamin D Receptor polymorphisms and risk of enveloped virus infection: A meta-analysis

INTRODUCTION

Vitamin-D plays a role regulating the immune response against to viral infection. In this sense, vitamin-D deficiency may confer increased susceptibility to enveloped virus infection such as HIV, Hepatitis, Dengue and Respiratory Syncytial virus infection, among others. Vitamin D activity is mediated by its receptor (VDR), which acts as a transcription factor modulating the expression of genes triggering the response against viruses. To date, six major VDR polymorphisms (Cdx, A1012G, FokI, BsmI, ApaI and TaqI) have been studied in the context of viral infection susceptibility. Reported studies show controversial results probably due to statistical lack of power and population genetic differences.

AIMS

To do a systematic review of the published data and to perform a meta-analysis examining the role of six VDR polymorphisms on infection susceptibility to enveloped virus.

RESULTS

From all markers and virus considered an association of FokI polymorphism with RSV infection emerges as significant. The worldwide distribution of risk T-allele reveals a lower prevalence in African populations that runs parallel with the relative lower incidence of RSV-associated severe ALRI in children <1 year described in African samples.

CONCLUSION

The results disclose FokI polymorphism as a relevant variant capturing the association of VDR polymorphisms with viral infection.

Genomics of human pulmonary tuberculosis: from genes to pathways

Purpose of review

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), remains a major public health threat globally. Several lines of evidence support a role for host genetic factors in resistance/susceptibility to TB disease and MTB infection. However, results across candidate gene and genome-wide association studies (GWAS) are largely inconsistent, so a cohesive genetic model underlying TB risk has not emerged.

Recent Findings

Despite the difficulties in identifying consistent genetic associations, genetic studies of TB and MTB infection have revealed a few well-documented loci. These well validated genes are presented in this review, but there remains a large gap in how these genes translate into better understanding of TB. To address this, we present a pathway based extension of standard association analyses, seeding the results with the best validated genes from candidate gene and GWAS studies.

Summary

Several pathways were significantly enriched using pathway analyses that may help to explain population patterns of TB risk. In conclusion, we advocate for novel approaches to the study of host genetic analysis of TB that extend traditional association approaches.

A reappraised meta-analysis of the genetic association between vitamin D receptor BsmI (rs1544410) polymorphism and pulmonary tuberculosis risk

BsmI (rs1544410) polymorphism located in intron 8 at the 3′-end of the vitamin D receptor (VDR) gene is known to be involved in the regulation of mRNA stability. Many studies evaluated the possible correlation between VDR BsmI polymorphism and the risk of pulmonary tuberculosis (PTB), and reported conflicting results. In the present study, an updated meta-analysis was performed to evaluate the above-said association. PubMed, Embase, and Google Scholar web-databases were searched for the relevant studies and a meta-analysis was performed by calculating pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for all the genetic models. A total of 19 studies comprising 3644 controls and 2635 cases were included in the present study. Overall no association of PTB in allelic contrast (b compared with B: P=0.285; OR =0.909, 95% CI =0.762–1.083), homozygous (bb compared with BB: P=0.881; OR =0.975, 95% CI =0.700–1.359), heterozygous (bB compared with BB: P=0.834; OR =1.017, 95% CI =0.872–1.185), dominant (bb compared with BB + Bb: P=0.451; OR =0.954, 95% CI =0.843–1.079) and recessive (bb + Bb compared with BB: P=0.983; OR =1.002, 95% CI =0.868–1.156) genetic models in comparison with wild-type allele and genotype BB were observed. However, variant allele (b compared with B: P=0.001; OR =2.289, 95% CI =1.661–3.154) showed increased risk of PTB in Asians. In conclusion, VDR BsmI polymorphism is not a risk factor for PTB in overall population. However, this polymorphism may be interrelated to an increased risk of PTB amongst Asians.

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.

Vitamin D receptor gene FokI polymorphisms and tuberculosis susceptibility: a meta-analysis

INTRODUCTION

The association between FokI polymorphism of vitamin D receptor (VDR) and tuberculosis (TB) susceptibility has been investigated previously; however, the results were inconsistent and conflicting. In the present study, a meta-analysis was performed to assess the relationship between VDR FokI gene polymorphism and the risk of TB.

MATERIAL AND METHODS

Databases including PubMed and Embase were searched for genetic association studies of FokI polymorphism of vitamin D receptor (VDR) and TB. Data were extracted by two independent authors and the pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to assess the strength of the association between VDR FokI gene polymorphism and TB risk. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity.

RESULTS

Thirty-four studies with a total of 5669 cases and 6525 controls were reviewed in the present meta-analysis. A statistically significant correlation was found between VDR FokI gene polymorphism and increased TB risk in two comparison models: the homozygote model (ff vs. FF: OR = 1.37, 95% CI: 1.17-1.60; P_{heterogeneity} = 0.001) and the recessive model (ff vs. Ff + FF: OR = 1.32, 95% CI: 1.14-1.52; P_{heterogeneity} = 0.006). Meta-regression found no source contributing to heterogeneity. However, sub-group analyses revealed that there was a statistically increased TB risk in the East and Southeast Asian population.

CONCLUSIONS

Synthesis of the available studies suggests that homozygosity for the FokI polymorphism of the VDR gene might be associated with an increased TB risk, especially in the East and Southeast Asian population. Additional well-designed, larger-scale epidemiological studies among different ethnicities are needed.

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.

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

Background

Vitamin D receptor (VDR) gene FokI polymorphism have been studied in relation to tuberculosis (TB) in many populations and provided inconsistent results. In this study, we carried out a meta-analysis to derive a more reliable assessment on FokI polymorphism and the risk of HIV-negative TB.

Methods

The Embase, PubMed, and Cochrane Library databases were used to undertake a comprehensive systematic literature review of all current published VDR gene FOKI association studies aimed at the risk of TB up to June 30, 2015. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were used to measure the strength of the models.

Results

A total of 14 studies (1,668 cases and 1,893 controls) were retrieved in the meta-analysis. The pooled OR was 1.60 (95% = 1.28–1.97, P<0.001; I² = 29.5%, and P = 0.141 for heterogeneity) in the best genetic model (recessive model: ff vs. fF+FF). In the subgroup analysis by ethnicities, a significantly increased risk was found in the Asian group (OR = 1.82, 95% CI = 1.42–2.33, P<0.001; I² = 31.0%, and P = 0.150 for heterogeneity) in the recessive model. Similarly, significant associations were also found in the polymerase chain reaction-restriction fragment length polymorphism group, high-quality studies, and the population based or hospital based groups. Moderate heterogeneity was found in this study.

Conclusion

Our results suggested that VDR FokI polymorphism contributes to increasing the risk of TB in HIV-negative individuals, especially in the Asian region. Further studies on this topic in other races are expected to be conducted in future.

Association between vitamin D receptor polymorphisms and haplotypes with pulmonary tuberculosis

The vitamin D receptor (VDR) is an important factor in activating immune response in different infectious diseases. The aim of the present study was to investigate the association between the VDR gene polymorphisms and pulmonary tuberculosis (PTB). The case control study was performed on 120 PTB patients and 131 healthy controls. Genetic analysis was performed by polymerase chain reaction and the restriction fragment length polymorphism method. The VDR Fok1 Ff genotype was associated with TB and the risk of PTB was two times higher in individuals with the Ff genotype. A higher frequency of f allele was observed in PTB patients and therefore, the f allele may be a risk factor for PTB susceptibility. There were no associations between the Taq1 and Bsm1 polymorphisms and PTB. In addition, haplotype analysis showed that the f-T-B and f-t-b haplotypes (Fok1, Taq1 and Bsm1) may have the potential to increase PTB susceptibility. In conclusion, the Ff genotype and f allele of the VDR Fok1 polymorphism were associated with PTB susceptibility. In addition, the f-T-B and f-t-b haplotypes may be the susceptible haplotypes for PTB.

Evaluating the Association between TaqI Variant of Vitamin D Receptor Gene and Susceptibility to Tuberculosis: A Meta-analysis

OBJECTIVES

Vitamin D has been shown to hamper the growth of Mycobacterium tuberculosis in macrophages. The actions of vitamin D are exerted through a vitamin D receptor (VDR). The genetic variant TaqI of VDR has been implicated in tuberculosis (TB) risk in several case-control studies. However, these studies have shown inconsistent results. Hence, a meta-analysis was conducted to investigate the potential relationship between VDR TaqI polymorphism and risk of developing TB.

MATERIALS AND METHODS

We performed a quantitative synthesis for published studies based upon the relationship between TaqI polymorphism and TB risk from PubMed (Medline) and Embase databases. The meta-analysis was performed and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for all genetic models.

RESULTS

A total of 21 studies including 2,960 TB cases and 3,894 controls were included in this study. The pooled analysis demonstrated no evidence of association between VDR TaqI genotypes and risk of TB in any of the genetic models; variant (t vs T: P = 0.618; OR = 1.051, 95% CI = 0.864-1.278), homozygous (tt vs TT: P = 0.120; OR = 1.336, 95% CI = 0.927-1.924), heterozygous (Tt vs TT: P = 0.925; OR = 0.988, 95% CI = 0.774-1.262), dominant model (tt + Tt vs TT: P = 0.805; OR = 1.032, 95% CI = 0.805-1.322), and recessive model (tt vs TT + Tt: P = 0.180; OR = 1.229, 95% CI = 0.909-1.660). No publication bias was detected during the analysis.

CONCLUSIONS

Overall findings of this meta-analysis suggest that genetic polymorphism TaqI of VDR gene may not contribute to the risk of TB. However, future larger studies with group of populations are warranted to analyze this relationship.

Kallikrein 3 and vitamin D receptor polymorphisms: potentials environmental risk factors for prostate cancer

Objective

To investigate the relationship and interaction of the single nucleotide polymorphisms (SNPs) of KLK3 and VDR and environmental factors with the predisposition to prostate cancer within Chinese population.

Methods

The comparison between 108 patients and 242 healthy people was carried out by using the TaqMan/MGB Probe Technology to determine the genotypes of KLK3(rs2735839 is located between KLK2 and KLK3) and VDR (rs731236 is located exon 9). Univariate and multivariate logistic regression model were used to assess the connection of genetic polymorphisms and environmental risk factors with PCa by collecting demographic information, as well as BMI, consumption of cigarettes, alcohol, and tea, exercise, and other environmental risk factors.

Results

The appearing frequencies of AA, AG, and GG genotypes at the SNPs rs2735839 (A/G) for KLK3 were 13.89%, 62.96% and 23.15% in PCa and 37.19%, 44.63%, 18.18% in control, respectively; these two groups are statistically different (P = 0.00). While the appearing frequencies of TT, TC, and CC genotypes at the SNPs rs731236 (T/C) for VDR were 88.89%, 9, 26%, 1.85% and 90.50%, 9.10%, 0.40% in control, respectively, with no significant statistical difference between the two group. The study confirmed decreasing risk in tea drinkers (OR = 0.58, 95% CI = 0.35-0.96).

Conclusions

Our studies indicate that environmental factor-tea drinking is associated with the development of PCa. The habit of drinking tea is a protective factor against PCa. The SNPs rs2735839 for KLK3 is strongly related to the development of PCa, while the SNPs rs731236 for VDR is not.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9759981571058803.

Vitamin-D pathway genes and HIV-1 disease progression in injection drug users

Vitamin-D has pleiotropic effects on calcium and bone metabolism, cellular growth control, cell differentiation and modulation of both innate and acquired immune response. Previous studies revealed the association of vitamin-D receptor gene (VDR) polymorphism with infection diseases including HIV-1 infection. To assess for association between polymorphisms of vitamin-D pathway genes CYP27B1, vitamin-D binding protein (VDBP) and VDR with HIV-1 infection, disease progression to acquired immunodeficiency syndrome (AIDS) was analysed according to CDC93 criteria in a cohort of 185 HIV-1 seroprevalent patients belonging to the injection drug users. Genotype data was obtained from rs10877012, rs3782130 and rs4646536 markers at CYP27B1 locus; rs7041 and rs4588 at VDBP locus; and rs11568820, rs4516035, rs2228570, rs1544410 and rs17878969 at VDR locus. Distribution of genotypes between patients grouped by outcome was compared by contingency table analysis. Marker-marker interaction was assessed by a MDR analysis. Assuming an additive model for VDR markers, a Kaplan-Meier survival analysis was employed to evaluate association with disease progression. Among vitamin-D pathway genes, VDR locus reveals specific 5'UTR and 3'UTR diplotype combinations associated with both, slower and faster progression to AIDS. Marker-marker interaction analysis indicates a strong interaction between VDR markers and a redundant effect for CYP27B1 markers. According to our results, VDR locus association follows an additive model in which increased genetic risk score for the VDR is directly correlated with AIDS progression rates. Our data supports a role of vitamin-D pathway gene variability on HIV-1 disease progression.

Host genome polymorphisms and tuberculosis infection: What we have to say?

Several epidemiology studies suggest that host genetic factors play important roles in susceptibility, protection and progression of tuberculosis infection. Here we have reviewed the implications of some genetic polymorphisms in pathways related to tuberculosis susceptibility, severity and development. Large case-control studies examining single-nucleotide polymorphisms (SNPs) in genes have been performed in tuberculosis patients in some countries. Polymorphisms in natural resistance-associated macrophage protein 1 (NRAMP1), toll-like receptor 2 (TLR2), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), interleukin-1 receptor antagonist (IL-1RA), IL-10, vitamin D receptor (VDR), dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), monocyte chemoattractant protein-1 (MCP-1), nucleotide oligomerization binding domain 2 (NOD2), interferon-gamma (IFN-γ), inducible nitric oxide synthase (iNOS), mannose-binding lectin (MBL) and surfactant proteins A (SP-A) have been reviewed. These genes have been variably associated with tuberculosis infection and there is strong evidence indicating that host genetic factors play critical roles in tuberculosis susceptibility, severity and development.

Vitamin D receptor gene polymorphisms on the risk of tuberculosis, a meta-analysis of 29 case-control studies

The relationship of four potentially functional polymorphisms of the vitamin D receptor (VDR) gene, ApaI, BsmI, FokI and TaqI , with tuberculosis susceptibility were considered. The aim of this meta-analysis was to explore the association between the four polymorphisms and tuberculosis risk in different ethnic backgrounds. Eligible case-control studies that were catalogued before April 1^st 2013 were enrolled, and the heterogeneity between the studies was evaluated using a χ² based Q-test. Fixed and random effect models were built to evaluate the association of the four polymorphisms with the risk of tuberculosis, and the association between the four polymorphisms and tuberculosis was expressed as the odds ratio (OR) and 95% confidence interval (CI). Finally, twenty nine qualified studies were enrolled for this meta-analysis that included 6179 tuberculosis cases and 6585 healthy controls. The variant homozygote genotype of the FokI polymorphism was associated with a significantly increased risk of tuberculosis when compared to the heterozygote and wild type homozygote genotypes in the Chinese population (ff vs. Ff+FF: OR_recessive=1.97, 95%CI: 1.32-2.93, P_bonferroni=0.0032; heterogeneity test: χ²=0.24, P=0.62). For European subjects, the homozygote and heterozygote genotypes of the BsmI polymorphism were associated with a significantly decreased risk of tuberculosis when compared to the wild type homozygote (bb+Bb vs. BB: OR_dominant=0.41, 95%CI, 0.22-0.76, P_bonferroni=0.02; heterogeneity test: χ²=2.59, P=0.11). Based on the above results, we conclude that variants of the VDR gene that are homozygous for the FokI polymorphism might be more susceptible to tuberculosis in Chinese. Furthermore, larger sample studies are warranted to confirm the protective effects of BsmI variants on tuberculosis in the Europeans.

Vitamin D-related host genetic variants alter HIV disease progression in children

BACKGROUND

Vitamin D deficiency is common in HIV infection and has been associated with advanced disease. This study investigated whether vitamin D-related genetic variants were associated with disease progression in HIV-infected children.

METHODS

The Fok-I (C/T), Bsm-I (G/A), GC (A/C), DHCR7 (G/T) and CYP2R1 (G/A) genetic variants were detected by real-time polymerase chain reaction in HIV-infected children who participated in the Pediatric AIDS Clinical Trials Group P152 and P300 protocols, which predated the availability of effective combination antiretroviral therapy. The primary endpoints included time to progression to the first HIV-related disease endpoint (≥2 opportunistic infection, weight growth failure) or death, which constituted the progression-free survival. Analyses were performed for age>2 years and ≤2 years separately adjusting for race and treatment effect.

RESULTS

Of the 998 children evaluated, 139 experienced HIV disease progression. For children>2 years, rapid disease progression was associated with the DHCR7 G allele compared with the T allele (G/G vs. T/T: hazard ratio [HR]=5.0, P = 0.035; G/T vs. T/T: HR=4.5, P=0.042; G/G+G/T vs. T/T: HR=4.8, P=0.036) and the Bsm-I A allele compared with the G allele (A/G vs. G/G: HR=2.2, P=0.014 and A/G+A/A vs. G/G: HR=2.0, P=0.026). In children≤2 years, the Bsm-I A allele increased the risk of disease progression in Hispanics (A/A vs. G/A+G/G: HR=2.8, P=0.03 and A/A vs. G/G: HR=2.8, P=0.046) and whites (A/A vs. G/G: HR=6.6, P=0.025 and A/A vs. G/A+G/G: HR=3.6, P=0.038).

CONCLUSIONS

Vitamin D-related host genetic variants that alter the availability and activity of vitamin D are associated with risk of HIV disease progression in children and may vary by age and race.

Role of IL6, IL12B and VDR gene polymorphisms in Plasmodium vivax malaria severity, parasitemia and gametocytemia levels in an Amazonian Brazilian population

OBJECTIVE

To investigate the influence of IL6, IL12B and VDR single nucleotide polymorphisms (SNPs) in uncomplicated Plasmodium vivax infection symptoms intensity, parasitemia and gametocytemia levels in a Brazilian Amazonian population.

METHODS

A total of 167 malaria patients infected by P. vivax have parasitemia and gametocytemia levels estimated before treatment. Fourteen clinical symptoms were evaluated and included in a principal component analysis to derive a clinical symptom index. Patients were genotyped for IL6-174C>G, IL12B 735T>C, 458A>G, 159A>C, and VDR FokI, TaqI, BsmI SNPs by Taqman 5' nuclease assays. A General Linear Model analysis of covariance with age, gender, exposure period and infection history and genetic ancestry was performed to investigate the association of genotypes with parasitemia and gametocytemia levels and with a clinical symptom index.

RESULTS

Higher parasitemia levels were observed in IL6-174C carriers (p=0.02) whereas IL12B CGT haplotype carriers presented lower parasitemia levels (p=0.008). VDR TaqIC/BsmIA haplotype carriers showed higher gametocyte levels than non-carriers (p=0.013). Based on the clinical index values the IL6-174C>G polymorphism was associated with malaria severity. The IL6-174C carriers presented a more severe clinical index when compared to GG homozygotes (p=0.001).

CONCLUSION

The present study suggests that IL6, IL12 and VDR influence severity, parasitemia and gametocytemia clearance in P. vivax infections, and highlights their potential role in malaria immune response in an Amazonian population.

Association of vitamin D receptor BsmI gene polymorphism with risk of tuberculosis: a meta-analysis of 15 studies

Background

Genetic variations in vitamin D receptor (VDR) may contribute to tuberculosis (TB) risk. Many studies have investigated the association between VDR BsmI gene polymorphism and TB risk, but yielded inconclusive results.

Methodology/Principal Findings

We performed a comprehensive meta-analysis of 15 publications with a total of 2309 cases and 3568 controls. We assessed the strength of the association between VDR BsmI gene polymorphism and TB risk and performed sub-group analyses by ethnicity, sample size and Hardy–Weinberg equilibrium (HWE). We found a statistically significant correlation between VDR BsmI gene polymorphism and decreased TB risk in four comparison models: allele model (b vs. B: OR = 0.78, 95% CI = 0.67, 0.89; P_{heterogeneity} = 0.004), homozygote model (bb vs. BB: OR = 0.61, 95% CI = 0.43, 0.87; P_{heterogeneity} = 0.001), recessive model (bb vs. Bb+BB: OR = 0.70, 95% CI = 0.56, 0.88; P_{heterogeneity} = 0.005) and dominant model (bb+Bb vs. BB: OR = 0.77, 95% CI = 0.61, 0.97; P_{heterogeneity} = 0.010), especially in studies based on Asian population. Sub-group analyses also revealed that there was a statistically decreased TB risk in “small” studies (<500 participants) and studies with P_HWE>0.5. Meta-regression and stratification analysis both showed that the ethnicity and sample size contributed to heterogeneity.

Conclusions

This meta-analysis suggests that VDR BsmI gene polymorphism is associated with a significant decreased TB risk, especially in Asian population.

Genetic variations creating microRNA target sites in the FXN 3'-UTR affect frataxin expression in Friedreich ataxia

Friedreich's ataxia (FRDA) is a severe neurodegenerative disease caused by GAA repeat expansion within the first intron of the frataxin gene. It has been suggested that the repeat is responsible for the disease severity due to impaired transcription thereby reducing expression of the protein. However, genotype-phenotype correlation is imperfect, and the influence of other gene regions of the frataxin gene is unknown. We hypothesized that FRDA patients may harbor specific regulatory variants in the 3'-UTR. We sequenced the 3'-UTR region of the frataxin gene in a cohort of 57 FRDA individuals and 58 controls. Seven single nucleotide polymorphisms (SNPs) out of 19 were polymorphic in our case-control sample. These SNPs defined several haplotypes with one reaching 89% of homozygosity in patients versus 24% in controls. In another cohort of 47 FRDA Reunionese patients, 94% patients were found to be homozygous for this haplotype. We found that this FRDA 3'-UTR conferred a 1.2-fold decrease in the expression of a reporter gene versus the alternative haplotype configuration. We established that differential targeting by miRNA could account for this functional variability. We specifically demonstrated the involvement of miR-124 (i.e hsa-mir-124-3p) in the down-regulation of FRDA-3'-UTR. Our results suggest for the first time that post-transcriptional regulation of frataxin occurs through the 3'-UTR and involves miRNA targeting. We propose that the involvement of miRNAs in a FRDA-specific regulation of frataxin may provide a rationale to increase residual levels of frataxin through miRNA-inhibitory molecules.

Innate immune gene polymorphisms in tuberculosis

Tuberculosis (TB) is a leading cause worldwide of human mortality attributable to a single infectious agent. Recent studies targeting candidate genes and "case-control" association have revealed numerous polymorphisms implicated in host susceptibility to TB. Here, we review current progress in the understanding of causative polymorphisms in host innate immune genes associated with TB pathogenesis. We discuss genes encoding several types of proteins: macrophage receptors, such as the mannose receptor (MR, CD206), dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN, CD209), Dectin-1, Toll-like receptors (TLRs), complement receptor 3 (CR3, CD11b/CD18), nucleotide oligomerization domain 1 (NOD1) and NOD2, CD14, P2X7, and the vitamin D nuclear receptor (VDR); soluble C-type lectins, such as surfactant protein-A (SP-A), SP-D, and mannose-binding lectin (MBL); phagocyte cytokines, such as tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6, IL-10, IL-12, and IL-18; chemokines, such as IL-8, monocyte chemoattractant protein 1 (MCP-1), RANTES, and CXCL10; and other important innate immune molecules, such as inducible nitric oxide synthase (iNOS) and solute carrier protein 11A1 (SLC11A1). Polymorphisms in these genes have been variably associated with susceptibility to TB among different populations. This apparent variability is probably accounted for by evolutionary selection pressure as a result of long-term host-pathogen interactions in certain regions or populations and, in part, by lack of proper study design and limited knowledge of molecular and functional effects of the implicated genetic variants. Finally, we discuss genomic technologies that hold promise for resolving questions regarding the evolutionary paths of the human genome, functional effects of polymorphisms, and corollary impacts of adaptation on human health, ultimately leading to novel approaches to controlling TB.

Short communication: Plasma levels of vitamin D in HIV patients initiating antiretroviral therapy do not predict immune restoration disease associated with Mycobacterium tuberculosis

Immune restoration disease associated with Mycobacterium tuberculosis (TB IRD) is clinically important among HIV patients commencing antiretroviral therapy in countries where tuberculosis is endemic. Vitamin D affects dendritic cell and T cell function and the antimicrobial activity of monocytes. Plasma levels of vitamin D and polymorphisms in the vitamin D receptor may affect tuberculosis, and HIV infection associates with vitamin D deficiency. Here we assess whether plasma vitamin D levels may predict TB IRD. Samples were available from prospective studies of TB IRD in Cambodia (26 cases), India (19 cases), and South Africa (29 cases). IRD cases and controls from each site were similar in age and baseline CD4(+) T cell count. Plasma samples were assessed using 25(OH) vitamin D immunoassay plates. DNA samples were available from a subset of patients and were genotyped for the VDR FokI (F/f) [C/T, rs10735810] SNP. When data from each cohort were pooled to assess ethnic/geographic differences, 25(OH)D levels were higher in Cambodian than Indian or South African patients (p<0.0001) and higher in South African than Indian patients (p<0.0001). TB IRD was not associated with differences in levels of 25(OH)D in any cohort (p=0.36-0.82), irrespective of the patients' prior TB diagnoses/treatment. Carriage of the minor allele of VDR FokI (F/f) was marginally associated with TB IRD in Indian patients (p=0.06) with no association in Cambodians. Neither plasma levels of vitamin D nor the vitamin D allele will usefully predict TB IRD in diverse populations from TB endemic regions.

Adjudication of the alleged role of vitamin d in the antimicrobial pathway

Dynamic interactions between microorganism and host have evolved in such a way that while microbial pathogens are the cause of many human infections, a symbiotic relationship is also known to exist. Another important anomaly is that exposure to pathogenic organisms does not necessarily result in development of clinical disease. The latter conclusion infers that susceptibility to infectious disease can be modified by host-related factors. Arguably the two most prominent factors are genetic variability and immunologic status of the exposed individual. Because of the Human Genome and the HapMap projects, developments in genotyping technology have brought the possibility of identifying associations between specific genetic alterations and common diseases closer to reality. In addition, a growing body of evidence suggests vitamin D has an important contributory role in the antimicrobial pathway.

Vitamin D status and expression of vitamin D receptor and LL-37 in patients with spontaneous bacterial peritonitis

BACKGROUND

Vitamin D, which exerts its effect through vitamin D receptor (VDR), and LL-37, a vitamin D-dependent antimicrobial peptide, are involved in many infectious diseases.

AIM

The objective of this study was to evaluate whether vitamin D status and expressions of VDR and LL-37 are involved in the pathogenesis of spontaneous bacterial peritonitis (SBP).

METHODS

Serum and ascitic fluid 25-dihydroxyvitamin D [25(OH)D] concentrations and levels of VDR and LL-37 in peritoneal leukocytes were measured by ELISA and real-time PCR methods in cirrhotic patients with SBP (n = 19) and cirrhotic patients with simple ascites (n = 28). The correlations between these levels and clinical variables were evaluated.

RESULTS

Cirrhotic patients with ascites showed low vitamin D concentrations in both serum and ascitic fluid. Lower serum vitamin D concentrations were observed in cirrhotic patients with Child-Pugh C class. 25(OH)D concentrations in ascitic fluid were positive correlated with that in serum (r = 0.74, P < 0.001). The SBP group showed significantly higher levels of both VDR and LL-37 mRNA expressions in peritoneal leukocytes than the simple ascites group (P = 0.005 and P = 0.003, respectively). In the SBP group, VDR and LL-37 expressions in peritoneal leukocytes were positively correlated (r = 0.70, P = 0.001).

CONCLUSIONS

Vitamin D insufficiency was universal among cirrhotic patients with ascites, and the situation was more severe with more serious cirrhosis. Expressions of peritoneal leukocytes VDR and LL-37 genes were simultaneously up-regulated in cirrhotic patients with SBP when compared with cirrhotic patients with simple ascites. It is indicated that the vitamin D-VDR system and its downstream gene, LL-37, are involved in the pathogenesis and antibacterial immune response to SBP.

Prostate cancer susceptibility Loci identified on chromosome 12 in African Americans

Prostate cancer (PCa) is a complex disease that disproportionately affects African Americans and other individuals of African descent. A number of regions across the genome have been associated to PCa, most of them with moderate effects. A few studies have reported chromosomal changes on 12p and 12q that occur during the onset and development of PCa but to date no consistent association of the disease with chromosome 12 polymorphic variation has been identified. In order to unravel genetic risk factors that underlie PCa health disparities we investigated chromosome 12 using ancestry informative markers (AIMs), which allow us to distinguish genomic regions of European or West African origin, and tested them for association with PCa. Additional SNPs were genotyped in those areas where significant signals of association were detected. The strongest signal was discovered at the SNP rs12827748, located upstream of the PAWR gene, a tumor suppressor, which is amply expressed in the prostate. The most frequent allele in Europeans was the risk allele among African Americans. We also examined vitamin D related genes, VDR and CYP27B1, and found a significant association of PCa with the TaqI polymorphism (rs731236) in the former. Although our results warrant further investigation we have uncovered a genetic susceptibility factor for PCa in a likely candidate by means of an approach that takes advantage of the differential contribution of parental groups to an admixed population.