Low Vitamin-D Levels Combined with PKP3-SIGIRR-TMEM16J Host Variants Is Associated with Tuberculosis and Death in HIV-Infected and -Exposed Infants

Predictors of TB disease in HIV-exposed children from Southern Africa

BACKGROUND: P1041 was a randomised, placebo-controlled isoniazid prophylaxis trial in South Africa. We studied predictors for TB in HIV-exposed children participating in the P1041 trial.METHODS: We included data from entry until Week 108. Predictors considered were type of housing, overcrowding, age, sex, ethnicity, tobacco exposure, weight-for-age percentile Z-score (WAZ), CD4%, viral load (VL), antiretroviral therapy (ART) and number of household smokers.RESULTS: Of 543 HIV-positive (HIV+) and 808 HIV-exposed uninfected (HEU) infants at entry, median age was 96 days (interquartile range: 92-105). Of 1,351 caregivers, 125 (9%) had a smoking history, and 62/1,351 reported current smoking. In 594/1,351 (44%) households, there was at least one smoker. Smoking caregivers consumed 1-5 cigarettes daily. In the HIV+ cohort, significant baseline TB predictors after adjusting covariates were as follows: WAZ (adjusted hazard ratio [aHR] 0.76, P = 0.002) and log10 HIV RNA copies/ml (aHR 1.50, P = 0.009). Higher CD4% (aHR 0.88, P = 0.002) and ART (aHR 0.50, P = 0.006) were protective. In the HEU cohort, smoking exposure was associated with reduced TB-free survival on univariate analysis, but not after adjustment in the multivariate model.CONCLUSION: Low WAZ and high VL were strong predictors of TB disease or death. Rising CD4 percentage and being on ART were protective in the HIV+ cohort.

A TMEM16J variant leads to dysregulated cytosolic calcium which may lead to renal disease

SIGIRR (single immunoglobulin IL-1 related receptor), PKP3 (plakophilin 3), and TMEM16J (anoctamin 9), a putative calcium-activated ion channel and phospholipid scramblase, control the immune response and the extent of inflammation. Variants of SIGIRR/PKP3/TMEM16J lead to severe inflammatory diseases such as pneumonia, enterocolitis, and kidney graft rejection. Meta-analysis of genome-wide association studies identified TMEM16J-T604A as a promotor for chronic kidney disease (CKD), but the disease mechanism and function of TMEM16J remain unknown. Here, we demonstrate TMEM16J as a calcium-activated calcium-permeable channel, which is expressed in the endoplasmic reticulum (ER). TMEM16J controls the intracellular distribution of calcium, and inhibits intracellular receptor-mediated Ca²⁺ signals and Ca²⁺ -dependent activation of ion channels, but augments transcription and release of pro-inflammatory cytokines. Renal epithelial cells expressing the variant TMEM16J-T604A show enhanced calcium signals when compared to cells expressing wt-TMEM16J, and demonstrate spontaneous transcription and release of cytokines. This study identifies TMEM16J as an important regulator of intracellular Ca²⁺ signals, ion channel activity, and cytokine release. TMEM16J may therefore affect immune response in renal tissue and immune cells.

Vitamin D and tuberculosis in children: a role in the prevention or treatment of the disease?

Despite the growing number of published studies, the role of vitamin D in the prevention or treatment of tuberculosis remains unclear. In this review we analyze current scientific literature to provide evidence about the relationship between vitamin D and TB, with a special focus on the pediatric population. While in vitro studies have shown relevant antimycobacterial immune-stimulatory and immunosuppressive effects of vitamin D, this has not panned out in vivo with active TB. On the contrary, there is some evidence that this tool could work as prevention - both against TB infection as well as progression from latent to active infection. However, only a few studies have evaluated this correlation in children. The potential link between tuberculosis and vitamin D levels is promising. If effective, vitamin D supplementation of at-risk populations would be an affordable public health intervention, particularly in light of the worldwide increase in identified TB cases and drug-resistance. Vitamin D might represent a new, affordable, safe and easy to access drug for the prevention and treatment of TB. For stronger evidence, considering the features of infection (relative low incidence of reactivation of latent infection in immunocompetent patients) we need clinical trials with large numbers of participants conducted in endemic regions with a prolonged follow-up time.

Exploring the value of Mycobacterium tuberculosis modified lipoprotein as a potential biomarker for TB detection in children

Background

Current TB diagnostic methods available have been developed for adults and development efforts have neglected the differences in disease and sampling that occur between adults and children. Diagnostic challenges are even greater in HIV co-infected children and infants.

Methods and results

We established a sandwich ELISA assay to detect Mycobacterium tuberculosis modified lipoprotein (TLP) ex vivo in plasma. The study population contains plasma samples from 21 patients with active TB and 24 control samples with no TB, collected in the International Maternal Pediatric Adolescent AIDS Clinical Trails (IMPAACT) P1041 study. Retrospective analysis was performed and the results demonstrate that the median plasma levels of TLP in control subjects are 2.7 fold higher than the median plasma values in active TB subjects (p < 0.001).

Conclusions

Plasma levels of TLP are elevated with active TB disease in HIV positive subjects and deserves further exploration as an indicator for TB detection in children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07140-9.

Polymorphism of genes associated with infectious lung diseases in Northern Asian populations and in patients with community-acquired pneumonia

The innate immune system is the first to respond to invading pathogens. It is responsible for invader recognition, immune-cell recruitment, adaptive-immunity activation, and regulation of inflammation intensity. Previously, two single-nucleotide polymorphisms of innate-immunity genes – rs5743708 (Arg753Gln) of the TLR2 gene and rs8177374 (Ser180Leu) of the TIRAP gene – have been shown to be associated with both pneumonia and tuberculosis in humans, but the data are contradictory among different ethnic groups. It has also been reported that rs10902158 at the PKP3-SIGGIR-TMEM16J genetic locus belongs to a haplotype race-specifically associated with tuberculosis. Meanwhile, a gradient of its frequency is observed in Asia. The aim of this work was to assess the effect of selection for the genotypes of the above-mentioned SNPs on the gene pools of populations living in harsh climatic conditions that contribute to the development of infectious lung diseases. We estimated the prevalence of these variants in white and Asian (Chukchis and Yakuts) population samples from Northern Asia and among patients with community-acquired pneumonia (CAP). Carriage of the rs5743708 A allele was found to predispose to severe CAP (odds ratio 2.77, p = 0.021), whereas the GG/CT genotype of rs5743708/rs8177374 proved to be protective against it (odds ratio 0.478, p = 0.022) in white patients. No association of rs10902158 with CAP (total or severe) was found among whites. Stratification of CAP by causative pathogen may help eliminate the current discrepancies between different studies. No significant difference in rs5743708 or rs8177374 was found between adolescent and long-lived white samples. Carriage of the alleles studied is probably not associated with predisposition to longevity among whites in Siberia. Both white and Asian populations studied were different from Western European and East Asian populations in the variants’ prevalence. The frequency of the rs8177374 T (Ser180Leu) variant was significantly higher in the Chukchi sample (p = 0, χ2 = 63.22) relative to the East Asian populations. This result may confirm the hypothesis about the selection of this allele in the course of human migration into areas with unfavorable climatic conditions.

A double burden of tuberculosis and diabetes mellitus and the possible role of vitamin D deficiency

Tuberculosis remains a major global health challenge, particularly in low-to-middle income countries such as China. At the same time, the country is facing a rapidly increasing diabetes incidence over the last 10 years. Diabetes aggravates the tuberculosis epidemic which poses a serious challenge in public health. In recent years, the high prevalence of vitamin D deficiency represents a global health problem, which is also associated with the risk of diabetes, and tuberculosis. Therefore, this review aims to provide an overall and updated understanding of the epidemiology of co-occurrence of tuberculosis and diabetes in China, and to elucidate the possible role of vitamin D deficiency. In conclusion, significant aggravation of the tuberculosis epidemic due to diabetes may exist in China for a relatively long period of time to come. Further, the double burden and its implications to public health in this country may be significantly influenced by the high prevalence of vitamin D deficiency. Bidirectional screening for tuberculosis and diabetes is recommended, and extra vitamin D may benefit especially in a situation of a heavy tuberculosis burden combined with prevalent vitamin D deficiency. Longitudinal studies to verify the role of vitamin D deficiency in the double burden, and trials on the effect of vitamin D supplementation are needed in the future.

Vitamin D status and risk of incident tuberculosis disease: A nested case-control study, systematic review, and individual-participant data meta-analysis

BACKGROUND

Few studies have evaluated the association between preexisting vitamin D deficiency and incident tuberculosis (TB). We assessed the impact of baseline vitamins D levels on TB disease risk.

METHODS AND FINDINGS

We assessed the association between baseline vitamin D and incident TB in a prospective cohort of 6,751 HIV-negative household contacts of TB patients enrolled between September 1, 2009, and August 29, 2012, in Lima, Peru. We screened for TB disease at 2, 6, and 12 months after enrollment. We defined cases as household contacts who developed TB disease at least 15 days after enrollment of the index patient. For each case, we randomly selected four controls from among contacts who did not develop TB disease, matching on gender and year of age. We also conducted a one-stage individual-participant data (IPD) meta-analysis searching PubMed and Embase to identify prospective studies of vitamin D and TB disease until June 8, 2019. We included studies that assessed vitamin D before TB diagnosis. In the primary analysis, we defined vitamin D deficiency as 25-(OH)D < 50 nmol/L, insufficiency as 50-75 nmol/L, and sufficiency as >75nmol/L. We estimated the association between baseline vitamin D status and incident TB using conditional logistic regression in the Lima cohort and generalized linear mixed models in the meta-analysis. We further defined severe vitamin D deficiency as 25-(OH)D < 25 nmol/L and performed stratified analyses by HIV status in the IPD meta-analysis. In the Lima cohort, we analyzed 180 cases and 709 matched controls. The adjusted odds ratio (aOR) for TB risk among participants with baseline vitamin D deficiency compared to sufficient vitamin D was 1.63 (95% CI 0.75-3.52; p = 0.22). We included seven published studies in the meta-analysis and analyzed 3,544 participants. In the pooled analysis, the aOR was 1.48 (95% CI 1.04-2.10; p = 0.03). The aOR for severe vitamin D deficiency was 2.05 (95% CI 0.87-4.87; p trend for decreasing 25-(OH)D levels from sufficient vitamin D to severe deficiency = 0.02). Among 1,576 HIV-positive patients, vitamin D deficiency conferred a 2-fold (aOR 2.18, 95% CI 1.22-3.90; p = 0.01) increased risk of TB, and the aOR for severe vitamin D deficiency compared to sufficient vitamin D was 4.28 (95% CI 0.85-21.45; p = 0.08). Our Lima cohort study is limited by the short duration of follow-up, and the IPD meta-analysis is limited by the number of possible confounding covariates available across all studies.

CONCLUSION

Our findings suggest vitamin D predicts TB disease risk in a dose-dependent manner and that the risk of TB disease is highest among HIV-positive individuals with severe vitamin D deficiency. Randomized control trials are needed to evaluate the possible role of vitamin D supplementation on reducing TB disease risk.

Micronutrient levels of tuberculosis patients during the intensive phase, a prospective cohort study

INTRODUCTION

The objectives of this study were to estimate the micronutrient deficiency levels of tuberculosis patients at the start and end of the intensive phase, and to identify the predictors of micronutrient deficiencies in tuberculosis patients.

METHODS

A prospective cohort study design was implemented. The sample size was calculated using Epi-info software. Systematic sampling technique was used. Descriptive statistics were used to estimate the micronutrient levels. The general linear model was used to predict the determinants of micronutrient level.

RESULTS

At the start of DOTS (directly observed treatment strategy), 64% of tuberculosis patients had a serum iron level less than 60 μg/dl, 41.9% of tuberculosis patients had serum zinc level less than 52 μg/dl, 29.7% of tuberculosis patients had serum selenium level less than 70 ng/dl, 40.5% of tuberculosis patients had serum vitamin d level less than 20 ng/ml, and 60.4% of tuberculosis patients had urine iodine level of less than 60.4 μg/dl. At the end of the intensive phase, 16.7% of tuberculosis patients had a serum iron level less than 60 μg/dl, <1% of tuberculosis patients had serum zinc level less than 52 μg/dl, <1% of tuberculosis patients had serum selenium level less than 70 ng/dl, 20.4% of tuberculosis patients had serum vitamin d level less than 20 ng/ml, and 53% of tuberculosis patients had urine iodine level of less than 60.4 μg/dl. Serum iron level was affected by HIV infection, hookworm infection, and site of tuberculosis infection: serum vitamin d level was affected by HIV infection: and alcohol dependency affected the serum zinc level of tuberculosis patients during the course of tuberculosis treatments.

CONCLUSION

Antituberculosis drugs were effective in normalizing the serum zinc and selenium level, but the serum level of iron, vitamin d and iodine were not normalized by the anti-tuberculosis drugs.

Tuberculosis susceptibility and protection in children

Children represent both a clinically important population susceptible to tuberculosis and a key group in whom to study intrinsic and vaccine-induced mechanisms of protection. After exposure to Mycobacterium tuberculosis, children aged under 5 years are at high risk of progressing first to tuberculosis infection, then to tuberculosis disease and possibly disseminated forms of tuberculosis, with accompanying high risks of morbidity and mortality. Children aged 5-10 years are somewhat protected, until risk increases again in adolescence. Furthermore, neonatal BCG programmes show the clearest proven benefit of vaccination against tuberculosis. Case-control comparisons from key cohorts, which recruited more than 15 000 children and adolescents in total, have identified that the ratio of monocytes to lymphocytes, activated CD4 T cell count, and a blood RNA signature could be correlates of risk for developing tuberculosis. Further studies of protected and susceptible populations are necessary to guide development of novel tuberculosis vaccines that could facilitate the achievement of WHO's goal to eliminate deaths from tuberculosis in childhood.

The association between vitamin D status and tuberculosis in children: A meta-analysis

BACKGROUND

Vitamin D deficiency (VDD) has been implicated in the pathogenesis of tuberculosis (TB), but most studies have not reported a significant association. We conducted a meta-analysis to explore the association between vitamin D status and TB in children.

METHODS

Web of Science, Ovid Medline, and EMBASE were searched for studies in English that discussed vitamin D status and TB in children before January 22, 2018.

RESULTS

From the 585 initially identified studies, we selected those that addressed an association between vitamin D status and TB according to our preselected inclusion criteria. Our meta-analysis included 10 studies. According to the random effects model, TB was significantly associated with VDD (ORs, 1.70; 95% CI, 1.20-2.42; P < .05) in children. Vitamin D levels were significantly lower in TB patients than in controls, with a mean difference d = -5.49 nmol/L (95% CI, -10.42 to -0.55; P < .05), indicating that VDD was significantly associated with TB (OR, 1.78; 95% CI, 1.30-2.44; P < .05) in children.

CONCLUSION

This study suggests that vitamin D levels are significantly lower in children with TB/latent TB infection than in controls. TB may contribute to VDD in children. Therefore, VDD may be associated with TB in children.

Malnutrition: Modulator of Immune Responses in Tuberculosis

Nutrition plays a major role in the management of both acute and chronic diseases, in terms of body’s response to the pathogenic organism. An array of nutrients like macro- and micro-nutrients, vitamins, etc., are associated with boosting the host’s immune responses against intracellular pathogens including mycobacterium tuberculosis (M.tb). These nutrients have an immunomodulatory effects in controlling the infection and inflammation process and nutritional deficiency of any form, i.e., malnutrition may lead to nutritionally acquired immunodeficiency syndrome, which greatly increases an individual’s susceptibility to progression of infection to disease. This narrative review looks at the various mechanisms by which nutrition or its deficiency leads to impaired cell mediated and humoral immune responses, which in turn affects the ability of an individual to fight M.tb infection or disease. There is very little evidence in the literature that any specific food on its own or a specific quantity can alter the course of TB disease or be effective in the treatment of malnutrition. Further clinical trials or studies will be needed to recommend and to better understand the link between malnutrition, tuberculosis, and impaired immunity.

Vitamin D deficiency associates with susceptibility to tuberculosis in Pakistan, but polymorphisms in VDR, DBP and CYP2R1 do not

Background

Single nucleotide polymorphisms (SNPs) in the genes encoding the vitamin D receptor (VDR) and the vitamin D binding protein (DBP) have been reported to modify the influence of vitamin D deficiency on susceptibility to active tuberculosis (TB) in the UK, but this phenomenon has not been investigated in settings with a high TB burden. SNPs in CYP2R1, which encodes a vitamin D 25-hydroxylase enzyme, are known to influence vitamin D status, but their potential role in determining susceptibility to TB has not previously been investigated in any setting.

Method

We conducted a case–control study in 260 pulmonary TB patients and 112 controls recruited in Lahore, Pakistan. Analyses were conducted to test for main effects of vitamin D status and SNPs in VDR (rs731236, rs2228570 and rs1544410), DBP (rs7041 and rs4588) and CYP2R1 (rs2060793, rs10500804 and rs10766197) on susceptibility to TB, and to investigate whether these SNPs modify the association between vitamin D status and disease susceptibility.

Results

Profound vitamin D deficiency (serum 25-hydroxyvitamin D concentration ≤ 20 nmol/L) was common among TB patients (118/260, 45 %), and was independently associated with susceptibility to TB (adjusted odds ratio 1.87, 95 % CI 1.15 to 3.04, P = 0.01). However, none of the SNPs investigated associated with susceptibility to TB, either in main effects analysis, or in interaction with vitamin D status.

Conclusion

Profound vitamin D deficiency was common among TB patients in this high-burden setting, and was independently associated with disease susceptibility. However, no statistically significant associations between SNPs in the vitamin D pathway and disease susceptibility was demonstrated.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0240-2) contains supplementary material, which is available to authorized users.