Frequency of hypovitaminosis D and its associated risk factors in newly diagnosed pulmonary tuberculosis patients

Hypovitaminosis D among newly diagnosed pulmonary TB patients and their household contacts in Uganda

An estimated one billion people globally live with hypovitaminosis D. Studies have indicated that vitamin D deficiency is a risk factor for active tuberculosis (TB) disease. The aim of this study was to determine the association between vitamin D deficiency and TB status among patients with active TB, latent TB infection (LTBI) and those without TB infection. In a cross-sectional study of active TB patients, LTBI, QuantiFERON GOLD testpositive and (QFN+TST+) household contact and controls QuantiFERON GOLD testnegative (QFN-TST-) samples vitamin D levels were compared. Vitamin D status was determined by measurement of total vitamin D levels with 56 samples of active TB patients, 17 with LTBI, and 22 without TB infection using electrochemiluminescence. The median interquartile range (IQR) age of the study participants was 28 (20-35) years, and the majority (63%) were females. The median (IQR) vitamin D levels were 18 ng/ml (14-24). All groups had vitamin D hypovitaminosis with significantly lower levels among active TB patients (17 ng/ml, 13, 2) than among LTBI individuals (23 ng/ml 16-29) and those without TB infection (22 ng/ml, 17-28).

Uptake of Vitamins D2, D3, D4, D5, D6, and D7 Solubilized in Mixed Micelles by Human Intestinal Cells, Caco-2, an Enhancing Effect of Lysophosphatidylcholine on the Cellular Uptake, and Estimation of Vitamins D' Biological Activities

Vitamins D have various biological activities, as well as intestinal calcium absorption. There has been recent concern about insufficient vitamin D intake. In addition to vitamins D₂ and D₃, there are lesser-known vitamins D₄–D₇. We synthesized vitamins D₅–D₇, which are not commercially available, and then evaluated and compared the mixed micelles-solubilized vitamins D uptake by Caco-2 cells. Except for vitamin D₅, the uptake amounts of vitamins D₄–D₇ by differentiated Caco-2 cells were similar to those of vitamins D₂ and D₃. The facilitative diffusion rate in the ezetimibe inhibited pathway was approximately 20% for each vitamin D type, suggesting that they would pass through the pathway at a similar rate. Lysophosphatidylcholine enhanced each vitamin D uptake by approximately 2.5-fold. Lysophosphatidylcholine showed an enhancing effect on vitamin D uptake by reducing the intercellular barrier formation of Caco-2 cells by reducing cellular cholesterol, suggesting that increasing the uptakes of vitamins D and/or co-ingesting them with lysophosphatidylcholine, would improve vitamin D insufficiency. The various biological activities in the activated form of vitamins D₄–D₇ were estimated by Prediction of Activity Spectra for Substances (PASS) online simulation. These may have some biological activities, supporting the potential as nutritional components.

Vitamin D and the promoter methylation of its metabolic pathway genes in association with the risk and prognosis of tuberculosis

Background

A variety of abnormalities in vitamin D metabolism have been reported in patients with active tuberculosis. However, intervention trials have produced inconsistent results. We hypothesized that genetic and epigenetic changes in the key genes of the vitamin D metabolic pathway may partly explain the differences between studies.

Methods

We performed a case-control study followed by a prospective cohort study. We recruited 122 patients with pulmonary tuberculosis and 118 healthy controls. The serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels were measured. The methylation of the promoter regions of key genes in the vitamin D metabolic pathway (CYP24A1, CYP27A1, CYP27B1, CYP2R1, and VDR) was detected using the Illumina MiSeq platform. The specific methylation profiles were examined as epigenetic biomarkers. The sensitivity, specificity, and receiver operating characteristic (ROC) curves were used to estimate the predictive value of the biomarkers.

Results

The baseline serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations in the cases were significantly lower than those in the controls (51.60 ± 27.25 nmol/L vs. 117.50 ± 75.50 nmol/L, Z = − 8.515, P < 0.001; 82.63 ± 51.43 pmol/L vs. 94.02 ± 49.26 pmol/L, Z = − 2.165, P = 0.03). We sequenced 310 CpG sites in five candidate genes. After Bonferroni correction, there were 55 differentially methylated CpG sites between cases and controls; 41.5% were in the CYP27B1 gene, 31.7% were in the CYP24A1 gene, 14.7% were in the VDR gene, and 12.3% were in the CYP27A1 gene. When we designated the CpG sites that remained significant after the Bonferroni correction as the biomarkers, the area under the curve (AUC) for the cumulative methylation was 0.810 (95% CI 0.754–0.866). There was an interaction between CYP27A1 methylation level and 1,25-dihydroxyvitamin D concentration associated with the risk of TB (OR_interaction = 4.11, 95% CI 1.26–13.36, P = 0.019). The serum 1,25-dihydroxyvitamin D concentration at the end of the intensive treatment stage was related to a patient’s prognosis (P = 0.008). There were 23 CpG sites that were individually related to the treatment outcomes, but the relationships were not significant after the Bonferroni correction.

Conclusion

Both serum vitamin D concentrations and the methylation levels of key genes in the vitamin D metabolic pathway are related to the risk and prognosis of tuberculosis.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0552-6) contains supplementary material, which is available to authorized users.

Mycobacterium tuberculosis: An Adaptable Pathogen Associated With Multiple Human Diseases

Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), is an extremely successful pathogen that adapts to survive within the host. During the latency phase of infection, M. tuberculosis employs a range of effector proteins to be cloud the host immune system and shapes its lifestyle to reside in granulomas, sophisticated, and organized structures of immune cells that are established by the host in response to persistent infection. While normally being restrained in immunocompetent hosts, M. tuberculosis within granulomas can cause the recrudescence of TB when host immunity is compromised. Aside from causing TB, accumulating evidence suggests that M. tuberculosis is also associated with multiple other human diseases, such as pulmonary complications, autoimmune diseases, and metabolic syndromes. Furthermore, it has been recently appreciated that M. tuberculosis infection can also reciprocally interact with the human microbiome, which has a strong link to immune balance and health. In this review, we highlight the adaptive survival of M. tuberculosis within the host and provide an overview for regulatory mechanisms underlying interactions between M. tuberculosis infection and multiple important human diseases. A better understanding of how M. tuberculosis regulates the host immune system to cause TB and reciprocally regulates other human diseases is critical for developing rational treatments to better control TB and help alleviate its associated comorbidities.

Serum Vitamin D Level as a Risk Factor for Female Genital Tuberculosis (FGTB)

Introduction

Vitamin D is now known to be essential to Mycobacterium tuberculosis containment and killing through activation of 25-hydroxyvitamin-D receptors (VDRs) present on all immune cells or obtained from dietary food stuffs as either vitamin D3 or vegetable vitamin D2 (also known as ergocalciferol).

Aim

To evaluate the association of serum vitamin D level between the Female Genital Tuberculosis (FGTB) cases and healthy controls.

Materials and Methods

Total 120 cases and 120 controls enrolled for the study following inclusion and exclusion criteria. Detailed clinical history was taken from each subjects. Total of 3 ml of the blood was collected in EDTA vial from each subject (case and control). Quantification of serum vitamin D level was measured by active human vitamin D ELISA kit using an ELISA reader. Statistical analysis was done using Statistical Package for Social Science (SPSS) version 21.0. A p-value <0.05 was considered as significant.

Results

A total of 120 confirmed FGTB cases and 120 healthy control enrolled for study. Out of 120 women 97.5%, 10.0%, 3.3%, 3.3% were detected positive for M. tuberculosis respectively. Comparing the mean demographic value of age and BMI were (29.03±3.127, 28.03±3.00) and (22.92±3.33, 24.15±3.97) respectively with the p=0.012* and p=0.010* found to be significant among cases and controls. The mean serum vitamin D level was 14.96±8.81 in cases and 23.00±8.83 in controls with p-value<0.001. There was a significant positive association found in low serum vitamin D level among FGTB cases than controls.

Conclusion

Vitamin D is important for normal immune cell function, as well as regression of FGTB disease. FGTB may be controlled by regulating the serum vitamin D level concentration. This study suggests that, vitamin D deficiency and BMI is strongly associated with the progression of active FGTB disease which alters the expression of antimicrobial peptide and lead to the persistence of TB infection. Therefore, serum vitamin D level may play an important role in treatment of FGTB.