Impact of vitamin D status and cathelicidin antimicrobial peptide on adults with active pulmonary TB globally: A systematic review and meta-analysis

Reduced expression of central innate defense molecules in pancreatic biopsies from subjects with Type 1 diabetes

AIMS/HYPOTHESIS

Defensins play a crucial role in the innate immune system's first defense against microbial threats. However, little is known about the defensin system in the pancreas, especially in relation to Type 1 diabetes. We explore the expression of defensins in different disease stages of Type 1 diabetes and correlated obtained findings to the degree of inflammation, providing new insights into the disease and the innate immune system.

MATERIAL AND METHODS

Pancreases from non-diabetic human organ donors of different age groups and donors with Type 1 diabetes with different disease duration were examined. Sections from head, body and tail of the pancreas were stained for eight different defensins and for immune cells; CD3+, CD45+, CD68+ and NES+ (granulocytes).

RESULTS

In non-diabetic adult controls the level of expression for defensins Beta-1,Alpha-1, Cathelicidin and REG3A correlated with the level of inflammation. In contrast, individuals with Type  1 diabetes exhibit a reduction or absence of several central defensins regardless of the level of inflammation in their pancreas. The expression of Cathelicidin is present in neutrophils and macrophages but not in T-cells in subjects with Type 1 diabetes.

CONCLUSIONS

Obtained findings suggest a pancreatic dysfunction in the innate immune system and the bridging to the adaptive system in Type 1 diabetes. Further studies on the role of the local innate immune system in Type 1 diabetes is needed.

The interaction between gut microbiome and bone health

PURPOSE OF REVIEW

This review critically examines interconnected health domains like gut microbiome, bone health, interleukins, chronic periodontitis, and coronavirus disease 2019 (COVID-19), offering insights into fundamental mechanisms and clinical implications, contributing significantly to healthcare and biomedical research.

RECENT FINDINGS

This review explores the relationship between gut microbiome and bone health, a growing area of study. It provides insights into skeletal integrity and potential therapeutic avenues. The review also examines interleukins, chronic periodontitis, and COVID-19, highlighting the complexity of viral susceptibility and immune responses. It highlights the importance of understanding genetic predispositions and immune dynamics in the context of disease outcomes. The review emphasizes experimental evidence and therapeutic strategies, aligning with evidence-based medicine and personalized interventions. This approach offers actionable insights for healthcare practitioners and researchers, paving the way for targeted therapeutic approaches and improved patient outcomes.

SUMMARY

The implications of these findings for clinical practice and research underscore the importance of a multidisciplinary approach to healthcare that considers the complex interactions between genetics, immune responses, oral health, and systemic diseases. By leveraging advances in biomedical research, clinicians can optimize patient care and improve health outcomes across diverse patient populations.

Association of circulating serum free bioavailable and total vitamin D with cathelicidin levels among active TB patients and household contacts

The free hormone hypothesis postulates that the estimation of free circulating 25 (OH)D may be a better marker of vitamin D status and is of clinical importance compared to total vitamin D fraction. The unbound fraction is involved in biological activities since it is able to penetrate into the cell. Studies have shown that cathelicidin/LL-37 inhibits the growth of Mycobacterium tuberculosis in a vitamin D-dependent manner and therefore adequate vitamin D is required for its expression. The study aimed to determine the association between serum bioavailable and total vitamin D with LL-37 levels in ATB patients, LTBI, and individuals with no TB infection. This was a cross-sectional study in which bioavailable vitamin D and LL-37 levels were measured using competitive ELISA kits and total vitamin D was measured using electrochemilumiscence and consequently determined their association. The mean (SD) bioavailable vitamin D levels of the study participants were 3.8 ng/mL (2.6) and the median (IQR) of LL-37 levels were 320 ng/mL (160, 550 ng/mL). The mean (SD) of total vitamin D levels was 19.0 ng/mL (8.3) ng/mL. Similar weak correlations were observed between the bioavailable and total vitamin D with LL-37 levels, therefore, deviating from our hypothesis.

Evaluation of circulating serum cathelicidin levels as a potential biomarker to discriminate between active and latent tuberculosis in Uganda

Background

Tuberculosis remains a major public health problem worldwide accounting for 1.4 million deaths annually. LL-37 is an effector molecule involved in immunity with both antimicrobial and immunomodulatory properties. The purpose of this study was to compare LL-37 circulatory levels among participants with active and latent tuberculosis and to determine its ability to discriminate between the two infectious states.

Methods

A cross-sectional study was performed among 56 active tuberculosis patients, 49 latent tuberculosis individuals, and 43 individuals without tuberculosis infection. The enzyme-linked immunosorbent assay was used to assess LL-37 levels. Data analysis was performed using STATA software and Graph pad Prism version 8. Mann-Whitney U test was used for correlation between variables with two categories and the Kruskal-Wallis test for three or more categories.

Results

The study had more female participants than males, with similar median ages across the three groups, 29.5, 25.0, and 23.0 years respectively. Active tuberculosis patients had significantly higher LL-37 levels compared to those with latent tuberculosis and without tuberculosis. The median/interquartile ranges were 318.8 ng/ml (157.9–547.1), 242.2 ng/ml (136.2–579.3), 170.9 ng/ml (129.3–228.3); p = 0.002 respectively. Higher LL-37 was found in the male participant with median/interquartile range, 424.8 ng/ml (226.2–666.8) compared to the females 237.7 ng/ml (129.6–466.6); p = 0.045. LL-37 had better discriminatory potential between active tuberculosis and no tuberculosis (AUC = 0.71, sensitivity 71.4% specificity = 69.8%) than with latent tuberculosis (AUC = 0.55, sensitivity = 71.4%, specificity = 44.9%). There was moderate differentiation between latent tuberculosis and no tuberculosis (AUC = 0.63, sensitivity = 44.9% specificity = 90.7%).

Conclusion

Significantly higher LL-37 levels were observed among active tuberculosis patients than those without tuberculosis infection and were, therefore able to discriminate between active tuberculosis and other tuberculosis infectious states, especially with no tuberculosis. Further assessment of this biomarker as a screening tool to exclude tuberculosis is required.

An Association Between Serum Vitamin D Levels and Serum Cathelicidin Antimicrobial Peptide (CAMP) Levels Among Tuberculosis Patients in Comparison with Control Subjects

Objectives:

The objective of this study is to compare the serum vitamin D and serum cathelicidin antimicrobial peptide (CAMP) levels among tuberculosis patients and healthy subjects and to determine the association between serum vitamin D and cathelicidin in tuberculosis.

Materials and Methods:

This is a case-control study carried out at the pulmonary medicine and pediatrics departments of a tertiary care hospital in Chengalpattu. The study included 180 tuberculosis cases and 90 control subjects of both sexes between the age group of 1 to 80 years. Serum was used to estimate vitamin D and CAMP. The study was analyzed using SPSS version 21 (IBM Corp. Armonk, New York). The results were evaluated using the chi-square test at a 95% confidence interval, and P value <.05 was considered highly significant.

Results:

This study observed vitamin D deficiency, vitamin D insufficiency, and optimum vitamin D among 55%, 41%, and 3.89% tuberculosis cases, respectively. Similarly, vitamin D deficiency, vitamin D insufficiency, and optimum vitamin D were seen in 40%, 50%, and 10% healthy controls, respectively.

Conclusion:

This study found no association between serum vitamin D and serum CAMP levels in tuberculosis patients and healthy controls.

25-Hydroxyvitamin D potentializes extracellular cathelicidin release from human PBMC stimulated ex vivo with either bacterial (LPS) or viral (P: IC) mimetics

Human cathelicidin refers to the cationic antimicrobial peptide hCAP18/LL-37. LL-37 is formed by cleavage of the propeptide hCAP18 coded by the CAMP gene. The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)D), has been shown to induce the CAMP gene expression through promoter activation. We previously failed to demonstrate in a clinical trial that supplementation of 25-hydroxyvitamin D (25(OH)D) improves LL-37 serum levels. The aim of this work was to evaluate the impact of 25(OH)D supplementation on intracellular expression of CAMP and secretion of LL-37 in an ex vivo model using the peripheral blood mononuclear cells (PBMC). PBMC collected from healthy donors and incubated with different concentrations of 25(OH)D (0 ng/ml: control (D0); 25 ng/ml: deficient (D25); 75 ng/ml: physiological (D75); 125 ng/ml: supraphysiological (D125)) were stimulated or not with lipopolysaccharide (LPS, 100 ng/ml) or synthetic double-stranded RNA Poly (I: C) (PIC, 10 µg/ml). The intracellular expressions of the CAMP gene and the hCAP18 peptide were measured respectively after 24-h and 48-h incubation periods. The concentration of LL-37 was determined in the culture medium after 48-h incubation. 25(OH)D significantly induced CAMP gene expression at 24 h with a maximum effect at a dose of D125 in either unstimulated (tenfold expression) or stimulated (LPS: 100-fold expression; PIC: 15-fold expression) conditions. Intracellular hCAP18 peptide was overexpressed at 48 h under unstimulated (1.5-fold, D125) and stimulated conditions, LPS (twofold, D125) and PIC (2.5-fold, D125). The secretion of LL-37 in the culture medium was significantly induced by 25(OH)D only in both stimulated (LPS and PIC) conditions in a dose-dependent manner. Our results demonstrate that 25(OH)D incubation increases intracellular expression of CAMP and hCAP18, but extracellular secretion of LL-37 antimicrobial peptide is increased by 25(OH)D only when PBMC from healthy donors were stimulated with bacterial or viral immune mimetic.

Benefits and Implications of Resveratrol Supplementation on Microbiota Modulations: A Systematic Review of the Literature

Resveratrol is a polyphenol that has been shown to possess many applications in different fields of medicine. This systematic review has drawn attention to the axis between resveratrol and human microbiota, which plays a key role in maintaining an adequate immune response that can lead to different diseases when compromised. Resveratrol can also be an asset in new technologies, such as gene therapy. PubMed, Cochrane Library, Scopus, Web of Science, and Google Scholar were searched to find papers that matched our topic dating from 1 January 2017 up to 18 January 2022, with English-language restriction using the following Boolean keywords: ("resveratrol" AND "microbio*"). Eighteen studies were included as relevant papers matching the purpose of our investigation. Immune response, prevention of thrombotic complications, microbiota, gene therapy, and bone regeneration were retrieved as the main topics. The analyzed studies mostly involved resveratrol supplementation and its effects on human microbiota by trials in vitro, in vivo, and ex vivo. The beneficial activity of resveratrol is evident by analyzing the changes in the host's genetic expression and the gastrointestinal microbial community with its administration. The possibility of identifying individual microbial families may allow to tailor therapeutic plans with targeted polyphenolic diets when associated with microbial dysbiosis, such as inflammatory diseases of the gastrointestinal tract, degenerative diseases, tumors, obesity, diabetes, bone tissue regeneration, and metabolic syndrome.

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).

High Vitamin D Concentrations Restore the Ability to Express LL37 by M. tuberculosis-Infected Human Macrophages

Vitamin D has an immunomodulatory function and is involved in eliminating pathogens. Vitamin D deficiencies reported in Type 2 diabetes mellitus (T2DM) patients make them more susceptible to developing tuberculosis (TB). The macrophages are the immune cells that control intracellular pathogens by producing the antimicrobial peptide cathelicidin-LL37. This pathway involves TLR activation by pathogens, vitamin D receptor (VDR) ligation, and the enzyme 1α-hydroxylase Cytochrome P450 Family 27 Subfamily B Member 1 (CYP27B1). However, it is not clear whether the biological actions of vitamin D are affected by high glucose concentrations. This study aimed to evaluate the vitamin D contribution in the expression of VDR and CYP27B1, involved in the conversion of an inactive to an active form of vitamin D in the infected macrophages using M. tuberculosis as an infection model. The expression of LL37 and the nucleus translocation of VDR were evaluated as the readout of the response of vitamin D and determined if those processes are affected by glucose concentrations. Macrophages from healthy donors were cultured under glucose concentrations of 5.5, 15, or 30 mM, stimulated with vitamin D in inactive (25(OH)D3) or active (1,25(OH)2D3) forms, and infected with M. tuberculosis. The vitamin D-dependent induction of LL37 and the expression of VDR and CYP27B1 genes were analyzed by qPCR, and VDR translocation was analyzed in nuclear protein extracts by ELISA. M. tuberculosis downregulated the expression of LL37 regardless of the glucose concentration, whereas VDR and CYP27B1 upregulated it regardless of the glucose concentration. After evaluating two concentrations of vitamin D, 1 nM or 1 μM, the high concentration (1 μM) was necessary to restore the induction of LL37 expression in M. tuberculosis-infected macrophages. High concentrations of the inactive form of vitamin D restore the infected macrophages’ ability to express LL37 regardless of the glucose concentration. This finding supports the idea that vitamin D administration in patients with T2DM could benefit TB control and prevention.

Vitamin D: role in chronic and acute diseases

Vitamin D is involved in bone health by promoting calcium absorption in the gut and maintaining serum calcium and phosphate concentrations, and by its action on bone growth and reorganization through osteoblasts and osteoclasts cells. Moreover, during the last three decades, novel actions of vitamin D have been discovered. Several systematic reviews and meta-analyses have shown links between serum vitamin D levels and non-communicable diseases. In line with these findings, a wide number of studies have suggested associations of vitamin D deficiency (VDD) with respiratory tract infections, osteoporosis, and other chronic and metabolic diseases such as obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM), cancer, rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). Vitamin D also exerts important actions in the clinical course of infectious and other acute diseases, particularly respiratory bacterial infections, tuberculosis, and virus infections, e.g., those generated by human immunodeficiency and SARS-CoV-2 (COVID-19) viruses. The present article aimed to update the role of vitamin D in chronic and acute diseases.

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To know the role of vitamin D in the prevention and treatment of non-communicable chronic diseases.

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To understand how vitamin D deficiency is related to obesity, insulin resistance and metabolic syndrome, type 2 diabetes, cancer, rheumatoid arthritis, osteoporosis, chronic pulmonary obstructive disease, and inflammatory bowel disease.

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To know the function of vitamin D in the prevention and treatment of acute infectious diseases of bacterial and viral origins, namely respiratory infections.

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To understand the role of vitamin D in the prevention of HIV and SARS-Cov2 infections

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To know how vitamin D status affects the course of critical illness diseases

Potential Role of Vitamins A, B, C, D and E in TB Treatment and Prevention: A Narrative Review

(1) Background: Tuberculosis (TB) is one of the world's top infectious killers, in fact every year 10 million people fall ill with TB and 1.5 million people die from TB. Vitamins have an important role in vital functions, due to their anti-oxidant, pro-oxidant, anti-inflammatory effects and to metabolic functions. The aim of this review is to discuss and summarize the evidence and still open questions regarding vitamin supplementation as a prophylactic measure in those who are at high risk of Mycobacterium tuberculosis (MTB) infection and active TB; (2) Methods: We conducted a search on PubMed, Scopus, Google Scholar, EMBASE, Cochrane Library and WHO websites starting from March 1950 to September 2021, in order to identify articles discussing the role of Vitamins A, B, C, D and E and Tuberculosis; (3) Results: Supplementation with multiple micronutrients (including zinc) rather than vitamin A alone may be more beneficial in TB. The WHO recommend Pyridoxine (vitamin B6) when high-dose isoniazid is administered. High concentrations of vitamin C sterilize drug-susceptible, MDR and extensively drug-resistant MTB cultures and prevent the emergence of drug persisters; Vitamin D suppresses the replication of mycobacterium in vitro while VE showed a promising role in TB management as a result of its connection with oxidative balance; (4) Conclusions: Our review suggests and encourages the use of vitamins in TB patients. In fact, their use may improve outcomes by helping both nutritionally and by interacting directly and/or indirectly with MTB. Several and more comprehensive trials are needed to reinforce these suggestions.