Age and low levels of circulating vitamin D are associated with impaired innate immune function

Exploring the link between fat-soluble vitamins and aging-associated immune system status: a literature review

The importance of vitamin D for a well-functioning immune system is becoming increasingly evident. Nevertheless, the other fat-soluble vitamins A, E and K also seem to play a central role regarding the adequate function of immune cells and to counteract excessive immune reactions and inflammatory processes. However, recognizing hidden hunger, particularly micronutrient deficiencies in vulnerable groups like the elderly, is crucial because older adults often lack sufficient micronutrients for various reasons. This review summarizes the latest findings on the immune modulating functions of fat-soluble vitamins in a physiological and pathophysiological context, provides a graphical comparison of the Recommended Daily Allowances between Deutschland, Austria, Confoederatio Helvetica (D-A-CH; eng. GSA, Germany, Switzerland, Austria), Deutsche Gesellschaft für Ernährung (DGE; eng. German Nutrition Society) and National Institutes of Health (NIH) across all age groups and, in particular, addresses the question regarding the benefits of supplementation of the respective micronutrients for the aging population of industrialized nations to strengthen the immune system. The following review highlights the importance of fat-soluble vitamins A, D, E and K which play critical roles in maintaining immune system function and, in some cases, in preventing excessive immune activation. Therefore, a better understanding of the relevance of adequate blood levels and consequently potential supplementation strategies may contribute to the prevention and management of infectious diseases as well as better overall health of the elderly.

Effects of Bovine Lactoferrin on the Maintenance of Respiratory and Systemic Physical Conditions in Healthy Adults-A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVES

We investigated the effects of bovine lactoferrin (LF) on the maintenance of the respiratory and systemic physical conditions.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted. Healthy adults at Kyushu University of Health and Welfare ingested a placebo or bovine LF (200 mg/day) for 12 weeks. The primary endpoints were the total respiratory and systemic symptom scores. The secondary endpoint was the activity of plasmacytoid dendritic cells (pDCs) in peripheral blood.

RESULTS

A total of 157 subjects were randomized (placebo, n = 79; LF, n = 78), of whom, 12 dropped out. The remaining 145 participants were included in the full analysis set (placebo group, n = 77; LF group, n = 68). The total scores for respiratory and systemic symptoms during the intervention were significantly lower in the LF group than in the placebo group. The expression of CD86 and HLA-DR on pDCs was significantly higher in the LF group than in the placebo group at week 12. Adverse events were comparable between the groups, and no adverse drug reactions were observed.

CONCLUSIONS

These results suggest that orally ingested LF supports the normal immune system via maintaining pDC activity, and maintains respiratory and systemic physical conditions in healthy adults.

Vitamin D as an adjunct to antibiotics for the treatment of acute childhood pneumonia

BACKGROUND

Children with acute pneumonia may be vitamin D deficient. Clinical trials have found that prophylactic vitamin D supplementation decreases children's risk of developing pneumonia. Data on the therapeutic effects of vitamin D in acute childhood pneumonia are limited. This is an update of a Cochrane Review first published in 2018.

OBJECTIVES

To evaluate the efficacy and safety of vitamin D supplementation as an adjunct to antibiotics for the treatment of acute childhood pneumonia.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trial registries on 28 December 2021. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared vitamin D supplementation with placebo in children (aged one month to five years) hospitalised with acute community-acquired pneumonia, as defined by the World Health Organization (WHO) acute respiratory infection guidelines. For this update, we reappraised eligible trials according to research integrity criteria, excluding RCTs published from April 2018 that were not prospectively registered in a trials registry according to WHO or Clinical Trials Registry - India (CTRI) guidelines (it was not mandatory to register clinical trials in India before April 2018).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and extracted data. For dichotomous data, we extracted the number of participants experiencing the outcome and the total number of participants in each treatment group. For continuous data, we used the arithmetic mean and standard deviation (SD) for each treatment group together with number of participants in each group. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

In this update, we included three new trials involving 468 children, bringing the total number of trials to seven, with 1601 children (631 with pneumonia and 970 with severe or very severe pneumonia). We categorised three previously included studies and three new studies as 'awaiting classification' based on the research integrity screen. Five trials used a single bolus dose of vitamin D (300,000 IU in one trial and 100,000 IU in four trials) at the onset of illness or within 24 hours of hospital admission; one used a daily dose of oral vitamin D (1000 IU for children aged up to one year and 2000 IU for children aged over one year) for five days; and one used variable doses (on day 1, 20,000 IU in children younger than six months, 50,000 IU in children aged six to 12 months, and 100,000 IU in children aged 13 to 59 months; followed by 10,000 IU/day for four days or until discharge). Three trials performed microbiological diagnosis of pneumonia, radiological diagnosis of pneumonia, or both. Vitamin D probably has little or no effect on the time to resolution of acute illness (mean difference (MD) -1.28 hours, 95% confidence interval (CI) -5.47 to 2.91; 5 trials, 1188 children; moderate-certainty evidence). We do not know if vitamin D has an effect on the duration of hospitalisation (MD 4.96 hours, 95% CI -8.28 to 18.21; 5 trials, 1023 children; very low-certainty evidence). We do not know if vitamin D has an effect on mortality rate (risk ratio (RR) 0.69, 95% CI 0.44 to 1.07; 3 trials, 584 children; low-certainty evidence). The trials reported no major adverse events. According to GRADE criteria, the evidence was of very low-to-moderate certainty for all outcomes, owing to serious trial limitations, inconsistency, indirectness, and imprecision. Three trials received funding: one from the New Zealand Aid Corporation, one from an institutional grant, and one from multigovernment organisations (Bangladesh, Sweden, and UK). The remaining four trials were unfunded.

AUTHORS' CONCLUSIONS

Based on the available evidence, we are uncertain whether vitamin D supplementation has important effects on outcomes of acute pneumonia when used as an adjunct to antibiotics. The trials reported no major adverse events. Uncertainty in the evidence is due to imprecision, risk of bias, inconsistency, and indirectness.

Vitamin D role in hepatitis B: focus on immune system and genetics mechanism

According to the World Health Organization (WHO) report, viral hepatitis has been a problem in human society. Vitamins play a significant role in preventing the hepatocarcinoma and liver cirrhosis. In this report, we will first focus on the vitamin D function in the immune system reactions, and then investigate its role in the viral infections and the signaling pathway of hepatitis B virus. The existence of the cytochrome P450 (CYP) 27B1 enzyme, which is involved in vitamin D synthesis in immune system cells, has drawn researchers ' attention to the field of immune system. Toll like receptor (TLR) play a significant role in the immune system, and are one of the primary receptors of the innate immune system. In addition, the synthesis of inflammatory cytokines, such as Interferon γ (IFNγ) and Interleukin-2 (IL-2) is one of the key roles of T helper type 1 (Th1) cells; these cells can suppress two cited cytokines via vitamin D. In the chronic phase of hepatitis B, Cytotoxic T lymphocytes (CTLs) cells have weaker performance than the acute phase of the disease. The association between vitamin D physiologies with viral infections is also confirmed by genetic studies, carried out on genetic variations of vitamin D receptor (VDR) R-encoding disease susceptibility gene. Vitamin D affects different phases of the disease. Therefore, further experiments in this area are proposed.

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.

Nutrition as Personalized Medicine against SARS-CoV-2 Infections: Clinical and Oncological Options with a Specific Female Groups Overview

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is acknowledged that vulnerable people can suffer from mortal complications of COVID-19. Therefore, strengthening the immune system particularly in the most fragile people could help to protect them from infection. First, general nutritional status and food consumption patterns of everyone affect the effectiveness of each immune system. The effects of nutrition could impact the level of intestinal and genital microbiota, the adaptive immune system, and the innate immune system. Indeed, immune system cells and mediators, which are crucial to inflammatory reaction, are in the structures of fats, carbohydrates, and proteins and are activated through vitamins (vit) and minerals. Therefore, the association of malnutrition and infection could damage the immune response, reducing the immune cells and amplifying inflammatory mediators. Both amount and type of dietary fat impact on cytokine biology, that consequently assumes a crucial role in inflammatory disease. This review explores the power of nutrition in the immune response against COVID-19 infection, since a specific diet could modify the cytokine storm during the infection phase. This can be of vital importance in the most vulnerable subjects such as pregnant women or cancer patients to whom we have deemed it necessary to dedicate personalized indications.

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.

Innate and Adaptive Immune Assessment at Admission to Predict Clinical Outcome in COVID-19 Patients

During the COVID-19 pandemic, many studies have been carried out to evaluate different immune system components to search for prognostic biomarkers of the disease. A broad multiparametric antibody panel of cellular and humoral components of the innate and the adaptative immune response in patients with active SARS-CoV-2 infection has been evaluated in this study. A total of 155 patients were studied at admission into our center and were categorized according to the requirement of oxygen therapy as mild or severe (the latter being those with the requirement). The patients with severe disease were older and had high ferritin, D-dimer, C-reactive protein, troponin, interleukin-6 (IL-6) levels, and neutrophilia with lymphopenia at admission. Moreover, the patients with mild symptoms had significantly increased circulating non-classical monocytes, innate lymphoid cells, and regulatory NK cells. In contrast, severe patients had a low frequency of Th1 and regulatory T cells with increased activated and exhausted CD8 phenotype (CD8⁺CD38⁺HLADR⁺ and CD8⁺CD27^-CD28^-, respectively). The predictive model included age, ferritin, D-dimer, lymph counts, C4, CD8⁺CD27^-CD28^-, and non-classical monocytes in the logistic regression analysis. The model predicted severity with an area under the curve of 78%. Both innate and adaptive immune parameters could be considered potential predictive biomarkers of the prognosis of COVID-19 disease.

Genetic Screening for TLR7 Variants in Young and Previously Healthy Men With Severe COVID-19

Introduction

Loss-of-function TLR7 variants have been recently reported in a small number of males to underlie strong predisposition to severe COVID-19. We aimed to determine the presence of these rare variants in young men with severe COVID-19.

Methods

We prospectively studied males between 18 and 50 years-old without predisposing comorbidities that required at least high-flow nasal oxygen to treat COVID-19. The coding region of TLR7 was sequenced to assess the presence of potentially deleterious variants.

Results

TLR7 missense variants were identified in two out of 14 patients (14.3%). Overall, the median age was 38 (IQR 30-45) years. Both variants were not previously reported in population control databases and were predicted to be damaging by in silico predictors. In a 30-year-old patient a maternally inherited variant [c.644A>G; p.(Asn215Ser)] was identified, co-segregating in his 27-year-old brother who also contracted severe COVID-19. A second variant [c.2797T>C; p.(Trp933Arg)] was found in a 28-year-old patient, co-segregating in his 24-year-old brother who developed mild COVID-19. Functional testing of this variant revealed decreased type I and II interferon responses in peripheral mononuclear blood cells upon stimulation with the TLR7 agonist imiquimod, confirming a loss-of-function effect.

Conclusions

This study supports a rationale for the genetic screening for TLR7 variants in young men with severe COVID-19 in the absence of other relevant risk factors. A diagnosis of TLR7 deficiency could not only inform on treatment options for the patient, but also enables pre-symptomatic testing of at-risk male relatives with the possibility of instituting early preventive and therapeutic interventions.

Cathelicidin levels in nasal secretions are associated with the severity of acute bronchiolitis

OBJECTIVE

To investigate the association of serum vitamin D and nasal secretion antimicrobial peptides (AMPs) levels with the severity of acute bronchiolitis.

STUDY DESIGN

We conducted a prospective single pediatric tertiary care center cohort study of inpatients aged 0-18 months with a first episode of acute bronchiolitis from November 1st 2014 to April 30th 2017. Disease severity was determined by the length of hospitalization and supplemental hospital data. Qualitative measurements included serum 25(OH)D and nasal secretion LL-37 and β-defensin-2 levels. Correlations were examined with the Mann-Whitney and Kruskal-Wallis criteria for qualitative and the correlation coefficient Spearman's rho for quantitative factors. Multiple linear and logarithmic regression were performed to adjust for confounding factors.

RESULTS

The study population consisted of 153 infants and toddlers with median age 3.1 months (interquartile range:1.6-4.9). No association was found between serum 25(OH)D and AMPs nasal secretions levels. Serum 25(OH)D and nasal secretion β-defensin-2 levels were not associated with the severity of bronchiolitis. In contrast, LL-37 levels were inversely associated with the length of hospitalization (rho = -0.340, p = .001), the need for medication use (p = .001), as well as the duration of oxygen supplementation (rho = -0.339, p = .001), and intravenous fluid administration (rho = -0.323, p = .001). This association remained significant after adjustment for potential confounders.

CONCLUSION

A significant association between LL-37 nasal secretions levels with the severity of acute bronchiolitis was found in hospitalized infants and toddlers. The role of LL-37 in the pathogenesis of bronchiolitis merits further investigation.

Effects of Serum Vitamin D Levels and Vitamin D Supplementation on Urticaria: A Systematic Review and Meta-Analysis

(1) Backgrounds: Several studies have shown that the level of 25-hydroxyvitamin D (25(OH)D) could affect urticaria. The association of Vitamin D (VitD) with urticaria has not been well established. (2) Methods: The up-to-date meta-analysis was performed to synthesize the new findings. We performed a systematic search in PubMed, EMBASE, Web of Science, and Cochrane Database. We included the observational studies with the comparisons of 25(OH)D between urticarial populations and controls and clinical studies with the clinical severity of urticaria records. (3) Results: A meta-analysis of seventeen studies of urticaria group vs. controls revealed a mean difference of −9.35 ng/mL (95% CI −12.27 to −6.44). There was also an association of urticaria with VitD deficiency. In the subgroup analysis of age and disease type, significant effects of 25(OH)D were found among adult and chronic urticarial populations. Six VitD supplementation trials showed a significant reduction in clinical urticarial score on intervention with VitD with the standard mean difference of −3.63 and −1.54 among randomized control studies and repeated measure trials, respectively. (4) Conclusions: The urticarial population, especially the adult chronic urticarial patients, may be associated with a high risk for lower serum 25(OH)D. VitD supplementations could result in a reduction of urticarial clinical symptoms.

Vitamin D status of Arab Gulf residents screened for SARS-CoV-2 and its association with COVID-19 infection: a multi-centre case-control study

OBJECTIVES

Vitamin D status in patients with COVID-19 is an on-going controversial issue. This study aims to determine differences in the serum 25(OH)D concentrations of Arab Gulf adult residents screened for SARS-CoV-2 and its association with risk of COVID-19 infection together with other comorbidities.

METHODS

In this multi-center, case-control study, a total of 220 male and female adults presenting with none to mild symptoms were screened for COVID-19 (n = 138 RT-PCR-confirmed SARS-CoV-2 positive and 82 negative controls). Medical history was noted. Anthropometrics were measured and non-fasting blood samples were collected for the assessment of glucose, lipids, inflammatory markers and serum 25(OH)D concentrations.

RESULTS

Serum 25(OH)D levels were significantly lower in the SARS-CoV-2 positive group compared to the negative group after adjustment for age and BMI (52.8 nmol/l ± 11.0 versus 64.5 nmol/l ± 11.1; p = 0.009). Being elderly (> 60 years) [Odds ratio 6 (95% Confidence Interval, CI 2-18; p = 0.001) as well as having type 2 diabetes (T2D) [OR 6 (95% CI 3-14); p < 0.001)] and low HDL cholesterol (HDL-c) [OR 6 (95% CI 3-14); p < 0.001)] were significant risk factors for COVID-19 infection independent of age, sex and obesity.

CONCLUSIONS

Among Arab Gulf residents screened for SARS-CoV-2, serum 25(OH) D levels were observed to be lower in those who tested positive than negative individuals, but it was the presence of old age, diabetes mellitus and low-HDL-c that were significantly associated with risk of COVID-19 infection. Large population-based randomized controlled trials should be conducted to assess the protective effects of vitamin D supplementation against COVID-19.

Vitamin D Status in Hospitalized Patients with SARS-CoV-2 Infection

BACKGROUND

The role of vitamin D status in COVID-19 patients is a matter of debate.

OBJECTIVES

To assess serum 25-hydroxyvitamin D (25OHD) levels in hospitalized patients with COVID-19 and to analyze the possible influence of vitamin D status on disease severity.

METHODS

Retrospective case-control study of 216 COVID-19 patients and 197 population-based controls. Serum 25OHD levels were measured in both groups. The association of serum 25OHD levels with COVID-19 severity (admission to the intensive care unit, requirements for mechanical ventilation, or mortality) was also evaluated.

RESULTS

Of the 216 patients, 19 were on vitamin D supplements and were analyzed separately. In COVID-19 patients, mean ± standard deviation 25OHD levels were 13.8 ± 7.2 ng/mL, compared with 20.9 ± 7.4 ng/mL in controls (P < .0001). 25OHD values were lower in men than in women. Vitamin D deficiency was found in 82.2% of COVID-19 cases and 47.2% of population-based controls (P < .0001). 25OHD inversely correlates with serum ferritin (P = .013) and D-dimer levels (P = .027). Vitamin D-deficient COVID-19 patients had a greater prevalence of hypertension and cardiovascular diseases, raised serum ferritin and troponin levels, as well as a longer length of hospital stay than those with serum 25OHD levels ≥20 ng/mL. No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate components.

CONCLUSIONS

25OHD levels are lower in hospitalized COVID-19 patients than in population-based controls and these patients had a higher prevalence of deficiency. We did not find any relationship between vitamin D concentrations or vitamin deficiency and the severity of the disease.

Can climatic factors explain the differences in COVID-19 incidence and severity across the Spanish regions?: An ecological study

BACKGROUND

Environmental factors play a central role in seasonal epidemics. SARS-CoV-2 infection in Spain has shown a heterogeneous geographical pattern This study aimed to assess the influence of several climatic factors on the infectivity of SARS-CoV-2 and the severity of COVID-19 among the Spanish Autonomous Communities (AA.CC.).

METHODS

Data on coronavirus infectivity and severity of COVID-19 disease, as well as the climatic variables were obtained from official sources (Ministry of Health and Spanish Meteorological Agency, respectively). To assess the possible influence of climate on the development of the disease, data on ultraviolet radiation (UVR) were collected during the months before the start of the pandemic. To analyze its influence on the infectivity of SARS-CoV-2, data on UVR, temperature, and humidity were obtained from the months of highest contagiousness to the peak of the pandemic.

RESULTS

From October 2019 to January 2020, mean UVR was significantly related not only to SARS-CoV-2 infection (cumulative incidence -previous 14 days- × 105 habitants, rho = - 0.0,666; p = 0.009), but also with COVID-19 severity, assessed as hospital admissions (rho = - 0.626; p = 0.017) and ICU admissions (rho = - 0.565; p = 0.035). Besides, temperature (February: rho = - 0.832; p < 0.001 and March: rho = - 0.904; p < 0.001), was the main climatic factor responsible for the infectivity of the coronavirus and directly contributed to a different spread of SARS-CoV-2 across the Spanish regions.

CONCLUSIONS

Climatic factors may partially explain the differences in COVID-19 incidence and severity across the different Spanish regions. The knowledge of these factors could help to develop preventive and public health actions against upcoming outbreaks of the disease.

Expression and Functionality Study of 9 Toll-Like Receptors in 33 Drug-Naïve Non-Affective First Episode Psychosis Individuals: A 3-Month Study

Toll-like receptors (TLRs) are a pivotal component of the innate immune system that seem to have a role in the pathogenesis of psychosis. The purpose of this work was to compare the expression and functionality of 9 TLRs in three peripheral blood mononuclear cells (PBMCs) (monocytes, B cells, and T cells) between 33 drug-naïve first-episode psychosis (FEP) individuals and 26 healthy volunteers, at baseline and after 3-month of antipsychotic treatment. The expression of TLRs 1–9 were assessed by flow cytometry. For the assessment of the TLR functionality, cells collected in sodium heparin tubes were polyclonally stimulated for 18 h, with different agonists for human TLR1–9. The results of our study highlight the role that TLR5 and TLR8 might play in the pathophysiology of psychosis. We found a lower expression of these receptors in FEP individuals, regarding healthy volunteers at baseline and after 3-month of treatment on the three PBMCs subsets. Most TLRs showed a lower functionality (especially reduced intracellular levels of TNF-α) in patients than in healthy volunteers. These results, together with previous evidence, suggest that individuals with psychosis might show a pattern of TLR expression that differs from that of healthy volunteers, which could vary according to the intensity of immune/inflammatory response.

Vitamin D Induces Differential Effects on Inflammatory Responses During Bacterial and/or Viral Stimulation of Human Peripheral Blood Mononuclear Cells

Streptococcus pneumoniae (pneumococcus) and respiratory syncytial virus (RSV) are the leading causes of respiratory infections amongst children <5 years of age. Co-infection with these pathogens is common during early life and often associated with increased disease severity. Epidemiological studies have shown that low levels of Vitamin D₃ (VitD₃) are associated with increased susceptibility to respiratory pathogens. However, the role of VitD₃ in the context of pneumococcal and RSV exposure are poorly understood. We found that VitD₃ significantly reduced Th17 cell expression and IL-17A and IL-22 secretion in peripheral blood mononuclear cells (PBMCs) when stimulated with a pneumococcal whole cell antigen (WCA). Levels of IFN-γ were also decreased whilst IL-10 and IL-1β were increased. Effects of VitD₃ on innate responses following RSV stimulation was limited, only reducing IL-6. VitD₃ also reduced the number of TLR2+CD14+ monocytes, whilst increasing TLR7+CD14+ monocytes and TLR4+CD56+ NK cells. In WCA-stimulated PBMCs, VitD₃ increased IL-1β levels but reduced TLR2+CD14+ monocytes. For pneumococcal WCA-RSV co-stimulation, VitD₃ only had a limited effect, mainly through increased IL-1β and RANTES as well as TLR4+CD56+ NK cells. Our results suggest that VitD₃ can modulate the inflammatory response to pneumococci but has limited effects during viral or bacterial-viral exposure. This is the first study to examine the effects of VitD₃ in the context of pneumococcal-RSV co-stimulation, with important implications on the potential role of VitD₃ in the control of excessive inflammatory responses during pneumococcal and RSV infections.

Isolated vitamin D supplementation improves the immune-inflammatory biomarkers in younger postmenopausal women: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

The aim of this study was to evaluate the effect of vitamin D (VitD) supplementation on immune-inflammatory biomarkers in younger postmenopausal women.

METHODS

In this double-blind, placebo-controlled trial, 160 postmenopausal women aged 50 to 65 years with amenorrhea ≥12 months were randomized into two groups: VitD group, oral supplementation with 1000 IU VitD3/day (n = 80) or placebo group (n = 80). The intervention time was 9 months, and the women were assessed at baseline and endpoint. Serum levels of interleukins (ILs)-1β, IL-5, IL-6, IL-10, IL-12ρ70, IL-17α, tumor necrosis factor-alpha, and interferon-gamma were determined by immunoassay. Plasma concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by high-performance liquid chromatography. Per-protocol analysis was adopted as the statistical method using a gamma distribution and repeated measures design, followed by Wald's multiple comparisons test.

RESULTS

The two groups were similar at baseline in terms of clinical and laboratory parameters. After 9 months, there was a significant increase of 25(OH)D levels in the VitD group (+45.4%, P < 0.001) and a decrease (-18.5%, P = 0.049) in the placebo group. A significant decrease in IL-5, IL-12p70, IL-17α, tumor necrosis factor-alpha, and interferon-gamma levels was observed in the VitD group (P < 0.05). IL-5 and IL-6 levels were significantly lower in the VitD group compared to the placebo group (P < 0.05). There were no significant intervention effects on serum IL-1β or IL-10 levels in either group (P > 0.05).

CONCLUSIONS

In younger postmenopausal women, isolated supplementation with 1000 IU of VitD3 for 9 months was associated with a reduction in proinflammatory biomarkers.

Can the Toll-like receptors 4 expression in peripheral blood mononuclear cells help assess the effectiveness of immunosuppression and the chance of a future good renal transplant function?

BACKGROUND

A small percentage of peripheral blood mononuclear cells (PBMCs) circulating during the kidney transplantation (KT) period remain in the blood long after transplantation. A part of the PBMCs penetrates the graft.

AIM

To examine if the choice of immunosuppression may change TLR4ex and how TLR4ex affects the transplant function in the future.

MATERIAL

The study population-143 transplanted patients (pts) (55 females, 88 males), mean age on recruitment day 50.33 ± 12.8 years old, mean BMI 25.04 ± 4.18. 41 pts. experienced delayed graft function (DGF+). 55 pts. were treated with cyclosporine A (CsA) and 88 with tacrolimus (Tac). All were treated with mofetil mycophenolate (MMF). The PBMCs acquisition and starting point of the follow-up (TLR-day) was at least one month after KT.

METHOD

We investigated averaged mRNA expression of Toll-like receptors 4 (TLR4ex) in non-stimulated peripheral blood mononuclear cells with the use of real-time polymerase chain reaction. The KT pts. (All, Tac, CsA, DGF+) were divided by the respective median of their TLR4ex (lower: L-TLR4ex, higher: H-TLR4ex). Main clinical parameters and transplant biopsy files (if available) were assessed on TLR-day and post follow-up.

RESULTS

We found that TLR4ex was reduced for a long time in patients who experienced delayed graft function. L-TLR4ex had a higher proportion of DGF+ patients, and patients treated with CsA but lower of those treated with Tac than in H-TLR4ex. The amplitude of changes in renal function parameters (ΔEGFR%/ΔsCr/ΔsCr%) was clearly less favorable for L-TLR4ex. Tacrolimus expressed a stabilizing effect. Both the positive vasculitis score and chronic graft nephropathy were more frequent in the L-TLR4ex group. On TLR-day an association of renal function and Tac concentration with TLR4ex was clear only in the tacrolimus population. The TLR4ex was lower in patients with a future deterioration of the graft function.

CONCLUSION

In kidney transplant recipients the occurrence of DGF results in a long-term reduction of the averaged TLR4ex in PBMC. Tacrolimus exerts a clear, stabilizing, positive and dose-dependent effect on TLR4ex. An improvement in renal transplant function may be expected in KT patients with high TLR4ex. Evaluation of the averaged TLR4ex can be used to assess the efficacy of immunosuppression in the treatment with tacrolimus and to estimate the likelihood of deterioration in renal function.

Bovine Lactoferrin Enhances TLR7-Mediated Responses in Plasmacytoid Dendritic Cells in Elderly Women: Results From a Nutritional Intervention Study With Bovine Lactoferrin, GOS and Vitamin D

During aging the immune system is dysregulated. Especially plasmacytoid dendritic cells (pDCs) and myeloid DCs (mDCs) have reduced Toll like receptor (TLR)-mediated responses resulting in increased susceptibility to infections. Consumption of bovine lactoferrin (bLF) has been shown to reduce infections with viruses. Galacto-oligosacharides (GOS) and vitamin D are associated with reduced pro-inflammatory cytokine levels in serum, and increased TLR7/8 responses, respectively. A double-blind placebo-controlled nutritional intervention study in elderly women was performed, to investigate the potential of bLF, GOS, and vitamin D to restore TLR responsiveness of pDCs and mDCs and to reduce inflammatory markers in serum. The nutritional intervention group (n = 15) received bLF for 3 weeks, followed by 3 weeks of bLF + GOS, and subsequently 3 weeks of bLF + GOS + vitamin D. The placebo group (n = 15) received maltodextrin for 9 weeks. Every 3 weeks, blood was collected and TLR responses of pDCs and mDCs, and inflammation-related markers in serum were measured. After 3 weeks of bLF supplementation, increased TLR7/8 and TLR1/2 responses were observed in pDCs of the nutritional intervention group compared to the placebo group. When the effects of the entire nutritional intervention were investigated, increased TLR1/2 mediated responses in mDCs were observed, and in serum sVCAM tended to decrease. Finally, based on the RAND-36 questionnaire physical function tended to improve in the intervention group. Since especially TLR7-mediated responses in pDCs were enhanced after bLF supplementation compared to placebo, this suggests that bLF may contribute to antiviral responses mediated by pDC in elderly women.Clinical trial registry number: NCT03026244, clinicaltrials.gov:

Vitamin D as an adjunct to antibiotics for the treatment of acute childhood pneumonia

BACKGROUND

Children with acute pneumonia may be vitamin D deficient. Clinical trials have found that prophylactic vitamin D supplementation decreases the risk of developing pneumonia in children. Data on the therapeutic effects of vitamin D in acute childhood pneumonia are limited.

OBJECTIVES

To evaluate the efficacy and safety of vitamin D supplementation as an adjunct to antibiotics for the treatment of acute childhood pneumonia.

SEARCH METHODS

We searched CENTRAL (2017, Issue 7), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register; Ovid MEDLINE Epub Ahead of Print; In-Process & Other Non-Indexed Citations; Ovid MEDLINE Daily and Ovid MEDLINE (1946 to July Week 4, 2017); and Embase (2010 to 28 July 2017). We also searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 28 July 2017. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including children (aged over one month and up to five years) hospitalised with acute community-acquired pneumonia, as defined by the WHO acute respiratory infection guidelines, that compared vitamin D supplementation with control.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and extracted data. For dichotomous data, we extracted the number of participants experiencing the outcome and the total number of participants in each treatment group. For continuous data, we used the arithmetic mean and standard deviation (SD) for each treatment group together with numbers of participants in each group. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included seven RCTs conducted in low-income countries that involved 1529 children (780 with pneumonia and 749 with severe or very severe pneumonia). Four studies used a single 100,000 IU dose of vitamin D₃ at the onset of illness or within 24 hours of hospital admission; two used a daily dose of oral vitamin D₃ (1000 IU for children aged up to one year and 2000 IU for children aged over one year) for five days; and one used a daily dose of oral vitamin D₃ (50,000 IU) for two days. One study reported microbiological and radiological diagnosis of pneumonia.The effects of vitamin D on outcomes were inconclusive when compared with control: time to resolution of acute illness (hours) (mean difference (MD) -0.95, 95% confidence interval (CI) -6.14 to 4.24; 3 studies; 935 children; low-quality evidence) mortality rate (risk ratio (RR) 0.97, 95% CI 0.06 to 15.28; 1 study; 193 children; very low-quality evidence); duration of hospitalisation (MD 0.49, 95% CI -8.41 to 9.4; 4 studies; 835 children; very low-quality evidence) and time to resolution of fever (MD 1.66, 95% CI -2.44 to 5.76; 4 studies; 584 children; very low-quality evidence).No major adverse events were reported.The GRADE assessment found very low-quality evidence (due to serious study limitations, inconsistencies, indirectness, and imprecision) for all outcomes except time to resolution of acute illness.One study was funded by the New Zealand Aid Corporation; one study was funded by an institutional grant; and five studies were unfunded.

AUTHORS' CONCLUSIONS

We are uncertain as to whether vitamin D has an important effect on outcomes because the results were imprecise. No major adverse events were reported. We assessed the quality of the evidence as very low to low. Several trials are ongoing and may provide additional information.

Cellular and molecular mechanisms of vitamin D in food allergy

Food allergies are becoming increasingly prevalent, especially in young children. Epidemiological evidence from the past decade suggests a role of vitamin D in food allergy pathogenesis. Links have been made between variations in sunlight exposure, latitude, birth season and vitamin D status with food allergy risk. Despite the heightened interest in vitamin D in food allergies, it remains unclear by which exact mechanism(s) it acts. An understanding of the roles vitamin D plays within the immune system at the cellular and genetic levels, as well as the interplay between the microbiome and vitamin D, will provide insight into the importance of the vitamin in food allergies. Here, we discuss the effect of vitamin D on immune cell maturation, differentiation and function; microbiome; genetic and epigenetic regulation (eg DNA methylation); and how these processes are implicated in food allergies.

Vitamin D and toll like receptors

It has been demonstrated that vitamin D (VD) significantly modulates immune responses. Toll like receptors (TLRs) are the main innate immunity receptors which are expressed on the cell membrane and intracellular vesicles and recognize several pathogen associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs) to induce immune responses. Based on the important roles played by TLRs in physiologic and pathologic functions of immune responses and due to the immunomodulatory functions of VD, it has been hypothesized that VD may present its immunomodulatory functions via modulation of TLRs. This review article collates recent studies regarding the interactions between VD and TLRs and discussed the controversial investigations.

Effect of vitamin D treatments on plasma metabolism and immune parameters of healthy dairy cows

The objective of this study was to investigate the possible beneficial effect of vitamin D repletion on certain immune parameters of vitamin D insufficient dairy cows. Twenty dairy cows in late lactation were treated daily with vitamin D in five different ways: sunlight exposure (SUN), D₂ supplementation combined with sunlight exposure (D2SUN), D₂ supplementation (D2), D₃ supplementation (D3), and D₂ and D₃ supplementation combined (D2D3). The cows had very low vitamin D levels at d 0 because of the vitamin D deprivation before the study. After 1 month of vitamin D repletion, all cows had plasma 25(OH)D levels within the normal range. Total 25(OH)D concentration was significantly higher in SUN, D2SUN and D2D3 than D2 or D3 at the end of the study. However, milk yield, as well as protein and fat content of the milk, was not influenced by vitamin D treatments. There was no difference obtained in the measured immune parameters: Leucocyte populations, somatic cell count, immunoglobulin concentrations in plasma and milk, and antigen-stimulated cytokine productions did not change in response to vitamin D repletion or difference in vitamin D sources, and no relations to plasma 25(OH)D levels were identified. Despite the fact that plasma 25(OH)D increased from a very low level to normal range, the present study did not show any effect of vitamin D repletion on the tested immune parameters of healthy dairy cows. Therefore, in this study, it was concluded that repletion to physiologically normal plasma 25-hydroxyvitamin D levels of vitamin D-depleted healthy dairy cows had no influence on immune parameters.

Expression of PBMC TLR4 in Renal Graft Recipients Who Experienced Delayed Graft Function Reflects Dynamic Balance Between Blood and Tissue Compartments and Helps Select a Problematic Patient

Both Toll-like receptor 4 (TLR4) and monocytes focus stimuli, causing them to contribute differently to chronic injury of a transplanted kidney.

AIM

The aim of our study was to determine if TLR4 monocyte is a diagnostic tool and possibly a target for therapeutic intervention.

MATERIALS

We studied 143 kidney transplant (KT) patients (88 male, 55 female; 50.3 ± 12.8 years); median was 10.4 post KT, follow-up was 11.4 months, and 46 patients had delayed graft function (DGF+) history. Control group (38 healthy volunteers) had monocyte mRNA-TLR4 expression (TLR4ex). DGF+ were divided by median of TLR4ex (-0.1034) into 2 groups: low-TLR4 expression (L-TLR4ex) and high-TLR4 expression (H-TLR4ex).

RESULTS

We showed that in comparison with DGF-, the DGF+ had much lower TLR4ex, and worse KT function both currently (TLR-day) (serum creatinine [sCr] P = .002; estimated glomerular filtration rate [eGFR] P = .001) and post follow-up (sCr P = .006; eGFR P = .005). The DGF+ with L/H-TLR4ex comparison showed no differences in TLR-day KT function but did show differences in post follow-up (sCr P = .01; eGFR P = .02; ΔeGFR% P = .001). Regression analysis showed an association between recipient age, tacrolimus concentration, and uremic milieu (ie, TLR-day sCr and GFR with TLR4ex). Reverse regression analysis indicated an association of TLR4ex (especially L/H-TLR4ex) with post follow-up parameters of KT function and numeric/qualitative measures of change.

CONCLUSION

DGF affects the fate of a graft. Within a several months after transplantation, TLR4ex of peripheral blood mononuclear cells declines in DGF patients. Low LR4ex in patients with DGF+ is associated with poor prognosis for the efficiency of the KT. In patients with DGF+, the proper selection of immunosuppression (tacrolimus dosing) is very important. Higher concentrations of tacrolimus may improve prognosis. The analysis of TLR4ex change may be a useful parameter for the real assessment of immunosuppression efficacy. It is important for transplanted organ function that peripheral blood mononuclear cells effectively leave circulation and remain in the graft.

Circulating cathelicidin LL-37 level is increased in euthymic patients with bipolar disorder

More and more data seems to imply that immune mechanisms are involved in the pathomechanism of bipolar disorder (BD). However, the primary role of cathelicidin LL-37 is defense against pathogens, more and more data indicated that this peptide strongly modulates immune system functioning and contributes to immune pathology of chronic and inflammatory diseases. No data is available on the level of LL-37 in bipolar patients. The aim of the study was to examine the circulating levels of cathelicidin LL-37 in euthymic patients with BD. Forty patients with BD and fifty-nine healthy volunteers were enrolled into the study. Concentration of LL-37 in serum was assessed using immunoenzymatic test ELISA. The mean LL-37 concentration in bipolar patients and in healthy subjects were 4.60 ± 7.65 ng/mL and 1.92 ± 2.89 ng/mL, respectively, and the difference was statistically significant (p = 0.035). Within the BD group LL-37 level was significantly higher in women than in men (p = 0.045). The evaluation of serum LL-37 concentration during stable 8 week treatment indicated that at baseline (T1) mean level of LL-37 was 5.82 ± 10.59 ng/mL; and after treatment (T2) was 4.33 ± 5.87 ng/mL; the difference between T1 and T2 was not significant. Elevated serum levels of LL-37 in bipolar patients may suggest the role of this peptide in the pathomechanism of BD.

The Role of Toll-Like Receptors and Vitamin D in Cardiovascular Diseases-A Review

Cardiovascular diseases are the leading cause of mortality worldwide. Therefore, a better understanding of their pathomechanisms and the subsequent implementation of optimal prophylactic and therapeutic strategies are of utmost importance. A growing body of evidence states that low-grade inflammation is a common feature for most of the cardiovascular diseases in which the contributing factors are the activation of toll-like receptors (TLRs) and vitamin D deficiency. In this article, available data concerning the association of cardiovascular diseases with TLRs and vitamin D status are reviewed, followed by a discussion of new possible approaches to cardiovascular disease management.

Toll-like receptors: Significance, ligands, signaling pathways, and functions in mammals

This review attempts to cover the implication of the toll-like receptors (TLRs) in controlling immune functions with emphasis on their significance, function, regulation and expression patterns. The tripartite TLRs are type I integral transmembrane receptors that are involved in recognition and conveying of pathogens to the immune system. These paralogs are located on cell surfaces or within endosomes. The TLRs are found to be functionally involved in the recognition of self and non-self-antigens, maturation of DCs and initiation of antigen-specific adaptive immune responses as they bridge the innate and adaptive immunity. Interestingly, they also have a significant role in immunotherapy and vaccination. Signals generated by TLRs are transduced through NFκB signaling and MAP kinases pathway to recruit pro-inflammatory cytokines and co-stimulatory molecules, which promote inflammatory responses. The excess production of these cytokines leads to grave systemic disorders like tumor growth and autoimmune disorders. Hence, regulation of the TLR signaling pathway is necessary to keep the host system safe. Many molecules like LPS, SOCS1, IRAK1, NFκB, and TRAF3 are involved in modulating the TLR pathways to induce appropriate response. Though quantification of these TLRs helps in correlating the magnitude of immune response exhibited by the animal, there are several internal, external, genetic and animal factors that affect their expression patterns. So it can be concluded that any identification based on those expression profiles may lead to improper diagnosis during certain conditions.

Serum levels of peptide cathelicidin LL-37 in elderly patients with depression

Cathelicidin LL-37 is a small cationic that plays an important role in antimicrobial defense, as it kills a broad spectrum of infectious agents by disrupting their membranes, including gram-positive and gram-negative bacteria, some viruses and fungi; and it neutralizes activity of bacterial endotoxins. Moreover, cathelicidin LL-37 exerts proinflammatory effect, while numerous reports indicate the role of inflammation in the development of depression. The purpose of this study was to evaluate the circulating levels of cathelicidin LL-37 in elderly depressed patients. Thirty-nine elderly (age ≥ 60 years) women with major depressive disorder and thirty-eight non-depressed elderly (age ≥ 60 years) women were included into the study. The mean serum cathelicidin LL-37 concentration in patients with depression and in healthy subjects were 2.40 ± 3.00ng/mL and 1.17 ± 3.04ng/mL, respectively, and the difference was statistically significant. No significant differences between mean serum CRP level and WBC count in MDD patients and control group were documented. There were no correlations between LL-37 level and age, BMI, GDS score, CRP level or WBC count. It can be assumed that elevated serum LL-37 levels in depressed patients may reflect inflammatory activation associated with depression.

Vitamin D3 Alters the Expression of Toll-like Receptors in Peripheral Blood Mononuclear Cells of Patients With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by production of inflammatory cytokines and autoreactive antibodies due to the loss of immune tolerance. Recognition of self-nucleic acids by intracellular Toll-like receptors (TLRs) can overactivate immune responses and this abnormal activation of TLRs contributes to the pathogenesis of the disease. In recent years, anti-inflammatory and immunomodulatory effects of 1,25-dihydroxyvitamin D3 (VitD3) on the immune system has received particular attention. The present study investigated the effects of vitamin D3 on the expression of TLR3, TLR7, and TLR9 in SLE patients. Study participants included 20 SLE patients and 20 age- and sex-matched healthy controls. Peripheral blood mononuclear cells (PBMCs) were isolated and cultured in the presence or absence of vitamin D3 (50 nM). Then RNA was extracted, cDNA was synthesized and gene expression levels of TLR3, TLR7, and TLR9 were assessed using real-time PCR. Up-regulated expression levels of TLR7 and TLR9 were observed in the PBMCs of SLE patients in comparison with controls. Culturing PBMCs with vitamin D3 significantly down-regulated the expression of TLR3 (8.86 ± 4.2 for SLE patients vs. 45.34 ± 18.6 for control; P = 0.03), TLR7 (17.91 ± 7.7 for SLE patients vs. 242.37 ± 89.6 for controls; P = 0.0001) and TLR9 (4.67 ± 1.9 for SLE patients vs. 8.9 ± 1.5 for controls; P = 0.007) in SLE patients in comparison with healthy controls. The results of the current study suggest that vitamin D3 could exert some of its immunomodulatory effects in SLE patients via affecting the expression levels of some TLRs. J. Cell. Biochem. 118: 4831-4835, 2017. © 2017 Wiley Periodicals, Inc.

Maternal Vitamin D Status and Adverse Birth Outcomes in Children from Rural Western Kenya

Maternal plasma 25-hydroxyvitamin D (25(OH)D) status and its association with pregnancy outcomes in malaria holoendemic regions of sub-Saharan Africa is poorly defined. We examined this association and any potential interaction with malaria and helminth infections in an ongoing pregnancy cohort study in Kenya. The association of maternal plasma 25(OH)D status with pregnancy outcomes and infant anthropometric measurements at birth was determined in a subset of women (n = 63). Binomial and linear regression analyses were used to examine associations between maternal plasma 25(OH)D and adverse pregnancy outcomes. Fifty-one percent of the women had insufficient (<75 nmol/L) and 21% had deficient (<50 nmol/L) plasma 25(OH)D concentration at enrollment. At birth, 74.4% of the infants had insufficient and 30% had deficient plasma 25(OH)D concentrations, measured in cord blood. Multivariate analysis controlling for maternal age and body mass index (BMI) at enrollment and gestational age at delivery found that deficient plasma 25(OH)D levels were associated with a four-fold higher risk of stunting in neonates (p = 0.04). These findings add to the existing literature about vitamin D and its association with linear growth in resource-limited settings, though randomized clinical trials are needed to establish causation.

Preferences of Young Adults Regarding Dissemination of Online Vitamin D Information

Purpose: To explore strategies for disseminating online information about vitamin D to young adults.

Methods: Participants were 50 males and females aged 18–25 years, living in Ontario, Canada. Eight focus groups (4 male; 4 female) were conducted; participants also completed a socio-demographic questionnaire. Audio files were transcribed verbatim; thematic analysis was used to identify key themes.

Results: Thematic analysis revealed that an effective educational intervention geared towards this population should be simple, brief, interesting, personally relevant, credible, and include incentives.

Conclusions: Feedback regarding intervention methodology could be used to inform interventions aiming to increase intake of vitamin D or other nutrients among young adults.

Vitamin D nutritional status and vitamin D regulated antimicrobial peptides in serum and pleural fluid of patients with infectious and noninfectious pleural effusions

BACKGROUND

Vitamin D and vitamin D dependent antimicrobial peptides such as Cathelicidin (LL-37) and β-defensin 2 have an important role in innate and adaptative immunity, but their role in pleural effusions has not been studied before.

METHODS

Serum and pleural fluid samples from 152 patients with pleural effusion were collected, corresponding to 45 transudates and 107 exudates, 51 infectious effusions (14 complicated and 37 non-complicated), 44 congestive heart failure effusions and 38 malignant effusions. The levels of 25 OH-vitamin D, 1,25-(OH)2-vitamin D, Vitamin D Binding Protein (VDBP), LL-37 and β-defensin 2, both in serum and pleural fluid were evaluated in this prospective study. Differences between groups were analysed using unpaired t tests or Mann-Whitney tests. Correlations between data sets were examined using Pearson correlation coefficient or Spearman rank correlation coefficient. Diagnostic accuracy was estimated using ROC curve analysis.

RESULTS

Low serum 25 OH vitamin D levels were found in all groups. Infectious effusions (IE) had higher serum and pleural fluid LL-37 levels compared to congestive heart failure or malignant effusions. Among IE, complicated had higher serum and pleural fluid LL-37 levels, and lower serum β-defensin-2 levels. Positive correlations were found between serum 25 OH-vitamin D levels and serum or pleural 1,25-(OH)2-vitamin D levels, and between 1,25-(OH)2-vitamin D and LL-37 serum. Diagnostic accuracy of the different molecules was moderate at best.

CONCLUSIONS

Hypovitaminosis D is highly prevalent in pleural effusions. LL-37 is produced intrapleurally in IE. This production is higher in complicated IE. No evidence of pleural production of β-defensin 2 was found in any of the groups. Diagnostic accuracy of the different molecules is at the best moderate for discriminating different types of effusions.

Age, serum 25-hydroxyvitamin D and vitamin D receptor (VDR) expression and function in peripheral blood mononuclear cells

The relationship between age, vitamin D status, expression and functionality of the vitamin D receptor (VDR), and key genes in the vitamin D pathway in immune cells is unclear. We enrolled adults 50 to 69 years old (20 subjects) and 70+ (20 subjects) and measured: 1) 25(OH)D levels by liquid chromatography/mass spectrometry; and 2) mRNA expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, cathelicidin, RIG-I, and interferon-β by qRT-PCR. Mean serum 25(OH)D was 30 ± 4 ng/mL and was not associated with age. Baseline expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, and RIG-I also did not differ by age; IFN-β expression, however, was higher in the 70+ year old group. 25(OH)D3- and 1,25(OH)2D3-induced VDR, TREM-1 and cathelicidin expression were similar between age groups, as was LPS-induced expression of VDR and of 1α-OHase. Ligand-induced 1,25D3-MARRS expression was higher in subjects ≥ 70 years. Serum 25(OH)D was inversely associated with LPS-stimulated VDR expression and with baseline or vitamin D-induced TREM-1 expression, adjusting for age, self-rated health, and functional status. In healthy adults ≥ 50 years, the expression and functionality of the VDR, 1α-OHase and key vitamin D pathway genes were not consistently associated with age.

Circulating Cathelicidin Concentrations in a Cohort of Healthy Children: Influence of Age, Body Composition, Gender and Vitamin D Status

Cathelicidin is an antimicrobial peptide whose circulating levels are related to vitamin D status in adults. This study sought to determine if circulating cathelicidin concentrations in healthy children are related to the age of the child, body composition and vitamin D status at birth and at the time of the study visit. Blood samples were obtained during yearly visits from 133 children, ages 2–7, whose mothers had participated in a pregnancy vitamin D supplementation RCT. Radioimmunoassay and ELISA were performed to analyze 25(OH)D and cathelicidin, respectively. Statistical analyses compared cathelicidin concentrations with concentrations of 25(OH)D at various time points (maternal levels throughout pregnancy, at birth, and child’s current level); and with race/ethnicity, age, gender, BMI, percent fat, and frequency of infections using Student’s t-test, χ², Wilcoxon ranked-sum analysis, and multivariate regression. The cohort’s median cathelicidin concentration was 28.1 ng/mL (range: 5.6–3368.6) and did not correlate with 25(OH)D, but was positively correlated with advancing age (ρ = 0.236 & p = 0.005, respectively). Forty patients evaluated at two visits showed an increase of 24.0 ng/mL in cathelicidin from the first visit to the next (p<0.0001). Increased age and male gender were correlated with increased cathelicidin when controlling for race/ethnicity, percent fat, and child’s current 25(OH)D concentration (p = 0.028 & p = 0.047, respectively). This study demonstrated that as children age, the concentration of cathelicidin increases. Furthermore, male gender was significantly associated with increased cathelicidin concentrations. The lack of association between vitamin D status and cathelicidin in this study may be due to the narrow range in observed 25(OH)D values and warrants additional studies for further observation.

Assessment of prevalence of hypovitaminosis D in multiethnic population of the United Arab Emirates

United Arab Emirates (UAE) has a high prevalence of hypovitaminosis D. Not much data are available regarding the prevalence of Vitamin D deficiency among multiethnic UAE adult population. (1) To determine the prevalence of hypovitaminosis D in multiethnic UAE population (2) To compare the Vitamin D status in Arab and non-Arab population (3) To identify the demographic variables associated with hypovitaminosis D. It was a retrospective study conducted at a secondary care hospital. Electronic case records of all the subjects who had checked their Vitamin D levels during the time period of May 2010–October 2012 were considered for the study. Vitamin D severe deficiency, deficiency, insufficiency, and sufficiency were defined as serum 25-hydroxy Vitamin D (25(OH)D) levels < 10 ng/mL, 10–20 ng/mL, 21–30 ng/mL, and > 30 ng/mL, respectively. A total 425 subjects were included for the data analysis. Vitamin D deficiency was diagnosed in 208 (48.9%) subjects followed by severe Vitamin D deficiency and insufficiency in 141 (33.2%) and 63 (14.8%) subjects, respectively. The overall prevalence of hypovitaminosis D was 96.9%. Negative association (r = −0.196, P < 0.01) was observed between body mass index (BMI) and 25(OH)D levels. Ethnicity was not (P = 0.103) a predictor of 25(OH)D levels. Majority of our study subjects had Vitamin D deficiency. There was no substantial difference in 25(OH)D levels of different ethnic groups. Female gender, age, and BMI were the predictors 25(OH)D levels.

Calcitriol-modulated human antibiotics: New pathophysiological aspects of vitamin D

Traditionally, calcitriol has been considered a calcium and phosphate regulating hormone, but has recently been shown to play a pivotal role in innate immunity. Many barrier and immune cells have membrane and intracellular receptors that recognize different microbial antigens. Activation of these receptors induces synthesis of 1α-hydroxylase, which acts on 25 hydroxyvitamin D to generate intracellular calcitriol. Calcitriol activates its receptor and enhances the synthesis of important human antibiotics like cathelicidin and β2-defensin while inhibiting hepcidin. These pluripotent peptides have an important role in innate immunity, and their regulation is abnormal in hypovitaminosis D. The literature on their secretion mechanisms, levels in different organic fluids, mechanism of action, and relationship with vitamin D is reviewed here.

Unique features of human cathelicidin LL-37

Cathelicidins are antimicrobial peptides produced by humans and animals in response to various pathogenic microbes. This review intends to provide a brief overview of the expression, structure, properties and function of human cathelicidin LL-37 which may be a therapeutic agent against a variety of bacterial and viral diseases, cancers, and hard-to-heal wounds. Cathelicidins act as a primary defense against bacteria and other pathogens in the case of inflammation. They are able to kill bacteria and fungi, inhibit and destroy bacterial biofilms, and possess antiviral and antiparasitics properties. They can also play a role in angiogenesis, wound healing, and the regulation of apoptosis. The host defense peptide LL-37 has emerged as a novel modulator of tumor growth and metastasis in carcinogenesis of various types of cancers. LL-37 is an antimicrobial peptide able of inducing various effects. It acts as an anti- and pro- inflammatory factor. Cathelicidins are able to directly and selectively destroy membranes of various microbes and cancer cells, but they do not attack normal cells. The role of cathelicidins in cancer is double-sided. They play an important role in killing cancer cells and may provide a new possibility for the development of cancer therapeutics. However, they also can participate in carcinogenesis. Due to its activity spectrum LL-37 could be applied in pharmacotherapy. Cathelicidin peptides could serve as a template for the development of modern anti-microbial and anti-viral drugs. LL-37 is an excellent candidate to develop into therapeutics for infected wounds.

Paradoxical changes in innate immunity in aging: recent progress and new directions

Immunosenescence, describing alterations, including decline of immune responses with age, is comprised of inappropriate elevations, decreases, and dysregulated immune responses, leading to more severe consequences of bacterial and viral infections and reduced responses to vaccination. In adaptive immunity, these changes include increased proportions of antigen-experienced B and T cells at the cost of naïve cell populations. Innate immune changes in aging are complex in spanning multiple cell types, activation states, and tissue context. Innate immune responses are dampened in aging, yet there is also a paradoxical increase in certain signaling pathways and cytokine levels. Here, we review recent progress and highlight novel directions for expected advances that can lead the aging field to a new era of discovery that will embrace the complexity of aging in human populations.

Vitamin D levels and cytokine profiles in patients with systemic lupus erythematosus

OBJECTIVES

To evaluate the expression of Th1, Th2, and Th17 cytokines in patients with systemic lupus erythematosus (SLE), and verify the association between serum cytokine levels and vitamin D concentration.

METHODS

The sample consisted of 172 patients with SLE. 25-Hydroxyvitamin D (25(OH)D) levels were measured by chemiluminescence and 25(OH)D levels <20 ng/mL were considered to reflect vitamin D deficiency. Serum cytokine levels were measured in once-thawed samples, using a Th1/Th2/Th17 CBA (cytometric beads array) kit.

RESULTS

One hundred and sixty-one (93.6%) patients were women and 128 (74.4%) were of European descent. Mean patient age was 40.5 ± 13.8 years, and mean age at diagnosis was 31.5 ± 13.4 years. At the time of study entry, patients had a median (IQR) SLEDAI of 2 (1-4) and SLICC of 0 (0-1). Mean 25(OH)D concentration was 25.4 ± 11.04 ng/mL. Fifty-nine (34.3%) patients had a vitamin D deficiency. No statistically significant associations were identified between cytokine and vitamin D levels. The most significant finding was a positive correlation between INF-α levels and SLEDAI (r(s) = 0.22, p = 0.04).

CONCLUSION

Although vitamin D deficiencies are highly prevalent in patients with SLE, vitamin D levels were not significantly associated with patient cytokine profiles. The positive correlation between IFN-α levels and SLEDAI showed in this study corroborates other findings in the literature. The present results did not replicate those of in vitro studies of the effect of vitamin D levels on cytokine profiles. Placebo-controlled intervention trials of the effect of vitamin D on cytokine profiles are still required before any definitive conclusions can be drawn regarding the association between these variables.

The role of Toll-like receptors and vitamin D in diabetes mellitus type 1--a review

It is widely accepted that type 1 diabetes mellitus (T1DM) is an autoimmune disease resulting from an interaction between immunologic, genetic and environmental factors. However, the exact mechanism leading to the development of T1DM remains incomplete. There is a large body of evidence pointing towards the important role of toll-like receptor (TLR) activation and vitamin D deficiency in T1DM pathogenesis. In this article, we review the available data on the influence of TLRs' level of activation and vitamin D status on the risk of the development of T1DM in humans and rodent models. We also summarize the current information regarding the interactions between TLRs' level of activation, vitamin D status and various environmental factors, such as enteroviral infections, the gut microbiota and breastfeeding substitution, among others. Our results stipulate that vitamin D seems to protect against T1DM by reducing the TLRs' level of activation.

Systematic review of association between vitamin D levels and susceptibility and disease activity of ankylosing spondylitis

OBJECTIVES

Vitamin D appears to have significant effects on both innate and acquired immunity and deficiency may be associated with both susceptibility and disease severity in some autoimmune conditions. There has been little focus on the potential immunomodulatory role of vitamin D in AS. This study systematically reviews the evidence for an association between vitamin D deficiency and disease susceptibility and severity in AS.

METHODS

A systematic review was conducted using Medline, EMBASE, Web of Science and conference abstracts of the European League Against Rheumatism (2002-13), British Society for Rheumatology (1993-2013) and ACR (2006-13).

RESULTS

Fifteen original articles and five conference abstracts met the criteria for inclusion. All were cross-sectional in design. Seven of 11 studies identified lower concentrations of 25-hydroxyvitamin D (25OHD) in AS patients compared with healthy controls. A significant inverse correlation between 25OHD and disease activity was observed in 5 of 11 studies. The majority of studies that failed to demonstrate significant findings used inappropriate statistical methods.

CONCLUSION

Cross-sectional studies using appropriate statistical analyses have highlighted that AS is associated with lower vitamin D concentrations. Within groups of AS patients there is some evidence that low vitamin D concentrations are associated with higher disease activity. However, there are insufficient published data to support an immunomodulatory role for vitamin D in AS. Further study with a longitudinal design is required to understand whether optimizing vitamin D in AS has potential as a disease-modifying intervention.

Nutrition, diet and immunosenescence

Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly.

Immunosenescence, aging, and systemic lupus erythematous

Senescence is a normal biological process that occurs in all organisms and involves a decline in cell functions. This process is caused by molecular regulatory machinery alterations, and it is closely related to telomere erosion in chromosomes. In the context of the immune system, this phenomenon is known as immunosenescence and refers to the immune function deregulation. Therefore, functions of several cells involved in the innate and adaptive immune responses are severely compromised with age progression (e.g., changes in lymphocyte subsets, decreased proliferative responses, chronic inflammatory states, etc.). These alterations make elderly individuals prone to not only infectious diseases but also to malignancy and autoimmunity. This review will explore the molecular aspects of processes related to cell aging, their importance in the context of the immune system, and their participation in elderly SLE patients.