Vitamin D and immunity

Vitamin D regulates microbiome-dependent cancer immunity

A role for vitamin D in immune modulation and in cancer has been suggested. In this work, we report that mice with increased availability of vitamin D display greater immune-dependent resistance to transplantable cancers and augmented responses to checkpoint blockade immunotherapies. Similarly, in humans, vitamin D-induced genes correlate with improved responses to immune checkpoint inhibitor treatment as well as with immunity to cancer and increased overall survival. In mice, resistance is attributable to the activity of vitamin D on intestinal epithelial cells, which alters microbiome composition in favor of Bacteroides fragilis, which positively regulates cancer immunity. Our findings indicate a previously unappreciated connection between vitamin D, microbial commensal communities, and immune responses to cancer. Collectively, they highlight vitamin D levels as a potential determinant of cancer immunity and immunotherapy success.

Investigation of serum level relationship of pro-inflammatory and anti-inflammatory cytokines with vitamin D among healthy Ghanaian population

BACKGROUND

The interplay between vitamin D status and inflammatory cytokines in a supposedly sufficient sunshine environment has not well been evaluated. The study sought to determine their association.

METHODS

This cross-sectional study involved 500 healthy adult blood donors from some selected hospitals in Ghana enrolled from June to November 2016. Venous blood samples were obtained from participants, 25(OH)D, TNF-alpha, IFN-gamma, and IL 10 were measured using enzyme linked immunosorbent assay (ELISA) technique. Serum levels of 25(OH)D < 20ng/ml were classified as being deficient or low.

RESULTS

The average age of the participants was 27.97 years. No statistically significant association was established between 25(OH) D status, mean age (p = 0.1693), and gender (p = 0.5461) of study participants. Similarly, the median 25(OH) D (p = 0.8392), IL-10 (p = 0.5355), TNF-alpha (p = 0.9740), and IFN-gamma (p = 0.6908) were not significantly different across gender. There was a significantly increased levels of TNF-alpha (p < 0.0001) and IFN-gamma (p < 0.0001) among participants with 25(OH) D deficiency compared to those without deficiency. Concurrently, participants with 25(OH)D deficiency had a significantly reduced levels of IL-10 (p < 0.0001) compared to those without 25 (OH) D deficiency. The most accurate biochemical markers for identifying 25 (OH) D deficiency were IFN-gamma (AUC = 0.879; p < 0.0001) followed by TNF-gamma (AUC = 0.849; p < 0.0001) and IL-10 (AUC = 0.707; p < 0.0001).

CONCLUSION

There was a significant association between vitamin D levels and pro-inflammatory cytokines (TNF-alpha, IFN-gamma) and anti-inflammatory cytokine (IL 10) among healthy Ghanaian populace.

Impact of vitamin D supplementation on the clinical outcomes of COVID-19 pneumonia patients: a single-center randomized controlled trial

BACKGROUND

Vitamin D supplementation for infectious diseases has been discussed, but its role in COVID-19 is unclear. Therefore, this study examined the clinical outcomes of COVID-19 pneumonia patients who received vitamin D supplementation.

METHODS

This prospective, open-label, randomized controlled trial was conducted in a university hospital between July 2020 and March 2022. The inclusion criteria were patients aged ≥ 18 years with COVID-19 pneumonia patients. The patients were randomized into two groups: an intervention group receiving vitamin D supplementation (alfacalcidol, two mcg orally daily) until discharge and a control group. The clinical outcomes were pneumonia treatment duration, length of hospital stay, and change in pneumonia severity index between enrollment and discharge. Subgroup analysis was conducted for supplemental oxygen use, high-dose corticosteroid administration, evidence of lymphopenia, C-reactive protein concentration, and total serum vitamin D concentration. Adverse events were monitored.

RESULTS

Two hundred ninety-four patients were recruited (147 per group). The two groups did not differ in pneumonia treatment duration to discharge (p = 0.788) or length of hospital stay (p = 0.614). The reduction in the pneumonia severity index between enrollment and discharge was more significant in the intervention group (p = 0.007); a significant decrease was also observed among patients who had C-reactive protein > 30 mg/L (p < 0.001). No adverse reactions were recorded.

CONCLUSIONS

Adding active vitamin D to standard treatment may benefit COVID-19 pneumonia patients who require supplemental oxygen or high-dose corticosteroid therapy or who have high C-reactive protein concentrations (> 30 mg/L) upon treatment initiation.

TRIAL REGISTRATION

Thai Clinical Trials Registry TCTR20210906005 (retrospectively registered, 6 September 2021).

Species identification, antifungal susceptibility patterns, and vitamin D3 level in women with vaginal candidiasis: a case-control study in Iran

Vulvovaginal candidiasis (VVC) is a fungal infection that is a global issue of women's health due to its association with morbidity, infertility, and economic costs. This study aimed to compare the vitamin D3 levels between women with VVC to healthy controls and determine the species distribution and susceptibility pattern of isolates. Species identification was performed using sequencing of the ITS-rDNA regions and amplification of the HWP1 gene. Antifungal susceptibility testing was determined by the disk diffusion method. Moreover, serum vitamin D3 levels were measured using a commercial ELISA (enzyme-linked immunosorbent assay) kit. Our results indicated that vitamin D3 level in women with VVC was lower than those of healthy women (p-value < .001). Candida albicans complex (62.8 percent) was the most common species, and most species were susceptible to fluconazole, itraconazole, ketoconazole, and nystatin. In conclusion, our study revealed a potential link between vitamin D3 deficiency and VVC in women. Although our findings showed significantly lower vitamin D3 levels in women with VVC, further research is needed to establish a definitive causative relationship between vitamin D3 deficiency and VVC. Nonetheless, our study highlights the potential importance of maintaining adequate levels of vitamin D3 and the need for further exploration in this area.

Changes in the Expression of TGF-Beta Regulatory Pathway Genes Induced by Vitamin D in Patients with Relapsing-Remitting Multiple Sclerosis

Vitamin D is an environmental factor related to multiple sclerosis that plays a significant role in immune regulation. TGF-β is a superfamily of cytokines with an important dual effect on the immune system. TGF-β inhibits the Th1 response while facilitating the preservation of regulatory T cells (FOXP3+) in an immunoregulatory capacity. However, when IL-6 is present, it stimulates the Th17 response. Our aim was to analyze the regulatory effect of vitamin D on the in vivo TGF-β signaling pathway in patients with relapsing-remitting multiple sclerosis (RRMS). A total of 21 patients with vitamin D levels < 30 ng/mL were recruited and supplemented with oral vitamin D. All patients were receiving disease-modifying therapy, with the majority being on natalizumab. Expression of SMAD7, ERK1, ZMIZ1, BMP2, BMPRII, BMP4, and BMP5 was measured in CD4+ lymphocytes isolated from peripheral blood at baseline and one and six months after supplementation. SMAD7 was overexpressed at six months with respect to baseline and month one. ERK1 was overexpressed at six months with respect to month one of treatment. No significant differences in expression were observed for the remaining genes. No direct correlation was found with serum vitamin D levels. BMPRII expression changed differentially in non-natalizumab- versus natalizumab-treated patients. Changes were observed in the expression of ERK1, BMP2, and BMP5 based on disease activity measured using the Rio-Score, BMP2 in patients who had relapses, and BMP5 in those whose EDSS worsened. Our results suggest indirect regulation of vitamin D in TGF-β pathway genes in patients with RRMS.

The role of vitamin D status on treatment outcome among HIV- infected children receiving care in Kisumu County, Kenya

Background

Kenya has a paediatric HIV burden of nearly 140,000 children, of which only 48% of those on antiretroviral therapy (ART) have achieved the desired viral suppression possibly due to vitamin D deficiency. We explored the influence of vitamin D levels on treatment outcome.

Method

We performed a cross-sectional study of 196 participants aged 3 - 14 years; among them 98 HIV infected who received treatment between 2019 - 2020 in Jaramogi Oginga Odinga Teaching and Referral Hospital, Kenya. The exposure was vitamin D levels, including deficient (<20 ng/ml), insufficient (≥20 - <30 ng/ml), and sufficient (30 - 50ng/ml). The outcome was optimal immune recovery (CD4 ≥ 500 cells/mm3) and optimal viral suppression (viral load ≤ 200 copies/ml). We compared difference in means for each vitamin D category between HIV infected and uninfected using independent t-test, multiple comparisons of vitamin D levels among age categories using ANOVA and post hoc test and Pearson correlation to correlate vitamin D levels, CD4 and viral load of HIV infected children.

Results

Compared with HIV uninfected, HIV infected recorded mean age ± standard deviation of10.65±2.17 years with 39(39.8%) males vs. 6.68±2.81 years with 52(53.1%) males p<0.001; and the difference in vitamin D mean levels was statistically significant [28.21 ± 6.39 infected vs.30.88 ± 6.62 uninfected] t = 2.94, df =194, p = 0.004, 95%CI (0.90 - 4.59). Among age categories, mean vitamin D varied significantly F (2,193) = 10.68, p =0.001; with higher levels observed between 1-4 years category {mean difference 4.64ng/ml, p = 0.02, [95%CI 1.49 - 7.78]} and 5-9 years category {mean difference 4.33ng/ml, p = 0.001, [95%CI 1.89 - 6.38]} as compared to 10 - 14 years respectively.Additionally, children with optimal immune recovery recorded higher proportion of vitamin D deficiency and insufficiency (12.24% and 42.86%) as compared with sub optimally recovered 1.02% and 4.08%); while children with optimal viral suppression recorded higher proportion of vitamin D deficiency and insufficiency (8.16% and 30.61%) as compared with sub optimally suppressed (5.1% and 16.3%).

Conclusion

Infections with HIV suppresses levels of vitamin D, but this has no influence on CD4 counts and viral load status in children receiving ART.

Vitamin D in SARS-CoV-2 patients with non-invasive ventilation support

BACKGROUND

Vitamin D (VitD) deficiency has been reported to be associated with respiratory tract infection. In this work we evaluated the concentration of VitD in COVID-19 patients experiencing acute respiratory infections of different levels of severity excluding those who underwent invasive respiratory support.

METHODS

The levels of serum VitD and C-reactive protein (CRP) were analyzed in 118 consecutive hospitalized COVID-19 patients (74 male, 44 female), confirmed with rRT-PCR. Of these patients with ventilation support 52 (44.1%) received oxygen via nasal cannula, oxygen mask or an oxygen mask with a reservoir, 48 (40.7%) were on a continuous positive airway pressure device (CPAP) and 18 (15,3%) on non-invasive mechanical ventilation (NIMV).

RESULTS

The median values (range) of VitD and of CRP were 15.1 ng/mL (1.3-73.3) and 14.2 mg/L (5.0-151.2), respectively. A negative correlation from VitD levels and those of CRP (correlation coefficient: 0.259: P=0.005) was observed. VitD levels in O<inf>2</inf> support patients were significantly higher than in both CPAP and NIMV patients. No statistical differences were found for CRP levels (P=0.834) among the three type of oxygen support. Fewer patients with O<inf>2</inf> support had VitD <30 ng/mL and <20 ng/mL than CPAP and NIMV patients. There were no relationships between VitD and the three classes of IgM (P=0.419) and of IgG (P=0.862) SARS-CoV-2 antibodies values. The behavior was the same for CRP.

CONCLUSIONS

Our study shows that a significant proportion of COVID-19 patients have a VitD deficiency and that this condition is more frequent in CPAP and in NIMV patients.

The Effect of a Gluten-Free Diet on Vitamin D Metabolism in Celiac Disease: The State of the Art

Celiac disease is a chronic autoimmune disorder involving the small intestine, characterized by villous atrophy, crypt hyperplasia and an increase in intraepithelial lymphocytes. Due to both calcium malabsorption and immune activation, a high prevalence of bone mass derangement is evident in this condition, regardless of the presence of overt malabsorption. Alterations of mineral metabolism are also frequently described, and in this review, the modifications of serum levels of vitamin D are analyzed, according to the available literature on this topic. In untreated patients, secondary hyperparathyroidism is responsible for the hyperconversion of 25-vitamin D into 1,25-vitamin D making mandatory the determination of serum levels of both vitamin metabolites to avoid a wrong diagnosis of vitamin D deficit. A gluten-free diet allows for a normalization of bone and mineral metabolism, reverting these abnormalities and raising some doubts on the need for vitamin supplementation in all the patients. Data available do not support this wide indication, and a complete evaluation of bone and mineral metabolism should be performed to select patients who need this therapeutic approach.

The association between serum 25-hydroxyvitamin D and the prevalence of herpes simplex virus

Previous studies have reported a potential anti-infection effect for vitamin D. However, the relationship between vitamin D status and herpes simplex virus (HSV) infection has not yet been evaluated. Therefore, this study aimed to determine the association between serum 25-hydroxyvitamin D [25(OH)D] and infection with HSV types 1 and 2 (HSV-1 and HSV-2). Data were collected from the National Health and Nutrition Examination Survey from 2007 to 2016. The association between 25(OH)D and HSV prevalence was evaluated using propensity score matching (PSM) and univariate and multivariate logistic regression analyses. Overall, 14 174 participants were included in the final analysis. Before PSM, 8639 (60.9%) had positive HSV-1 and 2636 (18.6%) had HSV-2. The HSV-1 and HSV-2 positive groups had more females and older individuals (p < 0.05). The HSV-2 patients had lower 25(OH)D levels than those with HSV-1. Age and gender did not differ in the groups after PSM (p > 0.05). The 25(OH)D level was significantly lower in the HSV-1 and HSV-2 groups than in the non-HSV infection groups. Multivariate logistic regression showed that serum 25(OH)D level was negatively associated with HSV-1 and HSV-2 infection (odds ratio [OR] = 0.730 and 0.691, p < 0.001, respectively). Vitamin D deficiency was an independent risk factor for both HSV-1 and HSV-2 (adjusted OR = 2.205 and 2.704, p < 0.001, respectively). Lower serum 25(OH)D levels correlated significantly with increased HSV-1 and HSV-2 infection risk.

Vitamin D and Colorectal Cancer: Current Perspectives and Future Directions

Vitamin D is considered to be the main mediator of the beneficial effects of sun exposure. In humans, highest expression of Vitamin D receptors is found in the intestinal tract. In addition, 1α,25-dihydroxyvitamin D3 (or calcitriol), the most active Vitamin D metabolite, plays important homeostatic roles in the intestine, particularly calcium absorption. Vitamin D deficiency is defined as a serum 25-hydroxyvitamin D [25(OH)D] level of < 20 ng/mL. Previous studies show that higher circulating 25(OH)D levels are associated with reduced risk of colorectal cancer (CRC) and improved survival. Most research to date has been conducted in animals, specifically mice. Although human studies have a limited number of participants, one study recruiting a large cohort of patients with advanced or metastatic CRC revealed that higher plasma 25(OH)D levels are associated with improved overall and progression-free survival. However, the effects of Vitamin D supplementation on incidence and mortality of CRC remain inconclusive. Although Vitamin D may help to prevent cancer, there is a paucity of research demonstrating conclusively that Vitamin D alters prognosis after chemotherapy. Here, we review the mechanisms by which Vitamin D affects CRC, as well as the results of clinical, epidemiological, and human intervention studies. We also discuss current perspectives and future directions regarding Vitamin D and CRC.

Effect of Vitamin D Supplementation on CD4 Count in HIV-Infected Children and Adolescents in North India: A Non-Randomized Comparative Study

BACKGROUND

HIV infection is still a serious public health issue globally. Suboptimal vitamin D status is highly prevalent in HIV-infected children and adolescents throughout the world.

OBJECTIVES

To evaluate the outcome of vitamin D supplementation on CD4 count in HIV-infected children and adolescents with suboptimal vitamin D status.

METHODS

Vitamin D level of HIV-infected children and adolescents were measured at enrolment. Suboptimal vitamin D level was defined as 25(OH)D < 30 ng/ml. Vitamin D insufficiency and deficiency were defined as 21-29 and <20 ng/ml, respectively. Children with suboptimal vitamin D levels were supplemented with vitamin D.

RESULTS

This was a single-centre, non-randomized comparative study enrolling 50 eligible participants. There were 20 patients who were vitamin D sufficient, 7 were vitamin D insufficient and 23 were found to be vitamin D deficient at enrolment. However, after supplementation, the status of sufficient remained same and 7 insufficient become sufficient, whereas in 23 deficient, 18 (78.3%) become sufficient and 5 (21.7%) become insufficient and this change was found statistically significant among the groups (χ2 = 6.52, p = 0.038). There was a significant improvement of CD4 count from baseline to 4 months in deficient group on vitamin D supplementation (p value < 0.001; 1.2-fold rise). No significant change was seen in vitamin D insufficient (p value = 0.791) and sufficient groups (p value = 0.168).

CONCLUSION

Vitamin D should be supplemented in HIV-infected children on ART with low CD4 counts.

Vitamin D status and associated factors among HIV-infected children and adolescents on antiretroviral therapy in Kampala, Uganda

Background

A high prevalence of suboptimal serum vitamin D has been reported among HIV infected children even in countries with high sunshine abundance throughout the year. Vitamin D is a potent immune modulator of innate and adaptive immune responses. Vitamin D regulates immune responses through the vitamin D receptor on CD4 cells. We aimed to determine the vitamin D status of HIV infected children and factors associated with suboptimal vitamin D.

Methods

This was a cross sectional study. We enrolled children aged between 6 months and 12 years attending an outpatient paediatric HIV clinic. Serum 25-hydroxyvitamin D (25(OH)D) was measured using the electrochemoluminisence method. Suboptimal vitamin D was defined as 25(OH)D <30 ng/ml, vitamin D insufficiency and deficiency were 21–29 ng/ml and <20 ng/ml respectively. Anthropometry, physical exam and medical history were documented. Logistic regression was performed.

Results

We enrolled 376 children with mean age (sd) 8.05 years (3.03), a median (IQR) duration of ART of 5.9 years (3.2–8.4). Majority of the children (64%) had been exposed to non nucleoside reverse transcriptase inhibitors (NNRTIs). A third were severely immunosuppressed (CD4% ≤15%) at ART initiation. At the time of the study, the majority (89%) were virologically suppressed (VL <1000 copies/ml). Prevalence of 25(OH)D <30 ng/ml was 49 (13%) of 375 participants and 11 (3%) had 25(OH)D <20 ng/ml. Lopinavir/ritonavir regimen was independently associated with 25(OH)D <30 ng/ml; OR 0.27 CI (0.13–0.57), p value-0.002. Serum 25(OH)D <20 ng/ml was associated with CD4 count ≤15% at ART initiation OR 6.55(1.30–32.9), p value—0.023 and use of NNRTIs; OR 10.9(1.22–96.2), p value—0.03.

Conclusion

We found a low prevalence of suboptimal vitamin D compared to earlier reports. Severe immunosuppression at ART initiation and use of NNRTIs increases odds of deficiency. Vitamin D supplementation should be considered in severely immunosuppressed children initiating ART.

Acute Radiation Syndrome and the Microbiome: Impact and Review

Study of the human microbiota has been a centuries-long endeavor, but since the inception of the National Institutes of Health (NIH) Human Microbiome Project in 2007, research has greatly expanded, including the space involving radiation injury. As acute radiation syndrome (ARS) is multisystemic, the microbiome niches across all areas of the body may be affected. This review highlights advances in radiation research examining the effect of irradiation on the microbiome and its potential use as a target for medical countermeasures or biodosimetry approaches, or as a medical countermeasure itself. The authors also address animal model considerations for designing studies, and the potential to use the microbiome as a biomarker to assess radiation exposure and predict outcome. Recent research has shown that the microbiome holds enormous potential for mitigation of radiation injury, in the context of both radiotherapy and radiological/nuclear public health emergencies. Gaps still exist, but the field is moving forward with much promise.

Brief Report: CYP27B1 rs10877012 T Allele Was Linked to Non-AIDS Progression in ART-Naïve HIV-Infected Patients: A Retrospective Study

BACKGROUND

HIV/AIDS progression is linked to vitamin D, which is regulated by several key cytochromes P450 (CYP). Single nucleotide polymorphisms (SNPs) in CYP genes influence vitamin D metabolism and serum levels. The objective of this study was to evaluate the association between CYP SNPs and the clinical AIDS progression in antiretroviral treatment (ART)-naïve HIV-infected patients.

METHODS

We performed a retrospective study in 661 ART-naïve HIV-infected patients who were stratified by their AIDS progression pattern [181 long-term nonprogressors (LTNPs), 332 moderate progressors, and 148 rapid progressors (RPs)]. Four CYP SNPs (CYP2R1 rs10500804, CYP2R1 rs1993116, CYP27B1 rs10877012, and CYP24A1 rs6013897) were genotyped using Agena Bioscience's MassARRAY platform. Correction for multiple testing was performed using the false discovery rate (Benjamini-Hochberg procedure).

RESULTS

The adjusted regression showed a significant association only for CYP27B1 rs10877012 SNP. When analyzing all HIV patients, the rs10877012 T allele was protective against AIDS progression (ordinal outcome) under the dominant [adjusted odds ratio (aOR) = 0.69; P = 0.021) and additive (aOR) = 0.75; P = 0.025] inheritance models. When analyzing LTNPs versus RPs, the rs10877012 T allele also showed a significant protective association under the dominant (aOR = 0.45; P = 0.004) and additive (aOR = 0.54; P = 0.008) inheritance models. P values remained significant after correcting by multiple comparisons only for the comparison of LTNPs versus RPs (extreme phenotypes).

CONCLUSIONS

The CYP27B1 rs10877012 T allele was linked to non-AIDS progression in ART-naïve HIV-infected patients. The rs10877012 SNP seems to have an impact on the clinical AIDS progression, possibly modifying vitamin D levels, which could be relevant for the pathogenesis of HIV infection.

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.

Protection from Ultraviolet Damage and Photocarcinogenesis by Vitamin D Compounds

Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D₃) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds.

Sarcopenia among patients after allogeneic hematopoietic stem cell transplantation and the impact of chronic graft-versus-host disease

PURPOSE

This study investigated the frequency and characteristics of sarcopenia among patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) with a specific focus on the chronic graft-versus-host disease (cGVHD) population and its association with malnutrition, vitamin D and clinical characteristics.

METHODS

We assessed sarcopenia, vitamin D levels, and nutritional status in 73 patients who underwent allo-HSCT, of which 45 were diagnosed with cGVHD. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People (EWGSOP) criteria.

RESULTS

Sarcopenia was diagnosed in 19.2% of patients after allo-HSCT with statistically no significant difference between cGVHD and non-cGVHD patients. The risk factor for sarcopenia was the male gender. Sarcopenia in allo-HSCT patients correlated strongly with malnutrition and with current corticosteroid treatment (p < 0.005). Among cGVHD patients sarcopenia additionally correlated strongly with the number of prior systemic immunosuppressive therapy lines (p < 0.005) and moderately with the intensity of immunosuppression, cGVHD severity global rating assessed by both the health care provider and the patient and joint and fascia cGVHD involvement (p < 0.05). Vitamin D deficiency was found in more than 54.8% of patients, but the correlation to sarcopenia was not found.

CONCLUSION

Sarcopenia was found to be common in long term survivors of allo-HSCT independently of the cGVHD diagnosis. Prospective longitudinal studies are needed for a better understanding of factors affecting the development of sarcopenia after allo-HSCT.

Lymphocyte and monocyte vitamin D receptor expression during paricalcitol or calcitriol treatments in patients with stage 5 chronic kidney disease

PURPOSE

In this study, we aimed to investigate the effect of paricalcitol and calcitriol usage on vitamin D receptor (VDR) contents of CD8+ , CD4+ lymphocytes and monocytes in stage 5d chronic kidney disease (CKD) patients.

METHODS

Thirty-six hemodialysis patients older than 18 years of age and 19 healthy controls (group HC) without any known acute or chronic diseases were included in the study. The group of patients undergoing scheduled hemodialysis comprised three subgroups: group CL: patients on calcitriol (n: 10), group PC: patients on paricalcitol (n: 13), and group NT: patients not taking any vitamin D or VDR activating medications (n: 13). CD8+/VDR, CD4+/VDR and MONO/VDR values were representing the ratio of VDR representing cells among related cell group. On the other hand, values of CD8+/MFI, CD4+/MFI and MONO/MFI have shown the total amount of cellular VDR content per cell which has been given as of mean fluorescence intensity in the flow cytometric process. Main CKD mineral bone disorder parameters such as a hemogram, serum BUN, creatinine, albumin, Ca, iP, iPTH, 25(OH)D₃ levels were also measured.

RESULTS

Average VDR contents in CD8+, CD4+ and monocytes were not different among three patient groups on hemodialysis. But in all hemodialysis subgroups, CD8+/VDR, CD4+/VDR, MONO/VDR, CD8+/MFI, CD4+/MFI and MONO/MFI levels were found to be higher compared with the healthy control subjects (p < 0.001). Among hemodialysis groups, no significant CD8+/VDR, CD4+/VDR, and MONO/VDR content differences were found with regard to the type of VDR activator agent used. There was no difference in serum levels of 25(OH)D₃ and CRP among groups participating in the study.

CONCLUSION

There was no difference between CD8+/VDR, CD4+/VDR, and MONO/VDR levels in hemodialysis patients using calcitriol or paricalcitol, suggesting that both treatment agents may have a similar effect on VDR contents in lymphocytes and monocytes in that patient population. But in all hemodialysis subgroups, CD8+/VDR, CD4+/VDR, and MONO/VDR levels were found to be higher compared with the healthy control subjects, suggesting an overexpression of VDR through a non CRP and/or 25(OH)D₃ dependent mechanism.

Effects of dietary 25-hydroxyvitamin D3 supplementation on growth performance, immune function and antioxidative capacity in weaned piglets

The study evaluated the effects of different doses of 25-hydroxyvitamin D₃ (25(OH)D₃) on growth performance, immune function and antioxidative capacity in piglets. In a 21-d trial, 35 weaned pigs were divided into five groups and diets were supplemented with 5.5 (control), 43.0, 80.5, 118.0 and 155.5 μg 25(OH)D₃/kg, respectively. No treatment effects were observed for average daily gain, average daily feed intake and feed to gain ratio. Increasing dietary 25(OH)D₃ levels increased serum 25(OH)D₃ concentrations linearly (p < 0.01), decreased the frequency of CD3+CD4+ and CD3+CD8+ T cells (p < 0.01), and the serum level of complement component 3 (p < 0.05). Supplementation of 80.5 and 118.0 μg 25(OH)D₃/kg enhanced the activity of serum glutathione peroxidase (p < 0.05) and addition of 43.0 μg 25(OH)D₃/kg increased the malondialdehyde concentration (p < 0.05). Overall, feeding high-dose 25(OH)D₃ to weaned pigs partly improved immune functions and the antioxidative capacity.

DBP rs16846876 and rs12512631 polymorphisms are associated with progression to AIDS naïve HIV-infected patients: a retrospective study

Background

Most of the circulating Vitamin D (VitD) is transported bound to vitamin D-binding protein (DBP), and several DBP single nucleotide polymorphisms (SNPs) have been related to circulating VitD concentration and disease. In this study, we evaluated the association among DBP SNPs and AIDS progression in antiretroviral treatment (ART)-naïve-HIV-infected patients.

Methods

We performed a retrospective study in 667 patients who were classified according to their pattern of AIDS progression (183 long-term non-progressors (LTNPs), 334 moderate progressors (MPs), and 150 rapid progressors (RPs)) and 113 healthy blood donors (HIV, HCV, and HBV negative subjects). We genotyped seven DBP SNPs (rs16846876, rs12512631, rs2070741, rs2282679, rs7041, rs1155563, rs2298849) using Agena Bioscience’s MassARRAY platform. The genetic association was evaluated by Generalized Linear Models adjusted by age at the moment of HIV diagnosis, gender, risk group, and VDR rs2228570 SNP. Multiple testing correction was performed by the false discovery rate (Benjamini and Hochberg procedure; q-value).

Results

All SNPs were in HWE (p > 0.05) and had similar genotypic frequencies for DBP SNPs in healthy-controls and HIV-infected patients. In unadjusted GLMs, we only found significant association with AIDS progression in rs16846876 and rs12512631 SNPs. In adjusted GLMs, DBP rs16846876 SNP showed significant association under the recessive inheritance model [LTNPs vs. RPs (adjusted odds ratio (aOR) = 3.53; q-value = 0.044) and LTNPs vs. MPs (aOR = 3.28; q-value = 0.030)] and codominant [LTNPs vs. RPs (aOR = 4.92; q-value = 0.030) and LTNPs vs. MPs (aOR = 3.15; q-value = 0.030)]. Also, we found DBP rs12512631 SNP showed significant association in the inheritance model dominant [LTNPs vs. RPs (aOR = 0.49; q-value = 0.031) and LTNPs vs. MPs (aOR = 0.6; q-value = 0.047)], additive [LTNPs vs. RPs (aOR = 0.61; q-value = 0.031)], overdominant [LTNPs vs. MPs (aOR = 0.55; q-value = 0.032)], and codominant [LTNPs vs. RPs (aOR = 0.52; q-value = 0.036) and LTNPs vs. MPs (aOR = 0.55; q-value = 0.032)]. Additionally, we found a significant association between DBP haplotypes (composed by rs16846876 and rs12512631) and AIDS progression (LTNPs vs RPs): DBP haplotype AC (aOR = 0.63; q-value = 0.028) and the DBP haplotype TT (aOR = 1.64; q-value = 0.028).

Conclusions

DBP rs16846876 and rs12512631 SNPs are related to the patterns of clinical AIDS progression (LTNP, MP, and RP) in ART-naïve HIV-infected patients. Our findings provide new knowledge about AIDS progression that may be relevant to understanding the pathogenesis of HIV infection.

Probiotic Supplementation in Patients with Alzheimer's Dementia - An Explorative Intervention Study

Background:

Dysbiosis of intestinal microbiota in the elderly can cause a leaky gut, which may result in silent systemic inflammation and promote neuroinflammation - a relevant pathomechanism in the early course of Alzheimer’s disease.

Objective:

The rebalancing of the microbiome could benefically impact on gut inflammation and immune activation.

Methods:

In this study, routine laboratory tests in twenty outpatients (9 females, 11 males, aged 76.7 ± 9.6 years) with Alzheimer’s disease were investigated. The mean Mini Mental State Examination score was 18.5 ± 7.7. Biomarkers of immune activation – serum neopterin and tryptophan breakdown - as well as gut inflammation markers and microbiota composition in fecal specimens were analyzed in 18 patients be-fore and after probiotic supplementation for 4 weeks.

Results:

After treatment a decline of fecal zonulin concentrations and an increase in Faecalibacterium prausnitzii compared to baseline were observed. At the same time, serum kynurenine concentrations in-creased (p <0.05). Delta values (before - after) of neopterin and the kynurenine to tryptophan ratios (Kyn/Trp) correlated significantly (p <0.05).

Conclusion:

Results show that the supplementation of Alzheimer’s disease patients with a multispecies probiotic influences gut bacteria composition as well as tryptophan metabolism in serum. The correlation between Kyn/Trp and neopterin concentrations points to the activation of macrophages and/or dendritic cells. Further studies are warranted to dissect the potential consequences of Probiotic supplementation in the course of Alzheimer’s disease.

Higher Sun Exposure is Associated With Lower Risk of Pediatric Inflammatory Bowel Disease: A Matched Case-control Study

OBJECTIVES

The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide. Ecological studies show higher incidence in regions at higher latitude or lower ambient ultraviolet radiation; individual-level associations with sun exposure have not been assessed.

METHODS

We recruited children (0-17 years) with IBD from 2 large hospitals in Melbourne, Australia. Control participants were recruited from the day surgery unit of one of the same hospitals. Questionnaires provided data on demographics, past sun exposure, the likelihood of sunburn (skin sensitivity) or tanning following sun exposure, use of sun protection, physical activity, and parental smoking and education. Grandparent ancestry was used to determine participant ethnicity. Cases and controls were matched on age and sex. We used conditional logistic regression to test the association between being an IBD case and past sun exposure at different ages, adjusted for a range of other factors.

RESULTS

After matching, n = 99 cases and n = 396 controls were included in the analysis. In multivariable analysis, for each 10 min increment in leisure-time sun exposure in summer or winter there was a linear 6% reduction in the odds of having IBD (P = 0.002). Results were similar in sensitivity analyses including only the most recently diagnosed cases, only Caucasian cases and controls, only those with symptom onset within the year before study entry, or additionally adjusted for age or physical activity.

CONCLUSIONS

Higher sun exposure in the previous summer or winter was associated with a reduced risk of having IBD. There are plausible pathways that could mediate this effect.

The lung microbiome, vitamin D, and the tuberculous granuloma: A balance triangle

Mycobacterium tuberculosis (Mtb) has the extraordinary ability to persist for decades within granulomas in the human host. These histopathological structures involved in both protection and pathogenesis, are subject to various influences from the host systemically and through micro-niche environments. Despite the fact that vitamin D (VD) has a key role in macrophage activation and mycobacterial clearance in the early stages of Mtb infection, the overall role of VD in granuloma maintenance or functionality has been scarcely studied. VD deficiency has long time been known to influence on gut microbiota composition, and recent studies have shown that it can also impact on respiratory microbiome. The human microbiota plays an important role in pathogen colonization resistance, and it has been proposed to play a potential role in TB pathogenesis. In this article, we have reviewed current knowledge on the interaction between VD, the lung microbiome and TB, and propose mechanisms by which the tuberculous granuloma's outcome could be modulated by these two factors. The determinants of the final fate of lung granulomas are still unclear, and deciphering the underlying drivers of Mtb infection outcome within those structures is of critical importance.

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

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

Ultraviolet radiation-induced immunosuppression and its relevance for skin carcinogenesis

The realisation that UV radiation (UVR) exposure could induce a suppressed immune environment for the initiation of carcinogenesis in the skin was first described more than 40 years ago. Van der Leun and his colleagues contributed to this area in the 1980s and 90s by experiments in mice involving UV wavelength and dose-dependency in the formation of such tumours, in addition to illustrating both the local and systemic effect of the UVR on the immune system. Since these early days, many aspects of the complex pathways of UV-induced immunosuppression have been studied and are outlined in this review. Although most experimental work has involved mice, it is clear that UVR also causes reduced immune responses in humans. Evidence showing the importance of the immune system in determining the risk of human skin cancers is explained, and details of how UVR exposure can down-regulate immunity in the formation and progression of such tumours reviewed. With increasing knowledge of these links and the mechanisms of UVR-induced immunosuppression, novel approaches to enhance immunity to skin tumour antigens in humans are becoming apparent which, hopefully, will reduce the burden of UVR-induced skin cancers in the future.

Vitamin D and the gut microbiome: a systematic review of in vivo studies

PURPOSE

Variation in the human microbiome has been linked with a variety of physiological functions, including immune regulation and metabolism and biosynthesis of vitamins, hormones, and neurotransmitters. Evidence for extraskeletal effects of vitamin D has been accruing and it has been suggested that the effect of vitamin D on health is partially mediated through the microbiome. We aimed to critically evaluate the evidence linking vitamin D and the gastrointestinal microbiome.

METHODS

We systematically searched the Embase, Web of Science, PubMed and CINAHL databases, including peer-reviewed publications that reported an association between a measure of vitamin D and the gastrointestinal microbiome in humans or experimental animals.

RESULTS

We included 10 mouse and 14 human studies. Mouse studies compared mice fed diets containing different levels of vitamin D (usually high versus low), or vitamin D receptor knockout or Cyp27B1 knockout with wild-type mice. Five mouse studies reported an increase in Bacteroidetes (or taxa within that phylum) in the low vitamin D diet or gene knockout group. Human studies were predominantly observational; all but two of the included studies found some association between vitamin D and the gut microbiome, but the nature of differences observed varied across studies.

CONCLUSIONS

Despite substantial heterogeneity, we found evidence to support the hypothesis that vitamin D influences the composition of the gastrointestinal microbiome. However, the research is limited, having been conducted either in mice or in mostly small, selected human populations. Future research in larger population-based studies is needed to fully understand the extent to which vitamin D modulates the microbiome.

Tryptophan and arginine catabolic enzymes and regulatory cytokines in clinically isolated syndrome and multiple sclerosis

Objectives

Clinically isolated syndrome (CIS) is the earliest clinical episode in multiple sclerosis (MS). A study of circulating cells from patients with CIS may help us understand the transition to, and processes associated with, the development of MS.

Methods

As immune cell activity can be determined by flux through metabolic pathways, the mRNA expression of l‐tryptophan‐ and l‐arginine‐catabolising enzymes, indoleamine 2,3‐dioxygenase (IDO) 1 and IDO2 and arginase (ARG) 1 and ARG2, respectively, was compared between peripheral blood mononuclear cells (PBMCs) from healthy controls, and patients with CIS and definite MS. As one measure of cell function, cytokine mRNA levels were analysed directly ex vivo and in cells after culture for 4 h in the absence of regulatory factors in autologous serum.

Results

When measured directly ex vivo, the expression of IDO and ARG was greater in cells from patients with CIS and MS than cells from healthy controls. Although not linked to IDO and ARG expression, PBMCs from the CIS patients were characterised by low IL‐10 and TGFB mRNA levels and not by greater expression of proinflammatory cytokines. When the cells were cultured for 4 h without autologous serum, pro‐ and anti‐inflammatory cytokine mRNA levels positively correlated with IDO1 expression, and TGFB mRNA levels correlated with ARG1 expression.

Conclusion

Higher IDO and ARG expression in CIS and MS provides one sustained homeostatic mechanism to control MS‐associated inflammation. However, potent extrinsic mediators in serum may regulate immune cell function in CIS and associations between IDO, ARG and cytokine expression.

On the Nature of Evidence and 'Proving' Causality: Smoking and Lung Cancer vs. Sun Exposure, Vitamin D and Multiple Sclerosis

If environmental exposures are shown to cause an adverse health outcome, reducing exposure should reduce the disease risk. Links between exposures and outcomes are typically based on 'associations' derived from observational studies, and causality may not be clear. Randomized controlled trials to 'prove' causality are often not feasible or ethical. Here the history of evidence that tobacco smoking causes lung cancer-from observational studies-is compared to that of low sun exposure and/or low vitamin D status as causal risk factors for the autoimmune disease, multiple sclerosis (MS). Evidence derives from in vitro and animal studies, as well as ecological, case-control and cohort studies, in order of increasing strength. For smoking and lung cancer, the associations are strong, consistent, and biologically plausible-the evidence is coherent or 'in harmony'. For low sun exposure/vitamin D as risk factors for MS, the evidence is weaker, with smaller effect sizes, but coherent across a range of sources of evidence, and biologically plausible. The association is less direct-smoking is directly toxic and carcinogenic to the lung, but sun exposure/vitamin D modulate the immune system, which in turn may reduce the risk of immune attack on self-proteins in the central nervous system. Opinion about whether there is sufficient evidence to conclude that low sun exposure/vitamin D increase the risk of multiple sclerosis, is divided. General public health advice to receive sufficient sun exposure to avoid vitamin D deficiency (<50 nmol/L) should also ensure any benefits for multiple sclerosis, but must be tempered against the risk of skin cancers.

Vitamin D and the Skin: An Update for Dermatologists

Vitamin D plays a key role in skeletal and cardiovascular disorders, cancers, central nervous system diseases, reproductive diseases, infections, and autoimmune and dermatological disorders. The two main sources of vitamin D are sun exposure and oral intake, including vitamin D supplementation and dietary intake. Multiple factors are linked to vitamin D status, such as Fitzpatrick skin type, sex, body mass index, physical activity, alcohol intake, and vitamin D receptor polymorphisms. Patients with photosensitive disorders tend to avoid sun exposure, and this practice, along with photoprotection, can put this category of patients at risk for vitamin D deficiency. Maintaining a vitamin D serum concentration within normal levels is warranted in atopic dermatitis, psoriasis, vitiligo, polymorphous light eruption, mycosis fungoides, alopecia areata, systemic lupus erythematosus, and melanoma patients. The potential determinants of vitamin D status, as well as the benefits and risks of vitamin D (with a special focus on the skin), will be discussed in this article.

Vitamin D in Human Immunodeficiency Virus Infection: Influence on Immunity and Disease

People living with human immunodeficiency virus (HIV) infection typically have hypovitaminosis D, which is linked to a large number of pathologies, including immune disorders and infectious diseases. Vitamin D (VitD) is a key regulator of host defense against infections by activating genes and pathways that enhance innate and adaptive immunity. VitD mediates its biological effects by binding to the Vitamin D receptor (VDR), and activating and regulating multiple cellular pathways. Single nucleotide polymorphisms in genes from those pathways have been associated with protection from HIV-1 infection. High levels of VitD and VDR expression are also associated with natural resistance to HIV-1 infection. Conversely, VitD deficiency is linked to more inflammation and immune activation, low peripheral blood CD4+ T-cells, faster progression of HIV disease, and shorter survival time in HIV-infected patients. VitD supplementation and restoration to normal values in HIV-infected patients may improve immunologic recovery during combination antiretroviral therapy, reduce levels of inflammation and immune activation, and increase immunity against pathogens. Additionally, VitD may protect against the development of immune reconstitution inflammatory syndrome events, pulmonary tuberculosis, and mortality among HIV-infected patients. In summary, this review suggests that VitD deficiency may contribute to the pathogenesis of HIV infection. Also, VitD supplementation seems to reverse some alterations of the immune system, supporting the use of VitD supplementation as prophylaxis, especially in individuals with more severe VitD deficiency.

The skin microbiome and immune system: Potential target for chemoprevention?

There has been increasing interest in understanding the role of the human microbiome in skin diseases. Microbiome studies are being utilized in skin cancer research in numerous ways. Commensal bacteria are being studied as a potential tool to judge the biggest environmental risk of skin cancer, ultraviolet (UV) radiation. Owing to the recognized link of skin microbes in the process of inflammation, there have been theories linking commensal bacteria to skin cancer. Viral metagenomics has also provided insight into virus linked forms of skin cancers. Speculations can be drawn for skin microbiome that in a manner similar to gut microbiome, they can be involved in chemoprevention of skin cancer. Nonetheless, there are definitely huge gaps in our knowledge of the relationship of microbiome and skin cancers, especially in relation to chemoprevention. The utilization of microbiome in skin cancer research seems to be a promising field and may help yield novel skin cancer prevention and treatment options. This review focuses on recent utilization of the microbiome in skin cancer research, and it explores the potential of utilizing the microbiome in prevention, earlier diagnosis, and treatment of skin cancers.

Sex Effects at the Ramparts: Nutrient- and Microbe-Mediated Regulation of the Immune-Metabolic Interface

The relationships between dietary compounds, derivative metabolites, and host metabolism and immunity are controlled by diverse molecular mechanisms. Essential contributions to these dynamics come from the community of microbes (the microbiome) inhabiting the human digestive tract. The composition and function of the microbiome are shaped by available nutrients, and reciprocally, these organisms produce an as yet poorly defined repertoire of molecules that communicate with the epithelial barrier and the mucosal immune system. We present evidence that diet-derived vitamins and lipids regulate immunity and metabolic function and highlight the diverse mechanisms through which these effects are impacted by sex. We discuss exciting new data emerging from studies using high-throughput sequencing technology, specialized mouse models, and bio-specimens, and clinical data from human subjects that have begun to reveal the complexity of these interactions. Also profiled in this chapter are the striking sex differences in pathways by which dietary nutrients and gut microbes modify metabolism, immunity, and immune- and inflammation-mediated diseases. Although the incidence, severity, and therapeutic responses of many autoimmune diseases differ by sex, the molecular mechanisms of these effects remain poorly understood.

Vitamin D deficiency accelerates ageing and age-related diseases: a novel hypothesis

Ageing can occur at different rates, but what controls this variable rate is unknown. Here I have developed a hypothesis that vitamin D may act to control the rate of ageing. The basis of this hypothesis emerged from studyng the various cellular processes that control ageing. These processes such as autophagy, mitochondrial dysfunction, inflammation, oxidative stress, epigenetic changes, DNA disorders and alterations in Ca²⁺ and reactive oxygen species (ROS) signalling are all known to be regulated by vitamin D. The activity of these processes will be enhanced in individuals that are deficient in vitamin D. Not only will this increase the rate of ageing, but it will also increase the probability of developing age-related diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and cardiovascular disease. In individual with normal vitamin D levels, these ageing-related processes will occur at lower rates resulting in a reduced rate of ageing and enhanced protection against these age-related diseases.

Bone health in Down syndrome

Patients with Down syndrome have a number of risk factors that theoretically could predispose them to osteoporosis, such as early aging, development disorders, reduced physical activity, limited sun exposure, frequent comorbidities and use of drug therapies which could affect bone metabolism. In addition, the bone mass of these people may be affected by their anthropometric and body composition peculiarities. In general terms, studies in adults with Down syndrome reported that these people have lower areal bone mineral density (g/cm²) than the general population. However, most of them have not taken the smaller bone size of people with Down syndrome into account. In fact, when body mineral density is adjusted by bone size and we obtain volumetric body mineral density (g/cm³), the difference between both populations disappears. On the other hand, although people with Down syndrome have risk factor of hypovitaminosis D, the results of studies regarding 25(OH)D in this population are not clear. Likewise, the studies about biochemical bone markers or the prevalence of fractures are not conclusive.

Vitamin D3 protects against prednisolone-induced liver injury associated with the impairment of the hepatic NF-κB/iNOS/NO pathway

The study was carried out to define whether prednisolone-induced damage to hepatic cells is accompanied by excessive nitric oxide (NO) levels associated with nuclear factor kappa B (NF-κB)/inducible NO synthase (iNOS) activation and evaluate the efficacy of the treatment with vitamin D3. Histopathological examination, activities of liver transaminases (alanine aminotransferase and aspartate aminotransferase), and cell death assays consistently showed that prednisolone (5 mg/kg body weight, 30 days) induces chronic liver injury in female Wistar rats. Specifically, increased hepatocellular necrosis and caspase-3-dependent apoptosis were observed. Prednisolone enhanced iNOS protein expression, NO generation, and tyrosine nitration in liver cells. Despite unchanged hepatic level of the NF-κB/p65 protein, prednisolone increased inhibitory κB-α (IκB-α) degradation, nuclear translocation, and phosphorylation of NF-κB/p65 at Ser311, indicating that NF-κB activation can be involved in the induction of iNOS/NO. All changes were associated with a 2.9-fold decrease in the serum content of 25-hydroxyvitamin D3 and significant reduction of hepatic vitamin D3 receptor (VDR) expression that points reliably to vitamin D3 deficiency and failures in VDR signaling. Vitamin D3 co-administration (100 IU/rat, 30 days) prevented glucocorticoid-evoked abnormalities in hepatic tissue. In conclusion, prednisolone-induced liver disturbances were associated with the impairment of NF-κB/iNOS/NO responses that can be ameliorated by vitamin D3 treatment through VDR-mediated mechanisms.

Narrowband UVB Phototherapy for Clinically Isolated Syndrome: A Trial to Deliver the Benefits of Vitamin D and Other UVB-Induced Molecules

Low vitamin D and insufficient sun exposure are additive independent risk factors for the development of multiple sclerosis (MS). The usual measure of vitamin D status, serum 25-hydroxy vitamin D [25(OH)D], is also a marker of recent exposure to the UVB rays of sunshine. The main evidence for a protective effect for MS development of higher 25(OH)D comes from observational studies, but this study design cannot separate out whether 25(OH)D is acting as a marker of vitamin D status, sun exposure, or both. In light of a lack of definitive outcomes in MS patients after trials of vitamin D supplementation and the ability of narrowband UVB to induce vitamin D, as well as other immune-regulatory molecules in skin, the Phototherapy for Clinically Isolated Syndrome (PhoCIS) trial was established to investigate the benefits of narrowband UVB, in addition to supplemented vitamin D, on MS development in individuals with Clinically Isolated Syndrome. We propose that the PhoCIS trial provides a fresh approach to re-defining the reported associations of 25(OH)D levels with MS development and progression.

Vitamin D and allergic airway disease shape the murine lung microbiome in a sex-specific manner

Background

Vitamin D is under scrutiny as a potential regulator of the development of respiratory diseases characterised by chronic lung inflammation, including asthma and chronic obstructive pulmonary disease. It has anti-inflammatory effects; however, knowledge around the relationship between dietary vitamin D, inflammation and the microbiome in the lungs is limited. In our previous studies, we observed more inflammatory cells in the bronchoalveolar lavage fluid and increased bacterial load in the lungs of vitamin D-deficient male mice with allergic airway disease, suggesting that vitamin D might modulate the lung microbiome. In the current study, we examined in more depth the effects of vitamin D deficiency initiated early in life, and subsequent supplementation with dietary vitamin D on the composition of the lung microbiome and the extent of respiratory inflammation.

Methods

BALB/c dams were fed a vitamin D-supplemented or -deficient diet throughout gestation and lactation, with offspring continued on this diet post-natally. Some initially deficient offspring were fed a supplemented diet from 8 weeks of age. The lungs of naïve adult male and female offspring were compared prior to the induction of allergic airway disease. In further experiments, offspring were sensitised and boosted with the experimental allergen, ovalbumin (OVA), and T helper type 2-skewing adjuvant, aluminium hydroxide, followed by a single respiratory challenge with OVA.

Results

In mice fed a vitamin D-containing diet throughout life, a sex difference in the lung microbial community was observed, with increased levels of an Acinetobacter operational taxonomic unit (OTU) in female lungs compared to male lungs. This effect was not observed in vitamin D-deficient mice or initially deficient mice supplemented with vitamin D from early adulthood. In addition, serum 25-hydroxyvitamin D levels inversely correlated with total bacterial OTUs, and Pseudomonas OTUs in the lungs. Increased levels of the antimicrobial murine ß-defensin-2 were detected in the bronchoalveolar lavage fluid of male and female mice fed a vitamin D-containing diet. The induction of OVA-induced allergic airway disease itself had a profound affect on the OTUs identified in the lung microbiome, which was accompanied by substantially more respiratory inflammation than that induced by vitamin D deficiency alone.

Conclusion

These data support the notion that maintaining sufficient vitamin D is necessary for optimal lung health, and that vitamin D may modulate the lung microbiome in a sex-specific fashion. Furthermore, our data suggest that the magnitude of the pro-inflammatory and microbiome-modifying effects of vitamin D deficiency were substantially less than that of allergic airway disease, and that there is an important interplay between respiratory inflammation and the lung microbiome.

Dietary Vitamin D Increases Percentages and Function of Regulatory T Cells in the Skin-Draining Lymph Nodes and Suppresses Dermal Inflammation

Skin inflammatory responses in individuals with allergic dermatitis may be suppressed by dietary vitamin D through induction and upregulation of the suppressive activity of regulatory T (T_Reg) cells. Vitamin D may also promote T_Reg cell tropism to dermal sites. In the current study, we examined the capacity of dietary vitamin D₃ to modulate skin inflammation and the numbers and activity of T_Reg cells in skin and other sites including lungs, spleen, and blood. In female BALB/c mice, dietary vitamin D₃ suppressed the effector phase of a biphasic ear swelling response induced by dinitrofluorobenzene in comparison vitamin D₃-deficient female BALB/c mice. Vitamin D₃ increased the percentage of T_Reg (CD3+CD4+CD25+Foxp3+) cells in the skin-draining lymph nodes (SDLN). The suppressive activity of T_Reg cells in the SDLN, mesenteric lymph nodes, spleen, and blood was upregulated by vitamin D₃. However, there was no difference in the expression of the naturally occurring T_Reg cell marker, neuropilin, nor the expression of CCR4 or CCR10 (skin-tropic chemokine receptors) on T_Reg cells in skin, SDLN, lungs, and airway-draining lymph nodes. These data suggest that dietary vitamin D₃ increased the percentages and suppressive activity of T_Reg cells in the SDLN, which are poised to suppress dermal inflammation.

25-Hydroxycholecalciferol response to single oral cholecalciferol loading in the normal weight, overweight, and obese

After a single cholecalciferol load, peak serum 25-hydroxycholecalciferol (25OHD) is lower in individuals with a higher body mass index (BMI), probably due to it being distributed in a greater volume. Its subsequent disappearance from the serum is slower the higher the individual's BMI, probably due to the combination of a larger body volume and a slower release into the circulation of vitamin D stored in adipose tissue.

INTRODUCTION

The aim of the study is to examine 25-hydroxycholecalciferol (25OHD) response to a single oral load of cholecalciferol in the normal weight, overweight, and obese.

METHODS

We considered 55 healthy women aged from 25 to 67 years (mean ± SD, 50.8 ± 9.5) with a BMI ranging from 18.7 to 42 kg/m(2) (mean ± SD, 27.1 ± 6.0). The sample was divided into three groups by BMI: 20 were normal weight (BMI ≤ 25 kg/m(2)), 21 overweight (25.1 ≤ BMI ≤ 29.9 kg/ m(2)), and 14 obese (BMI ≥ 30 kg/m(2)). Each subject was given 300,000 IU of cholecalciferol orally during lunch. A fasting blood test was obtained before cholecalciferol loading and then 7, 30, and 90 days afterwards to measure serum 25OHD, 1,25 dihydroxyvitamin D [1,25 (OH)2D], parathyroid hormone (PTH), calcium (Ca), and phosphorus (P). Participants' absolute fat mass was measured using dual energy X-ray absorptiometry (DEXA).

RESULTS

The fat mass of the normal weight subjects was significantly lower than that of the overweight, which in turn was lower than that of the obese participants. Serum 25OHD levels increased significantly in all groups, peaking 1 week after the cholecalciferol load. Peak serum 25OHD levels were lower the higher the individuals' BMI. After peaking, the 25OHD levels gradually decreased, following a significantly different trend in the three groups. The slope was similar for the overweight and obese, declining significantly more slowly than in the normal weight group. In the sample as a whole, there was a weakly significant negative correlation between fat mass and baseline 25OHD level, while this correlation became strongly significant at all time points after cholecalciferol loading.

CONCLUSIONS

The lower peak 25OHD levels seen in the obese and overweight is probably due to the cholecalciferol load being distributed in a larger body volume. The longer persistence of 25OHD in their serum could be due to both their larger body volume and a slower release into the circulation of the vitamin D stored in their adipose tissue.

The Non-Genomic Actions of Vitamin D

Since its discovery in 1920, a great deal of effort has gone into investigating the physiological actions of vitamin D and the impact its deficiency has on human health. Despite this intense interest, there is still disagreement on what constitutes the lower boundary of adequacy and on the Recommended Dietary Allowance. There has also been a major push to elucidate the biochemistry of vitamin D, its metabolic pathways and the mechanisms that mediate its action. Originally thought to act by altering the expression of target genes, it was realized in the mid-1980s that some of the actions of vitamin D were too rapid to be accounted for by changes at the genomic level. These rapid non-genomic actions have attracted as much interest as the genomic actions and they have spawned additional questions in an already busy field. This mini-review attempts to summarise the in vitro and in vivo work that has been conducted to characterise the rapid non-genomic actions, the mechanisms that give rise to these properties and the roles that these play in the overall action of vitamin D at the cellular level. Understanding the effects of vitamin D at the cellular level should enable the design of elegant human studies to extract the full potential of vitamin D to benefit human health.

Remission of Severe Myasthenia Gravis After Massive-Dose Vitamin D Treatment

BACKGROUND

Vitamin D has been shown to be related to autoimmune diseases, such as multiple sclerosis and psoriasis. Correlations have been reported between vitamin D levels and prevalence and severity of other autoimmune disorders, and also between vitamin D therapy and disease improvement and remission.

CASE REPORT

This is a case report of a patient with severe and refractory myasthenia gravis (MG) who followed a "high-dose vitamin D treatment", a massive-dose treatment (80,000 to 120,000 IU/day) promoted by a medical center in Brazil (but still not proven), and she had her first complete remission after this type of treatment with increased vitamin D serum levels (400 to 700 ng/mL).

CONCLUSIONS

This case report may reinforce the reported correlation between vitamin D level and disease severity and introduces a possible new use for vitamin D as a potential target for treating autoimmune diseases. We recommend large, double-blind, placebo-controlled, randomized studies using high-dose vitamin D treatment for refractory autoimmune diseases to reliably assess this pharmacotherapy target for these diseases.

Association between the serum level of vitamin D and systemic sclerosis in a Chinese population: a case control study

AIM

Several autoimmune diseases have been associated with reduced vitamin D levels. However, the serum level of vitamin D in Chinese systemic sclerosis (SSc) patients have not been reported. The aim of this study was to evaluate the serum levels of vitamin D in Chinese SSc patients and analyze the association between vitamin D and SSc.

METHODS

25-hydroxy vitamin D ¹²⁵ I RIA kit was applied to evaluate the serum levels of vitamin D in 60 SSc patients and 60 healthy controls from Anhui Provincial Hospital, China. The data of epidemiological and clinical characteristics of SSc patients were also collected.

RESULTS

The serum levels of vitamin D were significantly lower in SSc patients than that in healthy controls (26.51 ± 6.27 vs. 36.29 ± 14.24 ng/mL, P < 0.001). The ratio of pulmonary involvement in vitamin D insufficiency patients was higher than that in normal vitamin D patients, but the difference missed statistical significance. The differences in other aspects were not statistically significant in the two groups.

CONCLUSION

Serum levels of vitamin D in patients with SSc were lower than that in healthy controls. Further studies are needed to determine whether vitamin D supplement could provide some positive effects.

Mycobacterial infection induces a specific human innate immune response

The innate immune system provides the first response to infection and is now recognized to be partially pathogen-specific. Mycobacterium tuberculosis (MTB) is able to subvert the innate immune response and survive inside macrophages. Curiously, only 5-10% of otherwise healthy individuals infected with MTB develop active tuberculosis (TB). We do not yet understand the genetic basis underlying this individual-specific susceptibility. Moreover, we still do not know which properties of the innate immune response are specific to MTB infection. To identify immune responses that are specific to MTB, we infected macrophages with eight different bacteria, including different MTB strains and related mycobacteria, and studied their transcriptional response. We identified a novel subset of genes whose regulation was affected specifically by infection with mycobacteria. This subset includes genes involved in phagosome maturation, superoxide production, response to vitamin D, macrophage chemotaxis, and sialic acid synthesis. We suggest that genetic variants that affect the function or regulation of these genes should be considered candidate loci for explaining TB susceptibility.

May osteoarticular infections be influenced by vitamin D status? An observational study on selected patients

Background

Vitamin D deficiency has been associated with a high number of health outcomes, and its role on the immune system has been deeply investigated in recent years, although poor data are still available on vitamin D status in orthopedic infections including those of prosthetic implants.

Methods

We focused on preoperative values of 25(OH)D in selected groups of patients with septic (Group A) or aseptic (Group B) prosthetic loosening, infective bone disease such as septic arthritis and osteomyelitis (Group C) and other orthopedic pathologies (Group D) to evaluate differences in the vitamin D status.

Results

A high prevalence of vitamin D deficiency was recorded among the study population (16.5 ± 5.4 ng/mL, mean ± SD). Interestingly, all patients with an infection presented a higher 25(OH)D concentration (17.7 ± 5.3 ng/mL) in respect to uninfected ones (15.1 ± 5.6 ng/mL). Significantly higher levels of 25(OH)D were observed in patients with prosthetic joint infection (18.5 ± 6.5 ng/mL), when compared with those presenting an aseptic loosening (13.6 ± 9.4 ng/mL).

Conclusions

Deficiency in vitamin D levels have been found in orthopaedic patients. Prosthetic joint infections seems to be associated to higher values of vitamin D in respect to other bone infections or to other orthopaedic conditions requiring surgery.

More studies are needed to improve the knowledge on vitamin D status in these patients and to better clarify the role of vitamin D in relation to osteoarticular infections.

Vitamin D every day to keep the infection away?

Within the last decade, vitamin D has emerged as a central regulator of host defense against infections. In this regard, vitamin D triggers effective antimicrobial pathways against bacterial, fungal and viral pathogens in cells of the human innate immune system. However, vitamin D also mediates potent tolerogenic effects: it is generally believed that vitamin D attenuates inflammation and acquired immunity, and thus potentially limits collateral tissue damage. Nevertheless, several studies indicate that vitamin D promotes aspects of acquired host defense. Clinically, vitamin D deficiency has been associated with an increased risk for various infectious diseases in epidemiological studies; yet, robust data from controlled trials investigating the use of vitamin D as a preventive or therapeutic agent are missing. In this review, we summarize the current knowledge regarding the effect of vitamin D on innate and acquired host defense, and speculate on the difficulties to translate the available molecular medicine data into practical therapeutic or preventive recommendations.

Can skin exposure to sunlight prevent liver inflammation?

Liver inflammation contributes towards the pathology of non-alcoholic fatty liver disease (NAFLD). Here we discuss how skin exposure to sunlight may suppress liver inflammation and the severity of NAFLD. Following exposure to sunlight-derived ultraviolet radiation (UVR), the skin releases anti-inflammatory mediators such as vitamin D and nitric oxide. Animal modeling studies suggest that exposure to UVR can prevent the development of NAFLD. Association studies also support a negative link between circulating 25-hydroxyvitamin D and NAFLD incidence or severity. Clinical trials are in their infancy and are yet to demonstrate a clear beneficial effect of vitamin D supplementation. There are a number of potentially interdependent mechanisms whereby vitamin D could dampen liver inflammation, by inhibiting hepatocyte apoptosis and liver fibrosis, modulating the gut microbiome and through altered production and transport of bile acids. While there has been a focus on vitamin D, other mediators induced by sun exposure, such as nitric oxide may also play important roles in curtailing liver inflammation.