Vitamin D deficiency suppresses cell-mediated immunity in vivo

Vitamin D deficiency in dengue fever patients' coinfected with H. pylori in Pakistan. A case-control study

Introduction

Dengue fever is a vector-borne disease with an estimate of 390 million persons getting the infection each year with a significant public health impact. It has been reported DENV patients with vitamin D deficiency led to severe form of dengue infection; while H. pylori coinfection alters vitamin D receptors leading to vitamin D deficiency. We hypothesize that DENV patient's having low vitamin D along with H. pylori coinfection could have worsen dengue severity as well as vitamin D deficiency. In this case-control study, we compared (I) the vitamin D deficiency in dengue fever cases with or without H. pylori coinfection, and (II) negative dengue fever as a control with or without H. pylori coinfection. We have also assessed the correlation between vitamin D levels and its effect on warning signs of the dengue fever. Further, we have investigated whether coinfection with H. pylori has any effect on warning signs in the dengue fever patients and the vitamin D deficiency in all serotypes of the dengue virus infected patients.

Methods

In this case control study the association of the vitamin D levels with age, gender and H. pylori coinfection in dengue fever hospitalized patients was assessed using chi-square and multivariate logistic regression analysis.

Results

Four hundred dengue fever patients with H. pylori coinfection were compared with 400 dengue negative controls with H. pylori coinfection. The mean age was 29.96 ± 10.5 and 29.88 ± 10.7 years among cases and controls, respectively. Most dengue fever patients with H. pylori coinfection were deficient in vitamin D compared with negative dengue controls with H. pylori coinfection. In multivariate logistic regression, the dengue cases with H. pylori coinfection were.056 times (95% CI: 0.024, 0.128, P = 0.000) more likely to have vitamin D "deficiency', while compared with the cases who did not have H. pylori coinfection.

Conclusion

The present study proposes that vitamin D deficiency in dengue fever patients coinfected with H. pylori is much higher than the dengue fever negative controls coinfected with H. pylori. As hypothesized the DENV patient with H. pylori coinfection has vitamin D deficiency as well as increased dengue severity.

Strong tuberculin response after BCG vaccination is associated with low multiple sclerosis risk: a population-based cohort study

Background

Multiple sclerosis (MS) is characterized by inflammatory lesions in the central nervous system involving pro-inflammatory T-cells. Immune dysregulation is well described in prevalent disease, but it is not known whether this precedes disease development. Bacillus Calmette–Guérin (BCG) vaccination ameliorates MS-like disease in mice. In people vaccinated with BCG, the tuberculin skin test (TST) offers a standardized measure of a T-cell-mediated immune response. We therefore hypothesized that the strength of the TST response after BCG vaccination is associated with subsequent MS risk.

Methods

Using data from a Norwegian tuberculosis screening programme (1963–1975), we designed a population-based cohort study and related the size of TST reactions in individuals previously vaccinated with BCG to later MS disease identified through the Norwegian MS registry. We fitted Cox proportional hazard models and flexible parametric survival models to investigate the association between TST reactivity, MS risk and its temporal relationship.

Results

Among 279 891 participants (52% females), 679 (69% females) later developed MS. Larger TST reactivity was associated with decreased MS risk. The hazard ratio for MS per every 4-mm increase in skin induration size was 0.86 (95% confidence interval 0.76–0.96) and similar between sexes. The strength of the association persisted for >30 years after the TST.

Conclusion

A strong in vivo vaccine response to BCG is associated with reduced MS risk >30 years later. The immunological mechanisms determining TST reactivity suggest that skewed T-cell-mediated immunity precedes MS onset by many decades.

Centennial Review: Effects of vitamins A, D, E, and C on the chicken immune system

Vitamins are nutritional elements which are necessary for essential activities such as development, growth, and metabolism of cells. In addition to these conventional functions, vitamins A, D, E, and C have vital roles in normal function of the immune system as their deficiency is known to impair innate and adaptive host responses. By altering transcription of multiple immune system genes and contributing to antioxidant activities, these vitamins influence the immune system in different ways including modulation of cell-mediated and antibody-mediated responses, immunoregulation, and antiinflammatory effects. Furthermore, supplementation of these vitamins to poultry may assist the immune system to combat microbial pathogens while reducing detrimental effects associated with stress and enhancing responses to vaccines. In this article, the relationship between the chicken immune system and vitamins A, D, E, and C is reviewed, and evidence from the literature pertaining to how these vitamins exert their antiinflammatory, regulatory, and antimicrobial effects is discussed.

Micronutrients, Immunological Parameters, and Dengue Virus Infection in Coastal Ecuador: A Nested Case-Control Study in an Infectious Disease Surveillance Program

BACKGROUND

Micronutrients are known to modulate host immunity, and there is limited literature on this association in the context of dengue virus infection (DENV).

METHODS

Using a nested case-control design in a surveillance program, we measured the following: anthropometry; nutritional biomarkers including serum ferritin, soluble transferrin receptor, retinol-binding protein (RBP), 25-hydroxy vitamin D, folate, and vitamin B12; and a panel of immune response markers. We then compared these measures across 4 illness categories: healthy control, nonfebrile DENV, other febrile illness (OFI), and apparent DENV using multivariate polytomous logistic regression models.

RESULTS

Among 142 participants, serum ferritin (ng/mL) was associated with apparent DENV compared to healthy controls (odds ratio [OR], 2.66; confidence interval [CI], 1.53-4.62; P = .001), and RBP concentrations (µmol/L) were associated with apparent DENV (OR, 0.03; CI, 0.00-0.30; P = .003) and OFI (OR, 0.02; CI, 0.00-0.24; P = .003). In a subset of 71 participants, interleukin-15 levels (median fluorescent intensity) were positively associated with apparent DENV (OR, 1.09; CI, 1.03-1.14; P = .001) and negatively associated with nonfebrile DENV (OR, 0.89; CI, 0.80-0.99; P = .03) compared to healthy controls.

CONCLUSIONS

After adjusting for the acute-phase response, serum ferritin and RBP concentrations were associated with apparent DENV and may represent biomarkers of clinical importance in the context of dengue illness.

Bacillus Calmette-Guérin (BCG) stimulates changes in dendritic cell surface marker expression in vitamin D-deficient mice

Objective

Vitamin D (VD) deficiency increases susceptibility to tuberculosis and is an important immunomodulator. Dendritic cells (DCs) are important antigen-presenting cells that play a critical role during tuberculosis infection, and Mycobacterium tuberculosis modulates DC responses. The underlying mechanism is poorly understood. Our aim was to study changes in DC surface markers in VD deficient mice administered Bacillus Calmette-Guérin (BCG).

Methods

We divided C57BL/6 mice into a normal group and a VD deficient group. Two groups of mouse bone marrow-derived cells were isolated and cultured with granulocyte-macrophage colony-stimulating factor (20 ng/mL) and interleukin-4 (10 ng/mL) for 6 days. On day 7, BCG (0, 1 or 2 mg/mL) was administered to both groups for 24 hours. Non-adherent cells were harvested to assess DC phenotypic changes induced by different concentrations of BCG.

Results

Expression levels of CD80, MHC-I, MHC-II and CD86 on the surfaces of DCs from VD deficient mice were lower than those in DCs from normal mice. By contrast, the expression level of CD11c on DCs was higher in VD deficient mice than in normal mice. Changes in all factors were concentration-dependent.

Conclusions

These findings indicate that BCG reduced DC surface marker expression to modulate immune responses during M. tuberculosis infection.

Vitamin D is not required for adaptive immunity to listeria

Although ex vivo research suggests that vitamin D may play a role in innate and adaptive immunity, clear in vivo evidence is lacking. We have tested whether severe vitamin D deficiency alters the ability of mice to resist infection by Listeria. Our results show that vitamin D deficiency does not affect the LD50 of naïve mice in response to Listeria. To study the adaptive immune response, the LD50 for Listeria-immunized mice was determined for vitamin D-deficient and vitamin D-sufficient mice. Although the LD50 clearly increased by immunization with inactivated Listeria, there was no effect of vitamin D deficiency on survival of mice infected with wild-type Listeria. Thus, in this model of adaptive immunity, we could find no evidence of a role for vitamin D.

Lack of vitamin D signalling per se does not aggravate cardiac functional impairment induced by myocardial infarction in mice

Epidemiological studies have linked vitamin D deficiency to an increased incidence of myocardial infarction and support a role for vitamin D signalling in the pathophysiology of myocardial infarction. Vitamin D deficiency results in the development of secondary hyperparathyroidism, however, the role of secondary hyperparathyroidism in the pathophysiology of myocardial infarction is not known. Here, we aimed to explore further the secondary hyperparathyroidism independent role of vitamin D signalling in the pathophysiology of myocardial infarction by inducing experimental myocardial infarction in 3-month-old, male, wild-type mice and in mice lacking a functioning vitamin D receptor. In order to prevent secondary hyperparathyroidism in vitamin D receptor mutant mice, all mice were maintained on a rescue diet enriched with calcium, phosphorus, and lactose. Surprisingly, survival rate, cardiac function as measured by echocardiography and intra-cardiac catheterisation and cardiomyocyte size were indistinguishable between normocalcaemic vitamin D receptor mutant mice and wild-type controls, 2 and 8 weeks post-myocardial infarction. In addition, the myocardial infarction-induced inflammatory response was similar in vitamin D receptor mutants and wild-type mice, as evidenced by a comparable upregulation in cardiac interleukin-1-β and tumor-necrosis-factor-α mRNA abundance and similar elevations in circulating interleukin-1-β and tumor-necrosis-factor-α. Our data suggest that the lack of vitamin D signalling in normocalcaemic vitamin D receptor mutants has no major detrimental effect on cardiac function and outcome post-myocardial infarction. Our study may have important clinical implications because it suggests that the secondary hyperparathyroidism induced by vitamin D deficiency, rather than the lack of vitamin D signalling per se, may negatively impact cardiac function post-myocardial infarction.

Vitamin D Levels in Active TB, Latent TB, Non-TB Pneumonia and Healthy Children: A Prospective Observational Study

BACKGROUND

Growing evidence suggests that vitamin D deficiency might be implicated in the development of active tuberculosis (TB). We evaluated vitamin D levels in children with active TB compared to children with latent TB infection (LTBI), non-TB pneumonia (NTBP) and healthy controls to determine if there was a difference.

METHODS

In this prospective study, vitamin D levels were measured and compared between the four groups and adjusted for age, ethnicity, gender and season of sample collection.

RESULTS

Fifty-seven children were included: 24.6% active TB, 28.1% LTBI, 22.8% NPTB and 24.6% healthy controls. 36.8% of all children tested had an insufficient or deficient vitamin D level. Vitamin D level was significantly lower in active TB compared to other groups (p = 0.004).

CONCLUSIONS

Our study showed a correlation between hypovitaminosis D and active pulmonary TB.

Vitamin D: Physiology and Pathophysiology

Although vitamin D was initially considered a nutrient, it has been recognized that the molecules derived from vitamin D metabolism are best considered as a complex endocrine system. In this review article we summarize the basic concepts regarding vitamin D metabolism, transport, and genomic activity through the vitamin D receptor, facilitating activation or suppression of target genes. We also examine non-genomic actions, biological responses to vitamin D in classic target organs (intestine, bone, kidneys, and parathyroid glands), and in organs and tissues not related to mineral homeostasis.

Association of vitamin D receptor polymorphisms and type 1 diabetes susceptibility in children: a meta-analysis

BACKGROUND

There have been studies focused on FokI, BsmI, ApaI and TaqI polymorphisms of the vitamin D receptor (VDR) gene and susceptibility to type 1 diabetes mellitus with controversial results.

METHODS

This present study is a meta-analysis investigating the association between FokI, ApaI, TaqI and BsmI polymorphisms of VDR gene and type 1 DM in children. A literature search was performed using Medline, EMBASE, Cochrane and PubMed. Any study was considered eligible for inclusion if at least one of FokI, ApaI, TaqI and BsmI polymorphisms was determined, and outcome was type 1 DM at pediatric age.

RESULTS

A total of 9 studies comprising 1053 patients and 1017 controls met the study inclusion criteria. The pooled odds ratios (ORs) of the FokI, ApaI, TaqI and BsmI polymorphisms were combined and calculated. Forest plots and funnel plots of the OR value distributions were drawn. Our meta-analysis has demonstrated statistically significant associations between DM1 and VDR genotypes, BsmIBB (P < 0.05), BsmIBb, (P < 0.05), BsmIbb (P < 0.05), TaqITT (P < 0.05) and TaqItt (P < 0.05) in children.

CONCLUSION

The results indicated that BsmIBB, BsmIBb and TaqItt polymorphisms were associated with an increased risk of type 1 DM, whereas BsmIbb and TaqITT had protective effect for type 1 DM in children.

Vitamin D receptor polymorphisms and the polycystic ovary syndrome: A systematic review

Polycystic ovary syndrome (PCOS) is the most frequent endocrinological disorder that affects women of reproductive age, leading to metabolic alterations, such as hyperandrogenism, obesity, menstrual irregularities, insulin resistance, and polycystic ovaries. The etiology remains unclear, but several genetic and environmental factors have been correlated with manifestations of this syndrome. Vitamin D plays important roles in metabolic pathways affected by PCOS, including calcium homeostasis, the insulin pathway, and sex hormone synthesis. Vitamin D concentration has been related with the severity of this disorder, and vitamin D receptor polymorphisms have been shown in some studies to have an association with some of the patterns presented by PCOS. The objective of this study is to provide an up-to-date review about vitamin D receptor polymorphisms and their association with PCOS.

UVB radiation, vitamin D and multiple sclerosis

Achesonet al.(1960) observed an inverse relationship between sunlight exposure and the incidence of Multiple Sclerosis (MS).

Vitamin D and the Pathogenesis of Inflammatory Bowel Disease

Vitamin D has traditionally been known for its role in bone metabolism, but emerging evidence has suggested a broader role for vitamin D in immune regulation. Vitamin D deficiency has been associated with the pathogenesis of diverse autoimmune disorders and has similarly been implicated as a contributor to inflammatory bowel disease. In this review, we discuss animal, in vitro, genetic, and epidemiologic studies that have linked vitamin D deficiency with inflammatory bowel disease pathogenesis or severity. Nonetheless, we present the caveat in interpreting these studies in the context of reverse causation: Does vitamin D deficiency lead to gastrointestinal disease, or does gastrointestinal disease (with related changes in dietary choices, intestinal absorption, nutritional status, lifestyle) lead to vitamin D deficiency?

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.

1,25-Dihydroxyvitamin D3 Controls a Cohort of Vitamin D Receptor Target Genes in the Proximal Intestine That Is Enriched for Calcium-regulating Components

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) plays an integral role in calcium homeostasis in higher organisms through its actions in the intestine, kidney, and skeleton. Interestingly, although several intestinal genes are known to play a contributory role in calcium homeostasis, the entire caste of key components remains to be identified. To examine this issue, Cyp27b1 null mice on either a normal or a high calcium/phosphate-containing rescue diet were treated with vehicle or 1,25(OH)2D3 and evaluated 6 h later. RNA samples from the duodena were then subjected to RNA sequence analysis, and the data were analyzed bioinformatically. 1,25(OH)2D3 altered expression of large collections of genes in animals under either dietary condition. 45 genes were found common to both 1,25(OH)2D3-treated groups and were composed of genes previously linked to intestinal calcium uptake, including S100g, Trpv6, Atp2b1, and Cldn2 as well as others. An additional distinct network of 56 genes was regulated exclusively by diet. We then conducted a ChIP sequence analysis of binding sites for the vitamin D receptor (VDR) across the proximal intestine in vitamin D-sufficient normal mice treated with vehicle or 1,25(OH)2D3. The residual VDR cistrome was composed of 4617 sites, which was increased almost 4-fold following hormone treatment. Interestingly, the majority of the genes regulated by 1,25(OH)2D3 in each diet group as well as those found in common in both groups contained frequent VDR sites that likely regulated their expression. This study revealed a global network of genes in the intestine that both represent direct targets of vitamin D action in mice and are involved in calcium absorption.

Vitamin D deficiencies among tuberculosis patients in Africa: A systematic review

The aim of this study was to explore the existence of vitamin D deficiency (VDD) in tuberculosis (TB) patients living in Africa and to identify its predictor variables. PRISMA guidelines and checklists were used. The sources of the data were Medline/PubMed, Web of Science, Scopus, and Google Scholar databases. We identified 23 articles, of which 15 reported the status of vitamin D in TB with TB. The definition of serum vitamin D status was summarized as severe, deficient, and insufficient when the concentration of 25-hydroxyvitamin (OH)-D ≤25, ≤50, and ≤75 nmol/L, respectively. The reports showed that up to 88.9% and 96.3% of patients with TB tested by radioimmunoassay had VDD and vitamin D insufficiency, respectively. Statistically significant variables such as lack of sun exposure, inadequate dietary intake, season, clothing, comorbidities, low body mass index, age, skin pigmentation, use of antiretroviral therapy and anti-TB drugs, and socioeconomic status were identified as the main predictor variables of vitamin D status. VDD and vitamin D insufficiency were highly prevalent in TB patients in Africa. Further case-control studies are warranted to clarify the cause-effect relationship between vitamin D and TB and thereby, design valuable strategies to manage VDD among TB patients in Africa.

Efficacy of early treatment with calcimimetics in combination with reduced doses of vitamin d sterols in dialysis patients

Vitamin D is an important physiologic regulator of bone and mineral metabolism. In chronic kidney disease, reduced renal production of calcitriol contributes to secondary hyperparathyroidism (SHPT). Consequently, supplementation with vitamin D sterols is an important treatment for SHPT and its associated mineral and bone disorders. However, doses of vitamin D sterols required to suppress parathyroid hormone (PTH) secretion often promote hypercalcaemia and hyperphosphataemia. Therefore, there is a trade-off between reduced serum PTH and increased levels of serum calcium, phosphorus and calcium–phosphorus product. It has been suggested that treatment of SHPT with cinacalcet, a type II calcimimetic, with reduced doses of vitamin D sterols could enhance achievement of calcium and phosphorus treatment targets while maintaining goals for PTH. Recent clinical trials have evaluated this hypothesis and demonstrated that treatment with cinacalcet in combination with reduced doses of vitamin D sterols is an effective treatment for the management of SHPT.

Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE)

An increasing recognition has emerged of the complexities of the global health agenda—specifically, the collision of infections and noncommunicable diseases and the dual burden of over- and undernutrition. Of particular practical concern are both 1) the need for a better understanding of the bidirectional relations between nutritional status and the development and function of the immune and inflammatory response and 2) the specific impact of the inflammatory response on the selection, use, and interpretation of nutrient biomarkers. The goal of the Inflammation and Nutritional Science for Programs/Policies and Interpretation of Research Evidence (INSPIRE) is to provide guidance for those users represented by the global food and nutrition enterprise. These include researchers (bench and clinical), clinicians providing care/treatment, those developing and evaluating programs/interventions at scale, and those responsible for generating evidence-based policy. The INSPIRE process included convening 5 thematic working groups (WGs) charged with developing summary reports around the following issues: 1) basic overview of the interactions between nutrition, immune function, and the inflammatory response; 2) examination of the evidence regarding the impact of nutrition on immune function and inflammation; 3) evaluation of the impact of inflammation and clinical conditions (acute and chronic) on nutrition; 4) examination of existing and potential new approaches to account for the impact of inflammation on biomarker interpretation and use; and 5) the presentation of new approaches to the study of these relations. Each WG was tasked with synthesizing a summary of the evidence for each of these topics and delineating the remaining gaps in our knowledge. This review consists of a summary of the INSPIRE workshop and the WG deliberations.

Is there more to learn about functional vitamin D metabolism?

The state of information on the enzymes responsible for the conversion of vitamin D3 to 1α,25-dhydroxyvitamin D3 (1,25-(OH)2D3), the metabolic active form responsible for the well-known function of vitamin D on calcium metabolism and bone mineralization has been briefly reviewed. There remains an unidentified enzyme responsible for 25% of the 25-hydroxylation of vitamin D3, while 75% of serum 25-hydroxyvitamin D3 (25-OH-D3) arises from CYP2R1. The well-established suppression of multiple sclerosis (MS) by sunlight has been confirmed using the mouse model, experimental autoimmune encephalomyelitis (EAE). This suppression results from a narrow band of ultraviolet light (300-315nm) that does not increase serum 25-OH-D3. Thus, UV light suppresses EAE by a mechanism not involving vitamin D. Vitamin D deficiency unexpectedly suppresses the development of EAE. Further, vitamin D receptor knockout in susceptible mice also prevents the development of EAE. On the other hand, deletion of CYP2R1 and the 1α-hydroxylase, CYP27B1, does not impair the development of EAE. Thus, either vitamin D itself or a heretofore-unknown metabolite is needed for the development of a component of the immune system necessary for development of EAE. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Exponentially increasing incidences of cutaneous malignant melanoma in Europe correlate with low personal annual UV doses and suggests 2 major risk factors

For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology studies, we know one major risk factor for getting CMM is poor tanning ability and we now propose the other major risk factor may be the Human Papilloma Virus (HPV) because clinicians find β HPVs in over half the biopsies. Moreover, we uncovered yet another paradox; the increasing CMM incidences significantly correlate with decreasing personal annual UV dose, a proxy for low vitamin D3 levels. We also discovered the incidence of CMM significantly increased with decreasing personal annual UV dose from 1960, when it was almost insignificant, to 2000. UV and other DNA-damaging agents can activate viruses, and UV-induced cytokines can hide HPV from immune surveillance, which may explain why CMM also occurs in anatomical locations where the sun does not shine. Thus, we propose the 2 major risk factors for getting CMM are intermittent UV exposures that result in low cutaneous levels of vitamin D3 and possibly viral infection.

Parasites and chronic renal failure

Suppression of the human immune system results in an increase in susceptibility to infection by various infectious agents. Conditions such as AIDS, organ transplantation and chronic renal insufficiency (CRI) are the most important cause of insufficient immune response against infections. Long term renal disorders result in uremia, which can suppress human immune system. Parasitic infections are one of the most important factors indicating the public health problems of the societies. These infections can be more hostile and life threatening in susceptible individuals than in the normal people. In these patients some parasitic infections such as blastocystiosis, cryptosporidiosis and toxoplasmosis have been reported to be more prevalent. This review aimed to give an overview about parasitic infections in patients with renal disorders.

Vitamin D Status Affects Serum Metabolomic Profiles in Pregnant Adolescents

Vitamin D is linked to a number of adverse pregnancy outcomes through largely unknown mechanisms. This study was conducted to examine the role of vitamin D status in metabolomic profiles in a group of 30 pregnant, African American adolescents (17.1 ± 1.1 years) at midgestation (26.8 ± 2.8 weeks), in 15 adolescents with 25-hydroxy vitamin D (25(OH)D) ≥20 ng/mL, and in 15 teens with 25(OH)D <20 ng/mL. Serum metabolomic profiles were examined using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. A novel hierarchical mixture model was used to evaluate differences in metabolite profiles between low and high groups. A total of 326 compounds were identified and included in subsequent statistical analyses. Eleven metabolites had significantly different means between the 2 vitamin D groups, after correcting for multiple hypothesis testing: pyridoxate, bilirubin, xylose, and cholate were higher, and leukotrienes, 1,2-propanediol, azelate, undecanedioate, sebacate, inflammation associated complement component 3 peptide (HWESASXX), and piperine were lower in serum from adolescents with 25(OH)D ≥20 ng/mL. Lower maternal vitamin D status at midgestation impacted serum metabolic profiles in pregnant adolescents.

The seasonality of tuberculosis, sunlight, vitamin D, and household crowding

Background. Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years.

Methods. Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained.

Results. Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001).

Conclusions. The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis.

Children with hemoglobin E/β-thalassemia have a high risk of being vitamin D deficient even if they get abundant sun exposure: a study from Thailand

BACKGROUND

Vitamin D is a key component in calcium homeostasis, bone mineralization and immune function, and people with a vitamin D deficiency may therefore be at higher risk of osteoporosis, osteopenia, delayed growth and fractures. Vitamin D deficiency is a known clinical complication of patients with β-thalassemia major; however, as yet there are limited data on the vitamin D status of patients with Hb E/β-thalassemia. Hb E/β-thalassemia is characterized by a wide clinical heterogeneity ranging from non-transfusion dependency to transfusion dependency. Because patients with Hb E/β-thalassemia are so clinically diverse, the prevalence of vitamin D deficiency might differ among Hb E/β-thalassemia patients.

PROCEDURE

We investigated the vitamin D status of 109 children with Hb E/β-thalassemia who attended the Pediatric Hematology Clinic at the Siriraj Hospital in Bangkok, Thailand, from April 2009 to March 2010.

RESULTS

Forty-nine of the children were classified as transfusion-dependent (TD) and the remainder (n = 60) as non-transfusion-dependent (NTD). Only 10.1% of the children in our study had normal vitamin D levels, despite Thailand's geographic position 15° N and 100° E and climate, which provides abundant sunlight exposure and therefore efficient vitamin D synthesis. In addition, NTD children were significantly more likely to be vitamin D deficient than TD children (P = 0.01).

CONCLUSIONS

Our results highlight the importance of monitoring serum vitamin D levels in children with Hb E/β-thalassemia regardless of their clinical severity or the amount of sunlight they are exposed to.

CYP2R1 is a major, but not exclusive, contributor to 25-hydroxyvitamin D production in vivo

Bioactivation of vitamin D consists of two sequential hydroxylation steps to produce 1α,25-dihydroxyvitamin D3. It is clear that the second or 1α-hydroxylation step is carried out by a single enzyme, 25-hydroxyvitamin D 1α-hydroxylase CYP27B1. However, it is not certain what enzyme or enzymes are responsible for the initial 25-hydroxylation. An excellent case has been made for vitamin D 25-hydroxylase CYP2R1, but this hypothesis has not yet been tested. We have now produced Cyp2r1 (-/-) mice. These mice had greater than 50% reduction in serum 25-hydroxyvitamin D3. Curiously, the 1α,25-dihydroxyvitamin D3 level in the serum remained unchanged. These mice presented no health issues. A double knockout of Cyp2r1 and Cyp27a1 maintained a similar circulating level of 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3. Our results support the idea that the CYP2R1 is the major enzyme responsible for 25-hydroxylation of vitamin D, but clearly a second, as-yet unknown, enzyme is another contributor to this important step in vitamin D activation.

1,25-Dihydroxyvitamin D deficiency is associated with preterm birth in African American and Caucasian women

Vitamin (vit) D deficiency and preterm birth (PTB) are more prevalent among African American (AA) women compared to caucasian (Cau) women. Because vit D is important in regulating cell-mediated immune responses, vit D insufficiency or deficiency during pregnancy may enhance inflammation in pregnant women and increase the risk of PTB. In this study, circulatory levels of 25-hydroxy (OH) and 1,25-dihydroxy (OH)2 vit D were measured using chemiluminescence and radioimmunoassay techniques, respectively, in AA (n = 108) and Cau (n = 84) women who delivered at term and preterm. The results from this study suggest that the serum levels of the 25-(OH) vit D concentrations tend to decrease (P = .06) in the Cau women who delivered at preterm compared to those delivering at term. However, the 25-(OH) vit D levels in Cau and AA between term and preterm deliveries were not significantly different. The serum levels of 1,25-(OH)2 vit D were found to be significantly lower in AA women compared to Cau women (P < .02) at term, and in the Cau (P < .01) and AA (P < .04) women delivering at preterm compared to those delivering at term. One-way analysis of variance demonstrated that 1,25-(OH)2 vit D levels were significantly lower in participants delivering at preterm (<34 weeks and between 34 and 37 weeks) compared to those delivering at term (>37 weeks).These results suggest that low levels of serum 1,25-(OH)2 vit D are associated with PTB, and vit D can potentially be used as a novel diagnostic marker in the detection of PTB.

Vitamin D deficiency in medical patients at a central hospital in Malawi: a comparison with TB patients from a previous study

Objectives

To determine the prevalence of vitamin D deficiency (VDD) in adult medical, non-tuberculous (non-TB) patients. To investigate associations with VDD. To compare the results with a similar study in TB patients at the same hospital.

Design

Cross-sectional sample.

Setting

Central hospital in Malawi.

Participants

Adult non-TB patients (n = 157), inpatients and outpatients.

Outcome Measures

The primary outcome was the prevalence of VDD. Potentially causal associations sought included nutritional status, in/outpatient status, HIV status, anti-retroviral therapy (ART) and, by comparison with a previous study, a diagnosis of tuberculosis (TB).

Results

Hypovitaminosis D (≤75 nmol/L) occurred in 47.8% (75/157) of patients, 16.6% (26/157) of whom had VDD (≤50 nmol/L). None had severe VDD (≤25 nmol/L). VDD was found in 22.8% (23/101) of in-patients and 5.4% (3/56) of out-patients. In univariable analysis in-patient status, ART use and low dietary vitamin D were significant predictors of VDD. VDD was less prevalent than in previously studied TB patients in the same hospital (68/161 = 42%). In multivariate analysis of the combined data set from both studies, having TB (OR 3.61, 95%CI 2.02–6.43) and being an in-patient (OR 2.70, 95%CI 1.46–5.01) were significant independent predictors of VDD.

Conclusions

About half of adult medical patients without TB have suboptimal vitamin D status, which is more common in in-patients. VDD is much more common in TB patients than non-TB patients, even when other variables are controlled for, suggesting that vitamin D deficiency is associated with TB.

Novel vitamin D compounds and skin cancer prevention

As skin cancer is one of the most costly health issues in many countries, particularly in Australia, the possibility that vitamin D compounds might contribute to prevention of this disease is becoming increasingly more attractive to researchers and health communities. In this article, important epidemiologic, mechanistic and experimental data supporting the chemopreventive potential of several vitamin D-related compounds are explored. Evidence of photoprotection by the active hormone, 1α,25dihydroxyvitamin D3, as well as a derivative of an over-irradiation product, lumisterol, a fluorinated analog and bufalin, a potential vitamin D-like compound, are provided. The aim of this article is to understand how vitamin D compounds contribute to UV adaptation and potentially, skin cancer prevention.

Vitamin D deficiency affects the immunity against Mycobacterium tuberculosis infection in mice

The aim of the study is to investigate the immunological changes after stimulation with bacillus Calmette-Guerin (BCG) in mice with vitamin D deficiency. After weaning, mice were divided into the vitamin D-deficient group (-D group), the normal group (N group), and the vitamin D-supplemented group (+D group). Twelve-week-old mice were intraperitoneally injected with 0.5 mg/ml BCG (≥1.0 × 10(6) CFU/mg) and maintained for 6 weeks. Spleen lymphocytes were isolated, and the percentages of CD4(+) and CD8(+) lymphocytes were determined by flow cytometry. IFN-γ levels, IL-10 levels, and the TB-PPD-specific antibody titer were determined by ELISA. The inter-group difference was analyzed using one-way ANOVA, and multiple comparisons were analyzed using the LSD test. The percentage of CD4(+) cells was 27.1 ± 0.6 in the -D group, 23.62 ± 0.42 in the N group, and 19.46 ± 0.32 in the +D group (P < 0.05). The percentage of CD8(+) lymphocytes was 12.15 ± 0.61 in the -D group, 8.7 ± 0.64 in the N group, and 7.12 ± 0.48 in the +D group (P < 0.05). The CD4(+)/CD8(+) ratio was 2.23 ± 0.15 in the -D group, 2.71 ± 0.21 in the N group, and 2.73 ± 0.31 in the +D group (P < 0.05). The plasma IFN-γ levels were 416.42 ± 16.42 pg/ml in the -D group, 325.41 ± 11.16 pg/ml in the N group, and 276.26 ± 25.32 pg/ml in the +D group (P < 0.005). The plasma IL-10 levels were 16.45 ± 1.58 pg/ml in the -D group, 24.31 ± 2.16 pg/ml in the N group, and 26.28 ± 0.42 pg/ml in the +D group (P < 0.005). The serum TB-PPD-specific antibody level was significantly higher in the -D group than in the N and +D groups. Vitamin D deficiency affects the immunity against Mycobacterium tuberculosis infection in mice.

Vitamin D, multiple sclerosis and inflammatory bowel disease

It has now been more than 20years since the vitamin D receptor was identified in cells of the immune system. The immune system has now been established as an important target of vitamin D. Vitamin D receptor knockout and vitamin D deficient mice have a surplus of effector T cells that have been implicated in the pathology of multiple sclerosis (MS) and inflammatory bowel disease (IBD). The active form of vitamin D directly and indirectly suppresses the function of these pathogenic T cells while inducing several regulatory T cells that suppress MS and IBD development. There is reason to believe that vitamin D could be an environmental factor that may play a role in the development of these immune mediated diseases in the clinic but at present there has not been a causal relationship established. Nonetheless, current evidence suggests that improving vitamin D status and/or using vitamin D receptor agonists may be useful in MS and IBD.

Vitamin D and HIV progression among Tanzanian adults initiating antiretroviral therapy

Background

There is growing evidence of an association between low vitamin D and HIV disease progression; however, no prospective studies have been conducted among adults receiving antiretroviral therapy (ART) in sub-Saharan Africa.

Methods

Serum 25-hydroxyvitamin D (25(OH)D) levels were assessed at ART initiation for a randomly selected cohort of HIV-infected adults enrolled in a trial of multivitamins (not including vitamin D) in Tanzania during 2006–2010. Participants were prospectively followed at monthly clinic visits for a median of 20.6 months. CD4 T-cell measurements were obtained every 4 months. Proportional hazard models were utilized for mortality analyses while generalized estimating equations were used for CD4 T-cell counts.

Results

Serum 25(OH)D was measured in 1103 adults 9.2% were classified as vitamin D deficient (<20 ng/ml), 43.6% insufficient (20–30 ng/mL), and 47.2% as sufficient (>30 ng/mL). After multivariate adjustment, vitamin D deficiency was significantly associated with increased mortality as compared to vitamin D sufficiency (HR: 2.00; 95% CI: 1.19–3.37; p = 0.009), whereas no significant association was found for vitamin D insufficiency (HR: 1.24; 95% CI: 0.87–1.78; p = 0.24). No effect modification by ART regimen or change in the associations over time was detected. Vitamin D status was not associated with change in CD4 T-cell count after ART initiation.

Conclusions

Deficient vitamin D levels may lead to increased mortality in individuals receiving ART and this relationship does not appear to be due to impaired CD4 T-cell reconstitution. Randomized controlled trials are needed to determine the safety and efficacy of vitamin D supplementation for individuals receiving ART.

Intake of vitamins D and A and calcium and risk of non-Hodgkin lymphoma: San Francisco Bay Area population-based case-control study

Several nutrients identified as potentially cancer protective have been inconsistently associated with non-Hodgkin lymphoma (NHL) risk. Dietary history data, including use of vitamin supplements, were collected using a semiquantitative food frequency questionnaire administered during in-person interviews with 4,133 participants (2,052 cases, 2,081 controls) in a San Francisco Bay Area population-based case-control study. Data were used to determine the association of intake levels of vitamins D and A and calcium with risk of NHL and NHL subtypes. Odds ratios (OR) and 95% confidence intervals (CI) were computed as estimates of relative risk using adjusted unconditional logistic regression. Increasing vitamin D intake from food and supplements was positively associated with NHL risk in men (5th quintile: OR = 1.6, 95% CI = 1.0-2.4, P(trend) = 0.07) and with diffuse large B-cell lymphoma (DLBCL) in women and men (5th quintile: OR = 1.6, 95% CI = 1.0-2.5, P(trend) = 0.02); that was largely due to the effect in men (P(trend) = 0.03). These results do not support a strong role for vitamin D intake with NHL risk, with the exception of a potential association for DLBCL risk in men. Our results should be interpreted conservatively until further investigation in larger pooled studies can be conducted to better assess the role of vitamin D intake in lymphomagenesis.

Development of experimental autoimmune encephalomyelitis (EAE) in mice requires vitamin D and the vitamin D receptor

The development of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, has been studied in mice that were (i) vitamin D-deficient, (ii) minus the vitamin D receptor, (iii) minus a vitamin D 25-hydroxylase, and (iv) minus the vitamin D 25-hydroxyvitamin D-1α-hydroxylase. EAE development was markedly suppressed in mice lacking the vitamin D receptor and partially suppressed in vitamin D-insufficient mice. However, the absence of either of the two key hydroxylases (i.e., 25-hydroxylase and 1α-hydroxylase) neither inhibits nor enhances the development of EAE. These results indicate that vitamin D and the vitamin D receptor are required for the development of EAE. The results also suggest that 1,25-dihydroxyvitamin D(3) may not play a role in this autoimmune response.

Vitamin D as a therapy for colitis: a systematic review

BACKGROUND AND AIM

The effect of vitamin D supplementation on immune disorders has been a topical research focus. The aim of this systematic review was to examine the current evidence of the effect of vitamin D supplementation as a therapy for colitis.

METHODS

The following databases were searched: MEDLINE, Pubmed, Scopus, Web of Knowledge, Cinicaltrials.gov and the Cochrane Central Register of Controlled Trials using the terms 'inflammatory bowel disease' 'Crohn's disease' 'ulcerative colitis' 'colitis' [and] 'vitamin D'. Both human and animal studies published in English language were examined. The reference lists of included studies and review articles were manually searched for any relevant studies.

RESULTS

Four studies were included in this systematic review. All reported an improvement in disease activity with vitamin D supplementation. The only high quality human study reported a non-significant reduction of relapse rate for Crohn's disease. No major adverse effects of vitamin D supplementation were reported.

CONCLUSIONS

Although there is some evidence that supplemental vitamin D, as an adjunctive treatment, may help in controlling colitis, this evidence is not enough to justify using vitamin D in treating inflammatory bowel disease (IBD). Large high quality placebo-controlled randomised controlled trials are needed to explore a possible benefit of using vitamin D in treating IBD.

Maternal vitamin D status and child morbidity, anemia, and growth in human immunodeficiency virus-exposed children in Tanzania

BACKGROUND

Vitamin D may help prevent adverse pediatric outcomes, including infectious diseases and growth failure, based on its role in immune and metabolic functions. We examined the association of maternal vitamin D status and pediatric health outcomes in children born to human immunodeficiency virus (HIV)-infected women.

METHODS

Vitamin D status was determined in 884 HIV-infected pregnant women at 12 to 27 weeks of gestation in a trial of vitamin supplementation (not excluding vitamin D) in Tanzania. Information on child morbidities, anemia and hypochromic microcytosis, and anthropometry was recorded through monthly clinic visits. Generalized estimating equations and Cox proportional hazards models were used to assess the relationships of outcomes with maternal vitamin D status.

RESULTS

A total of 39% of women had low vitamin D levels (<32 ng/mL). Children born to women with low vitamin D status were 1.11 times more likely to report cough during follow-up (relative risk [RR], 1.11; 95% confidence interval [CI], 1.02-1.21). No significant associations were noted for other respiratory symptoms, diarrhea, or anemia outcomes. Low maternal vitamin D status was associated with significantly increased risk of stunting (height-for-age z score, <-2; RR, 1.29; 95% CI, 1.05-1.59) and being underweight (weight-for-age z score, <-2; RR, 1.33; 95% CI, 1.03-1.71).

CONCLUSIONS

Maternal vitamin D status may be important for preventing respiratory infections and ensuring optimal growth in HIV-exposed children.

Worldwide increasing incidences of cutaneous malignant melanoma

The incidence of cutaneous malignant melanoma (CMM) has been increasing at a steady rate in fair-skinned populations around the world for decades. Scientists are not certain why CMM has been steadily increasing, but strong, intermittent UVB (290-320 nm) exposures, especially sunburn episodes, probably initiate, CMM, while UVA (321-400 nm) passing through glass windows in offices and cars probably promotes it. The CMM incidence may be increasing at an exponential rate around the world, but it definitely decreases with increasing latitude up to ~50°N where it reverses and increases with the increasing latitude. The inversion in the incidence of CMM may occur because there is more UVA relative to UVB for most of the year at higher latitudes. If windows, allowing UVA to enter our indoor-working environment and cars, are at least partly responsible for the increasing incidence of CMM, then UV filters can be applied to reduce the rate of increase worldwide.

Vitamin D deficiency diminishes the severity and delays onset of experimental autoimmune encephalomyelitis

Multiple sclerosis incidence is clearly inversely related to sun exposure. This observation led to the idea that vitamin D might be responsible for this relationship. Providing super-physiologic doses of the hormonal form of vitamin D, 1α,25-dihydroxyvitamin D₃, suppresses an animal model of multiple sclerosis, i.e. experimental autoimmune encephalomyelitis (EAE) but causes unwanted hypercalcemia. Further, dietary calcium is needed for this activity of 1α,25-dihydroxyvitamin D₃. B10PL mice were maintained on a vitamin D-deficient diet for two generations to produce frank vitamin D deficiency. These animals showed delayed onset and reduced severity of EAE compared to control animals on the same diet and given vitamin D₃ or provided a vitamin D-containing chow diet. Thus, vitamin D deficiency interferes with the development of this autoimmune disease rather than increasing susceptibility.

Influence of 1,25-dihydroxy vitamin D3 on TLR4-induced activation of antigen presenting cells is dependent on the order of receptor engagement

The vitamin D metabolite, 1,25-(OH)₂D₃, binds the vitamin D receptor (VDR) to exert its regulatory effects at the transcription level. VDR is expressed in professional antigen-presenting cells (pAPCs), such as macrophages (Mø) and dendritic cells (DCs). We show for the first time that the 24-hydroxylase enzyme is activated in bone marrow-derived dendritic cell (BMDC), due to 1,25(OH)₂D₃ stimulation which resulted in the induction of its gene, CYP24A1. Furthermore, we provide evidence that the influence of 1,25-(OH)₂D₃ on TLR-4-L-induced activation of pAPC is dependent on the order of VDR and TLR-4 engagement. Thus, pre-treatment of pAPC with 1,25-(OH)₂D₃ partially inhibited LPS-induced nitric oxide (NO) production. However, these inhibitory effects were not observed when LPS and 1,25-(OH)₂D₃ were added simultaneously or when LPS preceded 1,25-(OH)₂D₃. Moreover, we found that 1,25-(OH)₂D₃ pre-treatment of pAPCs did not cause general suppression since it interfered with NO levels but not with the cytokines IL-6 or TNF-α. Consequently, engagement of VDR by 1,25-(OH)₂D₃ can partially interfere with TLR-4-L-induced activation of pAPCs only when it occurs before TLR-4 stimulation.

Vitamin D and methicillin-resistant Staphylococcus aureus nasal carriage

Studies have found that vitamin D plays an important role in mediating immune function via a number of pathways, including enhancing the release of antimicrobial peptides in the skin. Given these findings, we hypothesize that low serum vitamin D levels may increase the risk of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA). A secondary data analysis of the National Health and Nutrition Examination Survey 2001-2004 was performed to investigate the association between serum vitamin D levels and MRSA nasal carriage for the non-institutionalized population of the USA. An estimated 2.7 million persons (1.2% of the population) are MRSA nasal carriers. An estimated 63.3 million persons (28.4% of the population) are vitamin D deficient (serum vitamin D <20 ng/ml). In an adjusted logistic regression analysis controlling for age, race, gender, poverty income ratio, current health status, hospitalization in the past 12 months, and antibiotic use in the past month, individuals with vitamin D deficiency had a statistically significant increased risk of MRSA carriage of 2.04 (95% CI 1.09-3.84). Vitamin D deficiency is associated with an increased risk of MRSA nasal carriage. Further trials may be warranted to determine whether vitamin D supplementation decreases the risk of MRSA colonization.

Lipid-soluble vitamins A, D, and E in HIV-infected pregnant women in Tanzania

BACKGROUND/OBJECTIVES

There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings.

SUBJECTS/METHODS

This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals.

RESULTS

Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01).

CONCLUSIONS

Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions.

Renal cell therapy and beyond

Although current dialysis techniques have transformed acute and chronic renal failure from uniformly fatal clinical disorders into treatable diseases, these therapies replace only the water and solute clearance function of the kidney and have reached a point where little further therapeutic improvement can be anticipated. In addition to their metabolic and endocrine functions, renal tubule cells presumably play an important role in the systemic inflammatory balance by participating in the complex and dynamic network of leukocyte action and pro- and anti-inflammatory cytokines. Loss of this function may result in a propensity to develop systemic inflammatory response syndrome (SIRS), multiorgan dysfunction, and a high risk of death in acute kidney injury (AKI), and may relate to chronic inflammatory state in end-stage renal disease (ESRD). A renal tubule cell assist device (RAD) containing animal or human renal tubule cells has been recently developed with the purpose of integrating the functions of tubule cells with the filtration function of current dialysis to offer a more complete renal replacement therapy. The viability and functionality of this device were confirmed in in vitro experiments and large animal studies, and recently the RAD's clinical therapeutic benefit was demonstrated with a series of FDA-approved human trials. Another novel synthetic membrane extracorporeal device that binds and inhibits circulating leukocytes has been developed with the purpose of reducing microvascular damage promoted primarily via activated circulating leukocytes in AKI and SIRS. This device, called a selective cytopheretic inhibitory device, mimics immunomodulation and duplicates RAD efficiency in preliminary studies. Both devices may become comprehensive treatments, replacing full renal function and correcting inflammatory imbalance in patients with acute and chronic renal disorders.

Perinatal outcomes, including mother-to-child transmission of HIV, and child mortality and their association with maternal vitamin D status in Tanzania

BACKGROUND

Vitamin D is a strong immunomodulator and may protect against adverse pregnancy outcomes, mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV), and child mortality.

METHODS

A total of 884 HIV-infected pregnant women who were participating in a vitamin supplementation trial in Tanzania were monitored to assess pregnancy outcomes and child mortality. The association of these outcomes with maternal vitamin D status at enrollment was examined in an observational analysis.

RESULTS

No association was observed between maternal vitamin D status and adverse pregnancy outcomes, including low birth weight and preterm birth. In multivariate models, a low maternal vitamin D level (<32 ng/mL) was associated with a 50% higher risk (95% confidence interval [CI], 2%-120%) of MTCT of HIV at 6 weeks, a 2-fold higher risk of MTCT of HIV through breast-feeding among children who were HIV uninfected at 6 weeks (95% CI, 1.08-3.82), and a 46% higher overall risk of HIV infection (95% CI, 11%-91%). Children born to women with a low vitamin D level had a 61% higher risk of dying during follow-up (95% CI, 25%-107%).

CONCLUSIONS

If found to be efficacious in randomized trials, vitamin D supplementation could prove to be an inexpensive method of reducing the burden of HIV infection and death among children, particularly in resource-limited settings.

Heterogeneity of vitamin D receptor gene association with celiac disease and type 1 diabetes mellitus

OBJECTIVE

Vitamin D has been shown to exert multiple immunomodulatory effects and is known to suppress T-cell activation by binding to the vitamin D receptor (VDR). To determine whether VDR gene polymorphisms are related to the susceptibility to celiac disease, we investigated its implication as a candidate gene in the Basque population. Because celiac disease and type 1 diabetes share common susceptibility loci, we also analyzed families with type 1 diabetes mellitus.

METHODS

A total of 37 families with celiac disease and 64 type 1 diabetic families of Basque origin with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (Fok I, Bsm I, Apa I and Taq I). The AFBAC approach was used to test for association.

RESULTS

Comparison of VDR genotypes of the patients with those of 88 healthy individuals identified "ff" as a risk genotype for celiac disease [p = 0.01; OR = 3.45 (1.12-10.79)]. On the other hand, a significantly higher frequency of haplotype "fBAt" was observed in the type 1 diabetic group [p(c) = 0.02; OR = 4.4 (1.5-15.3)].

CONCLUSION

Our findings suggest that polymorphisms within the vitamin D receptor gene are markers of susceptibility to or protection from autoimmune diseases, although, at least in the Basque population, association of VDR variants with celiac disease and type 1 diabetes seems to be heterogeneous.