Vitamin D in HIV-Infected Patients

Effect of cholecalciferol on 25-hydroxyvitamin D in people living with HIV and vitamin D deficiency: A prospective observational study

OBJECTIVES

To assess the effect of oral cholecalciferol 50,000IU monthly administered in people living with HIV (PLHIV) and 25(OH)D deficiency followed over 48 weeks.

METHODS

A prospective observational study was conducted in a cohort of 110 PLHIV with 25(OH)D levels<20ng/mL. Changes in 25(OH)D levels were evaluated at 3, 6, and 12 months of treatment. The percentages of patients who achieved 25(OH)D levels>20 and >30ng/mL and changes in bone mineral density (BMD) were assessed.

RESULTS

One hundred ten PLHIV (79% men, mean age 49.46 years) were included. The mean (standard deviation, SD) time on antiretroviral treatment was 10.69 (8.31) years and all patients had a viral load<50copies/mL. The mean 25(OH)D levels of 15.10±3.22ng/mL at baseline increased significantly (P<0.001) to 27.89±7.79ng/mL at 3 months, 28.53±8.45ng/mL at 6 months and 27.89±7.92ng/mL at 12 months. A total of 87.27% had normal 25(OH)D levels at 12 months (>30ng/mL in 36.1% of patients and >20ng/mL in 51.5%). Parathormone levels (PTH) also decreased significantly. Treatment was safe and well tolerated. On the other hand, no significant changes were observed in BMD.

CONCLUSIONS

Monthly administration of 50,000IU of cholecalciferol was effective in normalizing 25(OH)D deficiency in 87% of PLHIV, without observing changes in bone mineral density.

Potential Advantages of a Well-balanced Nutrition Regimen for People Living with Human Immunodeficiency Virus Type -1

This review underscores the important role of nutrition in enhancing the management of Human Immunodeficiency Virus type 1 (HIV-1). Highlighting the efficacy of dietary interventions, including, the importance of omega-3 fatty acids, vitamins D and B-12, and the Mediterranean diet, we delineate how these beneficial nutritional strategies can improve the effectiveness of combined antiretroviral therapy (cART), mitigate its side effects, and ameliorate metabolic disorders in people living with HIV-1 (PLWH). Our review advocates for the integration and implementation of personalized nutritional assessments into the care plan for PLWH, proposing actionable strategies for healthcare providers in HIV-1 field. Summarizing the current standing of the relevance of the nutritional and well-planned diet recommended for the PLWH and emphasizing on the future research directions, this review establishes a foundation for nutrition as a cornerstone in comprehensive HIV-1 management. Our review aims to improve patients' health outcomes and overall quality of life for PLWH.

Vitamin D and Probability of Developmental Disorders among Perinatally HIV-Affected and Unaffected Ugandan Children

We tested the hypothesis that vitamin D deficiency (VDD) is associated with higher developmental disorder probability in 604 children with perinatal HIV infection (CPHIV, n = 199), HIV exposed and uninfected (CHEU, n = 196), and HIV unexposed uninfected (CHUU, n = 201). Children at 6-18 years old and their adult caregivers were assessed at enrollment, 6, and 12-month follow-ups. Serum 25-hydroxyvitamin-D (25OHD) levels in children quantified per the NHANES protocol were used to define VD categories as VDD (25OHD < 20 ng/mL), VD insufficient (VDI, 20 ≤ 25OHD ≤ 25 ng/mL), and VD sufficient (VDS = reference group if 25OHD > 25 ng/mL). Perinatal HIV status per DNA polymerase chain reaction/HIV rapid diagnostic tests included: CPHIV, CHEU, and CHUU. Developmental stage was defined as pre-adolescent (age < 11) vs. adolescent (age ≥ 11) years. Caregiver responses to standardized questions from Behavioral Assessment System for Children, Third Edition (BASC-3), were used to calculate probability scores for four disorders, namely: autism (ASD), attention deficit & hyperactivity (ADHD), emotional behavioral disorder (EBD), functional impairment (FI), and resiliency at 0, 6 and 12 months. Multivariable longitudinal models estimated VD-associated standardized mean difference (SMD) and corresponding 95% confidence intervals (95% CI) in respective probability scores in Statistical Analysis Software (v.9.4). Baseline VDD vs. VDS predicted higher probability scores of moderate clinical importance for ASD, ADHD, EBD, and higher FI among pre-adolescents (SMD = 0.32 to 0.40, 95% CI: 0.00 to 0.74). VDD was not associated with resiliency or any developmental disorders among adolescents. VDD predicted higher developmental disorder and FI scores over 12 months in a developmental stage-dependent manner. This relationship requires further understanding to appropriately target future interventions.

The effect of antiretroviral therapy initiation on vitamin D levels and four oral diseases among Kenyan children and adolescents living with HIV

OBJECTIVES

The impact of antiretroviral treatment (ART) on the occurrence of oral diseases among children and adolescents living with HIV (CALHIV) is poorly understood. The aim of this study was to determine the effect of ART timing on vitamin D levels and the prevalence of four oral diseases (dry mouth, dental caries, enamel hypoplasia, and non-herpes oral ulcer) among Kenyan CALHIV from two pediatric HIV cohorts.

METHODS

This nested cross-sectional study was conducted at the Kenyatta National Hospital, Nairobi, Kenya. CALHIV, 51 with early-ART initiated at <12 months of age and 27 with late-ART initiated between 18 months-12 years of age, were included. Demographics, HIV diagnosis, baseline CD4 and HIV RNA viral load data were extracted from the primary study databases. Community Oral Health Officers performed oral health examinations following standardized training.

RESULTS

Among 78 CALHIV in the study, median age at the time of the oral examination was 11.4 years old and median ART duration at the time of oral examination was 11 years (IQR: 10.1, 13.4). Mean serum vitamin D level was significantly higher among the early-ART group than the late-ART group (29.5 versus 22.4 ng/mL, p = 0.0002). Children who received early-ART had a 70% reduction in risk of inadequate vitamin D level (<20 ng/mL), compared to those who received late-ART (p = 0.02). Although both groups had similar prevalence of oral diseases overall (early-ART 82.4%; late-ART 85.2%; p = 0.2), there was a trend for higher prevalence of dry mouth (p = 0.1) and dental caries (p = 0.1) in the early versus late ART groups. The prevalence of the four oral diseases was not associated with vitamin D levels (p = 0.583).

CONCLUSIONS

After >10 years of ART, CALHIV with early-ART initiation had higher serum vitamin D levels compared to the late-ART group. The four oral diseases were not significantly associated with timing of ART initiation or serum vitamin D concentrations in this cohort. There was a trend for higher prevalence of dry mouth and dental caries in the early-ART group, probably as side-effects of ART.

Hypovitaminosis D Is Associated with Higher Levels of Inflammatory Cytokines and with HAM/TSP in HTLV-Infected Patients

Recent studies have shown the effects of vitamin D on host response to infectious diseases. Some studies detected a high prevalence of hypovitaminosis D in HIV-infected patients, but scarce information exists for HTLV-1 infection. We conducted a cross-sectional study to evaluate the frequency of hypovitaminosis D in HTLV-1 patients and its relationship with their immune response in HTLV-infected patients and in age- and gender-matched controls at a Brazilian rehabilitation hospital. We compared vitamin D, interleukin-6 (IL-6), tumoral necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) levels across groups. Logistic regression was utilized to assess the association between hypovitaminosis D and cytokine levels. We enrolled 161 HTLV-infected subjects (129 HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, 32 asymptomatic HTLV carriers) and equal number of HTLV-negative controls. We observed a significantly higher prevalence of hypovitaminosis D in patients with HAM/TSP than in HTLV asymptomatic carriers (p < 0.001), or controls (p < 0.001). HAM/TSP patients also had higher levels of IL-6 and IFN-γ than asymptomatic carriers. Patients with HAM/TSP and hypovitaminosis D had higher levels of TNF-α than asymptomatic HTLV carriers. These findings suggest hypovitaminosis D plays a role in HAM/TSP pathogenesis, and it needs to be evaluated in further studies.

Induction of Autophagy to Achieve a Human Immunodeficiency Virus Type 1 Cure

Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.

Association of Single Nucleotide Polymorphisms in the VDR and CYP27B1 Genes with Risk of Developing Vitamin D3 Deficiency

This study was carried out to investigate the relationship between common variants in two vitamin D pathway genes (VDR and CYP27B1) and vitamin D3 serum levels. In this study, serum vitamin D metabolite levels were measured in the blood samples of 200 patients with alopecia areata. Then, single nucleotide polymorphisms (SNPs) in VDR and CYP27B1 were analyzed using polymerase chain reaction (PCR)-sequencing. Sixty-three variations were observed in these genes (42 variations in CYP27B1 and 21 variations in VDR). A significant difference in Rs1544410 (odds ratio: 7, P < 0.0005) and rs4646536 (odds ratio: 4.043, P < 0.0005) variants was found between the patients and controls. The study showed the relationship between the two polymorphisms, Rs1544410 (odds ratio: 7, 95% CI, 1–8) and rs4646536 (odds ratio: 4.043, 95% CI, 3–14.038) on the genes VDR and CYP27B1, respectively, with increased risk of developing vitamin D3 insufficiency in the Iranian population. Therefore, SNPs in the VDR and CYP27B1 genes can be considered as prognostic biomarkers of the risk of developing vitamin D3 deficiency.

Serum vitamin D receptor and High Mobility Group Box-1 (HMGB1) levels in HIV-infected patients with different immunodeficiency status: A cross-sectional study

BACKGROUND

HIV-AIDS patients typically have hypovitaminosis D. Vitamin D is a key mediator in inflammatory and infectious diseases, which VDR mediates its biological effect. High-mobility group box 1 protein (HMGB1) modulates HIV-1 replication in vitro. Vitamin D played a role in inhibiting HMGB1 secretion in the animal study.

OBJECTIVES

This study aimed to examine differences and correlation of vitamin D receptor and HMGB1 protein levels in HIV patients with mild and severe immunodeficiency and healthy control participants.

METHODS

This study using a cross-sectional design conducted at Volunteer Counseling and Testing (VCT) Clinic in Mataram, West Nusa Tenggara, Indonesia, from January to June 2020. Three groups of study participants were classified as HIV patients with severe immune deficiency (SID), HIV patients with mild immune deficiency (MID), and healthy controls (HC).

RESULTS

Mean level of vitamin D receptor in SID HIV group was 25.89 ± 3.95 ng/ml, lower than those in MID-HIV group; 33.72 ± 1.69 ng/ml and in HC group; 50.65 ± 3.64 ng/ml. Mean levels of HMGB1 protein in the SID HIV group were 3119.81 ± 292.38 pg/ml higher than those in the MID HIV group 1553.55 ± 231.08 pg/ml and HC 680.82 ± 365.51 pg/ml. There was a significant and strong negative correlation (r = -0.932) between vitamin D receptor and HMGB1 levels (p < 0.01).

CONCLUSIONS

Strong negative correlation between VDR and HMGB1 in different immunodeficiency statuses suggesting an important role of vitamin D in inflammation control in HIV infection. However, it needs to be confirmed in a further prospective study.

Autophagy efficacy and vitamin D status: Population effects

Toll-like receptor (TLR) 2/1 signalling is linked to autophagy through transcriptional actions of the 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃)-vitamin D receptor (VDR) complex. Population-specific effects have been reported for TLR2/1-VDR signalling. We hypothesized that population effects extend to autophagy and are influenced by vitamin D status. Serum 25(OH)D₃ of healthy South Africans (Black individuals n = 10, White individuals n = 10) was quantified by LC-MS/MS. Primary monocytes-macrophages were supplemented in vitro with 1,25(OH)₂D₃ and stimulated with the lipoprotein Pam₃CysSerLys₄. TLR2, VDR, hCAP18, Beclin1, LC3-IIB, cytokines and CYP24A1 mRNA were quantified by flow cytometry and RT-qPCR, respectively. Black individuals showed significantly lower overall cumulative LC3-IIB (P < 0.010), but higher Beclin1, VDR, IL6 and TNFA (P < 0.050) than White individuals. 1,25(OH)₂D₃ enhanced autophagic flux in monocytes-macrophages from Black individuals upon TLR2/1 stimulation and strengthened autophagy in 25(OH)D₃ deficient individuals (independent cohort, n = 20). These findings support population-directed vitamin D supplementation.

Association of Low Vitamin D with Complications of HIV and AIDS: A literature Review

With the advent of combination antiretroviral therapy (cART), the survival of HIV patients has improved dramatically, but the complications of the disease and treatment have become an important issue in the management of HIV patients. Vitamin-D deficiency is common in HIV patients. Low vitamin-D is associated with different comorbidities in the HIV uninfected general population. In this review, we first briefly describe vitamin D synthesis and mechanism of action and we focus on the epidemiological and clinical data dealing with the relationship between vitamin D deficiency in HIV infection with several comorbidities which has been found to be increasingly common in patients living with HIV infection. We searched the PubMed database using the keywords "HIV," "vitamin D" and other common disorders or conditions that are relatively common in HIV infection. The other conditions included in the search were osteoporosis and fracture, cardiovascular disease, diabetes and insulin resistance, active tuberculosis, hepatitis-C co-infection, and HIV disease progression. Articles presenting original data as well as systematic reviews and met analysis related to HIV population were included in our analysis. Vitamin-D deficiency seems to be associated with several adverse outcomes in HIV patients but a definite cause and effect relationship with vitamin-D is yet to be confirmed in most of the cases. However, the literature supporting the efficacy of vitamin-D supplementation is lacking.

The Potential Protective Role of Vitamin D Supplementation on HIV-1 Infection

HIV infection remains a global and public health issue with the incidence increasing in some countries. Despite the fact that combination antiretroviral therapy (cART) has decreased mortality and increased the life expectancy of HIV-infected individuals, non-AIDS conditions, mainly those associated with a persistent inflammatory state, have emerged as important causes of morbidity, and mortality despite effective antiviral therapy. One of the most common comorbidities in HIV-1 patients is Vitamin D (VitD) insufficiency, as VitD is a hormone that, in addition to its physiological role in mineral metabolism, has pleiotropic effects on immune regulation. Several reports have shown that VitD levels decrease during HIV disease progression and correlate with decreased survival rates, highlighting the importance of VitD supplementation during infection. An extensive review of 29 clinical studies of VitD supplementation in HIV-infected patients showed that regardless of cART, when VitD levels were increased to normal ranges, there was a decrease in inflammation, markers associated with bone turnover, and the risk of secondary hyperparathyroidism while the anti-bacterial response was increased. Additionally, in 3 of 7 studies, VitD supplementation led to an increase in CD4+ T cell count, although its effect on viral load was inconclusive since most patients were on cART. Similarly, previous evidence from our laboratory has shown that VitD can reduce the infection of CD4+ T cells in vitro. The effect of VitD supplementation on other HIV-associated conditions, such as cardiovascular diseases, dyslipidemia or hypertension, warrants further exploration. Currently, the available evidence suggests that there is a potential role for VitD supplementation in people living with HIV-1, however, comprehensive studies are required to define an adequate supplementation protocol for these individuals.

CD4 T cell count is inversely associated with lumbar spine bone mass in HIV-infected men under the age of 50 years

HIV-infected men under the age of 50 years had a lower bone mass compared to that of HIV-uninfected men. Lower CD4 T cell counts, independent of whether antiretroviral therapy (ART) was used, were associated with lower BMD. HIV-infected patients with low CD4 T cell counts may need follow-up and intervention regarding bone health, including younger patients.

INTRODUCTION

HIV-infected patients have a low bone mineral density (BMD) owing to multifactorial interaction between common osteoporosis risk factors and HIV-related factors, including chronic inflammation and ART. Although HIV infection and ART might affect bone metabolism, little data is available for patients aged under 50 years. We aimed to investigate the association of HIV infection-induced low CD4 T cell counts and ART with BMD in men aged under 50 years.

METHODS

We performed an age- and body mass index-matched case-control study. BMD values of HIV-infected and HIV-uninfected men (< 50 years) were compared, and HIV-infected men were stratified by CD4 T cell counts and ART use.

RESULTS

After adjusting confounders, HIV-infected men with CD4 T cell counts ≥ 500 cells/μL (n = 28) and < 500 cells/μL (n = 139) had lower BMD at the femoral neck (FN, p < 0.001) and total hip (TH, p < 0.001) than HIV-uninfected men (n = 167). HIV-infected men with CD4 T cell counts < 500/μL had lower BMD at the lumbar spine (LS, p = 0.034) than those with counts of ≥ 500 cells/μL, but not at FN and TH. The CD4 T cell count (γ = 0.169, p = 0.031) was positively correlated with BMD at LS. There was no significant difference in the BMD (p = 0.499-> 0.999) between the ART-naïve (n = 75) and ART-user group (n = 92).

CONCLUSIONS

Despite their relatively younger age, HIV-infected men had a lower BMD than HIV-uninfected men. Lower CD4 T cell counts, irrespective of ART, might result in lower bone mass.

VDR polymorphisms influence immunological response in HIV-1+ individuals undergoing antiretroviral therapy

Vitamin D exerts an immuno-modulatory activity on several immune system cells through the vitamin D receptor (VDR). Herein, we verified that age and a therapeutic regimen containing protease inhibitors are associated with failures in antiretroviral therapies (ARVs). In addition, we assessed whether a VDR SNP (rs11568820: C allele and CC genotype) and GC (rs2228570-rs11568820) allelic combinations are associated with immunological failure (p < 0.05). Our findings suggest a possible role of VDR SNPs on immunological failure in HIV-1+ individuals undergoing regular ARVs.

Serum and Bronchoalveolar Lavage Fluid 25(OH)Vitamin D3 Levels in HIV-1 and Tuberculosis: A Cross-Sectional Study from a Tertiary Care Center in North India

BACKGROUND

Vitamin D is an immunomodulator, and its deficiency is associated with Tuberculosis (TB) infection. Bronchoalveolar lavage fluid (BALF) is a rich milieu of macrophages that form the first line of defense against invading TB bacilli. As there is an increased prevalence of vitamin D deficiency in TB and human immunodeficiency virus-1 (HIV-1) subjects, we intend exploring the possibility of a localized deficiency of vitamin D metabolites in BALF of these patients.

OBJECTIVE

The primary objective was to assess the level of 25D3 in serum and BALF of subjects and look for a significant difference among patients and controls. The secondary objective was to find a correlation between serum and BALF 25D3 levels.

METHODS

We performed a cross-sectional study with subjects divided into four groups: Controls (group 1), HIV positive without active TB (group 2), active TB without HIV (group 3), and HIV-TB coinfection (group 4). BALF and serum 25D3 levels were compared between the groups.

RESULTS

Among the 149 (an immunomodulator) successive subjects enrolled, there were 40 subjects in group 1 (HIV-TB-), 48 in group 2 (HIV+TB-), 37 in group 3 (HIV-TB+), and 24 in group 4 (HIV+TB+). Females constituted 31.6% of the study subjects. In groups 3 and 4, there were significantly lower serum 25D3 levels compared to group 1 (p-value group 3: 0.002; group 4: 0.012). In groups 2, 3, and 4, there were significantly lower BALF 25D3 levels compared to group 1 (p-value group 2: 0.000; group 3: 0.000; group 4: 0.001). There was a significant correlation between serum and BALF 25D3 levels (Spearman's rank correlation coefficient 0.318, p-value = 0.0001).

CONCLUSION

Lower levels of serum and BALF 25D3 were observed in HIV, TB, and HIV-TB coinfected patients. Localized deficiency of vitamin D metabolites might be associated with increased vulnerability to TB infection.

The interplay between vitamin D and viral infections

The pleiotropic role of vitamin D has been explored over the past decades and there is compelling evidence for an epidemiological association between poor vitamin D status and a variety of diseases. While the potential anti-viral effect of vitamin D has recently been described, the underlying mechanisms by which vitamin D deficiency could contribute to viral disease development remain poorly understood. The possible interactions between viral infections and vitamin D appear to be more complex than previously thought. Recent findings indicate a complex interplay between viral infections and vitamin D, including the induction of anti-viral state, functional immunoregulatory features, interaction with cellular and viral factors, induction of autophagy and apoptosis, and genetic and epigenetic alterations. While crosstalk between vitamin D and intracellular signalling pathways may provide an essential modulatory effect on viral gene transcription, the immunomodulatory effect of vitamin D on viral infections appears to be transient. The interplay between viral infections and vitamin D remains an intriguing concept, and the global imprint that vitamin D can have on the immune signature in the context of viral infections is an area of growing interest.

HYPOVITAMINOSIS D IN HIV-INFECTED PATIENTS

INTRODUCTION

Vitamin D (VD) deficiency is highly prevalent worldwide.

AIM

To assess the prevalence of hypovitaminosis D in HIV-positive Romanian patients compared to controls.

METHODS

Serum 25OHD concentration was measured in HIV-infected patients and a control sample, matched by age, sex and menopausal status. The 25OHD status was defined as: deficiency < 20 ng/mL (severe deficiency <10 ng/mL), insufficiency 20-30 ng/mL, normal >30 ng/mL.

RESULTS

We evaluated 118 HIV-positive patients (72 males, 46 females), aged 36.9±12.2 years. 98.14% of them were on complex antiviral regimens. The B/C hepatitis coinfection rate was 9.3%. The control sample consisted of 119 subjects, (74 males, 45 women). The median and interquartile range for serum 25OHD concentration in patients was 17.6 (9.7, 26.9) ng/mL and 23.7 (18.4, 27.5) ng/mL in controls (p=0.001). Only 15.96% of HIV-positive cases and 12.71% of controls had normal VD status. The percentage of cases with severe VD deficiency was significantly higher in HIV positive cases (23.52%) compared to HIV-negative controls (4.2%, p=0.001).

CONCLUSIONS

Hypovitaminosis D was identified in 84.04% of HIV-infected patients, but the serum 25OHD concentration was not associated with specific HIV-related factors in our sample. Clinical guidelines regarding VD status determination and supplementation in HIV patients are needed.

Prevalence of low bone mass and changes in vitamin D levels in human immunodeficiency virus-infected adults unexposed to antiretrovirals

INTRODUCTION

The prevalence of low bone mass is 3 times higher in people living with human immunodeficiency virus (PLWH) and using antiretrovirals than in the HIV-unaffected population. Changes in vitamin D levels is one of the factors associated with decreased bone mass. The objective of this study is to evaluate the low bone mass and altered vitamin D levels in PLWH who have not been exposed to antiretrovirals.

METHODS

A cross-sectional study was carried out with HIV-infected individuals between the ages of 18 and 55 years immediately prior to the start of antiretroviral therapy in a specialized reference center focusing on infectious and parasitic diseases. Results of clinical examination (patient's weight, height, blood pressure, and clinical history), laboratory tests, and X-ray absorptiometry, were collected.

RESULTS

Sixty patients were included, with a mean age of 34 years. Nine (16.7%) patients presented with low bone mass and 4 (7.1%) patients showed low total femur BMD. Analysis revealed that 23.3% and 36.7% of the patients had deficient and insufficient levels of 25-hydroxyvitamin D3, respectively.

CONCLUSIONS

Our study population presented with compromised bone health and with low bone mineral density and 25-(OH)-vitamin D levels.

Effect of baseline micronutrient and inflammation status on CD4 recovery post-cART initiation in the multinational PEARLS trial

BACKGROUND & AIMS

Nutritional deficiency and inflammation may impact CD4+ T cell recovery during combination antiretroviral therapy (cART), particularly in resource-limited settings where malnutrition is prevalent. The aim of this study was to investigate the relationship of micronutrient and inflammation biomarkers to CD4 recovery after cART initiation.

METHODS

We conducted a secondary analysis of a random sub-cohort sample (n = 270) from a multinational randomized trial of cART regimen efficacy among 1571 cART-naïve adults. We measured pre-cART serum levels of micronutrients (Vitamin A, B₆, B₁₂, D, total carotenoids, selenium, and iron) and inflammation (C-reactive protein, soluble CD14 (sCD14), IFNγ, TNFα, Interleukin-6, and C-X-C motif chemokine 10 (CXCL10/IP10), EndoCab (IgM)) biomarkers. Biomarker status (i.e. micronutrient deficiency vs. sufficiency and elevated vs. low inflammation) was defined using established cutoffs or quartiles. Mixed-effects linear regression models were used to determine the association of baseline (pre-cART) concentrations of individual biomarkers with CD4 recovery through 96 weeks post-cART initiation.

RESULTS

In models adjusting for time-dependent viral load and baseline CD4 count, age, sex, body mass index, country, treatment regimen, anemia and hypoalbuminemia status, pre-cART vitamin D deficiency was associated with lower CD4 recovery (-14.9 cells/mm³, 95% CI: -27.9, -1.8) compared to sufficiency. In contrast, baseline selenium deficiency (20.8 cells/mm³, 95% CI: 3.3, 38.3), vitamin A deficiency (35.9 cells/mm³, 95% CI: 17.6, 54.3) and high sCD14 (23.4 cells/mm³, 95% CI: 8.9, 37.8) were associated with higher CD4 recovery compared to sufficient/low inflammation status.

CONCLUSIONS

In summary, baseline vitamin D deficiency was associated with diminished CD4 recovery after cART initiation; impaired CD4 recovery may contribute to the poor clinical outcomes recently observed in individuals with vitamin D deficiency. Vitamin A, selenium and sCD14 were associated with CD4 recovery but future studies are needed to further explore these relationships.

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.

Pathway analysis of transcriptomic data shows immunometabolic effects of vitamin D

Unbiased genomic screening analyses have highlighted novel immunomodulatory properties of the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)₂D). However, clearer interpretation of the resulting gene expression data is limited by cell model specificity. The aim of the current study was to provide a broader perspective on common gene regulatory pathways associated with innate immune responses to 1,25(OH)₂D, through systematic re-interrogation of existing gene expression databases from multiple related monocyte models (the THP-1 monocytic cell line (THP-1), monocyte-derived dendritic cells (DCs) and monocytes). Vitamin D receptor (VDR) expression is common to multiple immune cell types, and thus, pathway analysis of gene expression using data from multiple related models provides an inclusive perspective on the immunomodulatory impact of vitamin D. A bioinformatic workflow incorporating pathway analysis using PathVisio and WikiPathways was utilized to compare each set of gene expression data based on pathway-level context. Using this strategy, pathways related to the TCA cycle, oxidative phosphorylation and ATP synthesis and metabolism were shown to be significantly regulated by 1,25(OH)₂D in each of the repository models (Z-scores 3.52-8.22). Common regulation by 1,25(OH)₂D was also observed for pathways associated with apoptosis and the regulation of apoptosis (Z-scores 2.49-3.81). In contrast to the primary culture DC and monocyte models, the THP-1 myelomonocytic cell line showed strong regulation of pathways associated with cell proliferation and DNA replication (Z-scores 6.1-12.6). In short, data presented here support a fundamental role for active 1,25(OH)₂D as a pivotal regulator of immunometabolism.

CRP Genotypes Predict Increased Risk to Co-Present with Low Vitamin D and Elevated CRP in a Group of Healthy Black South African Women

Low 25-hydroxyvitamin D (25(OH)D) and elevated C-reactive protein (CRP) concentrations are independently associated with adverse health outcomes, including cardiovascular disease (CVD). Although an inverse association between these factors has been described, the underlying mechanisms remain unknown. We postulate that environment-gene interactions, through which 25(OH)D interacts with single nucleotide polymorphisms (SNPs) within the CRP gene, modulate CRP; that certain CRP genotypes predispose individuals to a co-phenotype of low 25(OH)D and elevated CRP concentrations; and that this co-phenotype is associated with higher CVD risk. Twelve CRP SNPs were genotyped, and both 25(OH)D and CRP were quantified, in 505 black South African women. Alarmingly, 66% and 60% of the women presented with deficient/insufficient 25(OH)D and elevated CRP concentrations, respectively. CRP concentrations were higher in individuals with lower 25(OH)D concentrations. However, no 25(OH)D-CRP genotype interactions were evident. Several genotypes were associated with an altered risk of presenting with the co-phenotype, indicating a genetic predisposition. Women presenting with this co-phenotype had higher blood pressure and increased anthropometric measures, which may predispose them to develop CVD. We recommend increasing vitamin D fortification and supplementation efforts to reduce inflammation among black women with vitamin D deficiency, thereby possibly curbing diseases contingent on the co-phenotype described here.

Vitamin D Receptor: A Novel Therapeutic Target for Kidney Diseases

BACKGROUND

Kidney disease is a serious problem that adversely affects human health, but critical knowledge is lacking on how to effectively treat established chronic kidney disease. Mounting evidence from animal and clinical studies has suggested that Vitamin D Receptor (VDR) activation has beneficial effects on various renal diseases.

METHODS

A structured search of published research literature regarding VDR structure and function, VDR in various renal diseases (e.g., IgA nephropathy, idiopathic nephrotic syndrome, renal cell carcinoma, diabetic nephropathy, lupus nephritis) and therapies targeting VDR was performed for several databases.

RESULT

Included in this study are the results from 177 published research articles. Evidence from these papers indicates that VDR activation is involved in the protection against renal injury in kidney diseases by a variety of mechanisms, including suppression of RAS activation, anti-inflammation, inhibiting renal fibrogenesis, restoring mitochondrial function, suppression of autoimmunity and renal cell apoptosis.

CONCLUSION

VDR offers an attractive druggable target for renal diseases. Increasing our understanding of VDR in the kidney is a fertile area of research and may provide effective weapons in the fight against kidney diseases.

Methylation of the Vitamin D Receptor (VDR) Gene, Together with Genetic Variation, Race, and Environment Influence the Signaling Efficacy of the Toll-Like Receptor 2/1-VDR Pathway

BACKGROUND

The disparity in prevalence of infectious diseases across the globe is common knowledge. Vitamin D receptor (VDR)-mediated toll-like receptor (TLR) 2/1 signaling produces antimicrobial peptides, which is critical as a first line of defense in innate immunity. Numerous studies disclosed the independent role of genetic polymorphisms in this pathway, vitamin D status or season and more recently epigenetics, as factors contributing to infectious disease predisposition. Few studies address the interaction between environment, genetics, and epigenetics. Here, we hypothesized that VDR-mediated TLR2/1 signaling is influenced by a combination of environment, epigenetics and genetics, collectively influencing differential innate immunity.

METHODS

Healthy Black and White South Africans (n = 100) donated blood, while ultraviolet index (UVI) was recorded for the duration of the study. LC-MS/MS supported 25(OH)D₃ quantification. Monocyte/macrophage cultures, supplemented with/without 1,25(OH)₂D₃, were activated with the TLR2/1 elicitor, Pam₃CSK₄. VDR, cathelicidin antimicrobial peptide, hCAP-18, and 25-hydroxyvitamin D₃-24-hydroxylase expression were quantified by RT-qPCR or flow cytometry. Pyrosequencing facilitated VDR methylation analysis and single-nucleotide polymorphism (SNP) genotyping in regions pinpointed through a bioinformatics workflow.

RESULTS

Season interacted with race showing 25(OH)D₃ deficiency in Blacks. UVI correlated with 25(OH)D₃ and VDR methylation, likely influencing race differences in the latter. Regarding the TLR2/1 pathway, race differences in SNP genotype distribution were confirmed and functional analysis of VDR-mediated signaling showed interaction between race, season, and 25(OH)D₃ status. Multivariate OPLS-DA mirrored several interactions between UVI, 25(OH)D₃ status, DNA sequence, and methylation variants. Methylation of the third cytosine-phosphate-guanine dinucleotide (CpG) in the promoter CpG island (CGI) 1062, CGI 1062 CpG 3, significantly discriminated a 5.7-fold above average mean in VDR protein level upon TLR2/1 elicitation, the variation of which was further influenced by 25(OH)D₃ status and the VDR SNP TaqI.

CONCLUSION

Regulation of VDR-mediated TLR2/1 signaling is multifactorial, involving interaction between environment [UVI and consequent 25(OH)D₃ status], epigenetics (VDR methylation at key regulatory sites), and genetics (TLR1, TIRAP, and VDR SNPs).

High 25-hydroxyvitamin D is associated with unexpectedly high plasma inflammatory markers in HIV patients on antiretroviral therapy

Inflammation associated with low 25-hydroxyvitamin D (25(OH)D) is associated with increased morbidity and mortality among HIV-infected patients with vitamin D deficiency. We investigated the association between 25(OH)D and soluble biomarkers among HIV-infected patients on stable antiretroviral therapy. This is a cross-sectional study. This study focuses on assessment in subjects 40 years or older on stable antiretroviral therapy (ART) for >3 months. Chemiluminescent immunoassay was used to determine plasma 25(OH)D levels. Plasma soluble biomarkers were measured by Luminex technology. Multivariable linear regression analysis was used to assess the associations between log10-25(OH)D and soluble biomarkers.Of 138 patients, median age was 50.5 (45, 57) years and 25(OH)D was 34.0 (25.0, 42.3) ng/mL. The majority were males (88%) and had undetectable HIV RNA (84.8%); 19 (13.8%) had 25(OH)D ≥50 ng/mL. Spline regression analyses suggested a J-shaped relationship between various plasma biomarkers and 25(OH)D. Among subjects with 25(OH)D ≥20 ng/mL, multivariable linear regression showed positive association between 25(OH)D and interleukin (IL)-10 (β = 1.84, P < 0.001), IL-6 (β = 0.72, P = 0.02), MPO (β = 0.47, P = 0.02), serum amyloid A (β = 1.20, P = 0.04), and tumor necrosis factor (TNF)-α (β = 0.51, P = 0.04). High 25(OH)D (≥50 ng/mL) was associated with higher IL-6 (β = 0.30, P = 0.009), IL-8 (β = 0.14, = 0.005), IL-10 (β = 0.43, P = 0.02), and TNF-α (β = 0.20, P = 0.04), independent of age, sex, ethnicity, body mass index, hepatitis C co-infection, current smoking status, CD4%, and HIV RNA.In older HIV-infected patients, high 25(OH)D was associated with higher (not lower) levels of proinflammatory cytokines. Higher-than-optimal 25(OH)D may be associated with immune dysregulation and may pose a potential health risk among HIV-infected patients.

Hypovitaminosis D and hyperparathyroidism: effects on bone turnover and bone mineral density among perinatally HIV-infected adolescents

OBJECTIVES

The impact of hypovitaminosis D and secondary hyperparathyroidism on bone mineral density (BMD) in the setting of pediatric HIV infection remains unclear. This study aimed to determine the prevalence of hypovitaminosis D and hyperparathyroidism and their effects on bone turnover and BMD among HIV-infected adolescents in Southeast Asia.

DESIGN

A multicenter, cross-sectional study evaluating bone health and vitamin D metabolism in HIV-infected adolescents in Thailand and Indonesia.

METHODS

Perinatally HIV-infected adolescents aged 10-18 years on antiretroviral therapy with virologic suppression were enrolled. Serum 25-hydroxyvitamin D, intact parathyroid hormone, and bone turnover markers (C-terminal cross-linked telopeptide of type I collagen and procollagen type I amino-terminal propeptide) were assessed; serum 25-hydroxyvitamin D less than 20 ng/ml and intact parathyroid hormone more than 65 pg/ml were defined as hypovitaminosis D and hyperparathyroidism, respectively. Lumbar spine (L2-L4) BMD Z-score -2 or less was defined as low BMD.

RESULTS

Of 394 adolescents, 57% were women. The median age [interquartile range (IQR)] was 15.0 (13.3-16.9) years. The prevalence of hypovitaminosis D, hyperparathyroidism, and both conditions were 21% [95% confidence interval (CI): 17-25%], 17% (95% CI: 13-20%), and 5% (95% CI: 3-7%), respectively. Adolescents with hypovitaminosis D and secondary hyperparathyroidism had the highest median bone resorption (C-terminal cross-linked telopeptide of type I collagen: 1610 vs. 1270 ng/l; P = 0.04) and bone formation (procollagen type I amino-terminal propeptide: 572 vs. 330 μg/l; P = 0.02) markers, and the greatest proportion of low BMD (42 vs. 15%; P = 0.01) compared with the rest of the cohort.

CONCLUSION

Hypovitaminosis D complicated with secondary hyperparathyroidism was associated with increased bone turnover and bone loss. Early treatment of hypovitaminosis D before hyperparathyroidism occurs may be important to prevent bone mass deterioration.

[Tenofovir nephrotoxicity]

Tenofovir is currently the only commercially available nucleotidic reverse-transcriptase inhibitor of human immunodeficiency virus (HIV). It is overall very well tolerated and is prescribed to millions of patients-without any specific monitoring in developing countries. However a significant nephrotoxicity has been described. Acute nephrotoxicity is well characterized. Tenofovir is excreted in urine by proximal tubular epithelial cells. In case of cytoplasmic accumulation, tenofovir inhibits mitochondrial DNA polymerase γ, which causes a dysfunction of the respiratory chain, and in turn an alteration of the energy-deprived cells. Fanconi syndrome is the clinical expression of tenofovir acute toxicity, with sometimes an associated acute kidney failure. These abnormalities are usually reversible, at least partially, when tenofovir is discontinued. Tenofovir chronic toxicity has been debated but seems now well established by several cohort studies, even though it pathophysiology has yet to be understood. It manifests as an accelerated glomerular filtration rate decline in treated patients with no other renal abnormalities. The identification of this chronic toxicity was probably blurred by multiple cofactors, usually excluded from clinical trials. Simple measures such as dose adaptation to kidney function, identification of risk factors, and plasmatic tenofovir concentration monitoring can help decrease the risk of nephrotoxicity.

Vitamin D status in cats with feline immunodeficiency virus

Feline immunodeficiency virus (FIV) is a lentivirus that can lead to a syndrome of acquired immune dysfunction. Infected cats often remain asymptomatic for several years before immune dysfunction leads to an increased risk for the development of systemic diseases, neoplasia and opportunistic infections. FIV is structurally related to human immunodeficiency virus (HIV) and the pathogenesis of FIV‐related disease is similar to that seen in HIV‐infected patients. Observational studies have documented an association between low plasma vitamin D and HIV infection. Vitamin D status has been shown to be associated with HIV‐related disease progression, morbidity and mortality. The objective of this study was to examine the hypothesis that vitamin D status, as assessed by serum 25‐hydroxyvitamin D [25(OH)D] concentrations, are lower in cats with FIV infection compared to healthy control cats. Serum 25(OH)D concentrations were measured in 20 healthy cats, 39 hospitalized ill cats and 59 cats infected with FIV. Cats which were FIV infected had significantly lower 25(OH)D concentrations compared to healthy control cats. Serum 25(OH)D concentrations were not significantly different between FIV‐infected cats and hospitalized ill cats. Further investigations are warranted to determine whether vitamin D status influences the prognosis of cats infected with FIV.

Vitamin-D deficiency impairs CD4+T-cell count recovery rate in HIV-positive adults on highly active antiretroviral therapy: A longitudinal study

BACKGROUND & AIMS

We implemented a prospective study among human immunodeficiency virus (HIV)-positive adults to examine the association between vitamin-D deficiency (VDD) and insufficiency (VDI) vs sufficiency (VDS) and CD4+T-cell improvement over 18 months of highly active antiretroviral therapy (HAART).

METHODS

We used data from a randomized placebo-controlled micronutrient trial with 25-hydroxy vitamin-D (25(OH)D) measured at enrollment in 398 adults. CD4+T-cell count was measured repeatedly at months 0, 3, 6, 12 and 18. Linear mixed models quantified the vitamin-D-related differences in CD4+T-cell count and associated 99% confidence intervals at baseline and respective follow-up intervals.

RESULTS

At baseline 23%, 60% and 17% of participants were VDS, VDI and VDD, respectively. Absolute CD4+T- cell counts recovered during follow-up were persistently lower for baseline VDD and VDI relative to VDS participants. The greatest deficit in absolute CD4+T-cells recovered occurred in VDD vs VDS participants with estimates ranging from a minimum deficit of 26 cells/μl (99% CI: -77, 26) to a maximum deficit of 65 cells/μl (99% CI: -125, -5.5) during follow-up. This VDD-associated lower absolute CD4+T-cell gain was strongest among patients 35 years old or younger and among participants with a baseline body mass index of less than 25 kg/m(2).

CONCLUSIONS

VDD is associated with lower absolute CD4+T-cell count recovery in HIV-positive patients on HAART. Vitamin-D supplementation may improve CD4+T-cell recovery during HAART. However, future intervention studies are needed to definitively evaluate the effectiveness of this vitamin as an adjunct therapy during HAART.

Vitamin D3 supplementation in HIV infection: effectiveness and associations with antiretroviral therapy

Background

HIV infection and antiretroviral therapy (ART) may create unique risk factors for vitamin D insufficiency, including alterations of vitamin D metabolism by ART. We prospectively compared demographic and clinical parameters between vitamin D sufficient and insufficient HIV-infected (HIV+) adults, and assessed changes in these parameters among insufficient participants following standardized vitamin D supplementation.

Methods

HIV+ adults (≥18 years old) with HIV-1 RNA <50 copies/mL on ART were enrolled. Vitamin D sufficiency and insufficiency were defined as 25-hydroxyvitamin D (25(OH)D) ≥30 or <30 ng/mL, respectively. Insufficient participants received open-label vitamin D3 50,000 IU twice weekly for 5 weeks, then 8000 IU twice weekly to complete 24 weeks. The primary endpoint was success or failure to achieve 25(OH)D ≥30 ng/mL at week 24.

Results

Ninety-seven participants enrolled (34 vitamin D sufficient, 63 insufficient); 32 % female, 47 % non-White, median age 46 years, ART duration 5 years, CD4+ T lymphocyte count (CD4) 673 cells/mm³. 25(OH)D repletion was 83 % (95 % CI 71 %–90 %) successful. 25(OH)D levels correlated with both CD4 (r = 0.44, p = 0.01) and time on protease inhibitor (r = −0.35, p = 0.01). After adjusting for age, sex, race, nadir CD4 and baseline 25(OH)D: 1) current use of efavirenz exposure was associated with a 21.1 ng/mL higher week 24 25(OH)D level (p = 0.007), 2) per year use of zidovudine was associated with 7.1 ng/mL reduction in week 24 serum 25(OH)D (p = 0.05) and 3) every 1 ng/mL 25(OH)D increase was associated with a 3.3 cell/mm³ CD4 increase (p = 0.06).

Conclusion

Vitamin D₃ supplementation was effective in repleting 25(OH)D levels after 24 weeks. Current efavirenz use was positively associated with post-repletion 25(OH)D levels, while greater time on zidovudine was associated with lower post-repletion 25(OH)D levels. The association between improved CD4 recovery and vitamin D repletion suggests a potential benefit of vitamin D supplementation on immunologic recovery during HIV treatment.

Trial registration

This trial is registered at The Brazilian Clinical Trials Registry (U1111‐1165‐2537).

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-015-0072-6) contains supplementary material, which is available to authorized users.

Success of Standard Dose Vitamin D Supplementation in Treated Human Immunodeficiency Virus Infection

Background.  Vitamin D insufficiency is prevalent in human immunodeficiency virus-positive (HIV+) persons. Human immunodeficiency virus and antiretroviral therapy (ART) may create unique risk factors, and the optimal vitamin D repletion and maintenance regimen in HIV+ persons remains unclear. Methods.  Human immunodeficiency virus-positive adults on suppressive ART underwent routine serum 25-hydroxyvitamin D (25OHD) screening. Persons with vitamin D insufficiency (25OHD <30 ng/mL) received open-label, oral vitamin D3 50 000 international units (IU) twice weekly for 5 weeks, then 2000 IU daily to complete 12 weeks. We predicted 70% (95% confidence interval, 60%-80%) repletion to 25OHD ≥30 ng/mL compared with 85% among historical HIV-negative controls. Eighty participants provided 91% power to detect this difference. Ability to maintain 25OHD ≥30 ng/mL after 24 weeks was also assessed. Results.  Baseline characteristics were similar between the 82 vitamin D insufficient and 40 sufficient persons enrolled: 95% male, 60% white, 88% nonsmokers, median age 49 years, body mass index 26 kg/m(2), and CD4(+) T lymphocyte count 520 cells/mm(3). After 12 weeks, 81% (66 of 82) of insufficient persons achieved 25OHD ≥30 ng/mL (P = .32 vs historical controls), with only older age (odds ratio [OR] = 1.06; P = .06), higher baseline 25OHD (OR = 1.14; P < .01), white race (OR = 3.39; P = .04), and current smoking (OR = 0.25; P = .06) associated with successful repletion. After 24 weeks, 73% (48 of 66) maintained 25OHD ≥30 ng/mL, with tenofovir (OR = 5.00; P = .01) and abacavir use (OR = 0.23; P = .02) associated with success and failure, respectively, to maintain 25OHD levels. Conclusions.  The 25OHD repletion rates were comparable between HIV+ adults on suppressive ART and historical HIV-negative controls, indicating that successful oral repletion can be achieved in this population.

Vitamin D deficiency and altered bone mineral metabolism in HIV-infected individuals

Although patients with HIV infection are living decades longer than before with the advent of combination antiretroviral therapy, they have an increased rate of co-morbidities associated with chronic HIV, such as osteoporosis, cardiovascular disease, and immune dysfunction. Many of these complications are known to be affected by vitamin D status in the general population. Thus, the high rate of vitamin D deficiency among HIV-infected patients is alarming. Many observational and cohort studies have demonstrated that vitamin D deficiency is associated with these HIV-related complications, but randomized, placebo-controlled trials are limited. This paper reviews recent data on vitamin D deficiency in HIV infection.

An update on the association of vitamin D deficiency with common infectious diseases

Vitamin D plays an important role in modulating the immune response to infections. Deficiency of vitamin D is a common condition, affecting both the general population and patients in health care facilities. Over the last decade, an increasing body of evidence has shown an association between vitamin D deficiency and an increased risk for acquiring several infectious diseases, as well as poorer outcomes in vitamin D deficient patients with infections. This review details recent developments in understanding the role of vitamin D in immunity, the antibacterial actions of vitamin D, the association between vitamin D deficiency and common infections (like sepsis, pneumonia, influenza, methicillin-resistant Staphylococcus aureus, human immunodeficiency virus type-1 (HIV), and hepatitis C virus (HCV)), potential therapeutic implications for vitamin D replacement, and future research directions.

Hyperglycemia enhances kidney cell injury in HIVAN through down-regulation of vitamin D receptors

In the present study, we evaluated the effect of short term hyperglycemia on renal lesions in a mouse model (Tg26) of HIV-associated nephropathy (HIVAN). Control and Tg26 mice in groups (n=6) were administered either normal saline (FVBN or Tg) or streptozotocin (FVBN+STZ or Tg26+STZ). After two weeks, biomarkers were collected and kidneys were harvested. FVBN+ STZ and Tg26+STZ displayed elevated serum glucose levels when compared to FVBN and Tg26 respectively. Tg26+STZ displayed elevated (P<0.05) blood urea nitrogen (BUN) levels (P<0.05) and enhanced (P<0.01) proteinuria when compared to Tg26. Tg26+STZ displayed enhanced (P<0.001) number of sclerotic glomeruli and microcysts vs. Tg26. Renal tissues of Tg26 displayed down regulation of vitamin D receptor (VDR) expression and enhanced Ang II production when compared to FVBN mice. Hyperglycemia exacerbated down regulation of VDR and production of Ang II in FVBN and Tg mice. Hyperglycemia increased kidney cell reactive oxygen species (ROS) production and oxidative DNA damage in both FVBN and Tg26 mice. In in vitro studies, HIV down regulated podocyte VDR expression and also enhanced renin angiotensin system activation. In addition, both glucose and HIV stimulated kidney cell ROS generation and DNA damage and compromised DNA repair; however, tempol (superoxide dismutase mimetic), losartan (Ang II blocker) and EB1089 (VDR agonist) provided protection against DNA damaging effects of glucose and HIV. These findings indicated that glucose activated the RAS and inflicted oxidative stress-mediated DNA damage via down regulation of kidney cell VDR expression in HIV milieu both in vivo and in vitro.

HIV life cycle, innate immunity and autophagy in the central nervous system

PURPOSE OF REVIEW

In this era of modern combination antiretroviral therapy (cART) HIV-associated neurocognitive disorders (HAND) continue to affect a large portion of the infected population. In this review, we highlight recent discoveries that help to define the interplay between HIV life cycle, the innate immune system and cellular autophagy in the context of the central nervous system (CNS).

RECENT FINDINGS

Investigators have recently elucidated themes in HAND, which place it in a unique framework. Cells of macrophage lineage and probably astrocytes play a role in disseminating virus through the CNS. Each of these cell types responds to a diverse population of constantly evolving virus existing in an inflammatory environment. This occurs though the failure of both host antiviral mechanisms, such as autophagy, and innate immunological signalling pathways to control viral replication.

SUMMARY

The newest findings detailed in this review help define why HIV CNS disease is a difficult target for therapeutics and create hope that these new mechanisms may be exploited to attenuate viral replication and eliminate disease.

25-Hydroxyvitamin D insufficiency and deficiency is associated with HIV disease progression and virological failure post-antiretroviral therapy initiation in diverse multinational settings

BACKGROUND

Low 25-hydroxyvitamin D (25(OH)D) has been associated with increased HIV mortality, but prospective studies assessing treatment outcomes after combination antiretroviral therapy (cART) initiation in resource-limited settings are lacking.

METHODS

A case-cohort study (N = 411) was nested within a randomized cART trial of 1571 cART-naive adults in 8 resource-limited settings and the United States. The primary outcome (WHO stage 3/4 disease or death within 96 weeks of cART initiation) was met by 192 cases, and 152 and 29 cases met secondary outcomes of virologic and immunologic failure. We studied prevalence and risk factors for baseline low 25(OH)D (<32 ng/mL) and examined associated outcomes using proportional hazard models.

RESULTS

Low 25(OH)D prevalence was 49% and ranged from 27% in Brazil to 78% in Thailand. Low 25(OH)D was associated with high body mass index (BMI), winter/spring season, country-race group, and lower viral load. Baseline low 25(OH)D was associated with increased risk of human immunodeficiency virus (HIV) progression and death (adjusted hazard ratio (aHR) 2.13; 95% confidence interval [CI], 1.09-4.18) and virologic failure (aHR 2.42; 95% CI, 1.33-4.41).

CONCLUSIONS

Low 25(OH)D is common in diverse HIV-infected populations and is an independent risk factor for clinical and virologic failure. Studies examining the potential benefit of vitamin D supplementation among HIV patients initiating cART are warranted.

Change in vitamin D levels and risk of severe vitamin D deficiency over 48 weeks among HIV-1-infected, treatment-naive adults receiving rilpivirine or efavirenz in a Phase III trial (ECHO)

BACKGROUND

This analysis assessed changes in serum 25-hydroxyvitamin D (25[OH]D; the precursor form of active vitamin D) in antiretroviral-naive adults receiving rilpivirine or efavirenz over 48 weeks in a randomized, double-blind, Phase III trial (ECHO).

METHODS

ECHO included 690 patients randomized 1:1 to receive rilpivirine 25 mg once daily (n=346) or efavirenz 600 mg once daily (n=344), plus tenofovir disoproxil fumarate/emtricitabine. 25(OH)D was measured in stored serum samples collected at baseline, and weeks 24 and 48. Proportions of patients with optimal/sufficient (≥30 ng/ml), insufficient (21-29 ng/ml), deficient (10-20 ng/ml) and severely deficient (<10 ng/ml) 25(OH)D levels were determined. Data are presented for patients with paired baseline and week 48 25(OH)D data (rilpivirine, n=292; efavirenz, n=290).

RESULTS

After 48 weeks, mean 25(OH)D levels remained largely unchanged from baseline with rilpivirine (-0.2 ng/ml; P=0.57 versus no change), but were significantly reduced with efavirenz (-2.5 ng/ml; P<0.0001 versus no change). When adjusting for season of randomization and the combined variable of race (Black/African American, White/Caucasian, Asian, other race) and ethnicity (Hispanic or Latino and not Hispanic or not Latino), the conclusion about the treatment difference between the rilpivirine and efavirenz treatment groups remained valid. At baseline the proportion of patients with severe 25(OH)D deficiency was similar in both groups (5%) but was significantly lower with rilpivirine than efavirenz at week 48 (5% versus 9%, respectively; P=0.032). Furthermore, of the patients with 25(OH)D insufficiency/deficiency at baseline, the proportion who developed severe 25(OH)D deficiency at week 48 was significantly lower with rilpivirine than efavirenz (2% versus 8%, respectively; P=0.0079).

CONCLUSIONS

Rilpivirine had little effect on 25(OH)D, whereas efavirenz resulted in a significant reduction in 25(OH)D levels and an increase in the risk of severe 25(OH)D deficiency.

Vitamin D deficiency and insufficiency in HIV-infected children and young adults

BACKGROUND

Vitamin D insufficiency and HIV infection are both risk factors for chronic disorders, so it is important to consider vitamin D status in HIV-infected patients.

METHODS

We prospectively investigated serum 25-hydroxyvitamin D (25(OH)D) concentrations, determined by radioimmunoassay, in 113 HIV-infected children (age≤24 years) and 54 healthy controls matched for age and phototype. We assessed the prevalence of vitamin D deficiency and insufficiency (VDD and VDI) defined as 25(OH)D titers of <10 ng/mL and between 10 and 30 ng/mL, respectively, and their predictive factors.

RESULTS

The overall prevalence of VDD and VDI was 38.9% and 58.7%, respectively. Mean serum 25(OH)D concentrations were significantly higher in the HIV group than the control group (14.2±6.9 ng/mL vs. 10.4±5 ng/mL, P<0.001). Variables significantly associated with low serum 25(OH)D concentrations in HIV-infected children were dark phototype (P<0.001) and age (r=-0.19, P=0.03). Patients receiving efavirenz had a trend toward lower serum 25(OH)D concentrations (11.1±4.6 ng/mL vs. 14.6±7 ng/mL, P=0.1). Dark phototype was the only independent risk factor for VDD in HIV-infected children (odds ratio=14.6; 95% confidence interval: 2.4-89.9, P=0.004).

CONCLUSIONS

VDD and VDI were common in both HIV-infected and control groups, and serum 25(OH)D concentrations were significantly lower in controls than in HIV-infected children.

Prevalence and risk factors of osteopenia/osteoporosis in Turkish HIV/AIDS patients

BACKGROUND

Recent studies showed a high frequency of low bone mineral density (BMD) in HIV-infected patients and no reports have been issued in Turkey. Our aim was to evaluate BMD and risk factors for osteopenia/osteoporosis in HIV-infected patients that attended an outpatient clinic in Istanbul, Turkey.

METHOD

In order to determine the prevalence of BMD, 126 HIV-infected patients had been studied with dual energy X-ray absorptiometry (DEXA). The association between BMD and age, gender, body mass index (BMI), habits, 25(OH)vitamin D, HIV RNA, CD4 lymphocyte nadir, using and duration of highly active antiretroviral treatment (HAART) were investigated by using multivariate analysis.

RESULTS

Median age was 40.1 years (range, 20-70); 84% were male; 35.7% patients had AIDS, 63.5% were treated with HAART. Osteopenia and osteoporosis were diagnosed in 53.9% and 23.8%, respectively. Mean plasma HIV RNA was 5.2 (SD 1.0) log10 copies/mL and CD4 lymphocyte nadir was 313.8 (SD 226.2)/mm(3). Factors associated with bone loss were high viral load (p=0.034), using (p=0.033) and duration of HAART (p=0.008). No correlation had been seen between sex and osteopenia/osteoporosis (p=0.794). However, males showed higher rates of osteoporosis than females (p=0.042).

CONCLUSIONS

Our results show a very high prevalence of bone mass reduction in Turkish HIV-infected patients. This study supports the importance of both HIV and antiretroviral therapy in low BMD.

Tenofovir effect on the kidneys of HIV-infected patients: a double-edged sword?

Tenofovir disoproxil fumarate (TDF), the first nucleotidic inhibitor of HIV reverse transcription, became available in 2001. It has been extensively used worldwide and is now the most prescribed antiretroviral (ARV) drug. Its high antiviral activity and favorable metabolic profile are responsible for its success. Furthermore, TDF has been associated with other ARVs to form new combined antiretroviral treatments in only one tablet once-a-day, which increases treatment adherence. Fears of potential nephrotoxicity that tenofovir would have in common with two other drugs from the same family (adefovir, used to treat hepatitis B, and cidofovir, used to treat cytomegalovirus infections) were alleviated by the early clinical trials. Yet, in 2001, the first case of TDF-induced acute nephrotoxicity was published. Numerous cases have been published since then, and it is now established that TDF presents a tubular toxicity risk. Some facilitating factors have been identified, such as co-prescription of didanosine or boosted protease inhibitor, preexisting CKD, low body weight, and associated diabetes mellitus. Conversely, whether TDF is nephrotoxic in the long term is a highly debated question. Some studies suggest a decreased GFR when TDF is prescribed for a long period, while others indicate that TDF is safe for the kidneys even after many years of use. Here we review the differences in patient characteristics, study designs, and measured outcomes that can possibly explain these conflicting findings. We conclude with rational recommendation for appropriate TDF prescription.

Lipodystrophy and inflammation predict later grip strength in HIV-infected men: the MACS Body Composition substudy

Body fat changes in HIV-infected persons are associated with increased systemic inflammation and increased mortality. It is unknown whether lipodystrophy is also associated with declines in physical function. Between 2001 and 2003, 33 HIV-infected men with evidence of lipodystrophy (LIPO⁺), 23 HIV-infected men without lipodystrophy (LIPO⁻), and 33 seronegative men were recruited from the Multicenter AIDS Cohort Study (MACS) for the Body Composition substudy. Visceral adipose tissue (VAT) was assessed by quantitative computed tomography. Lean body mass (LBM) and extremity fat were measured by dual-energy x-ray absorptiometry. Insulin resistance was estimated by Homeostatic Model Assessment (HOMA). Serum interleukin (IL)-6, soluble tumor necrosis factor (TNF)-α receptors I and II (sTNFRI and sTNFRII), and highly sensitive C-reactive protein (hs-CRP) concentrations were quantified from archived serum samples. These measurements were correlated with grip strength measured in 2007 using linear regression. At the substudy visit, the LIPO⁺ group had higher HOMA, sTNFRI, sTNFRII, and IL-6 levels than the LIPO⁻ group. In 2007, the LIPO⁺ group had lower median grip strength than the LIPO⁻ group (34.4 vs. 42.7 kg, p=0.002). Multivariable analysis of HIV⁺ men showed older age, lower LBM, higher sTNFRII concentrations, and LIPO⁺ status [adjusted mean difference -4.9 kg (p=0.045)] at the substudy visit were independently associated with lower subsequent grip strength. Inflammation, lower LBM, and lipodystrophy in HIV-infected men were associated with lower subsequent grip strength. These findings suggest that inflammation may contribute to declines in functional performance, independent of age.

Inhibition of human immunodeficiency virus type-1 through autophagy

As an obligatory intracellular pathogen, human immunodeficiency virus type-1 (HIV) is dependent upon its ability to exploit host cell machinery for replication and dissemination, and to circumvent cellular processes that prevent its growth. One such intracellular process is autophagy, a component of the host defense against HIV with roles in innate immune signaling, adaptive immunity and intracellular degradation of HIV. During permissive infection, HIV down-modulates autophagy, promoting its own replication. Inducers of autophagy can overcome this suppression and inhibit HIV. This review summarizes recent advances in understanding the antiviral and replicative roles of autophagy during HIV infection. Dissecting the molecular mechanisms by which HIV utilizes autophagy may lead to the identification of novel drug candidates to treat and potentially eradicate HIV infection.

Vitamin D and HIV infection: a review of the clinical evidence

The positive effects of vitamin D in different acute and chronic diseases (e.g., bone and renal disorders, acute and chronic respiratory tract infections, and diabetes mellitus), and regulation of immune system function have been shown. In this review vitamin D status and the effects of its supplementation alone or in combination with other bone-modifying substances like calcium and bisphosphonates on the different aspects of human health have been investigated in HIV+ individuals. Three scientific electronic databases have been investigated for extracting related articles. Searching only PubMed yielded 59 results with ‘HIV OR AIDS’ and ‘Vitamin D’ keywords. Because many of the studies in this field are observational or cross-sectional, designing comprehensive and eligible randomized clinical trials has been recommended by several authors in order to develop evidence-based clinical practice guidelines to determine the best regimen of vitamin D supplementation in HIV-infected patients.

Vitamin D attenuates nucleoside reverse transcriptase inhibitor induced human skeletal muscle mitochondria DNA depletion

OBJECTIVE

To evaluate the impact of the active metabolite of vitamin D, 1α,25-dihydroxycholecalciferol (1,25D3), on nucleoside reverse transcriptase inhibitor (NRTI) induced mitochondrial DNA (mtDNA) depletion in human skeletal muscle myoblasts and myotubes.

DESIGN

mtDNA was quantified in human skeletal muscle myoblasts and myotubes following 1,25D3 and NRTI treatment using real-time PCR.

METHODS

Human skeletal muscle myoblasts and myotubes were treated with didanosine (ddI), stavudine (d4T), zidovudine (ZDV), lamivudine (3TC) and abacavir (ABC) alone or in combination either in the presence or absence of 1,25D3 for 5 days. Cells were harvested, DNA extracted and mtDNA quantified.

RESULTS

ddI and ddI-d4T significantly decreased both myoblast and myotube mtDNA in the absence of 1,25D3 compared with untreated controls (P≤0.029). In addition, the ZDV-3TC combination resulted in a 47% decrease in myotube mtDNA (P=0.005). 1,25D3 increased myotube mtDNA levels in ddI, ZDV, 3TC, ABC, ddI-d4T, d4T-3TC, ZDV-3TC, ZDV-ABC and ZDV-3TC-ABC-containing regimens and myoblast mtDNA levels in ddI, d4T, ZDV, 3TC, ddI-d4T, ZDV-3TC and ZDV-ABC-containing regimens. Of note, 1,25D3 protected against myotube mtDNA depletion following ZDV-3TC treatment, rendering them similar to 1,25D3 untreated controls (P=0.62), and increased both myotube and myoblast mtDNA two to three-fold in ddI-containing regimens (P<0.05).

CONCLUSION

1,25D3 confers a protective effect against NRTI-induced mitochondrial toxicity in skeletal muscle myoblasts and myotubes. These findings support a protective role for vitamin D in preventing mitochondrial toxicity and suggest that supplemental vitamin D may protect against NRTI-associated mitochondrial toxicity.

Cross-sectional study of vitamin D levels, immunologic and virologic outcomes in HIV-infected adults

CONTEXT

Vitamin D is increasingly recognized as an important immunomodulator. Lower levels of 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) are observed in persons living with HIV.

OBJECTIVE

The purpose of this study was to evaluate the relationship of 25(OH)D, and 1,25(OH)2D to HIV viral load, and CD4+ T cells in HIV-infected adults.

DESIGN

This was a cross-sectional study completed between January 2010 and April 2011.

SETTING

This study was conducted with volunteers who received HIV care in Wisconsin at either a University-based HIV clinic or an urban community HIV clinic.

PATIENTS

One hundred twelve adults with HIV infection participated in this study.

MAIN OUTCOME MEASURES

The primary outcome for this study was the relationship between 1,25(OH)2D and HIV viral load. Secondary outcomes included relationships between 25(OH)D and HIV viral load, 25(OH)D and 1,25(OH)2D to CD4+ T cells, and predictors of vitamin D deficiency.

RESULTS

The 112 volunteers included 24 women and 3 transgender individuals; 68% were from the university clinic, and 32% were from the urban clinic. Mean age was 44.2 years. The mean 25(OH)D level was 22.5 ng/mL; mean 1,25(OH)2D level was 23.5 pg/mL. Twenty-two percent had 25(OH)D ≤10 ng/mL; 53% had values <20 ng/mL, and 73% were ≤30 ng/mL. There was no association between vitamin D and CD4. A nonlinear relationship between viral load and 1,25(OH)2D was found. For 1,25(OH)2D below 32 pg/mL, for each 10 pg/mL decrease in 1,25(OH)2D, (log10) viral load increased by 0.84 (95% CI: 0.16-1.51, P = .015). For 1,25(OH)2D above 32 pg/mL, for each 10 pg/mL increase in 1,25(OH)2D, (log10) viral load increased by 0.36 (95% CI: 0.15-0.57, P = .0009).

CONCLUSION

Vitamin D deficiency was common in this HIV population, as seen in other HIV cohorts. A novel, U-shaped relationship between 1,25(OH)2D and viral load, with the lowest and highest 1,25(OH)2D levels seen with high viral loads, was found and deserves further study.

HIV compromises integrity of the podocyte actin cytoskeleton through downregulation of the vitamin D receptor

Alterations in the podocyte actin cytoskeleton have been implicated in the development of proteinuric kidney diseases. In the present study, we evaluated the effect of HIV on the podocyte actin cytoskeleton and the mechanism involved. We hypothesized that HIV may be compromising the actin cytoskeleton via downregulation of the vitamin D receptor (VDR) of conditionally immortalized differentiated human podocytes (CIDHPs). HIV-transduced podocytes (HIV/CIDHPs) not only displayed downregulation of VDR but also showed activation of the renin-angiotensin system (RAS) in the form of enhanced expression of renin and increased production of ANG II. Moreover, CIDHPs lacking VDR displayed enhanced ANG II production, and treatment of HIV/CIDHPs with EB1089 (vitamin D3; VD) attenuated ANG II production. HIV/CIDHPs as well as ANG II-treated CIDHPs exhibited enhanced expression of cathepsin (CTS) L. Additionally, losartan (an ANG II type I receptor blocker) inhibited both HIV- and ANG II-induced podocyte cathepsin L expression. Furthermore, VD downregulated HIV-induced podocyte CTSL expression. Both losartan and free radical scavengers attenuated HIV- and ANG II-induced podocyte reactive oxygen species (ROS) generation. HIV also led to cytosolic CTSL accumulation through enhancement of podocyte lysosomal membrane permeabilization; on the other hand, VD, losartan, and superoxide dismutase (SOD) attenuated HIV-induced enhanced podocyte cytosolic CTSL accumulation. Morphological evaluation of HIV/CIDHPs revealed sparse actin filaments and attenuated expression of dynamin. Interestingly, podocytes lacking CTSL displayed enhanced dynamin expression, and HIV/CIDHPs expressing CTSL exhibited downregulation of dynamin. These findings indicate that HIV-induced downregulation of podocyte VDR and associated RAS activation and cytosolic CTSL accumulation compromised the actin cytoskeleton.

Toll-like receptor 8 ligands activate a vitamin D mediated autophagic response that inhibits human immunodeficiency virus type 1

Toll-like receptors (TLR) are important in recognizing microbial pathogens and triggering host innate immune responses, including autophagy, and in the mediation of immune activation during human immunodeficiency virus type-1 (HIV) infection. We report here that TLR8 activation in human macrophages induces the expression of the human cathelicidin microbial peptide (CAMP), the vitamin D receptor (VDR) and cytochrome P450, family 27, subfamily B, polypeptide 1 (CYP27B1), which 1α-hydroxylates the inactive form of vitamin D, 25-hydroxycholecalciferol, into its biologically active metabolite. Moreover, we demonstrate using RNA interference, chemical inhibitors and vitamin D deficient media that TLR8 agonists inhibit HIV through a vitamin D and CAMP dependent autophagic mechanism. These data support an important role for vitamin D in the control of HIV infection, and provide a biological explanation for the benefits of vitamin D. These findings also provide new insights into potential novel targets to prevent and treat HIV infection.

Cells use macroautophagy (autophagy - ‘self-eating’, lysosome-dependent degradation and recycling of intracellular components in response to stress) as a mechanism to detect intracellular pathogens through pattern-recognition receptors such as Toll-like receptors (TLRs) that recognize signature molecules of pathogens that are essential for their survival. One such Toll-like receptor, TLR8, which is located in human macrophage endosomes, recognizes both imidazoquinoline compounds and uridine-rich single-stranded RNA such as human immunodeficiency virus type-1 (HIV) single-stranded RNA. In the present study we report that TLR8 activation in human macrophages induces the expression of the human cathelicidin microbial peptide (CAMP), the vitamin D receptor (VDR), and cytochrome P450, family 27, subfamily B, polypeptide 1 (CYP27B1), which 1α-hydroxylates the inactive form of vitamin D, 25-hydroxycholecalciferol, into its biologically active metabolite. Moreover, we demonstrate that TLR8 activation induces autophagy in human macrophages through a vitamin D and CAMP dependent mechanism, and that the induction of autophagy by TLR8 agonists inhibits HIV. These data support an important role for vitamin D in the control of HIV infection, and provide a biological explanation for the benefits of vitamin D. These findings also provide new insights into potential novel targets to prevent and treat HIV infection.