Vitamin D and clinical disease progression in HIV infection: results from the EuroSIDA study

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.

Factors associated with vitamin D deficiency in a population of 2044 HIV-infected patients

BACKGROUND AND AIMS

The high prevalence of vitamin D deficiency in HIV-infected patients has been demonstrated but there are still controversies regarding to the role of antiretroviral therapy (ART) in this setting. The aims of this study was to validate factors associated with vitamin D deficiency in a large cohort of HIV-infected patients.

METHODS

A retrospective analysis of 2044 consecutive patients from December 2005 to March 2011 was conducted. Factors independently associated with vitamin D deficiency (<30 ng/ml and <10 ng/ml) were analyzed. Vitamin D levels were compared according to CD4 count, viral load and ART modalities.

RESULTS

vitamin D was <30 ng/ml in 89.2% and <10 ng/ml in 32.4%. The median value was 13.8 ng/ml (4-102). Winter season, female sex, heterosexual acquisition of HIV, the need of second lines (complex and sequential treatment modalities) and a longer duration of ART were independently associated with vitamin D deficiency (<30 ng/ml). CD4 count <200/μl, advanced stages of disease and the current efavirenz use were independently associated with severe vitamin D deficiency (<10 ng/ml). Median vitamin D levels was 14.1 ng/dl when CD4 ≥200/μl, 11.5 ng/dl when CD4<200 (p = 0.0003). The ART modalities had a significant influence on vitamin D concentrations, the highest vitamin D level was observed in the absence of treatment.

CONCLUSIONS

In HIV-infected patients, vitamin D deficiency is associated with ART modalities and duration. The most severe vitamin D deficiencies are associated with low CD4 count, the use of efavirenz and advanced stages of disease severity.

Bone health and human immunodeficiency virus infection

Low bone mineral density is common among persons with human immunodeficiency virus (HIV) infection, and studies reporting increased fracture rates in this patient population are emerging. The causes of low bone mineral density, osteoporosis, and fractures in persons with HIV are likely multifactorial, involving traditional risk factors, HIV infection, and exposure to antiretroviral treatment. Specific antiretrovirals such as tenofovir may cause a greater loss of bone mineral density compared with other agents and have recently been linked to an increased risk for fracture. As a result, recent treatment guidelines suggest that clinicians consider avoiding tenofovir as initial therapy in postmenopausal women. Evaluating bone mineral density and vitamin D status in persons with HIV may be important steps in identifying those requiring pharmacotherapy; however, the appropriate timing for bone mineral density and vitamin D screening is uncertain, as is the appropriate method of replacing vitamin D in HIV-positive patients who are deficient. Further study is necessary to definitively determine the approach to evaluating bone health and managing low bone mineral density and vitamin D deficiency in patients with HIV infection.

Interventions to address chronic disease and HIV: strategies to promote exercise and nutrition among HIV-infected individuals

Food insecurity, micronutrient deficits, dyslipidemia, insulin resistance, obesity, cardiovascular disease, and bone disorders complicate the treatment of HIV infection. Nutrition and exercise interventions can be effective in ameliorating these symptoms that are associated with HIV and antiretroviral therapy (ART). In this literature review, we examine the most recent nutrition and exercise interventions for HIV-infected patients. Macronutrient supplementation can be useful in treating malnutrition and wasting. Multivitamin (vitamin B complex, vitamin C, and vitamin E) supplements and vitamin D may improve quality of life and decrease morbidity and mortality. Nutritional counseling and exercise interventions are effective for treating obesity, fat redistribution, and metabolic abnormalities. Physical activity interventions improve body composition, strength, and fitness in HIV-infected individuals. Taken collectively, the evidence suggests that a proactive approach to nutrition and physical activity guidance and interventions can improve outcomes and help abrogate the adverse metabolic, cardiovascular, and psychological consequences of HIV and its treatments.

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.

High-dose vitamin D3 supplementation is a requisite for modulation of skin-homing markers on regulatory T cells in HIV-infected patients

Vitamin D(3) is known to have an effect on the immune function. We investigated the immunomodulatory capability of vitamin D(3) in HIV-infected patients and studied the expression of chemokine receptors on regulatory T cells (Treg). Vitamin D(3)-deficient HIV-1-seropositive subjects were treated with cholecalciferol (vitamin D(3)) at a dose of 800 IU daily for 3 months (n=9) or 25,000 IU weekly for 2 months (n=7). Peripheral blood mononuclear cells (PBMCs) were isolated and analyzed for skin-homing (CCR4 and CCR10) and gut-homing (CCR9 and integrin α(4)β(7)) marker expression on Treg, by flow cytometry, before and after supplementation. Serum 25(OH)D(3) and parathyroid hormone (PTH) levels were determined at baseline and after the treatment period. Weekly doses of 25,000 IU cholecalciferol effectively achieved the optimal target serum 25(OH)D(3) concentration of >75 nmol/liter (30 ng/ml) in HIV-infected patients. High-dose cholecalciferol supplementation differentially influenced skin-homing markers on Treg with an increased level of CCR10 expression and while a reduction in CCR4 expression level was observed together with a lower percentage of Treg expressing CCR4. For both dosing regimens, there were no significant differences in the expression of gut-homing markers, CCR9, and integrin α(4)β(7). High-dose vitamin D(3) supplementation is needed to reverse vitamin D(3) deficiency in HIV-infected individuals and this results in modulation of skin-homing markers but not gut-homing markers expression on Treg. At a standard dose of 800 IU/day, vitamin D(3) is not effective in achieving an optimal 25(OH)D(3) concentration in patients with an underlying T cell dysfunction and is unable to exert any immunomodulatory effects.

Severe hypovitaminosis D correlates with increased inflammatory markers in HIV infected patients

BACKGROUND

Even though it has been suggested that antiretroviral therapy has an impact on severe hypovitaminosis D (SHD) in HIV infected patients, it could be speculated that the different levels of residual inflammation on HAART (Highly Active Anti Retroviral Therapy) could contribute to SHD and aggravate bone catabolism in these patients.

METHODS

A cross-sectional study was carried out in an unselected cohort of 263 HIV infected outpatients consulting during Spring 2010. Clinical examinations were performed and medical history, food habits, sun exposure and addictions were collected. Fasting blood samples were taken for immunological, virological, inflammation, endocrine and bone markers evaluations.

RESULTS

Ninety-five (36%) patients had SHD. In univariate analysis, a significant and positive association was found between SHD and IL6 (p = 0.001), hsCRP (p = 0.04), increased serum C-Telopeptides X (CTX) (p = 0.005) and Parathyroid Hormon (PTH) (p < 0.0001) levels. In multivariate analysis, SHD deficiency correlated significantly with increased IL-6, high serum CTX levels, lower mean daily exposure to the sun, current or past smoking, hepatitis C, and functional status (falls), but not with the time spent on the current HAART (by specific drug or overall).

CONCLUSIONS

SHD is frequent and correlates with inflammation in HIV infected patients. Since SHD is also associated with falls and increased bone catabolism, it may be of interest to take into account not only the type of antiretroviral therapy but also the residual inflammation on HAART in order to assess functional and bone risks. This finding also suggests that vitamin D supplementation may be beneficial in these HIV-infected patients.

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.

Changes in metabolic, inflammatory and coagulation biomarkers after HIV seroconversion--the Health in Men (HIM) Biomarker Substudy

BACKGROUND

Biomarkers of inflammation, coagulation, lipids and vitamin D have been associated with cardiovascular and mortality risk in HIV-infected individuals. Scarce data exist on changes in these markers from pre- to post-HIV seroconversion.

METHODS

The study participants were drawn from the Health in Men Study, which recruited HIV-negative homosexual men. Participants with incident HIV infection (n=26) were compared with HIV-negative controls (n=52) matched on age at enrolment, date of visit and reported intravenous drug use. Levels of metabolic (lipids and vitamin D), inflammatory (C-reactive protein and interleukin-6) and coagulation (D-dimer and fibrinogen) biomarkers were measured at pre- and post-HIV seroconversion visits and corresponding visits for controls. Random-effect models were used to compare changes in markers between cases and controls.

RESULTS

The median gap between pre- and post-seroconversion or matched first and second visits in controls was 12 months. HIV seroconversion was associated with decline in high density lipoprotein (HDL-C; difference in mean change between cases and controls -0.14 mmol/l; 95% CI -0.22, -0.01; P=0.035). There were no significant differences in changes in other lipids, markers of inflammation, coagulation or vitamin D.

CONCLUSIONS

Decline in HDL-C seems to be the main proatherogenic change within 1-1.5 years after HIV seroconversion. HIV seroconversion was not associated with profound changes in other lipids, or markers of inflammation, coagulation and vitamin D. Longitudinal assessment of these markers in comparable population needs further assessment.

Vitamin D deficiency and its association with low bone mineral density, HIV-related factors, hospitalization, and death in a predominantly black HIV-infected cohort

BACKGROUND

Low bone mineral density (BMD) is common among patients infected with human immunodeficiency virus (HIV) and present in higher rates in black subjects. This study assessed vitamin D levels in HIV cases versus noninfected matched controls to determine if deficiency was associated with BMD and HIV clinical outcomes.

METHODS

In total, 271 military beneficiaries with HIV underwent dual energy x-ray absorptiometry (DEXA) screening in 2001-2. Serum 25OH-vitamin D levels were determined using stored serum from the time of DEXA and 6-18 months prior. Two non-HIV-infected controls for each active duty case (n = 205) were matched on age, sex, race, zip code, and season using the Department of Defense Serum Repository (DoDSR). Vitamin D levels <20 ng/mL were considered deficient. HIV-related factors and clinical outcomes were assessed using data collected in the DoD HIV Natural History study.

RESULTS

In total, 165 of 205 (80.5%) active duty HIV cases had 2 matched controls available. HIV cases had greater odds of for vitamin D deficiency (VDD) compared with controls (demographics adjusted paired data odds ratio [OR], 1.46, 95% confidence interval [CI], .87-2.45), but this was not statistically significant. Blacks were disproportionately deficient (P <.001) but not relative to HIV status or BMD. Low BMD was associated with typical risk factors (low body mass index and exercise levels, alcohol use); given limited available data the relationship between tenofovir exposure and VDD or low BMD could not be determined. Analysis of HIV-specific factors and outcomes such as exposure to antiretrovirals, HIV progression, hospitalizations, and death revealed no significant associations with vitamin D levels.

CONCLUSIONS

VDD was highly prevalent in black HIV- infected persons but did not explain the observed racial disparity in BMD. Vitamin D deficiency was not more common among HIV- infected persons, nor did it seem associated with HIV- related factors/clinical outcomes.

Hyperparathyroidism and complications associated with vitamin D deficiency in HIV-infected adults in New York City, New York

Although recent studies report a high prevalence of vitamin D deficiency in HIV-infected adults similar to that in the general population, metabolic complications of vitamin D deficiency may be worsened with HIV infection and remain insufficiently characterized. We conducted a retrospective cross-sectional cohort study to determine prevalence and correlates of vitamin D deficiency and hyperparathyroidism among HIV-infected patients attending an urban clinic. Vitamin D deficiency was defined as 25(OH)-vitamin D <20 ng/ml and insufficiency as 20 to <30 ng/ml, and hyperparathyroidism as parathyroid-hormone >65 pg/ml. We used the X(2) test to compare proportions and logistic regression to assess for associations. Among 463 HIV-infected patients, the prevalence of vitamin D deficiency was 59%. The prevalence of hyperparathyroidism was 30% among patients with vitamin D deficiency, 23% among those with insufficiency, and 12% among those with sufficient vitamin D levels. Vitamin D deficiency was associated with increased odds of hyperparathyroidism. Severe vitamin D deficiency was associated with elevated alkaline phosphatase, a marker for increased bone turnover. Although efavirenz use was associated with vitamin D deficiency, and protease inhibitor use with decreased odds of vitamin D deficiency, there was no statistical difference in rates of hyperparathyroidism stratified by combination antiretroviral therapy (cART) use. Given the increased risk of osteopenia with HIV infection and cART use, vitamin D supplementation for all HIV-infected patients on cART should be prescribed in accordance with the 2011 Endocrine Society guidelines. In HIV-infected patients with severe vitamin D deficiency or hyperparathyroidism, screening for osteomalacia and osteopenia may be warranted.

Review of metabolic, immunologic, and virologic consequences of suboptimal vitamin D levels in HIV infection

Low 25-hydroxyvitamin D levels are common in the general and HIV-infected populations alike. Defined as levels less than 30 ng/mL, suboptimal vitamin D is known to afflict over 70% of representative samples from each group in resource-rich countries with even greater prevalence in resource-poor regions of the world. In both those with and without HIV, dark skin, low vitamin D intake, exiguous exposure to sunlight, and season act as risk factors for suboptimal vitamin D levels. In those infected with HIV, antiretroviral therapy, particularly non-nucleoside reverse transcriptase inhibitors (NNRTIs), increase risk for low vitamin D as well. Furthermore, metabolic aberrations, including obesity and hyperlipidemia, and miscellaneous risk factors, such as advanced AIDS and substance abuse, have been linked to suboptimal vitamin D in those with HIV. While the skeletal and cardiovascular systems of HIV patients may be adversely impacted as a result of low levels, recent data have also linked low vitamin D to decreased CD4 counts, higher viral loads, and to critical end points including progression to AIDS events and death. More research is needed to confirm these potential consequences of low vitamin D in those with HIV and to discern the benefits of routine screening for and treatment of low vitamin D in this population.

Prevalence of vitamin D deficiency and its related risk factor in a Spanish cohort of adult HIV-infected patients: effects of antiretroviral therapy

We analyzed serum 25(OH) cholecalciferol [25(OH)D] levels and factors related to deficiency (<20 ng/ml) or insufficiency (<30 ng/ml) in a cohort of Spanish HIV-infected patients and compared them with an age- and latitude-matched population from another study. We prospectively assessed 25(OH)D deficiency/insufficiency in a cohort of 352 HIV patients during 2009-2010. Predisposing factors were recorded and their relationship to low levels was assessed by logistic regression; a nutritional survey examined intake, nutritional status, and sunlight exposure in a subgroup of 92 patients. We studied the correlation of 25(OH)D with parathyroid hormone (PTH) and alkaline phosphatase. Age-, sex-, and race/ethnicity-adjusted vitamin D deficiency (<20 ng/ml) was 44.0% (95% CI, 38.8-49.4%) and insufficiency (<30 ng/ml) was 71.6% (95% CI, 66.9-76.3). Deficiency was 16.4% more prevalent in our sample than in non-HIV-infected Spaniards. Lower sunlight exposure was the only factor related to lower levels in the lifestyle and nutritional survey (p=0.045). In multiple logistic regression, higher body mass index (BMI), black race/ethnicity, lower seasonal sunlight exposure, men who have sex with men (MSM), and heterosexual transmission categories, efavirenz exposure and lack of HIV viral suppression were independently associated with deficiency/insufficiency. These variables predicted 79% of cases [AUC=0.872 (95% CI, 0.83-0.91)]. Patients receiving protease inhibitors (PIs) [OR 4.0 (95% CI, 1.3-12.3); p=0.014] or NNRTI [OR 3.6 (95% CI, 1.7-11.2); p=0.025] had higher odds of increased PTH levels; this was significant only in 25(OH)D-deficient patients (p=0.004). As in less insolated areas, the prevalence of vitamin D deficiency/insufficiency was high in HIV-infected patients in Spain; among treated patients, levels were higher with PIs than with efavirenz.

Risk factors for vitamin D deficiency and relationship with cardiac biomarkers, inflammation and immune restoration in HIV-infected youth

BACKGROUND

Vitamin D deficiency is common in HIV-infected individuals. In adults, traditional and HIV-related factors play a role in vitamin D status, and deficiency appears to impair immune restoration and exacerbate HIV complications, like cardiovascular disease (CVD). This study sought to determine factors contributing to vitamin D status in HIV-infected youth and investigate the relationship with CVD risk, inflammation and immune restoration.

METHODS

HIV-infected subjects (1-25 years old) were enrolled prospectively along with healthy controls that were group-matched by age, sex and race. HIV data were collected for the HIV-infected group, while traditional risk factors, including vitamin D intake, sun exposure, skin pigmentation, physical activity level and body mass index (BMI) were collected for both groups. Fasting lipids, plasma 25-hydroxyvitamin D (25[OH]D), and inflammation markers were measured.

RESULTS

In total, 200 HIV-infected subjects and 50 controls were enrolled. HIV group had 53% male, 95% Black and a mean age of 17.2 ±4.6 years. There was no difference in 25(OH)D between groups; 77% of HIV+ and 74% of controls had 25(OH)D<20 ng/ml. Only Fitzpatrick skin type was independently associated with 25(OH)D. No HIV variables were associated with 25(OH)D, even when HIV sub-populations were examined. Inflammation, CVD risk factors and immune restoration were not independently associated with 25(OH)D.

CONCLUSIONS

Vitamin D deficiency is common among HIV-infected youth. However, HIV factors, CVD risk, inflammation and immune restoration do not appear to have the same relationship with vitamin D as has been shown in adults. Supplementation trials are needed to determine if increasing 25(OH)D concentrations could better elucidate these relationships.

Correlation of increases in 1,25-dihydroxyvitamin D during vitamin D therapy with activation of CD4+ T lymphocytes in HIV-1-infected males

BACKGROUND

In HIV-1-infected individuals, levels of CD4+ T lymphocytes are depleted and regulatory T-lymphocytes (Tregs) are elevated. In vitro studies have demonstrated effects of vitamin D on the growth and differentiation of these cells. We speculated whether supplementation with vitamin D could have an effect on CD4+ T lymphocytes or Tregs in HIV-1-infected males.

METHODS

We conducted a placebo-controlled randomized study that ran for 16 weeks and included 61 HIV-1-infected males, of whom 51 completed the protocol. The participants were randomized to 1 of 3 daily treatments: (1) 0.5-1.0 µg calcitriol and 1200 IU (30 µg) cholecalciferol, (2) 1200 IU cholecalciferol, (3) placebo. Percentages of the following T-lymphocyte subsets were determined: naïve CD4+ and CD8+ cells, activated CD4+ and CD8+ cells, and CD3+CD4+CD25+CD127low Tregs. Furthermore 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and parathyroid hormone were measured.

RESULTS

No significant changes of the studied T-lymphocyte subsets occurred in the treatment groups compared to the placebo group. Increases in 1,25-dihydroxyvitamin D were associated with increases in activated CD4+ T lymphocytes (P = .001) and Tregs (P = .01) in adjusted models. Changes in parathyroid hormone correlated inversely with Tregs (P = .02). Smokers had higher levels of naïve CD4+ T lymphocytes (37% vs 25%;P = .01), naïve CD8+ T lymphocytes (28% vs 19%; P = .03), and Tregs (9% vs 7%; P = .03).

CONCLUSION

Cholecalciferol and calcitriol administered during 16 weeks did not change the levels of T-lymphocyte fractions compared to placebo. However, increases in 1,25-dihydroxyvitamin D were associated with an expansion of activated CD4+ cells and Tregs.

Prevalence and Factors Associated with Vitamin D Deficiency and Hyperparathyroidism in HIV-Infected Patients Treated in Barcelona

Vitamin D deficiency is an important problem in patients with chronic conditions including those with human immunodeficiency virus (HIV) infection. The aim of this cross-sectional study was to identify the prevalence and factors associated with vitamin D deficiency and hyperparathyroidism in HIV patients attended in Barcelona. Cholecalciferol (25OH vitamin D3) and PTH levels were measured. Vitamin D insufficiency was defined as 25(OH) D < 20 ng/mL and deficiency as <12 ng/mL. Hyperparathyroidism was defined as PTH levels >65 pg/mL. Cases with chronic kidney failure, liver disease, treatments or conditions potentially affecting bone metabolism were excluded. Among the 566 patients included, 56.4% were exposed to tenofovir. Vitamin D insufficiency was found in 71.2% and 39.6% of those had deficiency. PTH was measured in 228 subjects, and 86 of them (37.7%) showed high levels. Adjusted predictors of vitamin D deficiency were nonwhite race and psychiatric comorbidity, while lipoatrophy was a protective factor. Independent risk factors of hyperparathyroidism were vitamin D < 12 ng/mL (OR: 2.14, CI 95%: 1.19–3.82, P: 0.01) and tenofovir exposure (OR: 3.55, CI 95%: 1.62–7.7, P: 0.002). High prevalence of vitamin deficiency and hyperparathyroidism was found in an area with high annual solar exposure.

Vitamin D deficiency is not associated with early stages of thyroid autoimmunity

CONTEXT

Vitamin D deficiency has been identified as a risk factor for a number of autoimmune diseases including type 1 diabetes and multiple sclerosis.

OBJECTIVE

We hypothesized that low levels of vitamin D are related to the early stages of autoimmune thyroid disease (AITD).

DESIGN

Two case-control studies were performed. In the cross-sectional study A, euthyroid subjects with genetic susceptibility for AITD but without thyroid antibodies were compared with controls. Cases were subjects from the Amsterdam AITD cohort (euthyroid women who had first- or second-degree relatives with overt AITD) who at baseline had normal TSH and no thyroid antibodies; controls were healthy women examined at the same period. In the longitudinal study B, subjects who developed de novo thyroid peroxidase antibody (TPO-Ab) were compared with those who did not. Cases and controls were subjects from the Amsterdam AITD cohort who at baseline had normal TSH and no thyroid antibodies and during follow-up developed TPO-Ab (cases) or remained without thyroid antibodies (controls). Controls in both studies were matched for age, BMI, smoking status, estrogen use, month of blood sampling, and in study B for the duration of follow-up.

RESULTS

Serum 25(OH)D levels were as follows: study A: 21.0 ± 7.9 vs 18.0 ± 6.4 ng/ml (78 cases vs 78 controls, P=0.01); study B: baseline, 22.6 ± 10.3 vs 23.4 ± 9.1; follow-up 21.6 ± 9.2 vs 21.2 ± 9.3 ng/ml (67 cases vs 67 controls, NS).

CONCLUSIONS

Early stages of thyroid autoimmunity (in study A genetic susceptibility and in study B development of TPO-Ab) are not associated with low vitamin D levels.

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.

Adjudication of the alleged role of vitamin d in the antimicrobial pathway

Dynamic interactions between microorganism and host have evolved in such a way that while microbial pathogens are the cause of many human infections, a symbiotic relationship is also known to exist. Another important anomaly is that exposure to pathogenic organisms does not necessarily result in development of clinical disease. The latter conclusion infers that susceptibility to infectious disease can be modified by host-related factors. Arguably the two most prominent factors are genetic variability and immunologic status of the exposed individual. Because of the Human Genome and the HapMap projects, developments in genotyping technology have brought the possibility of identifying associations between specific genetic alterations and common diseases closer to reality. In addition, a growing body of evidence suggests vitamin D has an important contributory role in the antimicrobial pathway.

High frequency of vitamin D deficiency in HIV-infected patients: effects of HIV-related factors and antiretroviral drugs

OBJECTIVES

The aim of this study was to assess 25-hydroxyvitamin D (vitamin D) status in an HIV-infected adult population and to define HIV- and antiretroviral-related factors associated with vitamin D deficiency.

METHODS

Using data from a prospective cohort of HIV-infected adult patients followed in five French centres (Dat'AIDS cohort), we evaluated the prevalence of vitamin D deficiency/insufficiency (<30 ng/mL). A multiple linear regression model was used to examine risk factors for vitamin D deficiency (≤10 ng/mL).

RESULTS

Vitamin D deficiency/insufficiency was observed in 86.7% of the 2994 patients, including 55.6% with vitamin D insufficiency and 31.1% with vitamin D deficiency. In multivariate analysis, factors associated with vitamin D deficiency were current smoking [adjusted OR (aOR) 1.55], estimated glomerular filtration rate ≥90 mL/min/1.73 m(2) (aOR 1.51), vitamin D measurement not performed in summer (aOR 0.27), CD4 <350 cells/mm(3) (aOR 1.37 for CD4 200 to <350 and 1.62 for CD4 <200 cells/mm(3)) and antiretroviral therapy (aOR 2.61). Gender, body mass index, age, coinfection and previous AIDS were not associated factors. In the antiretroviral-treated population (n = 2660), besides the same factors found in the whole population, efavirenz was the only drug to be significantly associated with deficiency, with an aOR of 1.89 (95% CI 1.45-2.47).

CONCLUSIONS

Vitamin D deficiency is frequent in this HIV-infected population. Patients on antiretroviral therapy are at higher risk of vitamin D deficiency than antiretroviral-naive patients, with an increased risk in patients receiving efavirenz. No effect of the other antiretrovirals, including the latest (etravirine, darunavir, raltegravir), was found.

Vitamin D inhibits human immunodeficiency virus type 1 and Mycobacterium tuberculosis infection in macrophages through the induction of autophagy

Low vitamin D levels in human immunodeficiency virus type-1 (HIV) infected persons are associated with more rapid disease progression and increased risk for Mycobacterium tuberculosis infection. We have previously shown that 1α,25-dihydroxycholecalciferol (1,25D3), the active form of vitamin D, inhibits HIV replication in human macrophages through the induction of autophagy. In this study, we report that physiological concentrations of 1,25D3 induce the production of the human cathelicidin microbial peptide (CAMP) and autophagic flux in HIV and M. tuberculosis co-infected human macrophages which inhibits mycobacterial growth and the replication of HIV. Using RNA interference for Beclin-1 and the autophagy-related 5 homologue, combined with the chemical inhibitors of autophagic flux, bafilomycin A₁, an inhibitor of autophagosome-lysosome fusion and subsequent acidification, and SID 26681509 an inhibitor of the lysosome hydrolase cathepsin L, we show that the 1,25D3-mediated inhibition of HIV replication and mycobacterial growth during single infection or dual infection is dependent not only upon the induction of autophagy, but also through phagosomal maturation. Moreover, through the use of RNA interference for CAMP, we demonstrate that cathelicidin is essential for the 1,25D3 induced autophagic flux and inhibition of HIV replication and mycobacterial growth. The present findings provide a biological explanation for the benefits and importance of vitamin D sufficiency in HIV and M. tuberculosis-infected persons, and provide new insights into novel approaches to prevent and treat HIV infection and related opportunistic infections.

Macroautophagy (autophagy - ‘self-eating’, lysosome-dependent degradation and recycling of the intracellular components in response to stress) is an important host defense mechanism against viral and mycobacterial infections. Recent studies have described that activation of autophagy in macrophages reduces the viability of Mycobacterium tuberculosis and HIV due to an intimate autophagy-phagocytosis interaction. Low serum levels of the 25-hydroxycholecalciferol form of vitamin D have been associated with an increased risk for active tuberculosis and HIV disease progression as well as M. tuberculosis susceptibility. In this study, we report that the active form of vitamin D, 1α,25-dihydroxycholecalciferol inhibits the replication of HIV and M. tuberculosis in a concentration dependent manner. Moreover, by inhibiting key stages in the autophagy pathway, we demonstrate that the inhibition of HIV and mycobacterial growth during single infection or dual infection is dependent not only upon the induction of autophagy, but also through phagosomal maturation. Furthermore, through the use of RNA interference for the human cathelicidin microbial peptide we demonstrate that cathelicidin is essential for the 1α,25-dihydroxycholecalciferol induced autophagic flux and inhibition of HIV replication and mycobacterial growth. These findings suggest that the induction of autophagy has the potential to be useful in the treatment of persons co-infected with HIV and M. tuberculosis.

Effects of vitamin D deficiency and combination antiretroviral therapy on bone in HIV-positive patients

OBJECTIVES

In the era of combination antiretroviral therapy (cART), vitamin D deficiency, low bone mineral density (BMD) and fractures have emerged as subjects of concern in HIV-positive patients. Testing for vitamin D deficiency has been widely adopted in clinical practice even though the benefits of vitamin D supplementation in this population remain uncertain. The objective of this review was to evaluate the evidence for such a strategy.

DESIGN

Systematic review of the literature on vitamin D deficiency in HIV infection, the effects of cART on vitamin D status, and the effects of vitamin D deficiency and cART on parathyroid hormone (PTH), bone turnover, BMD and the incidence of fractures in HIV-positive patients.

METHODS

PubMed was used to identify relevant articles up to September 2011.

RESULTS

Vitamin D deficiency, secondary hyperparathyroidism and low BMD are common in HIV-positive patients. Efavirenz is associated with a reduction in 25-hydroxy vitamin D levels, tenofovir with secondary hyperparathyroidism, and cART with increased bone turnover and low BMD. The clinical significance of low BMD, however, remains unclear, especially in younger patients. Although the incidence of fractures may be increased in HIV-positive patients, the contribution of low BMD and vitamin D deficiency to these fractures is uncertain. Limited data on vitamin D supplementation in HIV-positive patients have shown transient, beneficial effects on PTH, but no effects on BMD.

CONCLUSION

The benefits of vitamin D supplementation in this population need to be demonstrated before widespread 'test and treat' policies can be recommended as part of routine clinical practice.

Reciprocal seasonal variation in vitamin D status and tuberculosis notifications in Cape Town, South Africa

Vitamin D deficiency is associated with susceptibility to tuberculosis (TB) in HIV-uninfected people in Europe, but it is not known whether such an association exists among HIV-infected people in subtropical Africa. We conducted a cross-sectional study to determine whether vitamin D deficiency was associated with susceptibility to active TB in HIV-uninfected (n = 196) and HIV-infected (n = 174) black Africans in Cape Town, South Africa. We also investigated whether there was evidence of seasonal variation in vitamin D status and TB notifications in this setting over an 8-y period. Vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] <50 nmol/L) was present in 232 (62.7%) of 370 participants and was associated with active TB in both HIV-uninfected (odds ratio = 5.2, 95% confidence interval: 2.8-9.7; P < 0.001) and HIV-infected (odds ratio = 5.6, 95% confidence interval: 2.7-11.6; P < 0.001) people. Vitamin D status varied according to season: The mean serum 25(OH)D concentration was highest in January through March and lowest in July through September (56.8 vs. 30.7 nmol/L, respectively; P < 0.001). Reciprocal seasonal variation in TB notifications was observed: The mean number of TB notifications per quarter for Cape Town in 2003 to 2010 was lowest in April through June and highest in October through December (4,222 vs. 5,080; P < 0.001). Vitamin D deficiency is highly prevalent among black Africans in Cape Town and is associated with susceptibility to active TB both in the presence and absence of HIV infection. Reciprocal seasonal variation in serum 25(OH)D concentration and TB notifications suggests that seasonal variations in vitamin D status and TB incidence in this setting are causally related.