Vitamin D status in Well-Controlled Caucasian HIV Patients in Relation to Inflammatory and Metabolic Markers--A Cross-Sectional Cohort Study in Sweden

Markers of intestinal immune activation and inflammation are not associated with preterm birth among women with low level HIV viremia

BACKGROUND

Maternal markers of intestinal immune activation may be used to predict preterm birth (PTB) in pregnant women living with HIV.

METHODS

This study used de-identified samples from the International Maternal Pediatric Adolescent AIDS Clinical Trials Group (IMPAACT) Protocol P1025 study. Singleton pregnancies with ≥3 ml plasma available and HIV viral load ≤400 copies/ml within 4 weeks of specimen collection were included. Frequency matching of PTB cases and term birth controls was performed on basis of maternal race, number of available plasma specimens, and timing of plasma sample collection in a 1:1 ratio. Plasma progesterone, 25-hydroxy vitamin D, soluble CD14, intestinal fatty acid binding protein (I-FABP), Lipopolysaccharide (LPS)-binding protein, and inflammatory cytokines (IL-1B, IFN-gamma, IL-6, TNF-alpha) were measured. Generalized mixed linear regression modeling was used to examine the association between PTB and biomarkers, adjusting for covariates and confounders. Data analyses were performed using SAS 9.4 (Cary, NC).

RESULTS

We included 104 PTB compared to 104 controls. Third trimester log2 IL-1B was lower among PTB versus term birth controls by univariate analysis (-1.50 ± 2.26 vs. -.24 ± 2.69, p = .01) though this association was no longer significant by regression modeling. In an uncontrolled, exploratory sub-analysis, subjects with prior PTB had increased odds of PTB with higher I-FABP [aOR 2.72, 95% CI 1.18-6.24] and lower IFN-gamma [aOR .23, 95% CI .12-.41] after adjustment for covariates and confounders.

CONCLUSIONS

Intestinal immune activation measured by soluble CD14 or intestinal fatty acid binding protein was not associated with preterm birth among pregnant women with low-level HIV viremia.

Prevalence and Predictors of Hypovitaminosis D in Ethiopian HIV-Infected Adults

Background

Hypovitaminosis D is associated with bone fracture and cardiovascular disease in patients receiving antiretroviral therapy. Currently, there are few data on the magnitude of hypovitaminosis D in people living with HIV in Sub-Saharan country. Therefore, the present study determines the magnitude of hypovitaminosis D in people living with HIV and its associated factors in Ethiopia.

Methods

A cross-sectional study was conducted among 171 adult people living with HIV at Debre Berhan Specialized Hospital. Serum vitamin D was measured. Multivariate logistic regression analysis and p-value <0.05 was used to identify the associated factors of hypovitaminosis D.

Results

In the present study, the prevalence of hypovitaminosis D was 129/171 (75.4%), with 11/171 (6.4%) having vitamin D deficiency and 118/171 (69%) having vitamin D insufficiency. Female sex was significantly associated with hypovitaminosis D (AOR: 3.01, 95% CI = 1.381–6.561, P = 0.006).

Conclusion

Our study found a high burden of hypovitaminosis D among adult people living with HIV on antiretroviral therapy. Female sex was associated with hypovitaminosis D.

Risk Factors of Hypovitaminosis D in HIV-Infected Patients on Suppressive Antiretroviral Therapy

Low serum vitamin D levels are very common in human immunodeficiency virus (HIV)-infected patients. In our cross-sectional study, we investigated the association between 25-hydroxyvitamin D (25(OH)D) levels and serum inflammation markers [C-reactive protein (CRP), white blood cells (WBC), D-dimers, platelet count (PLT)] in 148 HIV-infected patients on combined antiretroviral therapy [28 on tenofovir alafenamide (TAF)] and 40 healthy controls. The controls were significantly older (56.6 ± 19.1 years for HIV(-) vs. 45.1 ± 11.8 years for HIV(+); p = .001) and more females were observed in this group (65% for HIV(-) vs. 16.7% for HIV(+); p = .001). The vitamin D serum level was comparable in the two studied groups (74.2 ± 35.9 nmol/L for HIV(+) vs. 78.0 ± 27.6 nnmol/L for HIV(-), p = .545). In HIV-infected group, a significant positive correlation between CD4+ cell percentage and vitamin D level was observed (r = 0.17; p = .036). Furthermore, the significant negative correlation between vitamin D level and CD8+ cell percentage, PLT, CRP, and D-dimers was seen. In univariate analysis, only TAF use and AIDS status was associated with vitamin D level deficiency. No other antiretroviral (ARV) drug nor gender or smoking had influence on vitamin D serum level. In multivariate analysis, only AIDS status and CRP level were correlated with vitamin D level (slope estimate = 11.6 and p = .032 and slope estimate = -0.83 and p = .002; respectively). In summary, we report that low vitamin D level may be associated with high CRP level in HIV-infected patients on suppressive antiretroviral therapy, especially in AIDS phase. More larger studies are required to assess our observation concerning TAF use and vitamin D level in HIV-positive patients.

The microbial metabolite trimethylamine-N-oxide in association with inflammation and microbial dysregulation in three HIV cohorts at various disease stages

OBJECTIVE

HIV-1-infection infers an increased cardiovascular risk where gut dysbiosis and microbial translocation may contribute. We assessed TMAO, a microbial metabolite with atherosclerotic properties, in plasma of HIV-1-infected individuals at different clinical stages in relation to inflammatory markers, cardiovascular events and gut microbiota.

METHODS

Primary HIV-1-infected (n = 17) and chronic HIV-1-infected individuals (n = 22) were sampled before and after ART-initiation. In the chronic HIV-1-cohort, repeated faecal samples were analysed by 16SrRNA gene sequencing. HIV-1-infected individuals on longstanding ART (n = 101) and healthy HIV-1-negative individuals (n = 60), served as controls. TMAO and markers of immune activation were analysed by LC/MS/MS and immune assays, respectively.

RESULTS

TMAO levels were lower in untreated HIV-1-infected individuals, increased significantly after ART-initiation (P = 0.040 and P < 0.001) but remained similar to healthy controls. TMAO levels were not affected by ART, immune status or degree of systemic inflammation. Higher TMAO in HIV-1-infected individuals on longstanding ART was not significantly associated with cardiovascular risk (P = 0.38). Additionally, TMAO levels correlated inversely with Bacteroidetes (Rho: -0.62, P = 0.002), and positively with Firmicutes (Rho: 0.65, P = 0.001) but held no correlation to TMA-producing genera. Notably gut dysbiosis at follow-up was more pronounced in patients without increase in TMAO levels after ART characterized by loss of Bacteroidetes (P = 0.023) and significantly elevated LPS levels (P = 0.01).

CONCLUSION

Our data does not support that TMAO is a significant link between gut dysbiosis and inflammation in HIV-1-infection. We propose that HIV-1, microbial composition and ART disparately confound TMAO levels, thus limiting its role as a cardiovascular risk marker in HIV-1-infected individuals.

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.

Vitamin D and bone loss in HIV

PURPOSE OF REVIEW

Bone health has become an increasingly important aspect of the care of HIV-infected patients as bone loss with antiretroviral therapy (ART) initiation is significant and osteopenia and osteoporosis are highly prevalent. Vitamin D is tightly linked to calcium balance and bone health, and vitamin D deficiency is common in HIV. This review outlines the epidemiology of vitamin D deficiency in HIV, summarizes our current understanding of the relationship between vitamin D and bone loss in HIV and the impact of vitamin D supplementation in this patient group.

RECENT FINDINGS

Although data are conflicting as to whether vitamin D deficiency is more prevalent among HIV-infected individuals than in the general population, there are several reasons for why this patient group may be at heightened risk. Studies linking vitamin D deficiency to bone loss in HIV are limited; however, data from randomized clinical trials suggest a benefit of vitamin D supplementation for the prevention of bone loss with ART initiation and for the treatment of bone loss with bisphosphonate therapy.

SUMMARY

There are too limited data to recommend universal screening of vitamin D status or supplementation to all HIV-infected individuals. However, testing 25-hydroxyvitamin D levels in those at risk for deficiency and treating patients found to be deficient or initiating ART or bisphosphonate therapy should be considered. Further study on vitamin D supplementation is needed regarding the potential benefit on immune activation and restoration in this patient group.

Optimal vitamin D plasma levels are associated with lower bacterial DNA translocation in HIV/hepatitis c virus coinfected patients

OBJECTIVE

Vitamin D has been linked to the immune response modulation and the integrity of the intestinal mucosal barrier. Therefore, vitamin D might be involved in bacterial translocation related to HIV infection. Our major aim was to analyze the association between plasma levels of 25-hydroxy-vitamin D [25(OH)D] and bacterial 16S ribosomal DNA (bactDNA) in 120 HIV/hepatitis c virus (HCV) coinfected patients.

DESIGN

Cross-sectional study.

METHODS

Plasma 25(OH)D levels were quantified by enzyme immunoassay. The vitamin D status was defined as deficient (<25 nmol/l), insufficient (25-74 nmol/l), and optimal (≥75 nmol/l) plasma levels. Plasma bactDNA levels were measured by quantitative real-time PCR. For bactDNA levels the cutoffs used were as follows: low [<p25th (46 copies/μl)], moderate [p25th to p50th (78 copies/μl)], high [p50th to p75th (159 copies/μl)], and very high (>p75th).

RESULTS

Eighteen (15%) patients had 25(OH)D deficiency, 93 (77.5%) had insufficiency and nine (7.5%) had 25(OH)D optimal values. The bactDNA levels were lower in patients with 25(OH)D at least 75 nmol/l [37 copies/μl] than in patients with 25(OH)D insufficiency [84.2 copies/μl; P = 0.042]. Conversely, low bactDNA levels (<p25th) were found in 66.7% of patients with 25(OH)D optimal levels, whereas bactDNA levels above p25th were found only in 11.1% of them (P = 0.029). The plasma 25(OH)D not less than 75 nmol/l was associated with low bactDNA levels (<p25th) [adjusted OR = 8.13 (95% confidence interval = 1.82; 36.67); P = 0.006)]. The patients with optimal vitamin D status [25(OH)D ≥75 nmol/l] had lower plasma levels of CCL7 (P = 0.047) and basic fibroblast growth factor (P = 0.042).

CONCLUSION

The optimal vitamin D status was associated with low bacterial translocation and inflammation in HIV/HCV coinfected patients.

Vitamin D Levels and Markers of Inflammation and Metabolism in HIV-Infected Individuals on Suppressive Antiretroviral Therapy

Data on vitamin D insufficiency as a cause of inflammation and metabolic dysfunction in HIV-infected individuals are conflicting. We examined the relationships between levels of 25-hydroxyvitamin D [25(OH)D] and biomarkers of inflammation and metabolism in stored blood samples from a prospective trial of vitamin D repletion. Blood samples from HIV-infected individuals on antiretroviral therapy (ART) with HIV-1 RNA <200 copies/ml enrolled in a prospective study were analyzed for 25(OH)D levels, a broad panel of cytokines, highly sensitive C-reactive protein, D-dimer, adiponectin, leptin, and insulin. Correlations between markers and 25(OH)D levels were determined. The Wilcoxon Rank Sum test was used to compare markers between individuals 25(OH)D insufficient and sufficient at baseline and before and after repletion among those who were insufficient and repleted to ≥30 ng/ml after 12 weeks. Of 106 subjects with stored plasma [66 with 25(OH)D <30 ng/ml and 40 ≥ 30 ng/ml], the median age was 50, the CD4 count was 515 cells/mm(3), 94% were male, and the median baseline 25(OH)D was 27 ng/ml. Higher 25(OH)D levels were associated with lower tumor necrosis factor (TNF)-α (r = -0.20, p = 0.04) and higher adiponectin levels (r = 0.30, p = 0.002). Following successful repletion to 25(OH)D ≥30 ng/ml there were no significant changes in inflammatory or metabolic parameters. Our study found associations between low 25(OH)D levels and TNF-α and adiponectin. Repletion did not result in changes in markers of inflammation or metabolism. These data support continued study of the relationship between vitamin D, inflammation, and metabolism in treated HIV infection.