osteoprotegerin and HIV-Infections

Osteoporosis increases fracture risk, a cause of crippling morbidity and mortality. The immunoskeletal interface (ISI) is a centralization of cell and cytokine effectors shared between skeletal and immune systems. Consequently, the immune system mediates powerful effects on bone turnover. Physiologically, B cells secrete osteoprotegerin (OPG), a potent anti-osteoclastogenic factor that preserves bone mass. However, activated T cells and B cells secrete pro-osteoclastogenic factors including receptor activator of Nuclear factor-kappaB (NF-kB) ligand (RANKL), Interleukin (IL)-17A, and tumor necrosis factor (TNF)-α promoting bone loss in inflammatory states such as rheumatoid arthritis. Recently, ISI disruption has been linked to osteoporosis in human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS), where elevated B cell RANKL and diminished OPG drive bone resorption. HIV-antiretroviral therapy paradoxically intensifies bone loss during disease reversal, as immune reconstitution produces osteoclastogenic cytokines. Interestingly, in estrogen deficiency, activated T cells secrete RANKL, TNF, and IL-17A that amplify bone resorption and contribute to postmenopausal osteoporosis. T cell-produced TNF and IL-17A further contribute to bone loss in hyperparathyroidism, while T cell production of the anabolic Wingless integration site (Wnt) ligand, Wnt10b, promotes bone formation in response to anabolic parathyroid hormone and the immunomodulatory costimulation inhibitor cytotoxic T lymphocyte-associated protein-4-IgG (abatacept). These findings provide a window into the workings of the ISI and suggest novel targets for future therapeutic interventions to reduce fracture risk.

Topics: Animals; Antiretroviral Therapy, Highly Active; Bone and Bones; Bone Remodeling; Bone Resorption; Cytokines; Estrogens; HIV Infections; Humans; Immune System; Lymphocytes; NF-kappa B; Osteoclasts; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Tumor Necrosis Factor-alpha

The contributions of the receptor activator of nuclear factor kappa-B ligand (RANKL)/osteoprotegerin (OPG) axis to cardiovascular and bone disease in treated HIV-1 infection are not well defined.. Prospective, observational, longitudinal study.. In a subset analysis of a prospective randomized clinical trial, 234 HIV-1-infected antiretroviral therapy-naive participants received tenofovir-emtricitabine plus either atazanavir/ritonavir, darunavir/ritonavir, or raltegravir and achieved plasma HIV-1 RNA <50 copies per milliliter by week 24 and thereafter. Associations between plasma RANKL, OPG, or RANKL/OPG ratio levels with total, hip, and spine bone mineral density (BMD) loss or progression of carotid artery intima-media thickness were assessed longitudinally over 96 weeks.. Over 96 weeks, all treatment groups had similar and sustained declines in plasma RANKL, increases in plasma OPG, and subsequently, decreases in the RANKL/OPG ratio. There were no associations between plasma RANKL or RANKL/OPG ratio levels with total, hip, and spine BMD loss or progression of carotid artery intima-media thickness; however, plasma OPG in successfully treated HIV-infected patients (week 48 and 96) was associated with spine BMD loss.. In virologically suppressed HIV-infected patients, the evolution of bone disease could be linked to plasma OPG levels; however, the role of plasma levels of RANKL and RANKL/OPG ratio in the prediction of morbidity in treated HIV-1 infection may be limited.

Topics: Adult; Female; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; Prospective Studies; RANK Ligand

To determine the association among bone mineral density (BMD), inflammatory markers, and alterations in fat and lean mass in untreated HIV-infected individuals.. Cross-sectional analysis of antiretroviral therapy-naive persons enrolled into a randomized clinical trial.. Dual-energy x-ray absorptiometry for BMD and lean and fat mass and a laboratory assessment were performed. Soluble biomarkers included adipocytokines (leptin and adiponectin), inflammatory markers (high-sensitivity C-reactive protein and interleukin 6), and markers related to bone metabolism [osteoprotegerin (OPG)], receptor activator of nuclear factor κB ligand. BMD at the lumbar spine, total hip, and femoral neck was expressed as a Z score (number of standard deviations away from age-, race-, and sex-matched reference population).. Three hundred thirty-one subjects had a median (Q1, Q3) age of 36 (28, 45) years, were 89% men, and 44% white. The prevalence of low BMD (Z score ≤ -2 at any of the 3 sites) was 10%. No associations were detected between Z scores and high-sensitivity C-reactive protein, interleukin 6, or receptor activator of nuclear factor κB ligand (P ≥ 0.1). In a linear model adjusting for age, gender, race, and total fat mass, lower lumbar spine Z scores were associated with lower total lean mass, higher serum adiponectin, and lower OPG. Results at the total hip or femoral neck were similar.. Among antiretroviral therapy-naive HIV-infected individuals, lower BMD was associated with lower lean mass, higher adiponectin, and lower OPG, but not HIV disease variables or any of the inflammatory markers. These findings may have implications for bone metabolism in untreated HIV, in which hypoadiponectinemia and higher OPG may mitigate bone loss.

Topics: Adiponectin; Adult; Body Composition; Body Mass Index; Bone Density; C-Reactive Protein; Cross-Sectional Studies; Female; HIV Infections; HIV-1; Humans; Inflammation; Interleukin-6; Leptin; Male; Metabolism, Inborn Errors; Middle Aged; Osteoprotegerin; RANK Ligand

Bone mineral density (BMD) declines significantly in HIV patients on antiretroviral therapy (ART). We compared the effects of intermittent versus continuous ART on markers of bone turnover in the Body Composition substudy of the Strategies for Management of AntiRetroviral Therapy (SMART) trial and determined whether early changes in markers predicted subsequent change in BMD. For 202 participants (median age 44 years, 17% female, 74% on ART) randomized to continuous or intermittent ART, plasma markers of inflammation and bone turnover were evaluated at baseline and months 4 and 12; BMD at the spine (dual-energy X-ray absorptiometry [DXA] and computed tomography) and hip (DXA) was evaluated annually. Compared with the continuous ART group, mean bone-specific alkaline phosphatase (bALP), osteocalcin, procollagen type 1 N-terminal propeptide (P1NP), N-terminal cross-linking telopeptide of type 1 collagen (NTX), and C-terminal cross-linking telopeptide of type 1 collagen (βCTX) decreased significantly in the intermittent ART group, whereas RANKL and the RANKL:osteoprotegerin (OPG) ratio increased (all p ≤ 0.002 at month 4 and month 12). Increases in bALP, osteocalcin, P1NP, NTX, and βCTX at month 4 predicted decrease in hip BMD at month 12, whereas increases in RANKL and the RANKL:OPG ratio at month 4 predicted increase in hip and spine BMD at month 12. This study has shown that compared with continuous ART, interruption of ART results in a reduction in markers of bone turnover and increase in BMD at hip and spine, and that early changes in markers of bone turnover predict BMD changes at 12 months.

Topics: Adult; Alkaline Phosphatase; Anti-Retroviral Agents; Australia; Biomarkers; Bone Density; Collagen Type I; Female; Follow-Up Studies; HIV Infections; Humans; Male; Middle Aged; Osteitis; Osteocalcin; Osteoprotegerin; RANK Ligand; Spain; Spinal Diseases; United States

: Switching from boosted protease inhibitors (PI/r) to raltegravir (RAL) results in a better plasma lipid profile than continuing PI/r. Whether this strategy affects plasma biomarkers associated with atherosclerosis is unknown.. : We assessed 48-week changes in fasting lipids and several biomarkers including serum high-sensitivity C-reactive protein (hsCRP), monocyte chemoattractant protein 1 (MCP-1), osteoprotegerin, interleukin (IL) 6, IL-10, tumor necrosis factor alpha (TNF-α), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and P-selectin, adiponectin, insulin, and D-dimer in otherwise healthy, virologically suppressed HIV-infected patients treated with PI/r who randomly switched from PI/r to RAL or continued with PI/r in the SPIRAL trial. Biomarkers and lipids at baseline and 48-week changes between both study arms were compared. Correlations between changes in biomarkers and changes in lipids were also evaluated.. : Of 273 patients initiating study drugs in the SPIRAL trial, 233 (119 RAL, 114 PI/r) remained on allocated therapy for 48 weeks and had sera available for the purpose of this substudy. Triglycerides (-28%, P < 0.0001), total (-14%, P < 0.0001), low-density lipoprotein (-9%, P = 0.0069), and high-density lipoprotein (-10%, P = 0.0017) cholesterol decreased in RAL relative to the PI/r group. Among biomarkers, hsCRP (-40%, P < 0.0001), MCP-1 (-20%, P = 0.0003), osteoprotegerin (-13%, P = 0.0024), IL-6 (-46%,P < 0.0001), TNF-α (-27%, P = 0.0011), insulin (-26%, P < 0.0001), and D-dimer (-8%, P = 0.0187) decreased in RAL relative to PI/r group, whereas IL-10 (+1%, P = 0.7773), ICAM-1 (-6%, P = 0.1255), VCAM-1(0%, P = 0.8671), E-selectin (-9%, P = 0.2174), P-selectin (-6%, P = 0.3865), and adiponectin (+8%, P = 0.2028) remained unchanged. Biomarkers and lipids changes at 48 weeks were weakly correlated.. : Switching from PI/r to RAL induced significant changes in several cardiovascular biomarkers that were not completely explained by lipid changes.

Topics: Adult; Anti-HIV Agents; Atherosclerosis; Biomarkers; C-Reactive Protein; Chemokine CCL2; Drug Administration Schedule; E-Selectin; Fasting; Female; Follow-Up Studies; HIV Infections; HIV Protease Inhibitors; Humans; Interleukin-10; Interleukin-6; Lipids; Male; Middle Aged; Osteoprotegerin; P-Selectin; Pyrrolidinones; Raltegravir Potassium; Ritonavir; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Antiretroviral therapy (ART) has led to a significant decline in HIV-related morbidity and mortality in people living with HIV (PLWH). PLWH however experience non-AIDS ageing-associated comorbidities, including decreased bone mass and osteoporosis, earlier and more severely, than uninfected people. We previously reported that total B-cell production of the key osteoclastogenic cytokine receptor activator of NF-κB ligand (RANKL) was elevated in PLWH, concurrent with a decrease in total B-cell production of RANKL's physiological moderator Osteoprotegerin (OPG). The resulting increased total B-cell RANKL/OPG ratio was significantly associated with bone loss in the appendicular (long bones), but not axial (spine) skeletons of PLWH. A role for immature/transitional B cells (BImm) in HIV-induced bone loss has not been reported.. BImm frequency was determined by flow cytometry; plasma IL-7 was quantified by ELISA and bone mineral density (BMD) measured by dual X-ray absorptiometry (DXA) in a cross-sectional study of 62 ART-naive HIV-infected and 58 HIV-negative individuals.. BImm expansion correlated with the total B-cell RANKL/OPG ratio in HIV-infected individuals and inversely with BMD at the total hip, femoral neck and the lumbar spine, and with IL-7.. These data suggest that BImm contribute to the increased B-cell RANKL/OPG ratio in PLWH, and reveal a previously unrecognized link between BImm expansion and HIV-induced bone loss in the axial and appendicular skeletons of severely immunocompromised HIV-infected individuals. BImm expansion may be a novel biomarker for screening patients at risk of osteoporosis.

Topics: Adult; Bone Density; Bone Resorption; CD4-Positive T-Lymphocytes; Cross-Sectional Studies; Female; HIV Infections; Humans; Lymphopenia; Male; Middle Aged; Osteoprotegerin; Precursor Cells, B-Lymphoid; RANK Ligand

Both HIV infection and tenofovir disoproxil fumarate (TDF) treatment adversely impact bone metabolism and may lead to osteopenia, which has critical implications for youth with HIV (YWH). This study evaluates changes in the biomarkers of bone metabolism and inflammation among YWH receiving initial treatment with TDF- and non-TDF-containing antiretroviral therapies (ARTs). YWH [

Topics: Adolescent; Alkaline Phosphatase; Anti-HIV Agents; Biomarkers; Bone and Bones; Bone Density; Bone Diseases, Metabolic; Female; HIV Infections; Humans; Lymphocyte Activation; Macrophage Activation; Macrophages; Male; Osteopontin; Osteoprotegerin; Parathyroid Hormone; RANK Ligand; Tenofovir; Young Adult

Higher incidence of osteopenia and osteoporosis underlie increased rates of fragility fracture in HIV infection. B cells are a major source of osteoprotegerin (OPG), an inhibitor of the key osteoclastogenic cytokine receptor activator of nuclear factor-κB ligand (RANKL). We previously showed that higher B-cell RANKL/OPG ratio contributes to HIV-induced bone loss. T-cell OPG production in humans, however, remains undefined and the contribution of T-cell OPG and RANKL to HIV-induced bone loss has not been explored.. We investigated T-cell OPG and RANKL production in ART-naive HIV-infected and uninfected individuals in relation to indices of bone loss in a cross-sectional study.. T-cell RANKL and OPG production was determined by intracellular staining and flow cytometry, and plasma levels of bone resorption markers were determined by ELISA.. We demonstrate for the first time in-vivo human T-cell OPG production, which was significantly lower in HIV-infected individuals and was coupled with moderately higher T-cell RANKL production, resulting in a significantly higher T-cell RANKL/OPG ratio. T-cell RANKL/OPG ratio correlated significantly with BMD-derived z-scores at the hip, lumbar spine and femur neck in HIV-infected individuals with CD4 T-cell counts at least 200 cells/μl but not in those with lower counts.. Our data suggest that T cells may be a physiologically relevant source of OPG and T-cell RANKL/OPG imbalance is associated with HIV-induced bone loss in CD4 T-cell-sufficient patients. Both B and T lymphocytes may thus contribute to HIV-induced bone loss.

Topics: Adult; Bone Diseases, Metabolic; CD4 Lymphocyte Count; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Staining and Labeling; T-Lymphocytes

HIV-infected patients appear to have a significantly greater risk of non-AIDS comorbidities such as osteoporosis and atherosclerosis. Subjects with osteoporosis are at a higher risk of developing cardiovascular disease than those with normal bone mass, therefore a possible relation between these two conditions can be hypothesized. In the setting of HIV infection, several factors might contribute to bone disease and endothelial dysfunction. The aim of our study was to evaluate the relationship between bone and cardiovascular disease and to investigate the role of traditional factors, T-cell phenotype and osteoprotegerin in HIV positive subjects on effective antiretroviral therapy. We included 94 HIV positive subjects on antiretroviral therapy with virological suppression and 41 healthy subjects matched for age and gender as a control group. Carotid-Intima Media Thickness (c-IMT) and bone mineral density (BMD) were performed by ultrasound and DEXA, respectively. CD4+/CD8+ T-cell activation, senescence and osteoprotegerin plasma levels were measured by flow-cytometry and ELISA, respectively. Among HIV positive patients, 56.4% had osteopenia/osteoporosis and 45.7% had pathological c-IMT (>0.9 mm). Subjects with pathological c-IMT and BMD exhibited higher CD4+ and CD8+ activated, CD8+ senescent and osteoprotegerin than subjects with normal c-IMT and BMD. HIV positive subjects with osteopenia/osteoporosis had higher c-IMT than subjects with normal BMD, and linear regression analysis showed a negative correlation between BMD and c-IMT. Several factors are implicated in the pathogenesis of non-AIDS comorbidities in HIV positive patients. Osteoprotegerin together with inflammation and immunosenescence in HIV positive patients could affect bone and vascular system and could be considered as a possible common link between these two diseases.

Topics: Anti-HIV Agents; Biomarkers; Bone Diseases; Cardiovascular Diseases; Carotid Intima-Media Thickness; Comorbidity; Female; HIV Infections; Humans; Immunosenescence; Male; Middle Aged; Osteoprotegerin; Phenotype; T-Lymphocytes

Abnormalities in the osteoprotegerin (OPG)/receptor activator of nuclear factor-κB ligand (RANKL) axis have been observed in HIV-infected persons and have been implicated in cardiovascular disease (CVD) pathogenesis in the general population.. To determine associations of serum OPG and RANKL concentrations with HIV infection and subclinical atherosclerosis.. Cross-sectional study nested within the Multicenter AIDS Cohort Study.. Four US academic medical centers.. There were 578 HIV-infected and 344 HIV-uninfected men.. Coronary artery calcium (CAC) was measured by noncontrast cardiac computed tomography, and coronary stenosis and plaque characteristics (composition, presence, and extent) were measured by coronary computed tomography angiography. All statistical models were adjusted for traditional CVD risk factors.. OPG concentrations were higher, and RANKL concentrations were lower among HIV-infected men compared with HIV-uninfected men (P < 0.0001 each). Among HIV-infected men, higher OPG concentrations were associated with the presence of CAC, mixed plaque, and coronary stenosis >50%, but not with plaque extent. In contrast, among HIV-uninfected men, higher OPG concentrations were associated with the extent of both CAC and calcified plaque, but not with their presence. RANKL concentrations were not associated with plaque presence or the extent among HIV-infected men, but among HIV-uninfected men, lower RANKL concentrations were associated with greater extent of CAC and total plaque.. OPG and RANKL are dysregulated in HIV-infected men, and their relationship to the presence and extent of subclinical atherosclerosis varies by HIV status. The role of these biomarkers in CVD pathogenesis and risk prediction may be different in HIV-infected men.

Topics: Academic Medical Centers; Adult; Aged; Biomarkers; Calcium; Cohort Studies; Coronary Artery Disease; Coronary Vessels; Cross-Sectional Studies; Heart; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Tomography, X-Ray Computed; United States

HIV-infected patients have a significantly greater risk of cardiovascular disease. Several markers including osteoprotegerin have been shown to be involved in the development and progression of atherosclerosis. We investigated the relationship between T-cell phenotype, osteoprotegerin, and atherosclerosis evaluated by carotid intima-media thickness (c-IMT) in 94 HIV+ patients on suppressive antiretroviral therapy with Framingham score <10%. As for the control group, 24 HIV-negative subjects were enrolled. c-IMT was assessed by ultrasound. CD4+/CD8+ T-cell activation (CD38+ HLADR+) and senescence (CD57+ CD28-) were measured by flow cytometry. IL-6 and OPG levels were measured by ELISA kit. c-IMT was higher in HIV+ than in controls. Among HIV+ patients, 44.7% had pathological c-IMT (≥0.9 mm). CD8+ T-cell activation and senescence and OPG plasma levels were higher in HIV+ patients than in controls. Subjects with pathological c-IMT exhibited higher CD8+ immune activation and immunosenescence and OPG levels than subjects with normal c-IMT. Multivariate analysis showed that age, CD8+ CD38+ HLADR+, and CD8+ CD28- CD57+ were independently associated with pathological c-IMT. Several factors have been implicated in the pathogenesis of atherosclerosis in HIV patients. Immune activation and immunosenescence of CD8+ T cell together with OPG plasma levels might be associated with the development and progression of early atherosclerosis, even in the case of viral suppression.

Topics: Adult; Anti-HIV Agents; Atherosclerosis; Biomarkers; Carotid Intima-Media Thickness; Case-Control Studies; CD8-Positive T-Lymphocytes; Cellular Senescence; Disease Progression; Female; HIV Infections; Humans; Interleukin-6; Lymphocyte Activation; Male; Middle Aged; Osteoprotegerin

HIV infection is associated with high rates of osteopenia and osteoporosis, but the mechanisms involved are unclear. We recently reported that bone loss in the HIV transgenic rat model was associated with upregulation of B cell expression of the key osteoclastogenic cytokine receptor-activator of NF-κB ligand (RANKL), compounded by a simultaneous decline in expression of its physiological moderator, osteoprotegerin (OPG). To clinically translate these findings we performed cross-sectional immuno-skeletal profiling of HIV-uninfected and antiretroviral therapy-naïve HIV-infected individuals. Bone resorption and osteopenia were significantly higher in HIV-infected individuals. B cell expression of RANKL was significantly increased, while B cell expression of OPG was significantly diminished, conditions favoring osteoclastic bone resorption. The B cell RANKL/OPG ratio correlated significantly with total hip and femoral neck bone mineral density (BMD), T- and/or Z-scores in HIV infected subjects, but revealed no association at the lumbar spine. B cell subset analyses revealed significant HIV-related increases in RANKL-expressing naïve, resting memory and exhausted tissue-like memory B cells. By contrast, the net B cell OPG decrease in HIV-infected individuals resulted from a significant decline in resting memory B cells, a population containing a high frequency of OPG-expressing cells, concurrent with a significant increase in exhausted tissue-like memory B cells, a population with a lower frequency of OPG-expressing cells. These data validate our pre-clinical findings of an immuno-centric mechanism for accelerated HIV-induced bone loss, aligned with B cell dysfunction.

Topics: Adult; B-Lymphocytes; Bone Density; Cross-Sectional Studies; Cytokines; Female; HIV Infections; Humans; Male; Middle Aged; Models, Biological; NF-kappa B; Osteoporosis; Osteoprotegerin; RANK Ligand

The receptor activator of the NF-κB ligand (RANKL)-osteoprotegerin (OPG) axis has been shown to play a role in the inflammatory process of atherogenesis and may be regulated by changes in levels of cholesterol. However, the interplay between HIV-1 infection, lipids, the RANKL-OPG axis, and atherosclerosis is poorly defined. Serum RANKL, OPG, and RANKL/OPG ratio were retrospectively assessed for 91 subjects from a 3-year study of carotid artery intima-media thickness (CIMT), which enrolled triads of risk factor-matched persons that were HIV-1 uninfected (n=36) or HIV-1(+) with (n=29) or without (n=26) continuous protease inhibitor (PI)-based therapy for ≥2 years. Associations of serum RANKL, OPG, and RANKL/OPG ratio to the primary outcomes of levels of circulating lipids and atherosclerosis progression were determined using multivariate regression models. Serum RANKL and RANKL/OPG ratio were significantly lower in HIV-infected versus HIV-uninfected subjects (p<0.01). Multivariate models for HIV-1(+) subjects, but not in uninfected controls, demonstrated that perturbations in serum cholesterol levels were significantly associated (p<0.05) with perturbations in serum levels of RANKL and OPG, and their ratio (RANKL/OPG). There were no significant associations of serum RANKL, OPG, and RANKL/OPG with progression of atherosclerosis in HIV-1(+) subjects. Our results suggest that HIV-1 infection is associated with reductions in both serum RANKL and the RANKL/OPG ratio, and perturbations in the circulating levels of RANKL and OPG are significantly associated with increases in cholesterol levels, but not with progression of atherosclerosis.

Topics: Adult; Atherosclerosis; Case-Control Studies; Disease Progression; Female; HIV Infections; HIV-1; Humans; Lipids; Male; Middle Aged; Osteoprotegerin; Prospective Studies; RANK Ligand; Risk Factors

HIV-infected individuals have an increased prevalence of coronary artery disease. Receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin have been postulated as mediators of vascular calcification. 78 HIV-infected men and 32 healthy controls without history of coronary artery disease were prospectively recruited to undergo cardiac computed tomography and computed tomography angiography to assess coronary artery calcium and plaque burden. Soluble receptor activator of nuclear factor-κB ligand was lower in HIV-infected individuals than controls [2.52 (1.08-3.98) vs. 3.33 (2.44-4.64) pg/mL, P = 0.01, median (IQR) respectively]. Soluble receptor activator of nuclear factor-κB ligand was negatively associated with the number of coronary segments with plaque (Spearman ρ = -0.41, P < 0.001) and Agatston calcium score (ρ = -0.30, P < 0.01) in HIV-infected individuals even after adjusting for traditional cardiovascular risk factors.

Topics: Case-Control Studies; CD4 Lymphocyte Count; Coronary Angiography; Coronary Artery Disease; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; Prospective Studies; RANK Ligand

Bone mineral density decreases with antiretroviral therapy (ART) initiation, although the pathogenesis, including the role of tenofovir (TDF), is unclear. This study assessed changes in bone-turnover markers, osteoprotegerin (OPG), soluble receptor activator for nuclear factor-κβ ligand (sRANKL), and inflammation in subjects initiating TDF- versus non-TDF-containing regimens, and determined the relationship between bone turnover, OPG/sRANKL and inflammation.. This was a longitudinal observational study comparing levels of bone turnover markers (C-terminal telopeptide of type I collagen [CTX] and osteocalcin [OC]), OPG, sRANKL and inflammatory cytokines (soluble tumour necrosis factor [TNF]-α receptor [sTNFR]-I, sTNFR-II and interleukin-6) prior to ART and 6-12 months after ART initiation with a TDF- versus non-TDF-containing regimen in HIV-infected subjects 18-50 years old.. A total of 87 subjects were enrolled (TDF n=44 and non-TDF n=43). Groups were similar except subjects on TDF had a lower CD4(+) T-cell nadir (P<0.01) and were more likely to receive a protease inhibitor (PI; P=0.03). At pre-ART, 35% and 1% of subjects had CTX and OC above the normal range, respectively. Both increased with ART initiation, whereas OPG, sRANKL and inflammatory markers significantly decreased. In multivariate models, increases in OC were associated with TDF use, PI use and pre-ART levels of sTNFR-I, whereas increases in CTX were associated with CD4(+) T-cell nadir <50 cell/mm³. Increases in bone markers were unrelated to pre-ART levels of OPG/sRANKL and changes in OPG/sRANKL after ART initiation.. TDF use, PI use, TNF-α activity and advanced HIV disease are associated with changes in bone turnover markers, underscoring the complicated interaction between ART, bone turnover, inflammation and immune status, which extend beyond the OPG/RANKL system.

Topics: Adenine; Adolescent; Adult; Anti-HIV Agents; Biomarkers; Bone Density; Bone Remodeling; CD4 Lymphocyte Count; Collagen Type I; Cytokines; Female; HIV Infections; Humans; Inflammation; Longitudinal Studies; Male; NF-kappa B; Organophosphonates; Osteoprotegerin; Protease Inhibitors; RANK Ligand; Tenofovir; Tumor Necrosis Factor-alpha; Young Adult

Topics: Adult; Albuminuria; Female; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; Receptors, Tumor Necrosis Factor

Patients infected with HIV have an increased risk for accelerated atherosclerosis. Elevated levels of osteoprotegerin, an inflammatory cytokine receptor, have been associated with a high incidence of cardiovascular disease (including peripheral arterial disease, or PAD), acute coronary syndrome, and cardiovascular mortality. The objective of this study was to determine whether PAD is prevalent in an HIV-infected population, and to identify an association with HIV-specific and traditional cardiovascular risk factors, as well as levels of osteoprotegerin.. One hundred and two patients infected with HIV were recruited in a cross-sectional study. To identify the prevalence of PAD, ankle-brachial indices (ABIs) were measured. Four standard ABI categories were utilized: < or = 0.90 (definite PAD); 0.91-0.99 (borderline); 1.00-1.30 (normal); and >1.30 (high). Medical history and laboratory measurements were obtained to determine possible risk factors associated with PAD in HIV-infected patients.. The prevalence of PAD (ABI < or = 0.90) in a young HIV-infected population (mean age: 48 years) was 11%. Traditional cardiovascular risk factors, including advanced age and previous cardiovascular history, as well as elevated C-reactive protein levels, were associated with PAD. Compared with patients with normal ABIs, patients with high ABIs had significantly elevated levels of osteoprotegerin [1428.9 (713.1) pg/ml vs. 3088.6 (3565.9) pg/ml, respectively, p = 0.03].. There is a high prevalence of PAD in young HIV-infected patients. A number of traditional cardiovascular risk factors and increased osteoprotegerin concentrations are associated with abnormal ABIs. Thus, early screening and aggressive medical management for PAD may be warranted in HIV-infected patients.

Topics: Adult; Ankle Brachial Index; Cross-Sectional Studies; Female; HIV Infections; Humans; Male; Middle Aged; Osteoprotegerin; Peripheral Vascular Diseases; Risk Factors

Bone metabolism derangements have been reported in HIV-infected children and adolescents. Nuclear factor kappa B ligand (RANKL) and osteoprotegerin potently stimulate and inhibit, respectively, osteoclast formation and activity. We investigated the possible role of RANKL and osteoprotegerin on bone metabolism alterations in paediatric patients.. A prospective controlled longitudinal study. Measurements were obtained before and 6 months after switching antiretroviral regimen.. We studied 27 vertically HIV-infected children and adolescents (aged 4.9-17.3 years) on long-term HAART (70.1 +/- 1.5 months). All patients received lamivudine, stavudine and one protease inhibitor (PI). During follow-up, the PI was replaced with efavirenz and stavudine with tenofovir. We also enrolled 336 healthy children, aged 4.8-17.9 years. Concentrations of bone-specific alkaline phosphatase (BALP), N-terminal telopeptide of type I collagen (NTx), RANKL, and osteoprotegerin were measured at baseline and 6 months after switching.. BALP serum concentrations and NTx urine levels of HIV-infected patients were significantly higher than those of healthy children both at baseline and after 6 months (P < 0.001). Baseline osteoprotegerin and RANKL concentrations of HIV-infected patients were significantly higher than in healthy children (P < 0.0001). Both concentrations decreased after 6 months, and RANKL levels were no longer different to controls. At baseline the RANKL/osteoprotegerin ratio was significantly higher (P = 0.02) in HIV-infected children (0.27 +/- 0.07) compared with healthy children (0.078 +/- 0.01).. A marked alteration in the RANKL/osteoprotegerin system is present in patients receiving PI-based HAART. Short-term data indicate that replacing stavudine and PI with tenofovir and efavirenz restores the RANKL/osteoprotegerin equilibrium, and may thus lead to a reduction in the bone resorption rate.

Topics: Adolescent; Alkaline Phosphatase; Antiretroviral Therapy, Highly Active; Biomarkers; Bone Density; Bone Resorption; Child; Child, Preschool; Collagen Type I; Female; HIV Infections; Humans; Longitudinal Studies; Male; Osteoprotegerin; Peptides; Prospective Studies; RANK Ligand

To characterize osteoprotegerin (OPG) levels, bone remodelling and bone mineral density (BMD) in heavily pretreated HIV-infected patients on antiretroviral therapy, and to evaluate the clinical factors associated with bone density decline.. Heavily pretreated (> 5 years) HIV-positive patients were enrolled in this cross-sectional, observational study, which was based on a total body bone densitometry examination and a comprehensive evaluation of bone and mineral parameters.. Sixty-eight patients (55 male and 13 female) with a median age of 41 years (range 25-60 years) were included in the study. Their antiretroviral treatment lasted for 82 months. On the basis of the World Health Organization criteria, nine patients (13.2%) were osteoporotic [T-score < -2.5 standard deviation (SD)] and 19 patients (27.9%) were osteopenic (T-score between -1 and -2.5). The principal outcomes associated with the presence of a low BMD were high OPG and lysylpyridinoline/creatinine ratio (Dpd) values. Most of the patients (39 of 48; 81.25%) showed vitamin D insufficiency [Vitamin D (25(OH)D) < 18 ng/mL] with secondary hyperparathyroidism (13 of 50 patients: 26%), which proved to be correlated to osteocalcin (BGP) levels [parathyroid hormone (PTH) vs. BGP: r = 0.34; P < 0.01]. There was an inverse correlation between T-scores and serum osteocalcin and alkaline phosphatase (AP) levels, on one hand, and Dpd, on the other. High AP and Dpd values were associated with relative risks of 4.1 [95% confidence interval (CI) = 1.01-17.6] and 7.2 (95% CI = 1.67-31.03), respectively, of a pathological T-score. Multivariate analysis revealed that the factors associated with the presence of osteopenia or osteoporosis were older age and lower body mass index.. About 40% of our heavily pretreated subjects with advanced HIV infection had a low BMD, and 56% (24 of 44 patients) showed a high bone turnover rate with marked osteoclast activation. High OPG levels may protect against bone resorption.

Topics: Adult; Age Factors; Alkaline Phosphatase; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Biomarkers; Body Mass Index; Bone Diseases, Metabolic; Bone Remodeling; Creatine; Cross-Sectional Studies; Female; Glycoproteins; HIV Infections; Humans; Hyperparathyroidism, Secondary; Lymphocyte Count; Male; Middle Aged; Multivariate Analysis; Osteocalcin; Osteoporosis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; T-Lymphocytes; Time Factors; Vitamin D Deficiency

Members of the TNF superfamily have been shown to be instrumental in enhancing cell-mediated immune responses, primarily through their interactions with dendritic cells (DCs). We systematically evaluated the ability of three TNF superfamily molecules, CD40 ligand (CD40L), receptor activator of NF-kappaB ligand (RANKL), and TNF-alpha, to expand ex vivo EBV-specific CTL responses in healthy human individuals and ex vivo HIV-1-specific CTL responses in HIV-1-infected individuals. In both groups of individuals, we found that all three TNF family molecules could expand CTL responses, albeit at differing degrees. CD40L treatment alone was better than RANKL or TNF-alpha alone to mature DCs and to expand CTL. In healthy volunteers, TNF-alpha or RANKL could cooperate with CD40L to maximize the ability of DCs to expand virus-specific CTL responses. In HIV-1 infection, cooperative effects between TNF-alpha or RANKL in combination with CD40L were variable. TNF-alpha and RANKL cooperated with CD40L via differing mechanisms, i.e., TNF-alpha enhanced IL-12 production, whereas RANKL enhanced survival of CD40L-stimulated DCs. These findings demonstrate that optimal maturation of DCs requires multiple signals by TNF superfamily members that include CD40L. In HIV-1 infection, DCs may only require CD40L to maximally expand CTL. Finally, CTL responses were higher in CD4(+) T cell-containing conditions even in the presence of TNF family molecules, suggesting that CD4(+) T cells can provide help to CD8(+) T cells independently of CD40L, RANKL, or TNF-alpha.

Topics: Carrier Proteins; CD4-Positive T-Lymphocytes; CD40 Ligand; CD8-Positive T-Lymphocytes; Cell Differentiation; Cell Division; Cells, Cultured; Coculture Techniques; Culture Media, Conditioned; Dendritic Cells; Drug Combinations; Epitopes, T-Lymphocyte; Glycoproteins; Herpesvirus 4, Human; HIV Infections; HIV-1; Humans; Immunologic Memory; Immunophenotyping; Interleukin-10; Interleukin-12; Interleukin-15; Leukocytes, Mononuclear; Lymphocyte Depletion; Membrane Glycoproteins; Monocytes; NF-kappa B; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; T-Lymphocytes, Cytotoxic; Tumor Necrosis Factor-alpha

To investigate the possible role of osteoprotegerin (OPG) in bone metabolism in humans by measuring serum levels of OPG in five well-characterized patient populations with known or suspected pathology in bone homeostasis, but with differences in the pathogenesis of these disturbances.. The study comprised 34 patients with Cushing's syndrome (CS), 24 acromegalic patients, 16 patients with growth hormone deficiency (GHD), 29 HIV-infected patients, 25 patients with common variable immunodeficiency (CVI) and 59 age- and sex-matched healthy controls (CTR).. Serum levels of tumor necrosis factor (TNF)-alpha, OPG, C-terminal telopeptides of Type-I collagen (CTX-I) and osteocalcin were determined in all study subjects as well as cortisol (CS and CTR) and IGF-I (acromegaly, GHD and CTR).. OPG levels were significantly elevated in both CVI (median increase approximately 32%, P < 0.05) and HIV-infected patients with especially high levels in the latter group ( approximately 52%, P < 0.001), significantly correlated with increased TNFalpha levels (r = 0.47, P < 0.02). Also CS patients had elevated serum OPG ( approximately 24%, P < 0.01), significantly correlated with increased serum cortisol (r = 0.35, P < 0.05). In contrast, OPG levels in acromegalic and GHD patients were not different from healthy controls. No relationships were found between OPG levels and CTX-I or osteocalcin.. These findings suggest that enhanced OPG levels may be a compensatory response to enhanced osteoclast activity or negative bone remodeling balance in some conditions, but may also be a parameter of enhanced activity in the OPG system possibly correlated to enhanced activity of other members of the TNF family.

Topics: Acromegaly; Adult; Aged; Bone and Bones; Bone Remodeling; Common Variable Immunodeficiency; Cushing Syndrome; Female; Glucocorticoids; Glycoproteins; HIV Infections; Homeostasis; Human Growth Hormone; Humans; Hydrocortisone; Immunologic Deficiency Syndromes; Insulin-Like Growth Factor I; Male; Middle Aged; Osteocalcin; Osteoclasts; Osteoprotegerin; Peptide Fragments; Procollagen; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha