Bone disease and HIV infection

Perinatal HIV infection is associated with deficits in muscle function in children and adolescents in Zimbabwe

OBJECTIVES

To determine how muscle strength, power, mass, and density (i.e. quality) differ between children living with HIV (CWH) and those uninfected, and whether antiretroviral therapy (ART) regime is associated with muscle quality.

DESIGN

A cross-sectional study in Harare, Zimbabwe.

METHODS

The study recruited CWH aged 8-16 years, taking ART for at least 2 years, from HIV clinics, and HIV-uninfected children from local schools. Muscle outcomes comprised grip strength measured by hand-held Jamar dynamometer, lower limb power measured by standing long-jump distance, lean mass measured by dual-energy X-ray absorptiometry, and muscle density (reflecting intramuscular fat) by peripheral quantitative computed tomography. Linear regression calculated adjusted mean differences (aMD) by HIV status.

RESULTS

Overall, 303 CWH and 306 without HIV, had mean (SD) age 12.5 (2.5) years, BMI 17.5 (2.8), with 50% girls. Height and fat mass were lower in CWH, mean differences (SE) 7.4 (1.1) cm and 2.7 (0.4)kgs, respectively. Male CWH had lower grip strength [aMD 2.5 (1.1-3.9) kg, P  < 0.001], long-jump distance [7.1 (1.8-12.5) cm, P  = 0.006], muscle density [0.58 (0.12-1.05) mg/cm 3 , P  = 0.018, but not lean mass 0.06 (-1.08 to 1.21) kg, P  = 0.891) versus boys without HIV; differences were consistent but smaller in girls. Mediation analysis suggested the negative effect of HIV on jumping power in boys was partially mediated by muscle density ( P  = 0.032). CWH taking tenofovir disoproxil fumarate (TDF) had lower muscle density [0.56 (0.00-1.13)mg/cm 3 , P  = 0.049] independent of fat mass, than CWH on other ART.

CONCLUSION

Perinatally acquired HIV is associated, particularly in male individuals, with reduced upper and lower limb muscle function, not mass. Intra-muscular fat (poorer muscle quality) partially explained reductions in lower limb function. TDF is a novel risk factor for impaired muscle quality.

Bone mineral density among virologically suppressed Asians older than 50 years old living with and without HIV: A cross-sectional study

There are limited data regarding bone health in older people living with HIV (PWH), especially those of Asian ethnicity. We aimed to determine whether BMD in well-suppressed HIV-infected men and women aged ≥ 50 years are different from HIV-uninfected controls. In a cross-sectional study, BMD by dual-energy X-ray absorptiometry and calciotropic hormones were measured. A total of 481 participants were consecutively enrolled (209 HIV+ men, 88 HIV- men, 126 HIV+ women and 58 HIV- women). PWH were on average 2.5 years younger [men: 55.0 vs. 57.5 yr; women: 54.0 vs. 58.0 yr] and had lower body mass index (BMI) [men: 23.2 vs. 25.1 kg/m2; women: 23.1 vs. 24.7 kg/m2] compared to the controls. The median duration since HIV diagnosis was 19 (IQR 15-21) years in men and 18 (IQR 15-21) years in women. Three-quarters of PWH had been treated with tenofovir disoproxil fumarate-containing antiretroviral therapy for a median time of 7.4 (IQR 4.5-8.9) years in men and 8.2 (IQR 6.1-10) years in women. In an unadjusted model, HIV+men had significantly lower BMD (g/cm2) at the total hip and femoral neck whereas there was a tend toward lower BMD in HIV+women. After adjusting for age, BMI, and other traditional osteoporotic risk factors, BMD of virologically suppressed older PWH did not differ from participants without HIV (P>0.1). PWH had lower serum 25(OH)D levels but this was not correlated with BMD. In conclusion, BMD in well-suppressed PWH is not different from non-HIV people, therefore, effective control of HIV infection and minimization of other traditional osteoporosis risk factors may help maintain good skeletal health and prevent premature bone loss in Asian PWH. Clinical trial registration: Clinicaltrials.gov # NCT00411983.

Immune Reconstitution Bone Loss Exacerbates Bone Degeneration Due to Natural Aging in a Mouse Model

BACKGROUND

Immune reconstitution bone loss (IRBL) is a common side-effect of antiretroviral therapy (ART) in people living with HIV (PWH). IRBL acts through CD4 + T-cell/immune reconstitution-induced inflammation and is independent of antiviral regimen. IRBL may contribute to the high rate of bone fracture in PWH, a cause of significant morbidity and mortality. Although IRBL is transient, it remains unclear whether bone recovers, or is permanently denuded and further compounds bone loss associated with natural aging.

METHODS

We utilized a validated IRBL mouse model involving T-cell reconstitution of immunocompromised mice. Mice underwent cross-sectional bone phenotyping of femur and/or vertebrae between 6- and 20-months-of-age by micro-computed tomography (µCT) and quantitative bone histomorphometry. CD4 + T-cells were purified at 20 months to quantify osteoclastogenic/inflammatory cytokine expression.

RESULTS

While cortical IRBL in young animals recovered with time, trabecular bone loss was permanent, and exacerbated skeletal decline associated with natural aging. At 20-months-of-age, reconstituted CD4 + T-cells express enhanced osteoclastogenic cytokines including RANKL, IL-1β, IL-17A and TNFα, consistent with elevated osteoclast numbers.

CONCLUSIONS

IRBL in the trabecular compartment is permanent and further exacerbates bone loss due to natural aging. If validated in humans, interventions to limit IRBL may be important to prevent fractures in aging PWH.

Osteonecrosis of the humeral head in a human immunodeficiency virus-infected patient under tenofovir disoproxil fumarate-emtricitabine-lopinavir/ritonavir for 10 years: a case report

Background

Human immunodeficiency virus-infected patients are 100 times more likely to develop aseptic osteonecrosis compared with the general population. While 90% of cases concern the femoral head, the involvement of humeral bone remains rare.

Case presentation

We report a case of aseptic osteonecrosis of the left humeral head complicating antiretroviral therapy in a female, 46-year-old, Bissau-Guinean human immunodeficiency virus-infected patient received in a context of progressive pain in the left shoulder followed by limitation of articular movements. Standard x-ray of the shoulder allowed us to make the diagnosis by showing a typical image of osteonecrosis. The treatment was medical combined with physiotherapy.

Conclusions

Aseptic osteonecrosis should be systematically looked for in human immunodeficiency virus patients on antiretroviral treatment. In addition to femoral head aseptic necrosis, the involvement of the humeral bone should also be considered.

Dental implants in individuals living with HIV-1: Results from a prospective study in patients undergoing highly active antiretroviral therapy

OBJECTIVE

To assess survival and success rates of dental implants and the occurrence of peri-implant diseases (mucositis/peri-implantitis) in HIV-1-infected individuals.

MATERIAL AND METHODS

In this prospective study, 13 HIV-1-infected individuals undergoing highly active antiretroviral therapy (with undetectable plasma HIV RNA levels, and CD4+ T cells > 350/mm³ ) were followed after implant placement, as well as 13 non-HIV-1-infected matched controls. Patients enrolled in this study were followed up to 120 months (mean = 40.6 months; standard deviation = 22.2; range 18 -120 months). Twenty-five implants were placed in pristine healed sites for each group and bone augmentation procedures, when needed, were done only for contour augmentation. Patients were enrolled in a strict periodontal/peri-implant supportive therapy protocol with three recalls per year. The two groups were compared regarding subject-level characteristics (age, gender, smoking, diabetes) and implant-level characteristics (marginal bone level, peri-implant health status).

RESULTS

All the implants healed uneventfully and reached 100% survival rates (after at least 18 months) in both groups. There were no significant differences between groups for peri-implant diseases (mucositis/peri-implantitis) and for all subject-level co-variables (p > .05). Only the variables dental implant prosthesis type (DIPT) (p = .021, d = .86) and follow up (p = .011, d = .77) showed statistically significant differences between groups.

CONCLUSION

The findings suggest that well-controlled HIV-1-infected individuals are eligible to undergo implant therapy, achieving survival and success rates comparable to non-HIV-1-infected controls.

Bone Mineral Density in Antiretroviral Therapy-Naïve HIV-1-Infected Young Adult -Women Using Depot Medroxyprogesterone Acetate or Nonhormonal Contraceptives in Uganda

Most studies evaluating BMD in human immunodeficiency virus (HIV)‐infected populations have focused on antiretroviral therapy (ART)‐experienced patients. In this study, the association between HIV‐1 and/or depot medroxyprogesterone acetate (DMPA) and BMD among untreated HIV‐1–infected women in a resource‐limited setting was assessed before long‐term exposure to ART. The data were then compared with that of the 2005–2008 United States National Health and Nutrition Examination Survey data for non‐Hispanic White and Black women. Women aged 18–35 years, recruited from health facilities in Kampala, Uganda, were classified based on their combination of HIV‐1 status and DMPA use: (i) HIV‐1–infected current DMPA users, (ii) HIV‐1–infected previous DMPA users, (iii) HIV‐1–infected nonhormonal‐contraceptive users, and (iv) HIV‐uninfected nonhormonal‐contraceptive users. All HIV‐1–infected women reported being ART‐naïve at baseline. BMD was measured at the lumbar spine, total hip, and femoral neck using DXA. Multivariate linear regression was used to assess the association between HIV‐1 and/or DMPA and BMD Z‐scores. Baseline data were analyzed for 452 HIV‐1–infected (220 nonhormonal users, and 177 current and 55 previous DMPA users) and 69 HIV‐1–uninfected nonhormonal‐contraceptive users. The mean age was 26.1 years (SD, 4.2) with a median duration of DMPA use among current users of 24.0 months [medians (interquartile range), 12‐48]. A higher proportion of HIV‐1–infected previous (12.7%) or current DMPA users (20.3%) and nonhormonal users (15.0%) had low BMD (Z‐score ≤−2 at any of the three sites) compared with age‐matched HIV‐1–uninfected women (2.9%). HIV‐1 infection and DMPA use were independently associated with significantly lower mean BMD Z‐scores at all sites, with the greatest difference being among HIV‐1–infected current DMPA users (5.6%–8.0%) versus uninfected nonhormonal users. Compared with non‐Hispanic White and Black women, the Ugandan local reference population had generally lower mean BMD at all sites. Newer treatment interventions are needed to mitigate BMD loss in HIV‐1–infected women in resource‐limited settings. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Use of Bisphosphonates, Calcium and Vitamin D for Bone Demineralization in Patients with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome: A Systematic Review and Meta-Analysis of Clinical Trials

Background

The present study performed a systematic review and meta-analysis of clinical trials using bisphosphonates for bone demineralization in human immunodeficiency virus (HIV) patients.

Methods

A comprehensive literature search was performed from January 2004 to January 2020 considering the bone mineral density (BMD) of the lumbar spine (LS) as the main outcome. Out of 214 titles that met criteria, 9 studies fulfilled the selection criteria.

Results

A total of 394 patients were identified, and they were allocated into 2 groups: the intervention group (200 patients), to whom a combination of alendronate or zoledronate with calcium and vitamin D was administered; and control group (194 patients), to whom only calcium and vitamin D was administered. Clinical profile and indicators of bone metabolism of the participants were evaluated regarding effect size, homogeneity, and consistency. No substantial heterogeneity between the groups was found for the baseline variables, and there was high consistency to the main outcome. The meta-analysis shows a significant difference in post-treatment BMD, favoring the intervention over the control treatment. The intervention improved LS density up to 0.227 g/cm², raising the average to the levels of general population. Adverse effects related to intervention were fever immediately after zoledronate administration and gastrointestinal complaints during alendronate usage. Other adverse effects were barely reported and poorly connected to intervention by studies’ authors, despite all of them have been successfully resolved.

Conclusions

This study provides evidence that BMD post-treatment is better in HIV patients who used bisphosphonates combined with calcium and vitamin D.

Bone mineral density changes among people living with HIV who have started with TDF-containing regimen: A five-year prospective study

There are limited data regarding long-term BMD changes over time among treatment-naïve people living with HIV (PLHIV) after initiating combined antiretroviral therapy (cART) in Asia. We aimed to study bone mineral density (BMD) changes among treatment-naïve PLHIV started treatment with tenofovir disoproxil fumarate (TDF)- or non-TDF-containing regimen and HIV-uninfected controls in an Asian setting. The study was a five-year prospective study. BMD at lumbar spine (LS) (L1 to L4), total hip (TH), and femoral neck (FN) were measured by dual energy X-ray absorptiometry (DEXA) scans at baseline, months 12, 24 and 60. Multivariate logistic regression models were used to explore factors associated with mean BMD ≥5% reduction after 5 years of cART. A total of 106 PLHIV (75 and 31 started TDF- and non-TDF-containing regimen, respectively) and 66 HIV-uninfected individuals were enrolled. The mean percent changes of BMD were significantly different longitudinally between TDF and non-TDF users (p<0.001 for LS, p = 0.006 for TH and p = 0.02 for FN). HIV-positive status and on TDF-containing regimen was independently associated with BMD loss ≥5% at month 60 (adjusted odds ratio [aOR] 7.0, 95% confidence interval [95%CI] 2.3–21.0, P = 0.001 for LS; aOR 4.9, 95%CI 1.7–14.3, P = 0.003 for TH and aOR 4.3, 95%CI 1.6–11.2, P = 0.003 for FN) compared to HIV-uninfected individuals. In a multivariate model for PLHIV only, TDF use (vs. non-TDF, P = 0.005) and pre-treatment CD4+ count <350 cells/mm³ (vs. ≥350 cells/mm³, P = 0.02) were independently associated with ≥5% BMD loss in TH at month 60. Treatment-naïve PLHIV initiating treatment with TDF-containing regimen have higher BMD loss in a Thai cohort. TDF use and low pre-treatment CD4 count were independently associated with BMD loss at month 60 at TH. Earlier treatment initiation and interventions to prevent bone loss could improve skeletal health among PLHIV.

Clinicaltrials.gov: NCT01634607

Antiretroviral-naïve HIV-infected patients had lower bone formation markers than HIV-uninfected adults

There are limited studies regarding bone health among people living with HIV (PLHIV) in Asia. We compared bone mineral density (BMD), serum 25-hydroxyvitamin D (25(OH)D) status and bone turnover markers (serum procollagen type1 N-terminal propeptide (P1NP), osteocalcin (OC) and C-terminal cross-linking telopeptide of type1 collagen) among 302 antiretroviral therapy (ART) naive PLHIV compared to 269 HIV-uninfected controls from Thailand. People aged ≥30 years, with and without HIV infection (free of diabetes, hypertension, and active opportunistic infection) were enrolled. BMD at the lumbar spine, total hip, and femoral neck were measured using Hologic DXA at baseline and at 5 years. We analyzed BMD, serum 25(OH)D levels, and bone turnover markers at the patients' baseline visit. PLHIV were 1.5 years younger and had lower BMI. PLHIV had higher mean serum 25(OH)D level and similar BMD to the controls. Interestingly, PLHIV had significantly lower bone formation (serum P1NP and OC), particularly those with low CD4 count. Only a few participants had low bone mass. ARV naïve middle-aged PLHIV did not have lower BMD or lower vitamin D levels compared to the controls. However, PLHIV had lower bone formation markers, particularly those with low CD4 count. This finding supports the benefit of early ART.

Bone mass preservation with high-dose cholecalciferol and dietary calcium in HIV patients following antiretroviral therapy. Is it possible?

OBJECTIVE

To evaluate whether treatment with 100,000 IU/month (equivalent to 3200 IU/day) of cholecalciferol and 1 g/day of dietary calcium supplementation in HIV patients following different cART regimens yields normal levels of vitamin D3 and PTH as well as whether changes in bone mineral density are clinically significant.

METHODS

Consecutive HIV patients following different cART regimens received 100,000 IU/month (equivalent to 3200 IU/day) of cholecalciferol and 1 g/day of dietary calcium supplementation. The participants underwent BMD assessment via dual energy X-ray absorptiometry of the spine and hip at baseline (T0) and after 24 months (T1). Levels of 25(OH) vitamin D3 and parathyroid hormone (PTH) were assessed at T0 and T1. Quantitative variables were assessed with a paired t-test, independent t-test or analysis of variance, as appropriate. A chi-squared analysis was used to assess the association between qualitative variables. A p-value <0.05 was considered significant. Patients were divided into three groups depending on the cART regimen.

RESULTS

A total of 79 patients were included (40 males, 51% and 39 females, 49%), with a mean age of 46.6 (SD ±11.2) years, a baseline CD4 count of 649 cells/µl and a mean 25 hydroxycholecalciferol (25(OH) D3) value of 25 + 10 ng/ml. After 24 months, the 25(OH) D3 increased to 40 + 11 ng/ml. The initial BMDs at T0 were estimated as 0.919 (±0.27) and 0.867 (±0.14) g/cm² at the spine and hip, respectively. After 24 months, the BMD was 0.933 (±0.15) g/cm² at the spine and 0.857 (±0.14) g/cm² at the hip. Based on a BMD change exceeding 3%, a worsening was observed in 23% of patients at the spine and 27% at the hip, whereas stability or improvement was demonstrated in 77% of patients at the spine and 73% at the hip. Subgrouping patients based on antiretroviral therapy indicated that, at T1, there was a statistically significant increase in vitamin D3 concentration in all patients, while PTH concentration was not significantly reduced in patients taking tenofovir or efavirenz. BMD stability or improvement was demonstrated in 77% of patients at the spine and 73% at the hip after 24 months. The multivariate analysis confirms a decrease in vitamin D3 and an increase in PTH levels in smokers, as well higher vitamin D3 concentrations in males and lower spine BMDs in menopausal females.

CONCLUSION

The proposed protocol of cholecalciferol and dietary calcium supplementation is safe and valid for correcting vitamin D abnormalities in almost all patients as well as reducing PTH levels in a high percentage of patients; however, it is not sufficient for normalization, particularly in patients exposed to tenofovir or efavirenz. At the spine, no significant BMD change was found in any of the therapy groups. At the hip, our data confirm a modest negative effect on bone mass caused by tenofovir and efavirenz.

Distinct biomarker signatures in HIV acute infection associate with viral dynamics and reservoir size

Estimating the size of the viral reservoir is critical for HIV cure strategies. Biomarkers in peripheral circulation may give insights into the establishment of the viral reservoir in compartments not easily accessible. We therefore measured systemic levels of 84 soluble biomarkers belonging to a broad array of immune pathways in acute HIV infection in both antiretroviral therapy-naive (ART-naive) individuals as well as individuals who began ART upon early detection of HIV infection. These biomarkers were measured longitudinally during acute and chronic infection and their relationship to viral reservoir establishment and persistence was assessed. We observed several distinct biomarker pathways induced following HIV infection such as IFN-γ-signaled chemokines, proinflammatory markers, and TNF-α-family members. Levels of several of these factors directly correlated with contemporaneous viral loads and/or frequency of peripheral blood mononuclear cells harboring HIV DNA during acute HIV infection. MCP-1, MIP-3β, sTNFR-II, and IL-10 levels prior to ART associated with HIV DNA levels after 96 weeks of treatment, suggesting a link between early immune signaling events and the establishment and persistence of the viral reservoir during ART. Furthermore, they offer potentially novel tools for gaining insight into relative reservoir size in acutely infected individuals and the potential of associated risks of treatment interruption.

Bone mineral density and vitamin D concentration: the challenges in taking care of children and adolescents infected with HIV

BACKGROUND

The increase in life expectancy for patients living with human immunodeficiency virus (HIV) infection has resulted in health complications related to a chronic disease.

OBJECTIVES

To evaluate the prevalence of bone mineral density (BMD) alterations and vitamin D concentrations in HIV-infected children and adolescents and to verify the variations in those parameters during a 12-month interval.

METHODS

A prospective cohort study with a dual period of evaluation was conducted in 57 patients perinatally HIV-infected and one patient with sexual abuse in early infancy. Demographic, anthropometric, pubertal stage, viral load, T CD4+ cell count and antiretroviral therapy were evaluated. Biochemical tests and total body (TB) and lumbar spine (L1-L4) bone density evaluations by dual X-ray absorptiometry (DXA) were performed. Calcium or vitamin D supplements were prescribed if reduction in BMD or deficiency for vitamin D was detected.

RESULTS

58 patients (ages 5.4-18.3 years; 60.3% girls) were included (T0); 55 patients were reevaluated after 12 (±3) months (T1). Low bone mass for chronological age was found in 6/58 (10.4%) and 6/55(10.9%) patients at T0 and at T1, respectively. There was no statistical relationship between z-scores for BMD (BMD z-score) and the variables sex, fracture history, family history of osteoporosis, physical activity and pubertal stage. There was a relation between BMD z-score alterations for TB and HIV viral load at T1 (p=0.016). There was no association between duration or classes of antiretroviral therapy and bone density. The mean value of vitamin D in T0 was 23.43ng/mL±2.015 and in T1 22.1ng/mL±0.707 and considered insufficient levels for this population.

CONCLUSION

Patients infected with HIV are at risk for BMD alterations and lower vitamin D serum concentrations; both of these variables should be evaluated at routine examinations in order to improve both prevention and therapeutic planning.

Attitude of Health Care Workers (HCWs) toward Patients Affected by HIV/AIDS and Drug Users: A Cross-Sectional Study

Caring for HIV/AIDS patients and/or drug users requires health care workers (HCWs) to have good knowledge of the issues. Cultural differences in HCWs, combined with professional ethics and personal beliefs, could also result in conflicting attitudes, leading to difficulties related to looking after people affected by HIV/AIDS or drug users. A cross-sectional study was carried out to assess the attitude towards HIV/AIDS patients and/or drug users in a sample of workers operating in a large university hospital in southern Italy. A total of 736 workers were surveyed from May to November 2016. During the periodic occupational health surveillance, a questionnaire was administered about attitudes of discrimination, acceptance and fear towards these patients. Respondents showed average levels of acceptance to HIV/AIDS and drug user patients. As years of experience and professional training increased, scores for discrimination, acceptance of HIV/AIDS, acceptance of drug users and fear decreased. Factors positively influencing levels of attitudes were being female and younger. Supplementary education is needed to strengthen the awareness of HCWs.

Dental implants and bone augmentation in HIV-infected patients under HAART: Case report and review of the literature

The present study reviewed the literature regarding dental implants in HIV-infected patients and reports the long-term follow-up of three clinical cases of patients under HAART that received bone augmentation and dental implants. The first case presents a young patient with a large defect in the mandible, as a consequence of a longitudinal fracture, that was treated with guided bone regeneration (GBR) previously to implant placement. The second case reported is middle-aged man with a fractured upper lateral incisor treated with immediate placement and simultaneous GBR to repair the dehiscence due to the buccal bone resorption. The third case shows an elderly patient that underwent sinus lifting with the simultaneous placement of two implants. All cases were treated after patients were medically controlled and followed for at least 10 years. Controlled HIV-infected patients undergoing HAART may be candidates to implant rehabilitation, as long as their plasmatic HIV viral load and CD4+ T lymphocytes count are within the parameters that indicate immune stability. Long-term stability of soft and hard tissues can be obtained maintaining function and esthetics. However, stronger evidence, based on prospective, controlled clinical trials is needed to provide the dental and medical teams with conclusive data.

HIV infection and bone disease

The success of antiretroviral therapy in treating HIV infection has greatly prolonged life expectancy in affected individuals, transforming the disease into a chronic condition. A number of HIV-associated non-AIDS comorbidities have emerged in the ageing HIV-infected population, including osteoporosis and increased risk of fracture. The pathogenesis of fracture is multifactorial with contributions from both traditional and HIV-specific risk factors. Significant bone loss occurs on initiation of antiretroviral therapy but stabilizes on long-term therapy. Fracture risk assessment should be performed in HIV-infected individuals and bone mineral density measured when indicated. Lifestyle measures to optimize bone health should be advised and, in individuals at high risk of fracture, treatment with bisphosphonates considered.

Physiological and pathophysiological bone turnover - role of the immune system

Osteoporosis develops when the rate of osteoclastic bone breakdown (resorption) exceeds that of osteoblastic bone formation, which leads to loss of BMD and deterioration of bone structure and strength. Osteoporosis increases the risk of fragility fractures, a cause of substantial morbidity and mortality, especially in elderly patients. This imbalance between bone formation and bone resorption is brought about by natural ageing processes, but is frequently exacerbated by a number of pathological conditions. Of importance to the aetiology of osteoporosis are findings over the past two decades attesting to a deep integration of the skeletal system with the immune system (the immuno-skeletal interface (ISI)). Although protective of the skeleton under physiological conditions, the ISI might contribute to bone destruction in a growing number of pathophysiological states. Although numerous research groups have investigated how the immune system affects basal and pathological osteoclastic bone resorption, recent findings suggest that the reach of the adaptive immune response extends to the regulation of osteoblastic bone formation. This Review examines the evolution of the field of osteoimmunology and how advances in our understanding of the ISI might lead to novel approaches to prevent and treat bone loss, and avert fractures.

A Single-dose Zoledronic Acid Infusion Prevents Antiretroviral Therapy-induced Bone Loss in Treatment-naive HIV-infected Patients: A Phase IIb Trial

BACKGROUND

Human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are associated with bone loss leading to increased fracture rate among HIV-infected individuals. ART-induced bone loss is most intense within the first 48 weeks of therapy, providing a window for prophylaxis with long-acting antiresorptives.

METHODS

In a phase 2, double-blind, placebo-controlled trial, we randomized 63 nonosteoporotic, ART-naive adults with HIV initiating ART with atazanavir/ritonavir + tenofovir/emtricitabine to a single zoledronic acid (ZOL) infusion (5 mg) vs placebo to determine the efficacy of ZOL in mitigating ART-induced bone loss. Plasma bone turnover markers and bone mineral density (BMD) were performed at weeks 0, 12, 24, and 48 weeks. Primary outcome was change in C-terminal telopeptide of collagen at 24 weeks. Repeated-measures analyses using mixed linear models were used to estimate and compare study endpoints.

RESULTS

The ZOL arm had a 65% reduction in bone resorption relative to the placebo arm at 24 weeks (0.117 ng/mL vs 0.338 ng/mL; P < .001). This effect of ZOL occurred as early as 12 weeks (73% reduction; P < .001) and persisted through week 48 (57% reduction; P < .001). The ZOL arm had an 8% higher lumbar spine BMD at 12 weeks relative to the placebo arm (P = .003), and remained 11% higher at 24 and 48 weeks. Similar trends were observed in the hip and femoral neck.

CONCLUSIONS

A single dose of ZOL administered at ART initiation prevented ART-induced bone loss through the first 48 weeks of ART, the period when ART-induced bone loss is most pronounced. Validation of these results in larger multicenter randomized clinical trials is warranted.

CLINICAL TRIALS REGISTRATION

NCT01228318.

Long-term outcomes of oral rehabilitation with dental implants in HIV-positive patients: A retrospective case series

Background

The existing information on oral rehabilitations with dental implants in VIH-positive patients is scarce and of poor quality. Moreover, no long-term follow-up studies are available. Hence, the aims of this study were to describe the long-term survival and success rates of dental implants in a group of HIV-positive patients and to identify the most common postoperative complications, including peri-implant diseases.

Material and Methods

A retrospective case series of HIV-positive subjects treated with dental implants at the School of Dentistry of the University of Barcelona (Spain) was studied. Several clinical parameters were registered, including CD4 cell count, viral load and surgical complications. Additionally, the patients were assessed for implant survival and success rates and for the prevalence of peri-implant diseases. A descriptive statistical analysis of the data was performed.

Results

Nine participants (57 implants) were included. The patients’ median age was 42 years (IQR=13.5 years). The implant survival and success rates were 98.3% and 68.4%, respectively, with a mean follow-up of 77.5 months (SD=16.1 months). The patient-based prevalence of peri-implant mucositis and peri-implantitis were 22.2% and 44.4% respectively at the last appointment. Patients that attended regular periodontal maintenance visits had significantly less mean bone loss than non-compliant patients (1.3 mm and 3.9 mm respectively).

Conclusions

Oral rehabilitation with dental implants in HIV-positive patients seems to provide satisfactory results. In order to reduce the considerably high prevalence of peri-implant diseases, strict maintenance programmes must be implemented.

Key words:HIV infection, dental implants, oral implantology, complications, peri-implantitis, peri-implant diseases.

Bone health and HIV in resource-limited settings: a scoping review

PURPOSE OF REVIEW

Sub-Saharan Africa and other resource-limited settings (RLS) bear the greatest burden of the HIV epidemic globally. Advantageously, the expanding access to antiretroviral therapy (ART) has resulted in increased survival of HIV individuals in the last 2 decades. Data from resource rich settings provide evidence of increased risk of comorbid conditions such as osteoporosis and fragility fractures among HIV-infected populations. We provide the first review of published and presented data synthesizing the current state of knowledge on bone health and HIV in RLS.

RECENT FINDINGS

With few exceptions, we found a high prevalence of low bone mineral density (BMD) and hypovitaminosis D among HIV-infected populations in both RLS and resource rich settings. Although most recognized risk factors for bone loss are similar across settings, in certain RLS there is a high prevalence of both non-HIV-specific risk factors and HIV-specific risk factors, including advanced HIV disease and widespread use of ART, including tenofovir disoproxil fumarate, a non-BMD sparing ART. Of great concern, we neither found published data on the effect of tenofovir disoproxil fumarate initiation on BMD, nor any data on incidence and prevalence of fractures among HIV-infected populations in RLS.

SUMMARY

To date, the prevalence and squeal of metabolic bone diseases in RLS are poorly described. This review highlights important gaps in our knowledge about HIV-associated bone health comorbidities in RLS. This creates an urgent need for targeted research that can inform HIV care and management guidelines in RLS.

The global burden of oral diseases in pediatric HIV-infected populations: a workshop report

OBJECTIVES

To achieve a comprehensive understanding about the global burden of oral diseases in HIV-infected children and to identify research needs.

MATERIALS AND METHODS

A literature search was conducted in PubMed (2009-2014) to address five questions: (i) prevalence of oral diseases in HIV-infected compared with uninfected children, (ii) impact of oral diseases on quality of life, (iii) effect of antiretroviral exposure in utero on craniofacial and dental development, (iv) important co-infections and antiretroviral complications, and (v) value of atraumatic restorative treatment.

RESULTS

Studies showed a high prevalence of dental caries in HIV-infected children but the relationship between HIV infection and dental caries remains unclear. Also quality of life needs further investigation supported by better study designs and improvement of the instruments used. Up-to-date evidence suggested long-term harms associated with in utero antiretroviral exposure were minor but would require long-term follow-up through National Registries. The reviews also revealed the wide spectrum of metabolic disease due to antiretroviral therapy and co-infections such as tuberculosis. Finally, atraumatic restorative technique appears to be a simple and safe technique to treat dental caries but outcomes need further evaluation.

CONCLUSIONS

The impact of antiretroviral therapy in HIV-infected children has raised novel challenging questions in the field of oral health warranting future research.

AVASCULAR NECROSIS OF THE FEMORAL HEAD IN HIV-INFECTED PATIENTS: PRELIMINARY RESULTS FROM SURGICAL TREATMENT FOR CERAMIC-CERAMIC JOINT REPLACEMENT

Objectives: To evaluate the initial functional results and early complication rate of ceramic-ceramic total hip replacements among patients living with HIV who presented osteonecrosis of the femoral head. Method: Twelve HIV–positive patients with a diagnosis of osteonecrosis of the incongruent femoral head were evaluated using clinical and laboratory criteria and the WOMAC functional scale before and after treatment with joint replacement. Results: We observed that 83.3% of the subjects were taking protease inhibitors, 75% had dyslipidemia and 66.6% had lipodystrophy syndrome. The improvement over the evolution of the WOMAC score was statistically significant at six and twelve months after the operation, in comparison with the preoperative score. We did not observe complications secondary to this procedure. Conclusion: Total hip arthroplasty with a ceramic-ceramic implant for treating avascular necrosis of the hip is an appropriate surgical option for this portion of the population. It provides a significant initial functional improvement and a low early complication rate.

Barriers to access to care reported by women living with HIV across 27 countries

Increased access to successful antiretroviral therapy (ART) is necessary in order to achieve an AIDS-free generation. Importantly, slightly over half of the people living with HIV are women. Small studies have described many barriers to accessing treatment and care among women living with HIV. This cross-sectional, non-interventional, epidemiological study assessed the prevalence of barriers to accessing care for women living with HIV across 27 countries, divided into four global regions. HIV-positive women attending routine clinical visits were offered the opportunity to participate in the study. Data describing the study sites and demographic characteristics of the participating women were collected. Participating women filled out questionnaires including the Barriers to Care Scale (BACS) questionnaire, on which they reported the extent to which they found each of the 12 potential barriers to accessing health care problematic. A total of 1931 women living with HIV were included in the study: 760 from Western Europe and Canada (WEC), 532 from Central and Eastern Europe (CEE), 519 from Latin America (LA), and 120 from China. The mean age of participating women was 40.1 ± 11.4 years. A total of 88.2% were currently taking ART. A total of 81.8% obtained HIV treatment under a government health plan. The most prevalent barrier to care was community HIV/AIDS stigma. Community HIV/AIDS knowledge, lack of supportive/understanding work environments, lack of employment opportunities, and personal financial resources were also highly prevalent barriers to accessing care. These findings indicate that, more than 30 years after the start of the AIDS epidemic, stigma is still a major issue for women living with HIV. Continued efforts are needed to improve community education on HIV/AIDS in order to maximize access to health care among women living with HIV.

Prevalence and predictors of low bone mineral density and fragility fractures among HIV-infected patients at one Italian center after universal DXA screening: sensitivity and specificity of current guidelines on bone mineral density management

Low bone mineral density (BMD) is frequent in HIV infection regardless of the use of antiretroviral therapy (ART). Uncertainties remain, however, as to when in HIV infection BMD screening should be performed. We designed a prospective study to estimate the efficacy of universal BMD screening by dual-energy X-ray absorptiometry (DXA). Since April 2009 through March 2011, HIV patients attending our Center were offered femoral/lumbar DXA to screen BMD. Low BMD for chronological age, that is significant osteopenia, was defined as a Z-score ≤ -2.0 at femur and lumbar spine. Nontraumatic bone fractures (NTBFs) were evaluated. The final sample included 163 patients. A Z-score ≤ -2.0 at any site was observed in 19.6% of cases: among these, 18.8% had no indication to DXA using current Italian HIV guidelines for BMD screening. A lower femoral Z-score was independently associated with lower BMI, AIDS diagnosis, HCV co-infection, antiretroviral treatment, and NTBFs; a lower lumbar Z-score with age, BMI, Nadir CD4 T-cell counts, and NTBFs. Prevalence of NTBFs was 27.0%, predictors being male gender, HCV co-infection, and lower femoral Z-scores. Our results suggest that measuring BMD by DXA in all HIV patients regardless of any further specification may help retrieving one-fifth of patients with early BMD disorders not identified using current criteria for selective screening of BMD.

Structural Bone Deficits in HIV/HCV-Coinfected, HCV-Monoinfected, and HIV-Monoinfected Women

BACKGROUND

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) is associated with reduced bone mineral density (BMD) and increased fracture rates, particularly in women. The structural underpinnings for skeletal fragility in coinfected women have not been characterized. We used tibial peripheral quantitative computed tomography to evaluate skeletal parameters in women, by HIV/HCV status.

METHODS

We conducted a cross-sectional study among 50 HIV/HCV-coinfected, 51 HCV-monoinfected, and 50 HIV-monoinfected women. Tibial volumetric BMD and cortical dimensions were determined with peripheral quantitative computed tomography. Race-specific z scores for age were generated using 263 female reference participants without HIV infection or liver disease.

RESULTS

Coinfected participants had lower mean z scores for trabecular volumetric BMD (-0.85), cortical volumetric BMD (-0.67), cortical area (-0.61), and cortical thickness (-0.77) than reference participants (all P < .001). The smaller cortical dimensions were due to greater mean z scores for endosteal circumference (+0.67; P < .001) and comparable z scores for periosteal circumference (+0.04; P = .87). Trabecular volumetric BMD was lower in coinfected than in HCV- or HIV-monoinfected participants. HCV-infected women with stage 3-4 liver fibrosis had lower mean z scores for trabecular volumetric BMD, cortical thickness, and total hip BMD those with stage 0-2 fibrosis.

CONCLUSIONS

Compared with healthy reference patients, HIV/HCV-coinfected women had decreased tibial trabecular volumetric BMD, diminished cortical dimensions, and significant endocortical bone loss.

Changes in bone mineral density after 96 weeks of treatment with atazanavir/ritonavir or lopinavir/ritonavir plus tenofovir DF/emtricitabine in treatment-naive patients with HIV-1 infection: the CASTLE body composition substudy

: Antiretroviral therapy initiation is associated with declines in bone mineral density (BMD), which seem greatest with tenofovir disoproxil fumarate (DF)-containing regimens. Data comparing protease inhibitors are limited. This CASTLE substudy compared paired baseline with week 96 BMD in patients initiating tenofovir DF/emtricitabine plus atazanavir/ritonavir (n = 106) vs lopinavir/ritonavir (n = 70). In both groups, week 96 BMD declined significantly in arm, leg, trunk, and total body regions. Atazanavir/ritonavir was associated with smaller 96-week trunk and total body BMD declines compared with lopinavir/ritonavir [multivariate-adjusted least squares mean difference +2.00% (95% confidence interval: 0.52 to 3.45; P = 0.008) and +1.24% (95% confidence interval: 0.13 to 2.35; P = 0.029), respectively]. In addition, low baseline CD4 cell count (<50 cells per microliter) and increasing age were associated with larger declines in BMD.

HIV infection and osteoporosis

In the past two decades, the life expectancy of people living with HIV infection has increased significantly, and osteoporosis has emerged as a significant comorbidity. In addition to traditional risk factors for fracture, specific factors related to HIV infection are also likely to contribute, including antiretroviral therapy. The heterogeneity of the HIV-infected population in terms of age and ethnicity presents many challenges to the prevention and management of bone disease, and further studies are required to establish optimal approaches to risk assessment and treatment.

Skeletal health in adults with HIV infection

Concern has been raised that HIV infection, its treatment, or both adversely affect skeletal health. Cross-sectional studies show that bone mineral density (BMD) is 3-5% lower in patients infected with HIV than in uninfected controls, but patients with HIV infection are, on average, 5 kg lighter than uninfected people. After this weight difference is accounted for, BMD differences are smaller and not clinically relevant. Longitudinal studies show short-term BMD loss of 2-4% over 1-2 years when antiretroviral therapy is started, followed by longer periods of BMD increase or stability. Losses are greatest with treatment regimens that contain tenofovir. Patients infected with HIV have slightly higher fracture rates than controls, but the increased risk of fracture is substantially attenuated by adjustment for traditional risk factors for fracture. These reassuring findings suggest that management of skeletal health in HIV should follow guidelines for the general population. In general, effective antiretroviral treatment and avoidance of undernutrition are the two most important factors for maintenance of skeletal health in patients infected with HIV.

Secondary osteoporosis: pathophysiology & diagnosis

Osteoporosis is a skeletal disease characterized by decreased bone mass and microarchitectural changes in bone tissue that increase the susceptibility to fracture. Secondary osteoporosis is loosely defined as low bone mineral density or increased risk of fragility fracture caused by any factor other than aging or postmenopausal status. The purpose of this review is to discuss the current understanding of the pathophysiology and contribution to fracture risk of many of the more common causes of secondary osteoporosis, as well as diagnostic considerations, outlined by organ system. While not comprehensive, included are a wide array of diseases, conditions, and medications that have been associated with bone loss and susceptibility to fractures. The hope is to highlight the importance to the general clinician of screening for and treating the osteoporosis in these patients, so to limit the resultant increased morbidity associated with fractures.

Osteoporosis and fracture risk associated with HIV infection and treatment

Osteoporosis has emerged as an important co-morbidity of HIV infection and a modest increase in fracture risk has been documented. Bone loss from the spine and hip occurs after initiation of antiretroviral therapy but most data indicate that bone mineral density is stable in HIV-infected individuals established on long-term antiretroviral therapy. Assessment of fracture probability should be performed in individuals who have clinical risk factors for fracture. Adequate dietary calcium intake and vitamin D status should be ensured and in individuals with a high fracture probability, bisphosphonate therapy may be appropriate.

Complications related to fracture treatment in HIV patients: a case report

We present the case report of a 40-year-old woman who was HIV-positive in Highly Active Anti-Retroviral Therapy (HAART) and affected by femural pertrochanteric fracture, which was treated by endomedullary nailing. Two years after the surgical operation, the woman developed an aseptic symptomatic osteolysis around the implant. Hardware removal was resolutive. Aseptic and septic hardware mobilization, hardware removal, and implant decision in HIV patients with pertrochanteric fractures is discussed. The authors suggest close follow-up and prompt hardware removal, as soon as X-rays demonstrate healing signs, in HIV patients with fracture fixation, if general condition allows.

Different strategies of 25OH vitamin D supplementation in HIV-positive subjects

Summary A high incidence of 25OH vitamin D deficiency has been observed in HIV-infected subjects. The objective of this study was to evaluate the effect of cholecalciferol administration on serum 25OH vitamin D levels in HIV-infected patients. This prospective cohort study included 153 HIV-positive subjects; 47 were treated with 300,000 IU intramuscular cholecalciferol, 67 with 25,000 IU oral cholecalciferol monthly, while the remaining 39 did not receive any treatment. The group treated orally had an increase of serum 25OH vitamin D concentration, changing from 15.7 ± 12.2 ng/mL to 27.4 ± 11.6 ng/mL after 10 months (T10). The group treated with intramuscular supplementation had an improvement, changing from 18.5 ± 10.5 ng/mL to 32.9.0 ± 12.2 ng/mL at T10. One-way repeated measures analysis of variance indicated a significant difference for 25OH vitamin D variation (p = 0.002) among the three groups. A significant effect of time (p < 0.001) and group × time interaction (p < 0.001) was found: at T10, 25OH vitamin D values were significantly higher in the oral and intramuscular groups with respect to the control group. Our findings showed that the supplementation with cholecalciferol in patients with HIV-infection improved 25OH vitamin D serum levels, and suggest that the two types of administration are equivalent, but are insufficient for severe forms of hypovitaminosis.

Acceptability of bone antiresorptive therapy among HIV-infected adults at different stages of antiretroviral therapy

PURPOSE

Both HIV infection and antiretroviral therapy (ART) are associated with significant decreases in bone mineral density (BMD) and increased fracture rates. To prepare for a randomized controlled trial of prophylactic bone antiresorptive therapy during ART initiation, we assessed the acceptability of this strategy, bone health knowledge, and fracture risk among HIV-infected adults.

METHODS

HIV-infected adults with no history of osteoporosis were recruited from one tertiary and one primary care HIV clinic. Participants completed a questionnaire and underwent chart review. The primary outcome was the proportion of respondents expressing interest in taking prophylactic bone antiresorptive therapy in conjunction with ART.

RESULTS

Of 112 respondents, 25.0% were ART naïve, 23.2% had been taking ART for ≤1 year, and 51.8% had been taking ART for >1 year. Half (51.9%) indicated interest in taking short-course prophylactic bone antiresorptive therapy; this did not differ by ART status (53.6% among ART-naïve, 51.3% among ART-treated; P=0.84, chi-square test). In exploratory multivariable analysis adjusted for ART status, a greater number of pills taken per day was positively associated with this outcome (adjusted odds ratio [OR] =1.12 per pill, 95% confidence limit [CL] =1.01, 1.25), while male sex was inversely associated (adjusted OR =0.05, 95% CL =0.01, 0.24). Among those willing to take therapy, most (80.4%) were willing to do so for "as long as needed" and preferred weekly dosing (70.9%) to daily dosing (12.7%).

CONCLUSIONS

Half of this sample would be willing to take bone antiresorptive therapy together with ART, with preferences for weekly dosing and for whatever duration may be required. These data will inform the design of future trials to protect bone health in HIV.

Association of Blood Biomarkers of Bone Turnover in HIV-1 Infected Individuals Receiving Anti-Retroviral Therapy (ART)

OBJECTIVE

To evaluate the association of bone turnover biomarkers with blood levels of alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BAP), osteocalcin (OC), tartrate-resistant acid phosphatase (TRAP), parathyroid hormone (PTH), and other blood markers in HIV-1 infected men receiving anti-retroviral therapy (ART). Advances in the treatment of HIV-1 infection have extended the life span of HIV-1 infected individuals. However, these advances may come at the price of metabolic side effects and bone disorders, including premature osteopenia, osteoporosis and osteonecrosis.

METHODS

Analyses of Ostase BAP, osteocalcin, and TRAP in blood were measured in three groups of MACS participants: 35 HIV-1 infected men on ART (A); 35 HIV-1- infected men not on ART (B); and 34 HIV-1 uninfected men (C).

RESULTS

The mean and standard deviation results for groups A, B, and C were 19.7 ± 6.56, 17.2 ± 3.96, and 16.9 ± 5.78 for ostase BAP; 7.9 ± 9.53, 8.5 ± 8.30, and 5.5 ± 1.65 for osteocalcin; and 3.9 ± 1.04, 3.1 ± 0.81, and 2.5 ± 0.59 for TRAP, respectively. Simple and multivariate analyses showed significant differences in mean TRAP and BAP concentrations between the three groups. In addition strong correlations between blood levels of Ostase BAP and TRAP (r=0.570, p=0.0004), and between blood levels of Ostase BAP and PTH (r=0.436, P=0.0098) for HIV-1 infected men on ART were observed.

CONCLUSION

New strategies for measurement of blood and urine biochemical markers of bone formation and resorption during bone turnover can be useful for clinical monitoring of treatment of HIV-1 infected patients. Recently developed methods for measuring serum levels of TRAP and Ostase BAP represent superior laboratory tools for assessing the hyperactivity of osteoclasts, osteoblasts and bone loss in HIV-1 infected individuals receiving ART. Measurements of TRAP and BAP as bone turnover biomarkers are economical and are important for monitoring bone metabolism during ART and the need for osteoporosis treatment.

When to start antiretroviral therapy: as soon as possible

BACKGROUND

The debate regarding 'When to Start' antiretroviral therapy has raged since the introduction of zidovudine in 1987. Based on the entry criteria for the original Burroughs Wellcome 002 study, the field has been anchored to CD4 cell counts as the prime metric to indicate treatment initiation for asymptomatic individuals infected with Human Immunodeficiency Virus. The pendulum has swung back and forth based mostly on the relative efficacy, toxicity and convenience of available regimens.

DISCUSSION

In today's world, several factors have converged that compel us to initiate therapy as soon as possible: 1) The biology of viral replication (1 to 10 billion viruses per day) strongly suggests that we should be starting early. 2) Resultant inflammation from unchecked replication is associated with earlier onset of multiple co-morbid conditions. 3) The medications available today are more efficacious and less toxic than years past. 4) Clinical trials have demonstrated benefits for all but the highest CD4 strata (>500 cells/μl). 5) Some cohort studies have demonstrated the clear benefit of antiretroviral therapy at any CD4 count and no cohort studies have demonstrated that early therapy is more detrimental than late therapy at the population level. 6) In addition to the demonstrated and inferred benefits to the individual patient, we now have evidence of a Public Health benefit from earlier intervention: treatment is prevention.

SUMMARY

From a practical, common sense perspective we are talking about life-long therapy. Whether we start at a CD4 count of 732 cells/μl or 493 cells/μl, the patient will be on therapy for over 40 to 50 years. There does not seem to be much benefit in waiting and there likely is significant long-term harm. Do not wait. Treat early.

Bone and vitamin D metabolism in HIV

Human immunodeficiency virus (HIV) infection has progressed to a chronic disease and HIV positive individuals are living longer lives. This has lead to an increase in morbidity and mortality due to secondary issues, one being HIV bone disease. HIV infected pediatric and adult populations have a greater incidence in reduction of BMD as compared to the controls. Osteoporosis has been reported to be present in up to 15 % of HIV positive patients. We are starting to understand the mechanism behind the changes in HIV bone disease. Viral proteins interfere with osteoblastic activity either by direct interaction or by the inflammatory process that they induce. Anti-viral management, including highly active antiretroviral therapy (HAART), protease inhibitors, and nucleoside/nucleotide reverse transcriptase inhibitors (NRTI) also are involved in disrupting proper bone metabolism. Vitamin D levels have strong correlation with bone disease in HIV patients, and are dependent not only to chronic disease state, but interaction of pharmacologic management and inflammatory process as well. Work up of the secondary causes of osteopenia and osteoporosis should be undertaken in all patients. DEXA scan is recommended in all post-menopausal women with HIV, all HIV infected men 50 years of age or older and in those with a history of fragility fractures regardless of age or gender. Preventive measures include adequate nutrition, calcium and Vitamin D intake daily, muscle strengthening and balance exercises to increase BMD and reduce fractures. Bisphosphonates are considered to be the first line for the treatment of HIV associated bone disease. This review will describe how the balanced mechanism of bone metabolism is interrupted by the HIV infection itself, the complications that arise from HIV/AIDS, and its treatment options.

The Role of Inflammatory Cytokines, the RANKL/OPG Axis, and the Immunoskeletal Interface in Physiological Bone Turnover and Osteoporosis

Although it has long been recognized that inflammation, a consequence of immune-driven processes, significantly impacts bone turnover, the degree of centralization of skeletal and immune functions has begun to be dissected only recently. It is now recognized that formation of osteoclasts, the bone resorbing cells of the body, is centered on the key osteoclastogenic cytokine, receptor activator of NF- κ B ligand (RANKL). Although numerous inflammatory cytokines are now recognized to promote osteoclast formation and skeletal degradation, with just a few exceptions, RANKL is now considered to be the final downstream effector cytokine that drives osteoclastogenesis and regulates osteoclastic bone resorption. The biological activity of RANKL is moderated by its physiological decoy receptor, osteoprotegerin (OPG). New discoveries concerning the sources and regulation of RANKL and OPG in physiological bone turnover as well as under pathological (osteoporotic) conditions continue to be made, opening a window to the complex regulatory processes that control skeletal integrity and the depth of integration of the skeleton within the immune response. This paper will examine the interconnection between bone turnover and the immune system and the implications thereof for physiological and pathological bone turnover.

HIV and Bone Disease: A Perspective of the Role of microRNAs in Bone Biology upon HIV Infection

Increased life expectancy and the need for long-term antiretroviral therapy have brought new challenges to the clinical management of HIV-infected individuals. The prevalence of osteoporosis and fractures is increased in HIV-infected patients; thus optimal strategies for risk management and treatment in this group of patients need to be defined. Prevention of bone loss is an important component of HIV care as the HIV population grows older. Understanding the mechanisms by which HIV infection affects bone biology leading to osteoporosis is crucial to delineate potential adjuvant treatments. This review focuses on HIV-induced osteoporosis within the context of microRNAs (miRNAs) by reviewing first basic concepts of bone biology as well as current knowledge of the role of miRNAs in bone development. Evidence that HIV-associated osteoporosis is in part independent of therapies employed to treat HIV (HAART) is supported by cross-sectional and longitudinal studies and is the focus of this review.

Effect of alendronate on HIV-associated osteoporosis: a randomized, double-blind, placebo-controlled, 96-week trial (ANRS 120)

Low bone mineral density (BMD) is common in HIV-infected patients. Bisphosphonates such as alendronate potently inhibit bone resorption and are effective against osteoporosis. The aim of the ANRS 120 Fosivir trial was to evaluate the effect of alendronate on low BMD in HIV-infected patients. HIV-1-infected adults with a t-score≤-2.5 at the lumbar spine and/or total hip, as assessed by dual x-ray absorptiometry, and no other known risk factors for low BMD, were randomized to receive either extended-release alendronate 70 mg weekly or placebo for 96 weeks, with stratification for gender. All the patients also received daily calcium carbonate (500 mg) and vitamin D (400 U). The primary endpoint for efficacy was the percentage change in BMD at the site with a t-score≤-2.5. Forty-four antiretroviral-treated patients (42 men, 2 women) were enrolled. The median age was 45 years, the median CD4 cell count was 422/mm(3), and viral load was <400 copies/ml in 84% of patients. Baseline characteristics were well balanced between the alendronate (n=20) and placebo (n=24) groups. At baseline, 15 patients (75%) in the alendronate group and 17 patients (71%) in the placebo group had a t-score≤-2.5 at the lumbar spine. In the main analysis, BMD at the site with a t-score≤-2.5 increased by 7.1% and 1.0%, respectively, in the alendronate (n=14) and placebo (n=20) groups at week 96 [mean difference, 6.1% (95% CI 2.8 to 9.3); p=0.0003]. Alendronate 70 mg weekly for 96 weeks improves BMD in HIV-1-infected patients on antiretroviral therapy.

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis.

Low CD4 count is associated with an increased risk of fragility fracture in HIV-infected patients

BACKGROUND

Low bone mineral density in HIV-infected patients is an increasingly recognized clinical problem. The aim of this study was to determine the incidence, prevalence, and risk factors for development of low trauma or fragility fractures in an HIV-infected population.

METHODS

A 1:2 matched case-control study was performed of HIV-infected patients attending the Alfred Hospital between 1998 and 2009. Controls were matched on gender, age, and duration of HIV infection.

RESULTS

The overall fracture incidence rate was 0.53 per 100 person-years [95% confidence interval (CI): 0.43 to 0.65] and period prevalence of 3.34 per 100 patients (95% CI: 2.66 to 4.13). There were 73 low trauma fractures in 61 patients. Patients were predominantly male (89%) with a mean age of 49.8 years. Independent risk factors for fragility fracture were a CD4 cell count <200 cells per microliter odds ratio (OR): 4.91 (95% CI: 1.78 to 13.57, P = 0.002), corticosteroids OR: 8.96 (95% CI: 1.55 to 51.88, P = 0.014) and anti-epileptic medications OR: 8.88 (95% CI: 1.75 to 44.97, P = 0.008). There were no significant associations between HIV viremia (P = 0.18), use of or class of antiretroviral medication, and risk of fracture. Eighty-eight percent of patients with fracture had established osteopenia or osteoporosis.

CONCLUSION

This is the largest clinical study to date of fragility fractures occurring in an HIV-infected population. The study found that risk of fracture was strongly associated with a low CD4 cell count, use of corticosteroids, and anti-epileptic medications. There were no associations between fracture risk and viral load, use of class, or duration of antiretroviral agent.

Low bone mass prevalence, therapy type, and clinical risk factors in an HIV-infected Brazilian population

Low bone mineral density (BMD) has been described in human immunodeficiency virus (HIV)-infected patients, but data on associated factors are still unclear, and to our knowledge, no reports are available in Brazil. Our goal was to evaluate BMD in HIV patients attending an outpatient clinic in Vitoria, Brazil. A sectional study was performed in 300 HIV-infected patients to measure BMD by dual-energy X-ray absorptiometry (DXA). Age, gender, anthropometric parameters, nadir and current CD4 cell count, HIV viral load, smoking habit, and current antiretroviral therapy (ART) associations were investigated by multivariable analysis. Based on World Health Organization T-score ranges, low BMD (T-score <-1.0 standard deviation [SD] in postmenopausal women and men aged 50 and older or Z-score <- 2.0 SD in premenopausal women and men below the age of 50) was detected in 54.7% (95% confidence interval: 49.1-60.3%) of the 300 enrolled patients. The observed median age was 46 yr (interquartile range: 39-52), 58% were male, 88.5% were on ART, and 21.4% smoked. The following factors were identified, by multiple logistic modeling, as being independently associated with low BMD: (1) male gender (4.6 [1.28-16.39]), (2) body mass index lower than 25 kg/m(2) (2.9 [1.31-6.49]), (3) menopause (13.4 [2.53-71.12]), and (4) HIV-1 undetectable viral load (7.9 [1.96-32.25]). Conversely, zidovudine (0.2 [0.04-0.85]) and nevirapine (0.1 [0.02-0.38]) use were inversely associated with low BMD. Low BMD was frequently found in our cohort of about 300 Brazilian HIV-infected subjects. This study supports the need for periodic DXA testing in HIV outpatient clinics.

Bone mineral density in young women on methadone substitution

Little is known about bone mineral density (BMD) in patients with heroin addiction and subsequent methadone substitution. The goal of this study was to compare bone mass density of young HIV-negative women on long-term methadone treatment to a local group of young healthy women. Eleven women (aged 20-29) with previous heroin dependence and current methadone substitution (20-140 mg, median 60, daily) for 1.5-9 (median 3) years were compared to 30 healthy women (aged 20-28). Participants were examined with dual-energy X-ray absorptiometry of the lumbar spine (L2-L4), of the total proximal hip area, and of the femoral neck. Patients and controls had neither current nor lifetime underweight condition, had comparable ages at menarche, and did not differ significantly in current body mass index (21.9 ± 4.0, respectively, 20.5 ± 1.5 kg/m(2)) in spite of a largely unhealthy lifestyle (cigarette, alcohol, and cocaine consumption in patients). Patients' total-hip parameters were marginally lower than those of controls (BMD P = 0.054, T score P = 0.049), whereas the femoral neck and lumbar spine parameters did not differ significantly between the two groups. Long-term methadone substitution in HIV-negative women seems to slightly affect bone mass density.

Bone mineral density in HIV-infected women taking antiretroviral therapy: a systematic review

There is a high prevalence of osteoporosis in HIV-infected patients. Initially described in HIV-positive men, studies have also demonstrated a high prevalence of osteoporosis in HIV-infected women. It would appear that antiretroviral therapy (ART) plays an important role in the pathogenesis of osteoporosis in HIV-infected patients, although little is known about its importance in relation to osteoporosis and fractures in HIV-positive women. The aim of this systematic review was to evaluate the frequency of bone loss, bone mineral density (BMD) and fractures in HIV-positive women taking ART or protease inhibitors (PI). After screening 597 citations from the databases of PubMed, EMBASE and Lilacs, five studies were selected for the review. A difference was demonstrated of over 3% in the BMD at the femoral neck of HIV-positive women taking PI/ART. No difference was registered in the BMD at the lumbar spine between users and non-users of PI/ART. The lack of studies has made it impossible to reach any conclusion regarding the occurrence of fractures.