Antiretroviral Therapy-Induced Bone Loss Is Durably Suppressed by a Single Dose of Zoledronic Acid in Treatment-Naive Persons with Human Immunodeficiency Virus Infection: A Phase IIB Trial

Unilateral avascular necrosis of the right hip in an HIV patient with tearing of the rectus femoris and adductor longus muscles

A man in his 20s with a medical history of syphilis, chlamydia and HIV presented to the emergency department (ED) with 2 months of right hip pain and was found to have advanced avascular necrosis (AVN) of the right femoral head with secondary haemorrhage. The patient lacked the common risk factors of AVN in patients with HIV (PWH): ≥10 years of HIV diagnosis, extended duration on highly active antiretroviral therapy, trauma, corticosteroid use, alcohol abuse, systemic lupus erythematosus, obesity, smoking and dyslipidaemia. Given the extensive destructive changes in the hip joint and muscles, a right hip resection arthroplasty was performed, and the patient recovered well postoperatively. This case presents a learning opportunity for understanding bone pathologies in PWH and offers clinical guidance for the management of HIV-infected patients with a focus on optimising bone health.

Pharmacological and Behavioral Interventions to Mitigate Premature Aging in Patients with HIV

PURPOSE OF REVIEW

We sought to review pharmacological and behavioral interventions that have been publicly presented, published, or are currently ongoing to prevent or mitigate the effect of premature HIV-associated comorbidities.

RECENT FINDINGS

Multiple studies have been conducted in hopes of finding an effective intervention. While the choice of antiretroviral regimen influences recovery of immune function, several drugs used as adjunct treatments have proven effective to mitigate premature aging. Additionally, few behavioral interventions have exhibited some efficacy. Statins, angiotensin-receptor blockers, and anti-hyperglycemic agents as well as optimal adherence, exercise, and intermittent fasting among others have had beneficial impact on markers of immune activation and levels of inflammatory biomarkers. However, several investigations had inconclusive outcomes so further studies with larger sample sizes are warranted.

Bone Health in People Living with HIV/AIDS: An Update of Where We Are and Potential Future Strategies

The developments in Human Immunodeficiency Virus (HIV) treatment and in the care of people living with HIV (PLWHIV) and Acquired Immunodeficiency Syndrome (AIDS) over the last three decades has led to a significant increase in life expectancy, on par with HIV-negative individuals. Aside from the fact that bone fractures tend to occur 10 years earlier than in HIV-negative individuals, HIV is, per se, an independent risk factor for bone fractures. A few available antiretroviral therapies (ARVs) are also linked with osteoporosis, particularly those involving tenofovir disoproxil fumarate (TDF). HIV and hepatitis C (HCV) coinfection is associated with a greater risk of osteoporosis and fracture than HIV monoinfection. Both the Fracture Risk Assessment Tool (FRAX) and measurement of bone mineral density (BMD) via a DEXA scan are routinely used in the assessment of fracture risk in individuals living with HIV, as bone loss is thought to start between the ages of 40 and 50 years old. The main treatment for established osteoporosis involves bisphosphonates. Supplementation with calcium and vitamin D is part of clinical practice of most HIV centers globally. Further research is needed to assess (i) the cut-off age for assessment of osteoporosis, (ii) the utility of anti-osteoporotic agents in PLWHIV and (iii) how concomitant viral infections and COVID-19 in PLWHIV can increase risk of osteoporosis.

Gender and sex considerations in HIV and bone health

PURPOSE OF REVIEW

People with HIV (PWHIV) are at increased risk for osteoporosis and fractures, because of the effects of HIV and inflammation and antiretroviral therapy (ART) initiation as well as traditional risk factors. This review from recent literature focuses on sex differences in rates of bone disease, risk of fractures, and effects of ART.

RECENT FINDINGS

Women with HIV in resource-constrained settings experience bone loss because of the additive effect of initiating TDF-containing ART during pregnancy, lactation, and menopause. Children and adolescents experience lower bone accrual during the pubertal growth years. There has been less focus on bone health in recent trials of ART containing tenofovir alafenamide and/or integrase inhibitors. Very few clinical trials or studies compare sex-specific changes in inflammation, immune activation, response to ART and bone turnover or change in BMD resulting in significant knowledge gaps.

SUMMARY

More data is needed to determine changes in prevalence of osteopenia, osteoporosis, and fractures in the era of immediate initiation of ART at high CD4 cell counts and the use of more bone-friendly ART. The long-term effects of ART and low bone mass on fractures in the ageing population of PWHIV is yet to be realized.

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.

Protocol for a pilot randomised controlled trial of zoledronic acid to prevent bone loss following sleeve gastrectomy surgery

INTRODUCTION

Sleeve gastrectomy (SG) is an increasingly used and effective treatment for obesity; however, the rapid weight loss associated with SG adversely affects bone metabolism predisposing patients to skeletal fragility. Bisphosphonate medications have been evaluated for safety and efficacy in combating bone loss in patients with osteoporosis, but their use in SG-induced bone loss is limited. The goal of this study is to investigate how a one-time infusion of zoledronic acid compares to placebo, in its ability to combat SG-associated bone loss.

METHODS AND ANALYSIS

This research protocol is a 9-month, pilot randomized controlled trial (RCT) involving 30 adult SG patients randomised to receive an infusion of either 5 mg of zoledronic acid or placebo, 6 weeks following surgery. To be included participants must be <350 lbs/158.8 kg, free of bone-impacting pathologies or medications, and must have adequate serum calcium and vitamin D levels at baseline. The primary outcome is change in areal bone mineral density (aBMD) at the total hip. Secondary outcomes include change in aBMD of the femoral neck, and lumbar spine, and change in volumetric BMD at the lumbar spine. The primary aim will be tested using a linear mixed model fit with total hip aBMD at 9 months as the outcome. Treatment, participant sex and menopausal status will be considered in analysis. Groups will be compared using contrast statements at 9 months, with change over 9 months being the primary comparison.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board of the University of Nebraska Medical Center (IRB820-19). Written consent will be obtained from participants at enrolment by trained staff. Careful and thorough explanation are used in obtainment of consent and voluntariness is emphasised throughout the trial. The findings of this study will be presented locally, nationally, and published in peer-reviewed journals. Additional details will be reported on ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT04279392.

Lipid homeostasis and mevalonate pathway in COVID-19: Basic concepts and potential therapeutic targets

Despite encouraging progresses achieved in the management of viral diseases, efficient strategies to counteract infections are still required. The current global challenge highlighted the need to develop a rapid and cost-effective strategy to counteract the SARS-CoV-2 pandemic. Lipid metabolism plays a crucial role in viral infections. Viruses can use the host lipid machinery to support their life cycle and to impair the host immune response. The altered expression of mevalonate pathway-related genes, induced by several viruses, assures survival and spread in host tissue. In some infections, statins, HMG-CoA-reductase inhibitors, reduce cholesterol in the plasma membrane of permissive cells resulting in lower viral titers and failure to internalize the virus. Statins can also counteract viral infections through their immunomodulatory, anti-inflammatory and anti-thrombotic effects. Beyond statins, interfering with the mevalonate pathway could have an adjuvant effect in therapies aimed at mitigating endothelial dysfunction and deregulated inflammation in viral infection. In this review we depicted the historical and current evidence highlighting how lipid homeostasis and mevalonate pathway targeting represents a valid approach to rapidly neutralize viruses, focusing our attention to their potential use as effective targets to hinder SARS-CoV-2 morbidity and mortality. Pros and cons of statins and Mevalonate-pathway inhibitors have been also dissected.

Longitudinal change in bone mineral density among Chinese individuals with HIV after initiation of antiretroviral therapy

This is the first study to report changes in BMD and related risk factors among Chinese patients with HIV after initiation of tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy. Greater bone mineral density (BMD) loss was observed in patients treated with TDF, compared to those on non-TDF-containing regimens. Our findings provide important knowledge regarding the risk factors in the long-term clinical management of patients with HIV in China.

INTRODUCTION

Persons living with HIV (PLWH) are at increased risk for osteoporosis and fracture. Tenofovir disoproxil fumarate (TDF) has been associated with higher rates of bone mineral density (BMD) loss, osteoporosis, and fracture. Few studies have studied the impact among PLWH in Asia.

METHODS

We analyzed retrospectively patients from the outpatient HIV clinic of a large tertiary hospital in Beijing, China, from March 2007 to May 2016. Patients who had dual-energy X-ray absorptiometry testing prior to antiretroviral initiation and at 48 and/or 96 weeks after initiation were included in this analysis.

RESULTS

A total of 136 patients were included (mean age 36.0 ± 10.6 years) and over 90% participants were male and Han Chinese ethnicity. We observed greater declines in BMD at the spine from baseline to week 48 (-2.94% vs. -0.74%) and at the hip from baseline to week 96 (-4.37% vs. -2.34%) in the TDF group compared with the non-TDF group. With regard to HIV-specific parameters, longer duration since HIV diagnosis and undetectable viral load over time were associated with lower BMD at the hip [relative risk (RR) 0.97, 95% confidence index (CI) (0.95, 0.99) per 1 year increase and RR 0.96, 95%CI (0.94, 0.99), respectively] and femoral neck [RR 0.97, 95%CI (0.95, 0.99) per 1 year increase and RR 0.97, 95%CI (0.95, 0.998), respectively] over 96 weeks.

CONCLUSIONS

This is the first study to report changes in BMD among PLWH after initiation of TDF-based antiretroviral therapy in China. Our findings provide important knowledge for the long-term clinical management of PLWH from this region.

Increase in bone turnover markers in HIV patients treated with tenofovir disoproxil fumarate combined with raltegravir or efavirenz

Introduction

Accelerated bone loss and osteoporosis are multifactorial comorbidities related to HIV and its treatments; however, their mechanisms remain elusive. Identifying HIV treatments that are differentially linked to osteoporosis risk, and clinical factors associated with HIV-related osteoporosis may enable optimizing anti-retroviral treatment (ART) and anti-osteoporosis therapy in preventing or treating this debilitating complication. This study aims to evaluate the dynamics of bone turnover markers after initiation of two commonly used antiretroviral regimens.

Methods

A prospective matched cohort study. Thirty treatment-naïve male patients (mean age 40 ± 10y) who initiated treatment with truvada (tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)) + raltegravir or TDF/FTC + efavirenz were included in the study. Control group included 15 treatment-naive HIV patients. Serum morning fasting level of P1NP and CTX were measured 0, 1, 6, and 12 months after treatment initiation in the two study groups, and at 0, 6 and 12 months in the control group.

Results

In both treatment groups, but not in the control group, both markers increased significantly over time with no difference in BTM between patients treated with raltegravir or efavirenz. Levels of P1NP were statistically higher at 6 and 12 months after treatment initiation in both treatment groups compared to the controls, while CTX during treatment increased in both treatment groups but was significantly higher only in the raltegravir treatment group after 12 months. The ratio of area under the curve of P1NP/CTX correlated with CD4 increment.

Conclusions

Treatment initiation with raltegravir or efavirenz combined with TDF/FTC is associated with increased bone turnover. Thus, therapy that optimize bone turnover is needed to reduce bone loss at this vulnerable period and improve long-term bone health.

People living with HIV and fracture risk

PLHIV have an increased risk of osteoporosis and fractures when compared with people of the same age and sex. In this review, we address the epidemiology and the pathophysiology of bone disease and fractures in PLHIV. The assessment of fracture risk and fracture prevention in these subjects is also discussed. The spectrum of HIV-associated disease has changed dramatically since the introduction of potent antiretroviral drugs. Today, the survival of people living with HIV (PLHIV) is close to that of the general population. However, the longer life-span in PLHIV is accompanied by an increased prevalence of chronic diseases. Detrimental effects on bone health are well recognised, with an increased risk of osteoporosis and fractures, including vertebral fractures, compared to the general population. The causes of bone disease in PLHIV are not fully understood, but include HIV-specific risk factors such as use of antiretrovirals and the presence of chronic inflammation, as well as traditional risk factors for fracture. Current guidelines recommend the use of FRAX to assess fracture probability in PLHIV age ≥ 40 years and measurement of bone mineral density in those at increased fracture risk. Vitamin D deficiency, if present, should be treated. Bisphosphonates have been shown to increase bone density in PLHIV although fracture outcomes are not available.