Cerebral Vasoreactivity Evaluated by the Breath-Holding Challenge Correlates With Performance on a Cognitive Screening Test in Persons Living With Treated HIV Infection in China

HIV-Associated Neurocognitive Disorder: A Look into Cellular and Molecular Pathology

Despite combined antiretroviral therapy (cART) limiting HIV replication to undetectable levels in the blood, people living with HIV continue to experience HIV-associated neurocognitive disorder (HAND). HAND is associated with neurocognitive impairment, including motor impairment, and memory loss. HIV has been detected in the brain within 8 days of estimated exposure and the mechanisms for this early entry are being actively studied. Once having entered into the central nervous system (CNS), HIV degrades the blood-brain barrier through the production of its gp120 and Tat proteins. These proteins are directly toxic to endothelial cells and neurons, and propagate inflammatory cytokines by the activation of immune cells and dysregulation of tight junction proteins. The BBB breakdown is associated with the progression of neurocognitive disease. One of the main hurdles for treatment for HAND is the latent pool of cells, which are insensitive to cART and prolong inflammation by harboring the provirus in long-lived cells that can reactivate, causing damage. Multiple strategies are being studied to combat the latent pool and HAND; however, clinically, these approaches have been insufficient and require further revisions. The goal of this paper is to aggregate the known mechanisms and challenges associated with HAND.

Initiation of combined antiretroviral therapy confers suboptimal beneficial effects on neurovascular function in people with HIV

Introduction

Due to advances in combined anti-retroviral treatment (cART), there is an increased burden of age-related cerebrovascular disease (CBVD), in people living with HIV (PWH). The underlying CNS injury can be assessed by measuring cerebral blood flow (CBF) and cerebrovascular reactivity (CVR).

Methods

35 treatment-naïve PWH and 53 HIV negative controls (HC) were enrolled in this study. Study participants underwent T1-weighted anatomical, pseudo-continuous arterial spin labeling, and resting-state functional MRI to obtain measures of CBF and CVR prior to starting cART treatment and at two-time points (12 weeks and 2 years) post-cART initiation. Controls were scanned at the baseline and 2-year visits. We also measured plasma levels of microparticles of endothelial and glial origin and well-known endothelial inflammation markers, ICAM-1 and VCAM-1, to assess HIV-associated endothelial inflammation and the interaction of these peripheral markers with brain neurovascular function.

Results

HIV infection was found to be associated with reduced CVR and increased levels of endothelial and glial microparticles (MPs) prior to initiation of cART. Further, CVR correlated negatively with peripheral MP levels in PWH.

Discussion

Our results suggest that while cART treatment has a beneficial effect on the neurovascular function after initiation, these benefits are suboptimal over time.

Brief Report: Sex Differences in the Association Between Cerebrovascular Function and Cognitive Health in People Living With HIV in Urban China

BACKGROUND

Cardiometabolic and cerebrovascular disease are strong independent contributors to cognitive impairment in people living with HIV. Data suggest that cardiovascular risk may play a greater role in cognitive health in women than in men with HIV.

METHODS

We performed a cross-sectional study of 104 participants with virologically suppressed HIV from 2 clinics in urban China. Participants underwent neuropsychological testing from which we calculated T scores globally and in 5 cognitive domains. We assessed cerebral vasoreactivity of the middle cerebral arteries in response to breath holding. We constructed linear regression models to determine associations between cerebrovascular and cognitive function overall and stratified by sex.

RESULTS

Women were younger than men (48 versus 51 years, P = 0.053), had fewer years of education (9 years versus 12 years, P = 0.004), and fewer cardiometabolic risk factors (0 versus 1 factor, P = 0.008). In a model with all participants, cerebrovascular function was significantly associated with global cognition (2.74 higher T score per 1-point higher cerebral vasoreactivity [SE 1.30], P = 0.037). Cerebrovascular function remained significantly associated with global cognition among women (4.15 higher T score [SE 1.78], P = 0.028) but not men (1.70 higher T score [SE 1.74], P = 0.33). The relationships between cerebrovascular function and specific cognitive domains followed a similar pattern, with significant associations present among women but not men.

CONCLUSIONS

Women with well-controlled HIV may be more vulnerable to the effect of cerebrovascular injury on cognitive health than men. Studies evaluating strategies to protect against cognitive impairment in people living with HIV should include adequate representation of women and stratification of analyses by sex.

Trends and Clinical Characteristics of HIV and Cerebrovascular Disease in Low- and Middle-Income Countries (LMICs) Between 1990 and 2021

PURPOSE OF THE REVIEW

To describe trends and clinical characteristics of HIV and cerebrovascular disease between 1990 and 2021 in LMICs and identify the gaps in our understanding.

RECENT FINDINGS

In the era of antiretroviral therapy (ART), people living with HIV (PLWH) live longer and risk excess cerebrovascular events due to ageing and HIV-driven factors. Despite the highest burden of HIV infection in low-to-middle income countries, there is underreporting in the literature of cerebrovascular events in this population. We systematically reviewed published literature for primary clinical studies in adult PLWH and cerebrovascular disease in LMICs. The clinical phenotype of cerebrovascular disease among PLWH over the last three decades in LMICs has evolved and transitioned to an older group with overlapping cerebrovascular risk factors. There is an important need to increase research in this population and standardise reporting to facilitate understanding, guide development of appropriate interventions, and evaluate their impact.

Multidisciplinary collaborative integrated management of increasingly prominent HIV complications in the post-cART era

OBJECTIVES

With the prolonged survival time of AIDS patients, complications of various systems and organs of HIV infection are increasingly prominent. These diseases have become the major factors influencing the quality of life and prognosis of HIV-infected persons, and multidisciplinary cooperation treatment is urgently needed.

METHODS

The Chinese HIV/AIDS Clinical Trial Network has conducted a series of multicentre clinical cohort studies over the past 16 years, in which studies related to people living with HIV systemic complications. Based on the results of previous studies, this review establishes the complications of Chinese people living with HIV after long-term cART.

RESULTS

HIV's direct damage to human cells, chronic abnormal inflammatory activation after HIV infection, long-term drug side effects caused by cART and persistent reservoirs cause systemic complications in people living with HIV. We summarised the clinical characteristics of the complications of HIV infection in China from the aspects of the liver, cardiovascular, the nervous system, the kidney, bone metabolism, blood glucose, and lipid metabolism.

CONCLUSIONS

The management of the complications of HIV infection is a major link in improving the survival treatment and prognosis of patients in the future. The joint participation of doctors from different departments of general hospitals in the management of comorbidities is the main theme for future improvement of quality of life and prognosis for people living with HIV.