USC study measures brain volume differences in people with HIV

January 15, 2021

Nearly 38 million people around the world are living with HIV, which, with access to treatment, has become a lifelong chronic condition. Understanding how infection changes the brain, especially in the context of aging, is increasingly important for improving both treatment and quality of life.

In January, researchers at the Mark and Mary Stevens Neuroimaging and Informatics Institute (USC Stevens INI), part of the Keck School of Medicine of USC, and other international NeuroHIV researchers, published one of the largest-ever neuroimaging studies of HIV. The researchers pooled magnetic resonance imaging (MRI) data from 1,203 HIV-positive individuals across Africa, Asia, Australia, Europe and North America. Their findings were published in JAMA Network Open, an open-access journal from the American Medical Association.

"Brain injury caused by HIV can lead to cognitive challenges, even in those receiving treatment," says Talia Nir, PhD, a postdoctoral scholar at the USC Stevens INI's Laboratory of Brain eScience (LoBeS) and first author of the study. "Establishing a common pattern of effects on the brain across different populations is a key step toward addressing those issues. The strength of this large dataset is that it is more representative of an era where treatment for HIV infection is widely available."

The researchers looked at the link between blood plasma, which is routinely collected to monitor immune function and treatment response, and the volume of various structures in the brain. Lower white blood cell counts generally indicate that the immune system is being suppressed. Here, they found, for example, that participants with lower white blood cell counts also had less brain volume in the hippocampus and thalamus, parts of the brain's limbic system involved in regulating memory, emotion and behavior.

These findings are important because they were largely derived from brain scans of individuals undergoing antiretroviral therapy--and they indicate that people receiving such treatment may exhibit a different brain injury signature compared to untreated individuals, which earlier studies tended to focus on. They highlight deficits in brain areas that are also vulnerable to age-related neurodegenerative diseases.

Accelerated atrophy of the hippocampus, the region that showed the most consistent effects in the study, is a hallmark of neurodegenerative diseases such as Alzheimer's disease. Common age and HIV-related pathological processes, such as inflammation and blood brain barrier impairment, may accelerate age-related neurodegenerative processes.

"There are many factors that contribute to brain tissue loss and subsequent cognitive impairments as we age, and a person's immune function is no exception," says Neda Jahanshad, PhD, associate professor of neurology at the INI and one of the senior authors of the study. "Through these large-scale efforts, we're beginning to understand the link between immune function and brain alterations in individuals living, and aging, with HIV."

The analysis was a product of the Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) consortium's HIV Working Group, established by Jahanshad and colleagues in 2013 to pool harmonized data across neuroimaging studies. The ENIGMA network at large, led by the institute's associate director, Paul M. Thompson, PhD, unites neuroimaging researchers in 45 countries to study psychiatric disorders, neurodegenerative diseases and other aspects of brain function. In addition to housing ENIGMA, the USC Stevens INI is a powerhouse of neuroimaging and related science, known for large cohort analyses of imaging, genetics, behavioral, clinical and other data. Investigators from 13 existing HIV studies in the United States, France, Serbia, Australia, Thailand and South Africa collaborated on the JAMA Network Open paper.

Next, the team will analyze imaging data over time, including diffusion imaging data, another type of MRI data that maps the brain's white matter pathways, to further understand how clinical markers of HIV infection affect the brain and the rate of neurodegeneration. As part of that ongoing work, they are inviting researchers around the world to join the ENIGMA-HIV Working Group.

"With a greater collaborative effort, we hope to be able to assess how genetic, environmental, lifestyle and treatment-related factors may further impact neurological outcomes," Nir says.
-end-


Keck School of Medicine of USC

Related HIV Articles from Brightsurf:

BEAT-HIV Delaney collaboratory issues recommendations measuring persistent HIV reservoirs
Spearheaded by Wistar scientists, top worldwide HIV researchers from the BEAT-HIV Martin Delaney Collaboratory to Cure HIV-1 Infection by Combination Immunotherapy (BEAT-HIV Collaboratory) compiled the first comprehensive set of recommendations on how to best measure the size of persistent HIV reservoirs during cure-directed clinical studies.

The Lancet HIV: Study suggests a second patient has been cured of HIV
A study of the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene, finds that there was no active viral infection in the patient's blood 30 months after they stopped anti-retroviral therapy, according to a case report published in The Lancet HIV journal and presented at CROI (Conference on Retroviruses and Opportunistic Infections).

Children with HIV score below HIV-negative peers in cognitive, motor function tests
Children who acquired HIV in utero or during birth or breastfeeding did not perform as well as their peers who do not have HIV on tests measuring cognitive ability, motor function and attention, according to a report published online today in Clinical Infectious Diseases.

Efforts to end the HIV epidemic must not ignore people already living with HIV
Efforts to prevent new HIV transmissions in the US must be accompanied by addressing HIV-associated comorbidities to improve the health of people already living with HIV, NIH experts assert in the third of a series of JAMA commentaries.

The Lancet HIV: Severe anti-LGBT legislations associated with lower testing and awareness of HIV in African countries
This first systematic review to investigate HIV testing, treatment and viral suppression in men who have sex with men in Africa finds that among the most recent studies (conducted after 2011) only half of men have been tested for HIV in the past 12 months.

The Lancet HIV: Tenfold increase in number of adolescents on HIV treatment in South Africa since 2010, but many still untreated
A new study of more than 700,000 one to 19-year olds being treated for HIV infection suggests a ten-fold increase in the number of adolescents aged 15 to 19 receiving HIV treatment in South Africa, according to results published in The Lancet HIV journal.

Starting HIV treatment in ERs may be key to ending HIV spread worldwide
In a follow-up study conducted in South Africa, Johns Hopkins Medicine researchers say they have evidence that hospital emergency departments (EDs) worldwide may be key strategic settings for curbing the spread of HIV infections in hard-to-reach populations if the EDs jump-start treatment and case management as well as diagnosis of the disease.

NIH HIV experts prioritize research to achieve sustained ART-free HIV remission
Achieving sustained remission of HIV without life-long antiretroviral therapy (ART) is a top HIV research priority, according to a new commentary in JAMA by experts at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The Lancet HIV: PrEP implementation is associated with a rapid decline in new HIV infections
Study from Australia is the first to evaluate a population-level roll-out of pre-exposure prophylaxis (PrEP) in men who have sex with men.

Researchers date 'hibernating' HIV strains, advancing BC's leadership in HIV cure research
Researchers have developed a novel way for dating 'hibernating' HIV strains, in an advancement for HIV cure research.

Read More: HIV News and HIV Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.