by Pooja Shete on  January 20, 2021 at 12:53 AM AIDS/HIV News
Link Between HIV And Neurodegenerative Disease
Currently 38 million people around the world are living with HIV which is a lifelong chronic condition. It is increasingly important to understand how infection changes the brain especially in the relation with aging, to improve both treatment and quality of life.

The research conducted at the Mark and Mary Stevens Neuroimaging and Informatics Institute (USC Stevens INI) is published in the journal JAMA Network Open.

The researchers published one of the largest-ever neuroimaging studies of HIV for which magnetic resonance imaging (MRI) data from 1,203 HIV-positive individuals across Africa, Asia, Australia, Europe and North America was collected.


First author of the study, Talia Nir, PhD, a postdoctoral scholar at the USC Stevens INI's Laboratory of Brain eScience (LoBeS) said, "Brain injury caused by HIV can lead to cognitive challenges, even in those receiving treatment. 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 studied the association 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 indicate that the immune system is suppressed. They found that patients with lower white blood cell counts also had less brain volume in the hippocampus and thalamus. These parts of the brain are associated with regulating memory, emotion, and behavior.

The findings of this study are important as they were largely derived from brain scans of individuals undergoing antiretroviral therapy, which indicate that people receiving such treatment may exhibit a different brain injury signature compared to untreated individuals.

These brain scans highlight the deficits in brain areas that are also vulnerable to age-related neurodegenerative diseases.

A hallmark of neurodegenerative diseases like Alzheimer's disease is accelerated decrease in size of the hippocampus which is the region that showed the most consistent effects in the study.

HIV-related pathological processes and age like inflammation and blood brain barrier impairment can accelerate age-related neurodegenerative processes.

One of the senior authors of the study, Neda Jahanshad, PhD, associate professor of neurology at the INI said, "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. 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."

Further, the team will analyze neuroimaging data including diffusion imaging data, which is another type of MRI data that that maps the brain's white matter pathways. This will improve their understanding about how clinical markers of HIV infection affect the brain and the rate of neurodegeneration.

Nir said, "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."



Source: Medindia

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