MRI to Replace Standard Invasive Method to Find HIV in the Brain?

HIV and AIDS have long been associated with neurological and cognitive issues, even in early stages. The virus is believed to spread to the brain in about 10 to 15% of patients.

“At the moment, we have to perform a lumbar puncture to confirm this, which involves inserting a needle into the back to draw out the spinal fluid and test it for HIV,” Ravi Gupta, MB BChir, (picture) a professor at University College London (UCL) in England, said in a news release. This invasive procedure requires patients to remain in the hospital for a few hours, but an alternative method may be able to weed out patients who really don’t need further follow-up.

The UCL team explained that data are lacking to address a neurological issue and magnetic resonance imaging (MRI) scans with cerebrospinal fluid (CSF). However, these two factors lead a physician to perform a lumbar puncture. CSF results in either discordance (viral load (VL) in CSF 0.5 log10 copies HIV-1 RNA greater than plasma VL) or escape) detection of HIV VL >50 copies/mL in patients with CSF with suppressed plasma VL <50 copies/mL).

The researchers examined information gathered from 146 patients with HIV and suspected cognitive problems from 2011 to 2015. These patients made up 163 lumbar punctures, had a median age of 45.3 (interquartile range (IQR): 39.6-51.5), and median CD4 count of 430 (IQR: 190-620) cells/mL.

Of all the patients, HIV was active in the brain in 22 of them (15%). These 22 patients made up 24 lumbar punctures (14.7%) that showed CSF discordance. Of those 24, 10 lumbar punctures in 9 patients were CSF escape.

When compared to patients with normal-looking white matter, those who had definite signs of change in white matter, called diffuse white matter signal abnormalities, were 10 times more likely to have HIV in the brain. The researchers explained that both CSF discordance and escape were linked to these abnormalities on cranial MRI scans in a multivariate analysis (adjusted odds ratio: 10.3 (95% confidence interval (CI): 2.3-45.0), P = 0.007 and 56.9 (95% CI, 4.0-882.8), P = 0.01, respectively). The 7 patients with CSF escape, making up 10 lumbar punctures, were diagnosed with HIV more than 7 years early. Of those, 6 patients had resistance data and all of them had evidence of drug-resistant virus in plasma.

“Before we had effective treatments for HIV, AIDS often led to dementia and other problems in the brain,” Gupta continued. “Thankfully, this is less common now that we can treat HIV, but up to half of HIV patients still report cognitive problems.”

Diffuse white matter signal abnormalities are known to be connected to cognitive issues in people with HIV, and the virus can spark the inflammation which causes the problems. Now there’s more proof showing that MRIs can help detect which patients with HIV are most at risk for developing cognitive issues.

Although antiretroviral therapy (ART) has greatly changed what it means to be living with HIV, the medications aren’t enough to prevent cognitive issues related to the virus inflammation.

“Where HIV has spread to the brain, we can change the treatment regime to add drugs that cross the blood-brain barrier more effectively to control the infection,” Gupta explained.

The study, “Diffuse White Matter Signal Abnormalities on Magnetic Resonance Imaging Are Associated With Human Immunodeficiency Virus Type 1 Viral Escape in the Central Nervous System Among Patients With Neurological Symptoms,” was published in Clinical Infectious Diseases. The news release was provided by UCL.

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