Is it possible to detect lingering HIV in the brain? MRI scans can do it, say scientists!

New Delhi: Human immunodeficiency virus (HIV) is one of the most feared as well as the most misunderstood infections in the world.

Many myths related to it have often caused stigmatization among people infected with it. Unfortunately, many HIV-positive people are unaware that they are infected with the virus.

Normally, the primary tests for diagnosing HIV and AIDs include the ELISA Test – ELISA, which stands for enzyme-linked immunosorbent assay, is used to detect HIV infection. If an ELISA test is positive, the Western blot test is usually administered to confirm the diagnosis.

However, a team of scientists, including one of Indian origin, has found that HIV can be identified in the brain despite effective drug treatment with the help of an MRI scan.

"Before we had effective treatments for HIV, AIDS often led to dementia and other problems in the brain," said Professor Ravi Gupta from University College London (UCL).

"Thankfully this is less common now that we can treat HIV, but up to half of HIV patients still report cognitive problems," Gupta said.

"We see evidence that HIV has spread to the brain in around ten to fifteen percent of these patients, but in most cases the symptoms are down to other causes," he said.

"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. This is quite an invasive procedure that requires patients to stay in hospital for several hours," he added.

"Our new study shows that MRI scans could help to identify high-risk individuals for further follow-up tests," Gupta said.

The team looked at data from 146 HIV patients who were investigated for cognitive problems between 2011 and 2015.

There was evidence that HIV was active in the brain in 22 patients (15 per cent), and patients whose brains showed definite signs of change in the white matter were ten times more likely to have HIV in the brain than those with normal white matter appearances.

These changes in the brain, called diffuse white matter signal abnormalities, are linked to cognitive problems and can be triggered by inflammation in the brain caused by HIV infection.

"HIV treatments have come a long way, but patients whose HIV is suppressed by drugs can still have cognitive problems due to HIV related inflammation," said Gupta.

"MRI scans can help to diagnose these patients, whether showing an elevated risk of HIV-related problems or finding a different cause that can then be treated," he said.

"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," he added.

The study was published in the journal Clinical Infectious Diseases.

(With PTI inputs)