AIDS dementia mystery solved by Blore scientists

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AIDS mystery solved by Blore scientists

From Kalyan Ray, DH News Service, New Delhi:

Though it sounds whacky, Indian HIV strain actually is better than

its US counterpart.

Scientists at Jawaharlal Nehru Centre for Advanced Scientific

Research, Bangalore and National Brain Research Centre (NBRC),

Manesar have demonstrated that HIV does not cause dementia in India

due to a genetic change that renders the culprit neurotoxin harmless.

But the HIV found in the US can trigger dementia resulting in memory

loss in almost one-third of all HIV/AIDS patients. But the Indian HIV

just cannot kill the brain cells.

HIV-Dementia link

" The wrongdoer is a protein known as `Tat' that causes dementia in

USA. But the protein undergoes a genetic change in India, which is

one of the contributing factors for lack of dementia here, " Dr

Udaykumar Ranga, the team leader at the JNCASR told Deccan Herald.

Affecting almost 20-30 per cent HIV/AIDS patients in the USA, HIV

associated dementia leads to declining in thinking, reasoning,

memory, judgement, concentration and problem-solving.

" We have demonstrated that Indian strain of HIV-1 (subtype C, which

is the dominant strain here) reduces the neuro-toxicity of causative

protein. It was a scientific mystery, " said Dr Pankaj Seth at the

NBRC. The findings have been reported in the journal ls of

Neurology.

Since the Indian patients are spared from dementia, they can have a

better quality of life.

`Tat' puzzle unsolved

However, it is not known why this toxin is weak in the Indian sub-

type of the dreaded virus.

Normally, dementia triggers death of brain cells in the elderly

leading to memory loss and other intellectual faculties. " In HIV

positive patients, the virus accelerates the death process in

relatively young people, " Dr Ranga explained.

Even accepting that dementia is under-reported, scientists were

intrigued by lack of symptoms in India which houses more than 24 lakh

HIV/AIDS patients.

Elsewhere

But is the situation same in South Africa, China and Brazil where

also similar HIV strains are in circulation?

Dr Ranga claimed that following the lead provided by JNCASR, these

nations are now trying to find out the extent of dementia in HIV/AIDS

patients in their countries.

Solving the puzzle was a complicated affair due to the absence of an

appropriate animal model for experimentation.

Since dementia affected human brains were barely available to study

disease progression, the NBRC-JNCASR team depended solely on the cell

culture to crack the mystery.

The National Brain Research Centre researchers derived a

sophisticated stem cell-based culture system to identify the point

mutation. " In order to spot the genetic change, we just simulated

what happened inside a brain when HIV strikes, " Dr Seth added.

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