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Wednesday, 5 June, 2002, 18:04 GMT 19:04 UK
Drug 'speeds up' HIV
The drug appears to speed up virus reproduction
The drug appears to speed up virus reproduction
The drug methamphetamine may increase the replication of HIV cells in the brain, scientists suggest.

A US study looking at feline immunodeficiency virus found exposing the virus to the drug increased the cells ability to replicate FIV by as much as 15-fold.

FIV and HIV viruses are closely related and FIV can provide scientists with a good model for finding out more about the human virus.

The researchers, from Ohio State University, say if further studies in animals confirm their findings, it could help explain how HIV and FIV act in the brain, and the cognition problems and dementia sometimes suffered by Aids patients.


After two weeks of chronic methamphetamine exposure, the ability of these infected cell lines to mass-produce virus increases dramatically

Professor Michael Podell, Ohio State University
Methamphetamine has a powerful effect on the brain, producing an intense rush which is followed by up to 36 hours of stimulation, excitation, talkativeness, feelings of well being, confidence and alertness.

The Ohio team focussed on astrocytes, nerve cells which could make up as much as half of the brain, and which could play a key part in immunity.

'Dramatic increase'

It was already known that FIV and HIV infected astrocytes, but it was thought the viruses remained dormant within the cells.

However, the researchers found FIV was only able to infect the cell when it is linked to a specific type of immune cell called a peripheral blood mononuclear cell.

But once the virus infects cells, it mutates into a different strain and seems to be separate to the infection of the immune system, meaning drugs targeted there will not affect astrocyte infection in the brain.

Michael Podell, professor of veterinary clinical sciences and neurosciences, who led the research, said; "We found that after two weeks of chronic methamphetamine exposure, the ability of these infected cell lines to mass-produce virus increases dramatically.

"We found that if you treat these astrocyte cell limes with methamphetamine at the time that they are infected with FIV, and if you continuously expose them to the drug, you can see as much as a 15-fold increase in viral replication."

He added: "You can basically take this cell that normally has a limited ability to consistently replicate virus and just dramatically turn it on, simply by adding methamphetamine."

The team are now looking at data from experiments on cats, to see if the findings are replicated.

They aim to find out exactly why the drug has such an apparently significant effect on virus replication in the brain.

Cocaine research

Mr Keith Alcorn, senior editor at the National Aids Manual, told BBC News Online: "Methamphetamine use is quite significant in gay men with HIV in the US, though not so much in the UK.

"This is certainly something that should be investigated further," specifically whether regular recreational methamphetamine users with HIV have more cognitive problems than people who are not regular users of the drug.

He said research into the effects of cocaine, which had looked at a different type of cell, had found the drug also increased how fast the virus replicated.

"What's been found with cocaine is that it increases the number of a particular type of receptors on the surface of CD4 lymphatic immune cells.

"That's why you get huge increases in HIV replication when mice are exposed to cocaine.

"It's not clear from this study whether methamphetamine might be having the same effect."

The research is published in the Journal of NeuroVirology.

See also:

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