Applying immunity: 5,000 delegates from around the world are attending the International AIDS Society Conference in Sydney from 22 to 25 July.
Credit: International AIDS Society
SYDNEY: Human trials have begun of a revolutionary HIV treatment that genetically modifies people's cells, experts at a Sydney conference were told yesterday.
U.S. professor John Rossi said the world-first trials began recently at the City of Hope hospital in California, the culmination of research to halt the virus that began in the early 1990s.
"We have already enrolled our first patient, who will be infused with his own genetically modified blood stem cells and we will enrol four more patients after him," said Rossi, the head of the hospital's molecular biology division.
Inhibiting replication
The process, known as intra-cellular immunity, involves changing the DNA of immune cells, known as T-cells, which the HIV virus normally locks into and infects before replicating and spreading.
A piece of DNA is introduced into the cells that makes them recognise HIV as a threat, stimulating the body's natural cellular defence mechanism to prevent the HIV-infected cell from replicating.
"Our approach has been to take blood stem cells and T-cells out of patients that are HIV infected and introduce into these cells genes that produce products that inhibit HIV replication," Rossi told the International Aids Society conference in Sydney, Australia.
"This would be long-term, this is a permanent modification of these cells, so that as long as these cells persist in the patient, they will have resistance to the HIV infection."
Rossi said the ultimate goal of the research was to either completely control the HIV virus or reduce its presence in patients to such an extent that they needed fewer drugs to survive.
"It's a landmark trial in many ways and we're very excited about being the first people in the world to do this," he said.
Methamphetamine link
The conference also heard that a US study showed a link between HIV infection in gay men and increased use of drugs such as methamphetamines.
Researcher Christopher Hurt from the University of North Carolina said the study showed that between 2000 and 2005, the proportion of HIV-positive U.S. men under 30 who also took club drugs almost tripled from 1.7 to five per cent.
Hurt said research confirmed that gay sex and club drugs were a dangerous combination. "Gay men were already at risk and now they're becoming even more vulnerable."
Hurt said increased use of drugs such as methamphetamine had the potential to dramatically increase HIV infection rates among gay men.
"The libido is stimulated on methamphetamine and we also know that if you stay awake for hours and hours and hours you're more likely to have marathon sessions of sex," he said. "And more sex equals more risk for this group."
