July 24, 2012

Still Looking For AIDS Cure, But Scientists Are Optimistic

Lee Rannals for - Your Universe Online

An AIDS Conference in Washington D.C. on Tuesday gave hope in the search for finding a cure for the disease that caused nearly 30 million deaths since the 1980s.

With around 34 million people around the world living with HIV, experts say a cure is more crucial than ever before, because the rate of infections is outpacing the world's ability to medicate people.

"For every person who starts antiretroviral therapy, two new individuals are infected with HIV," Javier Martinez-Picado of the IrsiCaixa AIDS Research Institute in Spain told the International AIDS Conference in Washington on Tuesday.

He said scientists can now "envision a cure from two different perspectives," by either eradicating the virus from a person's body, or coaxing the body to control the virus on its own.

One extraordinary case came recently with a man in his 40s who was HIV-positive, and was diagnosed with leukemia.

Timothy Ray Brown needed a series of medical interventions, including total body irradiation and two bone marrow transplants from a compatible donor, who had a mutation in the CCR5 gene. People who do not have CCR5 are immune to HIV because the virus is unable to penetrate the cells.

"Five years after the (first) transplant the patient remains off antiretroviral therapy with no viral rebound," Martinez-Picado told the conference. "This might be the first ever documented patient apparently cured of an HIV infection."

Although the case has provided scientists with plenty of data for research, the process that has cured Brown carries a high risk of death and toxicity.

"Unfortunately this type of intervention is so complex and risky it would not be applicable on a large scale," he told the attendees.

A group who may possess some more secrets to finding a cure are known as "elite controllers." They test positive for HIV, but do not appear to have the virus in the blood, even without treatment. Researchers believe there may be a few hundred of these people in the world.

Another group is the post-treatment controllers, who are people that started therapy early, and are able to stop it without seeing the virus rebound. About five to 15 percent of HIV-infected people may fit this category.

Martinez-Picado talked about a "promising" study published in the journal Nature on Tuesday that looks into using new drugs to get rid of the virus when it holes up, or lies dormant in the immune system.

The University of North Carolina researchers studied eight HIV-positive men taking antiretrovials and probed how a lymphoma drug could activate and disrupt the dormant virus.

Patients who took the drug showed an average 4.5-fold increase in the levels of HIV RNA in their CD4+ T cells, which is evidence that the virus was being unmasked. This could be a potential strategy for attacking latent HIV infection.