Why Some With HIV Are Healthier 

01:10 PM Sep. 26, 2002 PDT

Researchers at Rockefeller University in New York have used a protein chip technology to identify three proteins, called alpha-defensins, that allow a small number of HIV patients to remain healthy after contracting HIV.

They hope their findings will lead to a treatment for AIDS, which affects 40 million people worldwide and has killed 25 million.

"This is not going to be the ultimate solution but it is another weapon we can use in our arsenal against HIV," Dr. David Ho of the Aaron Diamond AIDS Research Center at Rockefeller, who helped lead the study, said in a telephone briefing.

Linqi Zhang, an associate professor who also participated in the study, said the study is a big step, but patients won't reap immediate rewards.

"In the short term it's safe to say the affected community should pay attention to this, but it will not make any difference to them tomorrow," he said.

The discovery will surely spur new studies on the mechanism of these proteins that could lead to treatments, he said.

The proteins themselves are too large and unwieldy to be used directly as drugs, the researchers said.

Since 1986, researchers have known that in certain HIV-infected patients the CD8 cells were making something unique, but they didn't know exactly what it was.

Long-term non-progressors are not immune to HIV. Their CD8 cells cut the activity of HIV by between 40 and 60 percent, and eventually they do start to become ill.

HIV patients now can take a cocktail of drugs called highly active antiretroviral therapy or HAART, which can keep them well for years. But the drugs are not a cure, they have serious side effects, are expensive and eventually the virus infecting each patient mutates so that they do not work as well.

A technology called the ProteinChip invented by Ciphergen Biosystems helped the researchers identify the three alpha-defensins.

The alpha-defensins have a very low molecular weight, which made them difficult to identify using older technologies, said Ciphergen chief financial officer Matthew Hogan.

The Rockefeller researchers are now doing further work to find out exactly how the proteins block the progression of AIDS.

Other AIDS researchers said Ho's study, published in the journal Science, did not explain the whole story of long-term non-progressors.

The immune systems of non-progressor patients also make a compound called beta-chmokines. Their exact function remains unknown.

Ho stressed that much more work needs to be done.

"We wish to be somewhat cautious. I think it is not entirely clear whether we could take this discovery and turn it into a useful therapy," he said.

Reuters contributed to this report.