As many as one in 300 HIV patients never get sick and never suffer damage to their immune systems and AIDS experts said on Wednesday they want to know why.

Most have gone unnoticed by the top researchers, because they are well, do not need treatment and do not want attention, said Dr. Bruce Walker of Harvard Medical School.

But Walker and colleagues want to study these so-called “elite” patients in the hope that their cases can help in the search for a vaccine or treatments.

“What in the heck is going on in people that successfully control this virus?” Walker asked a news conference held at the 16th International Conference on AIDS.

“If we can figure out how people are doing that, we can try to replicate it.”

So far Walker and colleagues have not been able to find out why certain people can live for 15 years and longer with the virus and never get ill. The AIDS virus usually kills patients within two years if they are not treated.

Some even appear to have weak immune responses, he noted. “Is it just that these people got infected with a wimpy virus? The answer to that is no,” Walker said.

“Some of the people know who infected them,” he added, and in those cases, the person who infected the “elite” patients always went on to become ill.

A few years into the AIDS epidemic, researchers identified people who were called “long-term non-progressors.” These were patients infected with HIV who did not become ill.

Many have become ill as the years have gone by, and required treatment.

Walker said a few of the long-term non-progressors were now classified as “elite” patients. But the difference is that the “elite” status is clearly defined by how much virus they have circulating in their blood.

Loreen Willenberg, of Diamond Springs, California, is a newly designated “elite.” Now 52 and healthy, she said she became infected in 1992.

BAD DREAM

“I dreamed that I was HIV positive,” Willenberg told the news conference. “I was really going through a very bad flu.” She sought testing, and after getting an inconclusive result was later declared HIV positive.

HIV patients are not immediately put onto drugs that can keep them healthy, but wait until the virus reaches a certain level in the blood or until the virus kills a certain number of immune system cells called CD4 T-cells.

Willenberg, a landscape designer, never got to that point. “I am in perfect health. I think I have had maybe only one cold in the past 14 years,” she said.

Walker has tracked down 200 elite patients and has now joined up with other prominent AIDS researchers to find at least 1,000 “elites” in North America and as many as possible globally.

Based on research done so far, Walker estimates there are 2,000 of them in the United States. His team wants to take blood and DNA samples to see what might be different about them. Confidentiality is promised.

The recently published map of the human genome will make this possible. They will compare key genetic sequences of the “elite” patients to genetic readouts from healthy people and from other HIV patients. Maybe a few genetic variations can explain what is happening, Walker hopes.