SAN FRANCISCO (CBS 5) — A 45-year-old man now living in the Bay Area may be the first person ever cured of the deadly disease AIDS, the result of the discovery of an apparent HIV immunity gene.

Timothy Ray Brown tested positive for HIV back in 1995, but has now entered scientific journals as the first man in world history to have that HIV virus completely eliminated from his body in what doctors call a “functional cure.”

Brown was living in Berlin, Germany back in 2007, dealing with HIV and leukemia, when scientists there gave him a bone marrow stem cell transplant that had astounding results.

“I quit taking my HIV medication the day that I got the transplant and haven’t had to take any since,” said Brown, who has been dubbed “The Berlin Patient” by the medical community.

Brown’s amazing progress continues to be monitored by doctors at San Francisco General Hospital and at the University of California at San Francisco medical center.

“I’m cured of HIV. I had HIV but I don’t anymore,” he said, using words that many in the scientific community are cautiously clinging to.

Scientists said Brown received stem cells from a donor who was immune to HIV. In fact, about one percent of Caucasians are immune to HIV. Some researchers think the immunity gene goes back to the Great Plague: people who survived the plague passed their immunity down and their heirs have it today.

UCSF’s Dr. Jay Levy, who co-discovered the HIV virus and is one of the most respected AIDS researchers in the world, said this case opens the door to the field of “cure research,” which is now gaining more attention.

“If you’re able to take the white cells from someone and manipulate them so they’re no longer infected, or infectable, no longer infectable by HIV, and those white cells become the whole immune system of that individual, you’ve got essentially a functional cure,” he explained.

UCSF’s Dr. Paul Volberding, another pioneering AIDS expert who has studied the disease for all of its 30 years cautioned that while “the Berlin Patient is a fascinating story, it’s not one that can be generalized.”

Both doctors stressed that Brown’s radical procedure may not be applicable to many other people with HIV, because of the difficulty in doing stem cell transplants, and finding the right donor.

“You don’t want to go out and get a bone marrow transplant because transplants themselves carry a real risk of mortality,” Volberding said.

He explained that scientists also still have many unanswered questions involving the success of Brown’s treatment.

“One element of his treatment, and we don’t know which, allowed apparently the virus to be purged from his body,” he observed. “So it’s going to be an interesting, I think productive area to study.”

Volberding continued, “Knock on wood, (Brown) hasn’t had any recurrence now for several years of the virus, and that hasn’t happened before in our experience.”

As a result, at the San Francisco AIDS Foundation some are now using the word “cure” after so many avoided it for decades.

“You sort of felt like you couldn’t say ‘cure’ for a number of years. Scientists and clinicians and people with HIV alike felt that was a promise that was never going to be realized and it was dangerous to direct a lot of energy toward it,” said Dr. Judy Auerbach. “And now things have shifted.”

The California Institute of Regenerative Medicine is currently funding stem cell research in the Bay Area based on Brown’s case in the hopes of replicating his success for broader populations of people with HIV.

The institute said it plans to begin clinical trials next year.

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