Man Cured of HIV Received Immunity From Stem Cell Transplant
A man who tested positive for HIV in 1995 and who received a bone marrow stem cell transplant from someone with immunity to the disease has what doctors call a “functional cure.” According to the Daily Mail Online, researchers say that tests “strongly suggest that cure of HIV infection has been achieved” for Timothy Ray Brown.
One percent of Caucasians have immunity to HIV
Although human immunodeficiency virus (HIV) is a dreaded condition, not everyone who is exposed to the virus develops the disease. Scientists have determined that a small percentage of the population seems to be naturally resistant to the virus, and the reason seems to be a gene called CCR5.
According to Dr. Robin Kimmel at Stanford University, many individuals who are resistant to HIV have a mutated CCR5 gene, referred to as CCR5-delta32. Most forms of HIV are unable to infect cells if CCR5 is not on the surface.
People who have one copy of CCR5-delta32, which appears in up to 20 percent of Caucasians, seem to have some protection against HIV. The mutation also makes the disease less severe if they do contract the disease. However, people who have two copies of the CCR5-delta32 gene (which means they inherited it from both parents) are essentially immune to HIV infection. About 1 percent of Caucasians have both copies.
Brown, who now lives in the San Francisco Bay Area, was residing in Berlin, Germany, in 2007 when he received the bone marrow transplant. At the time he had both leukemia and HIV. He told CBS5 that “I quit taking my HIV medication the day that I got the transplant and haven’t had to take any since.”
Doctors at San Francisco General Hospital and at the University of California at San Francisco (UCSF) medical center continue to monitor the “Berlin Patient,” who says “I’m cured of HIV.” However, UCSF’s Dr. Paul Volberding and Dr. Jay Levy, both highly respected AIDS experts, emphasize that Brown’s transplant procedure may not be available for many people with HIV.
Such a bone marrow stem cell transplant procedure is difficult to perform, carries a risk of death, and requires the right donor. Scientists still have many unanswered questions about Brown’s treatment. There is also the possibility that HIV is still somewhere hidden in Brown’s body.
For now, it appears Brown has been cured of HIV as the result of a bone marrow stem cell transplant. The California Institute of Regenerative Medicine is now funding stem cell research based on this case and plans to initiate clinical trials in 2012.