A 42 year old unnamed American man living in Berlin is allegedly cured of AIDS. While living with HIV/AIDS for more than a decade, the patient developed leukemia unrelated to the disease. Before recieving a marrow transplant however his doctor recalled that some people carry a genetic mutation that seems to make them resistant to HIV infection. If the mutation, called Delta 32, is inherited from both parents, it prevents HIV from attaching itself to cells by blocking CCR5, a receptor that acts as a kind of gateway. Roughly one in 1,000 Europeans and Americans have inherited the mutation from both parents, and out of a pool of 80 suitable donors, the 61st person tested carried the proper mutation.
Before the transplant, the patient endured powerful drugs and radiation to kill off his own infected bone marrow cells and disable his immune system — a treatment fatal to between 20 and 30 percent of recipients. He was also taken off the potent drugs used to treat his AIDS. His medical team feared that the drugs might interfere with the new marrow cells' survival. They risked lowering his defenses in the hopes that the new, mutated cells would reject the virus on their own.
Anthony Fauci, director of the National Institute of Allergy and Infections Diseases in the U.S., said the procedure was too costly and too dangerous to employ as a firstline cure. But he said it could inspire researchers to pursue gene therapy as a means to block or suppress HIV.
"It helps prove the concept that if somehow you can block the expression of CCR5, maybe by gene therapy, you might be able to inhibit the ability of the virus to replicate," Fauci said.
David Roth, a professor of epidemiology and international public health at the London School of Hygiene and Tropical Medicine, said gene therapy as cheap and effective as current drug treatments is in very early stages of development.
"That's a long way down the line because there may be other negative things that go with that mutation that we don't know about."
Even for the patient in Berlin, the lack of a clear understanding of exactly why his AIDS has disappeared means his future is far from certain.
"The virus is wily," Huetter said. "There could always be a resurgence."
Before the transplant, the patient endured powerful drugs and radiation to kill off his own infected bone marrow cells and disable his immune system — a treatment fatal to between 20 and 30 percent of recipients. He was also taken off the potent drugs used to treat his AIDS. His medical team feared that the drugs might interfere with the new marrow cells' survival. They risked lowering his defenses in the hopes that the new, mutated cells would reject the virus on their own.
Anthony Fauci, director of the National Institute of Allergy and Infections Diseases in the U.S., said the procedure was too costly and too dangerous to employ as a firstline cure. But he said it could inspire researchers to pursue gene therapy as a means to block or suppress HIV.
"It helps prove the concept that if somehow you can block the expression of CCR5, maybe by gene therapy, you might be able to inhibit the ability of the virus to replicate," Fauci said.
David Roth, a professor of epidemiology and international public health at the London School of Hygiene and Tropical Medicine, said gene therapy as cheap and effective as current drug treatments is in very early stages of development.
"That's a long way down the line because there may be other negative things that go with that mutation that we don't know about."
Even for the patient in Berlin, the lack of a clear understanding of exactly why his AIDS has disappeared means his future is far from certain.
"The virus is wily," Huetter said. "There could always be a resurgence."
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