Esperance vs hype. Gero Hütter tried to contain excitement media about his "cured" patient at a press conference in Berlin.
Johannes Eisele / Reuters
Yet another rash of stories touting a putative cure HIV / AIDS has grabbed the media. This involves a man with both leukemia and HIV, who received a stem cell transplant specifically designed for both the treatment of her cancer and to its new blood cells resistant to HIV infection . As Wall Street Journal first reported on November 8, for nearly 2 years, man has not taken anti-HIV drugs, and doctors have not found the virus in his blood.
basic science behind the transplant sense. The man, an American living in Germany, received chemotherapy and radiation therapy for the ablation of its blood cells to the Charite Hospital in Berlin. Then, he received a bone marrow stem cell transplant from a person who naturally had a genetic mutation that disrupts a protein called CCR5. HIV uses this receptor to enter cells, and they become resistant to infection with HIV, he is paralyzed. Several gene therapy studies are underway that use similar strategies ( Science , August 3, 07, p. 612).
Like every previous recovery story, however, it has a long list of warnings. A real cure, for example, would mean that the infected person has become virus free. But as the human doctor, Gero Hütter, acknowledged at a recent meeting on viral persistence and eradication organized by the American Foundation for research against AIDS (amfAR), low levels of HIV may escape detection by all but the most sensitive tests, and these tests has not yet been performed on the patient's blood. Whenever "cured" people's blood was tested with these techniques in the past, the researchers found the virus. Indeed, the participants at the amfAR meeting agreed to double the only man "functionally" cured. It is possible, if not probable, that hosts the virus in tiny amounts in cells that are not ablated before her transplant
Other warnings also stress the limits of this advance. Removal of a person from the bone marrow and then transfused with the cells of the other is a high-risk procedure, leading to death in nearly one third of patients. Hütter said at a press conference in Berlin on November 12. "The therapy has a high mortality rate so that it can not be justified ethically other than in this particular situation where the patient must have a transplant because of another disease," he said . "I say this in order to reduce false hopes."
The procedure also costs somewhere in the neighborhood of $ 250,000, which puts it out of reach for most people infected with HIV worldwide. Finally, the American apparently still facing serious health problems, and HIV, if she is still in her body, could find a way into fortified blood cells: People who naturally have mutated CCR5 genes and thus no operating receptors were infected when HIV operates a related cellular receptor.
the bottom line is that the resistance does not equal full protection, said Mario Stevenson, who studies how HIV causes disease at the University of Massachusetts, Worcester. "It is a proof of concept for gene therapy, but it is not a cure."
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