After receiving bone marrow transplants for cancer treatment, two Australian men are now, seemingly, HIV free.
The two men, having received bone marrow transplants for the treatment of lymphoma and leukemia, no longer have the HIV virus detectable within them. However David Cooper, the doctor who announced the findings during a press briefing ahead of the 20th International AIDS Conference, won’t go as far as calling the men cured. HIV can remain hidden within the body for years before re-activating itself and beginning to reproduce again. During this time, the virus cannot be properly targeted by antiretroviral therapy, and thus has a chance of returning at any time.The fact that the HIV has “disappeared” from the patients bodies is due to the bone-marrow donor having a rare variant of the CCR5 gene, which prevents the HIV virus from infecting targeted cells. The HIV virus typically uses the CCR5 gene (which is found on the surface of the white blood cell), to enter target cells. However, due to this rare variation in the gene, the virus is not able to. With the bone-marrow transplant, this gene is now present in the bodies of the two Australian men. However, they still risk the virus returning in the future if they don’t continue strict retroviral treatment.
This said, a person has been previously “cured” of HIV follow a bone marrow transplant. American Timothy Brown received a bone marrow transplant in 2008, in an effort to treat leukemia. Since then, even without continuing the antiretroviral treatment, he has remained free of the virus. This was due to both Mr. Brown and the bone marrow donor having the CCR5 gene variant within them prior to the transplant.
Bone marrow transplants do have a 10% morality rate, so its not quite the quick fix people wish it could be. However, personalized gene therapy may let doctors use the CCR5 gene to “cure” the disease in the future. The more we study the HIV virus, which was used to kill cancer cells in a child last year, the more chance we stand of eradicating it.