Saturday, December 13, 2008
Cured of HIV
[Photo of bone marrow cell from Time Magazine]
It seems that for the first time, a person may have been cured of HIV. This is huge news, but at the same time of questionable relevance to the public health world and the millions living with HIV/AIDS.
An American patient with HIV and leukemia underwent a bone marrow transplant to treat the cancer. What is different is that the doctor took advantage of the situation to carry out an experiment: he used bone marrow of a donor that had a genetic mutation that made him virtually immune to HIV infection.
The mutation prevents a molecule called CCR5 from appearing on the surface of cells. Without CCR5, the HIV virus can't enter cells. It seems that about 1% of caucasians have the mutation from both parents, which makes them virtually immune to HIV. Another 20% of white people are thought to have one copy of the mutation, which makes them somewhat less susceptible to the disease.
The discovery that some people seemed to be immune to HIV was a breakthrough in its own right, and started people thinking about how that knowledge can be used to prevent or treat HIV/AIDS in others. This latest discovery, is a significant step forward. Unfortunately, even if the patient remains free of HIV, which is by no means guaranteed, the treatment is hardly replicable. Bone marrow transplants are no joke; 30% of patients die during surgery. But this raises the prospects of finding a means of prevention or cure through gene therapy.