16 Dec 2010 09:40
There has been a recent report of a man cured of HIV infection. I do hope it’s true but, having seen the ups and downs of the decades of this pandemic and knowing the biology of the disease, I sincerely doubt it.
The article appeared in the scientific journal Blood (http://bit.ly/icF40a); the report is not available to the public despite the fact that the research was funded by public money. However, it’s worth tracking down the report and the previous ones to which it refers (http://bit.ly/g9QwfU – in the New England Journal of Medicine—full text publicly available). In this report, a man was transplanted with stem cells following treatment for acute myeloid leukaemia—treatment for which included destroying his native immune system and bone marrow cells (where HIV lives). This outcome took several treatment attempts of chemotherapy and ‘ablation’ therapy until it was successful. The stem-cell transplant took hold and several years later, the man still has no detectable HIV in his blood-stream.
Nice. But there’s a wrinkle. There are a couple of highly separated compartments in the body, one of which is the brain. In order for HIV to get into the brain in the first case, it needs to be actively transported there; it can’t get there itself unless there’s a tear in what’s called the blood-brain barrier. The blood-brain barrier is normally very difficult to cross and only specialist cells can do it. Of the few cells that can cross this barrier (using a set of molecular keys) is one of the monocyte-macrophage type—which happens to be one that HIV infects and uses to piggy-back across that barrier into the brain. This is how we get HIV-associated cognitive disorders and ‘dementia’. Having studied HIV-dementia and having grown bits of brain with HIV in the lab many years ago, it’s an area of particular interest to me. Having HIV in my own brain makes it of even greater interest.
A significant proportion of people with HIV have the virus in the brain. This man may well have had it too—and still have it; he may be the only one who has it in the brain and not the rest of the body. He may stay HIV-negative (by blood-test) for the rest of his life yet still come down in due course with HIV-dementia. Or, of course, the virus may find a way to get back into the rest of the body too in due course.
All in all, this is an interesting and extremely important case-report—but it’s not evidence of a ‘cure’. I do wish people—especially non-scientists such as these physicians on this team—would be very, very careful about using that term. And I wish groups like the AIDS Policy Project would be more circumspect and less political in their awards (http://bit.ly/etmf1w). It doesn’t help those of us who are actually living with the reality of the disease.