Last summer, researchers in Boston announced that they had two patients, men who had battled HIV for years but who now appeared to be virus free. The men had received a treatment similar to that of Timothy Ray Brown, the "Berlin Patient". Like Brown, the men had cancer and had received radiation and chemotherapy treatments followed by bone marrow transplants. But there were some key differences. Brown's radiation and chemo regimes were much harsher, for one thing. For another, his new bone marrow came from a donor with the CCR5-delta32 mutation, which seems to provide natural resistance to HIV infection. The Boston men got their new bone marrow from donors who did not have that mutation.
Nevertheless, both men had seen their viral loads fall to undetectable levels. They hit the news in July after being off of antiretroviral drugs for seven and 15 weeks, respectively, with no return of the virus. Unfortunately, the virus re-emerged in one of the two men the very next month. It re-emerged in the other man in November.
It's worth noting that scientists have never touted the Berlin Patient treatment as a good idea for the majority of HIV patients. As dangerous as it is expensive, it's not worth the risk for anyone who doesn't already have a cancer that requires bone marrow transplantation. Nor is it practical for the millions of HIV patients who lack access to high-tech medical intervention. Instead, trying this treatment is more about learning. Scientists want to know more about how HIV works and where it hides in the body, in hopes that they can discover something that will enable them to help a wider swath of people.
Henrich and other researchers say bone marrow transplants, which are risky and can be lethal, are not a practical or ethical approach to treating HIV, especially in patients who do not have cancer.
But the Boston findings help researchers better understand how and where HIV persists in the body, potentially helping them design treatments that may be more precise in eradicating the virus.
Henrich's team is now scouring its data to figure out why one patient was able to fend off the virus's return months longer than the other patient they studied. Among the factors they are scrutinizing are the age when each was infected with HIV, the manner of infection, and the levels of virus in each patient before they underwent bone marrow transplantation.