The story of the "Berlin Patient", Timothy Ray Brown, has popped up again in the news, as we approach the 30th anniversary of the discovery of HIV, the AIDS virus. The story is indeed captivating--Brown has experienced a functional cure of his AIDS due to a targeted adult stem cell transplant.

The story first broke in 2008, and initial transplant results were published in the New England Journal of Medicine. Brown was treated for leukemia with an adult stem cell transplant, which is becoming a standard treatment. But the doctors, knowing that Brown had AIDS, used specific adult stem cells from a donor selected because the donor's cells lacked a key protein, CCR5, that the AIDS virus must bind to infect a cell. Not only did Brown recover from his leukemia, but the AIDS virus seemed to disappear from his system.

More recently in late 2010, Mr. Brown was identified as the patient and the doctors put forth a tentative claim of a cure. The most recent paper, "Evidence for the cure of HIV infection by CCR532/32 stem cell transplantation", was published in the journal Blood.

It would be difficult to find a matching CCR5-negative adult stem cell donor for every AIDS patient, and the current treatment protocol can be rough, so this particular technique wouldn't be generally applicable to every AIDS patient, but the results provide a proof-of-principle for using adult stem cells lacking the virus target molecule, CCR5. Indeed, other researchers are working on altering a patient's own adult stem cells to resist HIV infection, and a few patients have participated in an initial clinical trial to test engineered adult stem cells as a potential treatment for AIDS.