Back in 2007, Timothy Brown, an HIV-positive patient who also suffered from leukemia, was given a stem cell transplant. In November of 2008, the BBC reported that the patient, an American living in Berlin, appeared to no longer show signs of either HIV or leukemia.
Recently, Brown, often referred to as, simply, "the Berlin patient," gave an interview to the German magazine Stern, and AIDS Map published an update on the continuing story of his health. Here's the essence of why the treatment was successful:
The man received bone marrow from a donor who had natural resistance to HIV infection; this was due to a genetic profile which led to the CCR5 co-receptor being absent from his cells. The most common variety of HIV uses CCR5 as its ‘docking station’, attaching to it in order to enter and infect CD4 cells, and people with this mutation are almost completely protected against infection.
The million dollar question continues to be whether the solution is scalable. Since 2009, scientists have been investigating the possibility of "engineering and introducing CCR5-deficient stem cells," but even if they are successful, they "will be expensive, so in the early stages it is likely that they would be reserved for people with no remaining treatment options or a cancer requiring bone marrow or stem cell transfer."
AIDS Map notes that the treatment is not without its share of complications, and it's crucial to be clear that we haven't arrived at a widespread cure. Still, the possibility of an approach worth funding cause for some excitement—it certainly is for Mr. Brown.