This is sort of fascinating:

Doctors who carried out a stem cell transplant on an HIV-infected man with leukaemia in 2007 say they now believe the man to have been cured of HIV infection as a result of the treatment, which introduced stem cells which happened to be resistant to HIV infection.

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 ‘Berlin patient’ is an HIV-positive man who developed acute myeloid leukaemia, received successful treatment and subsequently experienced a relapse in 2007 that required a transplant of stem cells.

Doctors chose stem cells from an individual who had an unusual genetic profile: a mutation inherited from both parents that resulted in CD4 cells that lacked the CCR5 receptor. This mutation, called CCR5 delta 32 homozygosity, is present in less than 1% of Caucasians in northern and western Europe, and is associated with a reduced risk of becoming infected with HIV.

This is because all new infecting viruses need to use the CCR5 receptor on CD4 cells when infecting an immune system cell of the CD4 type.

It’s not a magic bullet, it seems, and if you read the entire piece, you’ll see that it was a grueling treatment created for a specific set of circumstances, but it could point scientists in the right direction in curing the damn disease once and for all.

[h/t Gawker]