HIV/AIDS cured through stem-cell transplant in London

Only two persons have defeated the human immunodeficiency (HIV) virus so far. The first, called the Berlin Patient, beat acquired immunodeficiency syndrome (AIDS) after two stem cell transplants a decade ago.

Now another person in London has fully got rid of the virus from his body. No traces of HIV RNA (ribonucleic acid) was detected in his bloodstream 18 months after antiretroviral therapy was stopped.

This person, called the London Patient, received a bone marrow transplant from a donor immune to HIV three years ago. The donor, who is unrelated to the patient, has a genetic mutation called CCR5 delta 32, which gives resistance to HIV. A very tiny percentage of the world's population have resistance to HIV, and most of them are of North European descent.

The procedure did not have too many complications, except a period when the donor’s immune cells attacked the recipient's immune cells. Not all HIV patients can be cured this way though; only those who also carry cancer have a fighting chance to beat HIV.

Scientist are not absolutely certain how the mechanism works.