A second case of someone probably cured of HIV has been reported

ESTABLISHED HIVHIV infection is easy to control but impossible to cure. Or almost impossible. The exception seems to be Timothy Brown, a man often referred to as the Berlin patient. In 2006, after a decade of successfully suppressing his infection with antiretroviral drugs, Mr Brown developed an unrelated blood cancer, acute myeloid leukaemia. To treat this life-threatening condition he opted, the following year, for a blood-stem-cell transplant. And, at the same time, he volunteered as a guinea pig for an experimental anti- treatment, which worked. Now, a team of doctors in London have reported a similar case.Blood-stem-cell transplantation is an established, though extreme, treatment for various sorts of blood cancer. Stem cells are the precursors from which particular tissues grow. Blood-stem-cell transplantation involves using drugs (backed up, in Mr Brown’s case, by radiotherapy) to kill a patient’s natural blood-producing tissue, the bone marrow, and then transfusing in new stem cells from a donor.