Timothy Ray Brown, aka the “Berlin patient,” the only person to be cured of HIV, may finally have company. A decade after Brown became famous thanks to a stem cell transplant that eliminated his HIV infection, a similar transplant from a donor who has HIV-resistant cells appears to have cured another man, dubbed the “London patient.”
“This is a big deal,” says Sharon Lewin, who heads the Peter Doherty Institute for Infection and Immunity in Melbourne, Australia. “It tells us that Timothy Brown wasn’t a one-off.” Although the interventions that the two patients received could only be used on a tiny fraction of the 37 million HIV-infected people worldwide, their stories point to cure strategies that could be more widely applicable.
To treat blood cancers, both HIV-infected men received stem cell transplants from people who carried a mutation in the gene for CCR5, a cell surface molecule that many HIV strains use to infect cells. Beforehand, each had been treated with toxic chemicals in a “conditioning” regimen meant to kill off their existing cancerous
bone marrow cells. After HIV-resistant blood cells derived from the transplant supplanted the recipients’ vulnerable cells, the two patients stopped taking the antiretroviral (ARV) drugs that had been damping down their infections.