LONDON/CHICAGO (Reuters) – Scientific investigation into the world’s second man cleared of the AIDS virus is zooming in on a gene and a treatment side-effect, as newly-enthused researchers strive to find a cure for the disease that has killed millions.
Known as the “London Patient”, the man had HIV and a type of blood cancer called Hodgkin’s lymphoma. He responded successfully to a bone marrow transplant from a donor with rare genetic resistance to HIV infection.
The transplant cleared the man’s cancer and his HIV, but the resistant genes may not be the sole cause of his HIV remission.
Since the pandemic began in the 1980s, more than 70 million people have been infected with HIV and about 35 million have died, most in Africa. Medical advances mean tests can detect HIV early, new drugs can control it, and there are ways to stop it spreading – but 37 million people still live with the virus.
The London Patient’s case gives fresh hope to scientists and pharmaceutical researchers who have spent decades looking for ways to end AIDS. HIV expert Sharon Lewin said two factors were probably at play in his success story: the genetic resistance and a transplant side-effect that attacks immune cells.
“The new bone marrow is resistant to HIV, and also the new bone marrow is actively eliminating any HIV-infected cells through something called ‘graft versus host’ disease,” said Ms Lewin, co-chair of the International AIDS Society’s cure research advisory board and a researcher at Australia’s Doherty Institute.
The London Patient joins the first case of this kind, Timothy Ray Brown – or the “Berlin Patient” – whose HIV was eradicated by a similar transplant treatment in 2007. It involved the destruction of his immune system and transplanted stem cells with a gene mutation called CCR5 that resists HIV.
The AIDS virus uses CCR5 to enter cells, but if the gene is mutated, HIV cannot latch onto cells and infect them.