Two HIV-positive men, treated in a Boston hospital in 2008 and 2010 respectively, were thought to have been ‘functionally cured’ of HIV after being given bone marrow transplants from uninfected donors.
After several years of being apparently ‘virus free’, both men decided to stop antiretroviral treatment (ART).
Recently, however, it was reported that both men had seen the virus return after 12 and 32 weeks respectively. Both are now back on ART.
Researchers expressed disappointment with the result as it shows that HIV still persists even when some of the most sensitive blood tests fail to detect it. It may also show that there may be important long-lived reservoirs of HIV outside the blood compartment.
The Boston patients had been compared with Timothy Brown, an American who received a different type of stem-cell transplant to treat leukaemia. Unlike the Boston patients, his donor’s bone marrow also carried a specific mutation known to interfere with HIV’s ability to infect blood cells.
Brown continues to remain free of detectable levels of HIV.
The other hope of a possible ‘functional cure’ of HIV is a baby in Mississippi who was given antiretroviral drugs within hours of her HIV-positive mother giving birth. The baby appears to have remained free of the virus for the past three years.
Despite the HIV virus returning to the Boston patients, the president of the International AIDS Society, Nobel Prize-winning virologist Francoise Barre-Sinoussi, remains optimistic that a functional cure will one day be found.
"It exists naturally," she told The Guardian, "so we scientists should be able to induce it."