Doctors say that a British man living with HIV may be the second known adult to be “functionally cured” of HIV, following a stem cell transplant.
The man joins Timothy Ray Brown, who was the first person declared to be free of HIV after being given the treatment for leukemia in 2007.
The London patient was given the treatment three years ago, which involves transplanting stem cells containing a rare genetic mutation – CCR5 delta 32 – which resists HIV infection.
“There is no virus there that we can measure. We can’t detect anything,” said the man’s doctor, Professor Ravindra Gupta.
Gupta says that after three years and 18 months off antiretroviral treatment (ART), highly sensitive tests can still find no trace of HIV.
But Gupta cautioned against describing it as a cure, saying the London patient is “functionally cured” or “in remission”.
“It’s too early to say he’s cured,” he said.
Gupta’s caution is more than earned – there have been a handful of other cases in which doctors believed patients to be free of the virus, only to see it return.
In 2013 two American men were reported as potentially cured but later saw the virus return, while The Mississippi Baby was believed to be the first infant cured of HIV until the virus returned four years after treatment began.
The London patient became HIV-positive in 2003, before being diagnosed with Hodgkin’s lymphoma in 2012.
Gupta said the transplant was “his last chance of survival”, with the procedure going smoothly but leading to serious complications including a bout of graft versus host disease.
The procedure is only able to be performed under rare circumstances, requiring an exact match donor from a small group of people who have the CCR5 mutation. The procedure has a roughly 20% mortality rate.
Gupta said it may be significant that both patients experienced the graft versus host complication, and could suggest that the donor immune cells attacking the recipient’s immune system may play as much of a role in the process of eliminating HIV as the CCR5 mutation itself.
While the procedure is not feasible as a large-scale treatment for HIV, International AIDS Society cure research board co-chair Sharon Lewin said it gives researchers new avenues of study to explore.
“We haven’t cured HIV, but [this] gives us hope that it’s going to be feasible one day to eliminate the virus,” she said.
Gupta said that scientists “need to understand if we could knock out this (CCR5) receptor in people with HIV, which may be possible with gene therapy.”
The London patient has requested that his medical team not reveal his identifying details.