Researchers will be presenting details on a British HIV patient
who has gone into remission after stem-cell treatment today at the Conference
on Retroviruses and Opportunistic Infections currently being held in Seattle.
It will coincide with the release of a study on the case published in the
journal Nature.

Timothy Brown, the so-called “Berlin patient” who underwent
similar treatment in Germany in 2007 is, according to experts, still HIV-free.

Reuters reports that the British man received a bone marrow
transplant from an HIV resistant donor three years ago and since coming off ARVs
18 months ago, sensitive tests still show no trace of infection.

 “There is no virus
there that we can measure. We can’t detect anything,” said Ravindra Gupta, a
professor and HIV biologist who co-led a team of doctors treating the man.

The case is a proof of the concept that scientists will one
day be able to end AIDS, the doctors said, but does not mean a cure for HIV has
been found.

Gupta described his patient as “functionally cured” and “in
remission” but cautioned: “It’s too early to say he’s cured.”

Gupta, now at Cambridge University, treated the London
patient when he was working at University College London. The man had
contracted HIV in 2003, Gupta said, and in 2012 was also diagnosed with Hodgkin’s

In 2016, when he was very sick with cancer, doctors decided
to seek a transplant match for him. “This was really his last chance of
survival,” Gupta told Reuters in an interview.

The donor – who was unrelated – had a genetic mutation known
as ‘CCR5 delta 32’, which confers resistance to HIV.

The transplant went relatively smoothly, Gupta said, but
there were some side effects, including the patient suffering a period of
“graft-versus-host” disease.

Most experts say it is inconceivable such treatments could
be a way of curing all patients. The procedure is expensive, complex and risky.
To do this in others, exact match donors would have to be found in the tiny
proportion of people — most of them of northern European descent — who have the
CCR5 mutation that makes them resistant to the virus.

Specialists said it is also not yet clear whether the CCR5
resistance is the only key – or whether the graft versus host disease may have
been just as important. Both the Berlin and British patients had this
complication, which may have played a role in the loss of HIV-infected cells,
Gupta said.

Sharon Lewin, an expert at Australia’s Doherty Institute and
co-chair of the International AIDS Society’s cure research advisory board, told
Reuters the London case points to new avenues for study.

“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.