Second Person Goes Into HIV Remission After Stem Cell Treatment

A second person has gone into remission from HIV after receiving a stem cell transplant, doctors announced on Monday.

The man, known as the "London patient" was being treated for advanced Hodgkin's lymphoma—a type of cancer that affects the blood. He was given a transplant of hematopoietic stem cells from a donor with two copies of a mutation relating to CCR5—a protein on the surface of white blood cells plays a role in the immune system. CCR5 is known to be a co-receptor for HIV, so its mutations can boost resistance to infection.

Since the transplant, the London patient has had undetectable levels of HIV for 18 months. His doctors say it is too early to say he has been cured.

His case has been published in the journal Nature.

"At the moment the only way to treat HIV is with medications that suppress the virus, which people need to take for their entire lives, posing a particular challenge in developing countries," lead author Ravindra Gupta said in a statement. "Finding a way to eliminate the virus entirely is an urgent global priority, but is particularly difficult because the virus integrates into the white blood cells of its host."

The London patient is only the world's second person to go into remission from HIV. The first, Timothy Ray Brown—previously known as the "Berlin patient"—received a similar but more aggressive form of treatment for his leukemia. In 2007, Brown received a hematopoietic stem cell transplantation from a donor with two genetic copies of the CCR5 receptor, then had another transplant a year later following a relapse. He has been in remission ever since and is said to be the first person in the world to have been cured of HIV.

Doctors have since tried to replicate Brown's treatment but without success.

Following his bone marrow transplant, the London patient also got two copies of the CCR5 receptor. After an interruption to his anti-retroviral therapy, which would normally keep the HIV under control, doctors discovered HIV was undetectable.

The researchers said the latest findings show that Brown's case was not a one-off, and that there were ways to target the CCR5 receptor to treat HIV.

"By achieving remission in a second patient using a similar approach, we have shown that the Berlin patient was not an anomaly, and that it really was the treatment approaches that eliminated HIV in these two people," Gupta said. "Continuing our research, we need to understand if we could knock out this receptor in people with HIV, which may be possible with gene therapy."

Eduardo Olavarria, one of the study's co-authors, said: "While it is too early to say with certainty that our patient is now cured of HIV, and doctors will continue to monitor his condition, the apparent success of haematopoietic stem cell transplantation offers hope in the search for a long-awaited cure for HIV/AIDS."

Following the announcement, doctors not involved in the case said it was a step forward toward finding new treatments for HIV.

Graham Cooke, from Imperial College London, said: "This second London patient, whose HIV has been controlled following bone marrow transplantation, is encouraging. Other patients treated in a similar way since the Berlin patient have not seen similar results. This should encourage HIV patients needing bone marrow transplantation to consider a CCR5 negative donor if possible.

"If we can understand better why the procedure works in some patients and not others, we will be closer to our ultimate goal of curing HIV. At the moment the procedure still carries too much risk to be used in patients who are otherwise well, as daily tablet treatment for HIV is usually able to maintain patient's long-term health."

Andrew Freedman, from the U.K.'s Cardiff University, said the case was interesting and potentially significant. "As with the Berlin patient who remains free of all traces of the virus more than 10 years later, this patient received stem cells from a donor with a specific genetic mutation rendering them resistant to HIV," he said.

"As the authors caution, it is still too early to be certain that this second patient has been cured of HIV. Much longer follow-up will be needed to ensure the virus does not re-emerge at a later stage.

"While this type of treatment is clearly not practical to treat the millions of people around the world living with HIV, reports such as these may help in the ultimate development of a cure for HIV. This is likely to be many years away and until then, the emphasis needs to remain on prompt diagnosis of HIV and initiation of life-long combination antiretroviral therapy (cART). cART is highly effective both in restoring near normal life expectancy and preventing onward transmission to others."

This article has been updated to include quotes from Ravindra Gupta and Eduardo Olavarria.