The world's second HIV patient is cured

According toNew York Times, scientists describe this case as a long-term remission. Timothy and this second patient both received bone marrow transplants intended to treat cancer, not HIV.

Is bone marrow transplantation an effective cure for HIV?

Bone marrow transplantation is unlikely to be a realistic treatment option in the near future. Powerful drugs are currently available to control HIV infection, but transplants carry many risks, with serious side effects that can last for years.

However, experts say feeding the body with transplanted immune cells to fight HIV could be as successful as an actual treatment.

Dr. Annemarie Wensing, a virologist at the University Medical Center Utrecht (Netherlands), said this should inspire people that a cure is not a dream, but a reality.

HIV virus (blue) attacks white blood cells (orange). Photo:NIBSC.

The anonymous patient, in London (UK), called "The London Patient", said he felt it was his responsibility to help doctors understand how the disease happened so they could research it.

When scientists told him he might have been cured of both cancer and HIV, the patient was stunned. "It's truly extraordinary. I never thought there would be a cure in my lifetime," the London patient said.

The man had Hodgkin lymphoma and received a bone marrow transplant from a donor with the CCR5 mutation in May 2016. He was also treated with immunosuppressants. He stopped taking anti-HIV drugs in September 2017. Eighteen months later, he was completely HIV-free.

Dr. Ravindra Gupta, a virologist at University College London, said that although the man did not suffer as many illnesses as Timothy after the transplant, the procedure worked. The transplant killed the cancer without causing harmful side effects. The transplanted immune cells, now resistant to HIV, appeared to have completely replaced the vulnerable cells in the patient’s body.

So far, the study is following 38 people with HIV who have received bone marrow transplants. The London patient is the 36th on the list. Another person, number 19, known as the Dusseldorf patient, has been off HIV medication for four months.

The study’s scientists repeatedly analyzed the patients’ blood for signs of the virus. They found a trace of infection, albeit very small, in one of the 24 tests. However, it could just be the result of contamination in the sample.

The results showed no circulating virus in the tests. HIV antibodies were still present in the patients' blood, but the levels decreased over time, following a similar trajectory to that seen in Mr. Timothy.

The future of bone marrow transplantation

Some experts are uncertain about the relevance of bone marrow transplants to the treatment of AIDS in general because only two people have been cured.

"I'm not sure what this tells us," said Dr. Anthony Fauci, director of the UK's National Institute of Allergy and Infectious Diseases. "It worked for Timothy Ray Brown, and now we have another case. So now what? Now what do we do with it?"

The researchers say they will develop gene therapies to knock out CCR5 on immune cells or their precursor stem cells. These modified cells, which fight HIV, will eventually clear the virus from the body.

An important caveat to any similar approach is that patients remain vulnerable to a form of HIV called X4, which uses a different protein, CXCR4, to enter cells.

This would work if someone had a virus that actually only uses CCR5 to get in, said Dr. Timothy J. Henrich, an AIDS expert at the University of California, Berkeley. Even if a person only has a small amount of X4 virus, it can still replicate a lot.

In fact, one case of a bone marrow transplant that eliminated all HIV virus but then quickly relapsed due to X4. Even to guard against this virus, Mr. Timothy still takes daily medication to prevent relapse.