Although it is generally thought that HIV/AIDS cannot be cured, many patients with the virus can live a mostly normal life with anti-viral treatment that keeps the virus at a low level.
No matter how successful transplants are in the patients who need them, it's unlikely they will ever be the primary way in which doctors treat people with HIV.
But it also effective against cancer because the new "graft" cells work better against the disease.
Nearly 1 million people die annually from HIV-related causes.
Harvard AIDS researcher Bruce Walker said that if you talk to people who are taking HIV medications, they desperately want to get off them. It also suggests that this is a promising avenue to pursue in our quest for a long-term HIV cure. "But it also underscores the scale of the task ahead".
Globally, 36.9 million people were living with HIV in 2017. Drug resistance is one of the main concerns.
There is good reason, however, to believe that the London Patient's recovery offers a viable pathway to combat HIV. A conditioning regimen, which may include chemotherapy and radiation to the entire body, prepares a patient to accept a stem cell treatment, such as a bone marrow transplant, by making room for the new stem cells. In addition, they are not affordable to most. But in the process, doctors used donors who had a genetic mutation rendering them, and their bone marrow cells, resistant to the virus.
It took considerable effort, but the researchers were able to find a donor who fit the bill. The London patient infected with HIV and Hodgkin's lymphoma received bone marrow cells from a donor who had a defective CCR5 gene in his cancer treatment.
Wu Hao, a professor of infectious diseases at Beijing Youan Hospital, said the research is important and may have value in the search for a cure for HIV patients.
Graphic on how HIV attacks white blood cells.
"Stem cell transplants are an established treatment, particularly for blood related cancer with 70 per cent success rate". Unfortunately, the treatment the Berlin and London patients had have failed in other patients, so it is not considered a cure. If adapted to immunotherapy and other treatments already coming into broad use, it could pave the way toward a cure. "We need to understand if we could knock out this (CCR5) receptor in people with HIV, which may be possible with gene therapy", he said. Cells without a working CCR5 receptor are essentially locked up to the virus. "I think that finding a scalable cure that is safe and can be applied to a vast majority of individuals living with HIV is definitely attainable, but we have a lot more work to go".
For starters, the HIV-1 virus adapts quickly to new environments and has proven adept at developing workarounds to survive. That person, dubbed the "Essen patient", died. He and his colleagues will continue to monitor the man's condition, as it is still too early to say that he has been cured of HIV.
Moreover, there is still the question of what will happen if the patient misses a shot. The patient's name, nationality or age has not been made public.
Gene therapy might be another way to go, said Dr. Jeffrey C. Laurence, an oncologist and HIV researcher at Weill Cornell Medicine's Center for Blood Disorders in NY.
Nevertheless, these latest results support targeting CCR5 as a therapeutic approach for HIV infection, possibly involving a gene-editing strategy created to introduce a mutation into the CCR5 gene of a patient's own cells, although it's still early days.