A second patient has been declared free of the HIV virus after receiving stem-cell treatment though researchers say that it is premature to conclude that the patient has been cured of the disease. A paper on this research was published in Nature on March 5, 2019.
The UK patient, who has only been identified as male, had been diagnosed with both HIV and advanced Hodgkin’s lymphoma. He had undergone chemotherapy to treat his cancer and had received a stem-cell transplant that replaced his white blood cells with HIV-resistant versions from a donor. Rather than just any donor, the London patient was given a stem-cell transplant from a donor who had two mutated copies of the CCR5 gene. CCR5 is the most commonly used receptor by HIV-1 and people who have two mutated copies of the gene are resistant to the HIV infection since the virus is unable to enter host cells. Roughly just one percent of people of European descent have two copies of this mutation and are resistant to HIV infection.
The study reports that the patient was able to stop taking antiretroviral drugs, a standard treatment for HIV, after 16 months. He has now been in remission from cancer and HIV for 18 months.
Scientists from University College London, Imperial College London, University of Cambridge and University of Oxford contributed to this research.
“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,” said Professor Ravindra Gupta, the study’s lead author, 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,” he added.
This is not the first time this therapy was used to free a patient from the HIV virus. About 10 years ago, Timothy Ray Brown, aka the “Berlin patient,” also underwent this stem-cell treatment and is still in remission from the virus. Brown, who had been diagnosed with HIV and a form of blood cancer, had received a much more aggressive treatment in the form of two transplants, total body irradiation (radiotherapy) and a chemotherapy drug. He had also received a stem-cell transplant from a healthy donor who had natural immunity to the HIV virus.
“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,” said Professor Gupta.
However, experts have said that this treatment would not be suitable for most patients who have HIV, but do not have cancer and will therefore not require a bone-marrow transplant, a serious procedure with potentially fatal complications. Researchers have warned that this approach is not appropriate as a standard HIV treatment, but it offers hope for a new generation of treatment strategies that might eliminate HIV altogether.
Professor Eduardo Olavarria, who was also involved in the study, 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.”