Stem Cell Transplant Potentially "Cures" Second HIV Patient
Although cautious about using the word “cure,” researchers have described a second person globally to be cleared of HIV, the virus that causes AIDS. The first patient was Timothy Ray Brown, also dubbed the “Berlin Patient,” who was cured of HIV in 2007. The new study was published in the journal Nature. The new patient, who remains unnamed, is dubbed the “London Patient.”
Both Timothy Brown and the new patient were treated with stem cell transplants from donors carrying a rare genetic mutation called CCR5-delta 32. This made these patients resistant to HIV. The new patient has been in remission for 18 months after he stopped receiving antiretroviral drugs.
“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 Ravindra Gupta, lead author of the study and a researcher at the Division of Infection and Immunity at the University College London (UCL), reported CNN.
It is of note that the November 2018 story of Chinese researcher He Jiankui using gene editing technique CRISPR to alter the genes of human embryos is related. In seven couples, He disabled the CCR5 gene in embryos. The men in all seven couples had HIV and the women did not. The gene editing’s goal wasn’t to prevent transmission of HIV, He said, because all seven men’s HIV infections were strongly suppressed by standard HIV drugs. The researcher’s goal was apparently to give the children protection. To date, a pair of twins have been born from He’s controversial procedure, with another woman pregnant.
The London Patient will be continued to be monitored. Gupta indicates that it is too early to declare he has been cured of HIV. Gupta also notes that the method used is not appropriate for all patients. However, it does offer new hope for HIV patients and the potential of adding new treatment strategies, including gene therapies.
Although science has come a long way since HIV/AIDS emerged in the 1980s, the disease still affects about 37 million people globally, and about 1 million people die from HIV-related causes every year. Treatment typically involves a cocktail of antiretroviral therapy, which HIV patients take their entire lives.
The London Patient was a UK resident diagnosed with HIV in 2003. He began antiretroviral therapy in 2012. He was later diagnosed with advanced Hodgkin’s lymphoma. Gupta and his team treated him with a stem cell transplant in 2016 after he received chemotherapy. He then continued to receive antiretroviral therapy for 16 months.
Then, to evaluate whether the HIV-1 infection was actually in remission, he went off the usual antiretroviral therapy. He has been in remission for 18 months. Testing has confirmed that his HIV viral load is undetectable.
In the case of the Berlin Patient, Timothy Ray Brown, he had HIV and was being treated with antiretrovirals when he was diagnosed with acute myeloid leukemia (AML). After receiving two bone marrow transplants, he was determined to be cured of HIV-1.
A few years after he stopped antiretroviral therapy, small amounts of HIV were identified in his blood. However, he was considered clinically cured of his infection. Researchers and physicians have attempted similar approaches with HIV patients, but until now, Brown was the only person considered cured of HIV until the London Patient.
Sharon Lewin, director of the Peter Doherty Institute for Infection and Immunity and a professor of medicine at the University of Melbourne, told CNN, “Coming 10 years after the successful report of the Berlin Patient, this new case confirms that bone marrow transplantation from a CCR5-negative donor can eliminate residual virus and stop any traces of virus from rebounding.”
Lewin was not involved in this study. She went on to say, “Two factors are likely at play: The new bone marrow is resistant to HIV, and also, the new bone marrow is actively eliminating any HIV-infected cells.”
Although promising, it is not completely understood why the procedure works in some patients and not in others. Graham Cooke, a professor of infectious diseases at Imperial College London, stating to the Science Media Centre, said, “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.”
The technique used with the London Patient is not currently believed to be scalable, safe or economically viable for the general HIV population.