There have been no signs of the presence of the HIV virus in the past 19 months. For the second time in history, a patient with AIDS seems to have been cured of the infection. The news is reported by the scientific journal Nature that explains how the person, treated in London, is in withdrawal from the disease after finishing the treatment. About 12 years have passed since the first case of a patient treated in Berlin.

As more than a decade ago, also in this case the man, known only as “patient of London,” performed a transplant of bone marrow to treat a blood cancer, receiving stem cells from donors with a rare genetic mutation that prevents the HIV virus from taking hold. “By obtaining remission in a second patient with a similar approach, we have shown that the ‘Berlin patient’ was not an anomaly, ” said Ravindra Gupta , a professor at the University of Cambridge , referring to the first known functional cure. 

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Image: Axios

Millions of AIDS patients worldwide control the disease with so-called antiretroviral therapy, but treatment does not eliminate the virus from patients. “At the moment, the only way to treat HIV is with drugs that suppress the virus, which people have to take throughout life,” said Gupta. “This is a particular challenge in developing countries”. There are about 37 million people living with HIV worldwide, but only 59% receive antiretroviral drugs.

Gupta and his team stressed that the transplant of bone marrow – a dangerous and painful procedure – is not a viable option for the treatment of HIV. But a second case of remission and probable care after such a transplant will help scientists narrow down the range of treatment strategies. Both the London and the Berlin patients performed stem cell transplants from donors carrying a genetic mutation that prevents the expression of an HIV receptor known as CCR5. “Finding a way to completely eliminate the virus is an urgent global priority, but it is particularly difficult because the virus integrates into white blood cells,” explained Gupta.

The study carried out by his team describes an anonymous male patient in Britain who was diagnosed with HIV infection in 2003 and who has been on antiretroviral therapy since 2012. In the same year he was diagnosed with advanced Hodgkin’s lymphoma, a deadly cancer. He underwent a hematopoietic stem cell transplantation in 2016 from a donor with two copies of a variant of the CCR5 gene, a combination present in about 1% of the world population. People with this feature are resistant to most HIV-1 virus strains.

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Image: Evening Standard

After bone marrow transplantation, the London patient continued antiretroviral therapy for 16 months, then stopped. Tests have confirmed that the patient’s viral load has not been detected since then. The Berlin patient – treated for leukemia – received two transplants and underwent total body radiation, while the British patient received a less intensive transplantation and chemotherapy. 

The research group is presenting the results at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle, Washington. “A second case reinforces the idea that a cure is possible”, told La Presse Sharon R Lewin, Director of the Peter Doherty Institute for Infection and Immunity and the University of Melbourne. “A bone marrow transplant as a cure is not feasible, but we can try to find out what part of the transplant could have made the difference.”