The man in London has been off his anti-retroviral therapy common among HIV positive patients, for the past 18 months. However, researchers say this does not change the fate of 30 million people suffering from HIV.
A man from London has become the second person to be free of HIV as a result of a stem cell transplant reports the Daily Mail. The transplant was done in treatment for the man's cancer. According to the report, doctors had hoped that they could find a donor who would have the 'HIV-resistant genes that could also wipe out his cancer and virus in one fell swoop'. The man had contracted the HIV positive virus back in 2003 and was getting anti-retroviral therapy (ART), commonly used by HIV positive patients. But in 2016, he was diagnosed with a type of cancer that goes by the name of Hodgkin's Lymphoma. This, unfortunately, was more life-threatening than his HIV-positive virus and required immediate treatment. The only other person to have survived the same life-threatening technique was Timothy Ray Brown also commonly referred to as the 'Berlin Patient' since his treatment took place in Germany 12 years ago. There are similarities in the two cases in the fact that they were both HIV positive and both had cancer (Brown had leukemia) and were borh treated for their respective cancers through stem cell transplants leading to its remission.
While the two cases of definitely shine a light on AIDS and cancer treatment of the future, researchers and doctors who carried out the latest procedure say that the way forward needs caution since the same treatment cannot be administered to just about anyone. After the Berlin case, many hailed it as a breakthrough. However, every other attempt in the intervening years on the same lines has been unsuccessful with many cases having devastating consequences.
Experts have threfore cautioned that the reality for the 37 million people living with HIV does not change at all. Apart from living with HIV, both men were in the advanced stages of cancer. For them, a life-threatening and complex stem cell transplant was the last resort. Stem cell therapy is known to be dangerous and an improbable option compared to taking a daily pill and going for ART. Many have gone on to live for years on this treatment.
Dr Anthony Fauci, head, HIV/AIDS division at the National Institutes of Health, said, the recent case of the successful stem cell therapy 'fortifies the proof of concept' shown in the Berlin patient that donor cells from someone who is HIV-resistant can wipe out a recipient's HIV but only if they survive the transplant. "It's completely non-practical from the standpoint for the broad array of people who want to get cured."
He further added, "If I have Hodgkin's disease or myeloid leukemia that's going to kill me anyway, and I need to have a stem cell transplant, and I also happen to have HIV, then this is very interesting. But this is not applicable to the millions of people who don't need a stem cell transplant." Another leading expert in the field, Dr Janet Siliciano of Johns Hopkins, acknowledged that the findings have limited impact in a real-world sense although it showed that the first case was not a fluke.
She said, "I think it's very exciting. Now we know that it's not just the Berlin patient. Now we know that n=2." The case was published in the science journal Nature and involved reports by researchers from four universities - University College London, Imperial College, Oxford University and Cambridge University.
Most people carry a gene called the CCR5. This is the gene that HIV targets and uses as an entry point into the immune system. A minority in the world, around 1 percent of the population of the world, carry a mutation of this gene that prevents it from expressing and blocking the gene altogether. As a result, such people are genetically resistant to the HIV virus. Such a group has also earned the name - 'elite controllers' - because they naturally 'control' the virus as if they were on virus-suppressing medication.
Like the Berlin patient, the London patient's doctors found a donor with a CCR5 mutation. About 1 percent of these 'elite controllers' group descend from northern Europeans, inherited the mutation from both parents and are immune to most HIV. The donor had this double copy of the mutation too. Researcher Ravindra Gupta of University College London said, "That's why this has not been observed more frequently."
The patient voluntarily stopped taking HIV drugs to see if the virus would come back - something doctors do not typically recommend because it hasn't worked since the Berlin patient. What's more, the Berlin patient's case was slightly different - he stopped taking his anti-retroviral therapy before his transplant. Out of caution, the London patient's doctors kept him on his drugs throughout. In a sense, the transplant changed the London man's immune system, giving him the donor's mutation and HIV resistance.