Breakthrough hope after second man ‘cured’ of HIV
Genetically editing HIV patients to stop the virus attaching to their immune system could be on the horizon after a British man was ‘‘cured’’ of the disease using mutated stem cells.
In 2016, a man named only as ‘‘The London Patient’’ received stem cells from a donor with natural immunity to HIV at Hammersmith Hospital, and doctors announced yesterday he has been free of disease for 18 months.
Natural immunity occurs in some people through a gene mutation which stops the growth of a little docking arm on the outside of white blood cells that allows HIV to grab on.
But transplanting stem cells between strangers is dangerous, requiring patients to undergo chemotherapy to strip away their own immune system first.
Donors carrying the mutation are also rare, so instead specialists want to develop gene therapy to insert the protective variant of the CCR5 gene.
‘‘Continuing our research, we need to understand if we could knock out this receptor in people with HIV, which may be possible with gene therapy,’’ said Prof Ravindra Gupta, of University College London and the University of Cambridge, the study’s lead author.
The breakthrough comes 10 years after the first patient was cured of HIV. Known originally as ‘‘The Berlin Patient’’ and later identified as Timothy Ray Brown, an American, he also received a transplant of stem cells – yet attempts to replicate his cure have all failed until now.
‘‘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,’’ added Prof Gupta. ‘‘By achieving remission in a second patient, we have shown the Berlin Patient was not an anomaly, and that it really was the treatment approaches that eliminated HIV in these two people.’’
A new gene therapy would use a kind of molecular scissors to snip away the common CCR5 gene and replace it with the mutated version.
Last year, a Chinese scientist shocked the world by genetically editing the embryos of two babies to give them the same mutated gene and protect them against HIV. Despite being globally condemned, it proved such therapies are possible.
Tweaking the genetic code of adults is likely to prove less controversial, and the first trials to genetically edit humans using a technique called Crispr are already under way for blood disorders like beta thalassaemia.
The new patient, who has chosen to remain anonymous, is said to be in ‘‘sustained remission’’, with doctors hopeful he is now completely disease-free. ‘‘The patient is very well and is living a normal day-to-day life,’’ said study author Prof Eduardo Olavarria, of Imperial College Healthcare NHS Trust and Imperial College London.
‘‘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 stem cell transplantation offers hope in the search for a longawaited cure for HIV/Aids. Using Crispr to genetically engineer a patient’s own cells could be a possibility, though there are no trials yet as the technology isn’t quite ready.’’
Anton Pozniak, president of the International Aids Society, said the new results represented a ‘‘critical moment in the search for an HIV cure’’.
‘‘These new findings reaffirm our belief that HIV is curable,’’ he said. ‘‘The hope is this will eventually lead to a safe, costeffective and easy strategy to achieve these results using gene technology, or antibody techniques.’’
Timothy Ray Brown, the original ‘‘Berlin Patient’’, said: ‘‘It proves that HIV can be cured and that’s what basically gives people hope. It gives the scientists hope that they should keep looking for finding cures for HIV, and also gives patients hope that there will be a cure that will help them one day. It’s a wonderful thing not having to wake up in the morning and know I have to take medication.’’
The research was published in the journal Nature .– Telegraph Group