AN American man is still HIV-free more than three years after receiving a stem cell transplant, suggesting the first-ever cure of the virus that causes AIDS.
But while the highly risky technique used on the man known as the ‘Berlin Patient‘ would not work for most of the 33 million people with HIV worldwide, scientists say the research shows important progress toward a universal cure.
“Our results strongly suggest that cure of HIV has been achieved in this patient,” said the study in the journal Blood, a publication of the American Society of Haematology.
The process began in 2006 when 44-year-old American Timothy Ray Brown, who had been HIV positive for more than a decade, sought treatment for acute myeloid leukaemia, a lethal blood cancer.
After a first round of chemotherapy failed, his German doctor, Gero Hutter, thought he would see if he could perform a bone marrow transplant using a donor with a rare genetic mutation that is naturally resistant to HIV.
About one in 100 Caucasian people, or 1% of the population, have the mutation, known as Delta 32, that prevents the protein CCR5 from appearing on the cell surface.
Since HIV enters the cell through CCR5 molecules, when they are absent HIV cannot penetrate.
After rejecting dozens of potential donors, Hutter found a match and performed the bone marrow transplant using stem cells from the HIV-resistant donor in February 2007.
Hutter’s first study, published last year, showed no sign HIV had re-emerged even though the patient had ceased anti-retroviral therapy to suppress HIV.
The latest findings show Brown still shows no trace of either the AIDS-causing virus or leukaemia.
But because Brown’s ordeal left him temporarily unable to walk or talk and statistics showing around 30% of patients do not survive bone marrow transplants, AIDS experts sounded a note of caution.
“I think we need a lot more research to try to replicate this without putting a patient’s life in danger,” said Karen Tashima, director of the HIV clinical trials programme at The Miriam Hospital in Rhode Island.
“Since we have good anti-retroviral therapy that can control the virus, it would be unethical to give somebody such an extreme treatment.”
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