A patient with HIV has been declared free of the virus after undergoing successful stem-cell transplantation for treatment of blood cancer
A person with HIV from Britain appears to be free of the virus after receiving a stem-cell transplant. Stem-cell transplant was carried out in this patient for treatment of a form of leukaemia that was not responding to treatment. This replaced the white blood cells with HIV-resistant versions in the London patient, according to a research published today in the journal Nature.
The stem-cell technique was first carried out in 2009 for Timothy Ray Brown from Berlin who also a had a form of treatment resistant blood cancer. Bone-marrow transplantation is a technique where blood cells of the patient is destroyed and replenished with stem cells transplanted from a healthy donor.
“If you’re well, the risk of having a bone-marrow transplant is far greater than the risk of staying on tablets every day”
A team of researchers led by Ravindra Gupta, an infectious diseases physician at the University of Cambridge, UK, picked a donor who had two copies of a mutation in the CCR5 gene, which gives people resistance to HIV infection. Normally, the HIV binds to these receptors and attacks the cells, but a deletion in the CCR5 gene stops the receptors from functioning properly. About 1% of people of European descent have two copies of this mutation and are resistant to HIV infection.
The team found that the virus completely disappeared from the patient’s blood after the transplant. The patient stopped taking anti-HIV (antiretroviral) drugs after 16 months, and even after 18 months of stopping medication the virus is undetectable says the researchers. The procedure successfully replaced the patient’s white blood cells with the HIV-resistant variant.
Gupta however, warns that the patient can only be called cured if the patient’s blood remains HIV-free for longer period.
Graham Cooke, a clinical researcher at Imperial College London, indicates that this kind of treatment wouldn’t be suitable for most people with HIV who don’t have cancer. “If you’re well, the risk of having a bone-marrow transplant is far greater than the risk of staying on tablets every day,” he says. Most people with HIV respond well to daily antiretroviral treatment.
But Cooke adds that for those who need a transplant to treat leukaemia or other diseases, it seems reasonable to try and find a donor with the CCR5 mutation, which wouldn’t add any risk to the procedure.