Bone marrow stem-cell therapy appears to have eradicated HIV in two patients
Both patients, who were treated in Boston and had been on long-term drug therapy to control HIV, received stem-cell transplants after developing lymphoma, a type of blood cancer.
Timothy Henrich from the Harvard Medical School says doctors have been unable to find any evidence of the HIV infection in the men since the transplants.
Dr Henrich, who made the announcement at an international AIDS Society conference in Kuala Lumpur, said it is too early to say for sure that the virus has disappeared from their bodies altogether.
However, he reported that one patient has now been off antiretroviral drug treatment for 15 weeks and the other for seven weeks.
Dr Henrich first reported last July that the two men had undetectable levels of HIV in their blood after their stem-cell treatment, but at that time they were still taking medicines to suppress HIV.
“Dr Henrich is charting new territory in HIV eradication research,” said Kevin Robert Frost, the chief executive officer of the Foundation for AIDS Research, which funded the study
The revelation has raised hopes for a cure of the virus, which infects about 34 million people worldwide, but experts in the field are urging caution until more work is done.
Using stem-cell therapy is not seen as a viable option for widespread use, since it is extremely expensive, but the latest cases could open new avenues for fighting the disease.
The latest cases resemble that of Timothy Ray Brown, known as “the Berlin patient”, who became the first person to be cured of HIV after receiving a bone marrow transplant for leukaemia in 2007. There are, however, important differences between the cases.
While Mr Brown’s doctor used stem cells from a donor with a rare genetic mutation, known as CCR5 delta 32, which renders people virtually resistant to HIV, the two Boston patients received cells without this mutation.
Scientific advances since HIV was first discovered more than 30 years ago mean the virus is no longer a death sentence and the latest antiretroviral AIDS drugs can control the virus for decades.
But many people do not get therapy early enough, prompting the World Health Organisation to call for faster roll-out of medicines after patients test positive.
In the meantime, Australian scientists said they are optimistic they have discovered a way for millions more people to get access to crucial antiretroviral drugs.
They have found a lower daily dose of one drug is just as effective, yet far cheaper, than the current dosage.