Scientists see second HIV remission
A HIV positive man has become the second person to go into sustained remission from the virus and cleared of AIDS after receiving a bone-marrow transplant.
The case is the second ever observed of sustained HIV remission according to a UK study, although the authors say it's too early to confirm whether the patient is indeed "cured" of the virus which causes AIDS. The man, known as the "London Patient", has been in remission for 19 months.
Another patient, Timothy Brown, known as the "Berlin Man" was sent into remission 10 years ago by a similar treatment, but attempts to replicate the result have failed until now.
The London Patient received a transplant of stem cells from a donor who had the rare gene mutation CCR5. The mutation is related to HIV resistance.
The London Patient stopped taking antiretroviral drugs 19 months ago, with "no viral rebound", which Peter Doherty Institute for Infection and Immunity director Professor Sharon Lewin called "impressive."
"Coming 10 years after the successful report of the Berlin Patient, this new case confirms that bone marrow transplantation from a CCR5-negative donor can eliminate residual virus and stop any traces of virus from rebounding," Prof Lewin said.
Experts said the results were exciting, but remained conservative about current capabilities of widespread replication of the "cure" for the tens of millions of people affected by HIV worldwide.
'WE NEED TO BE CAUTIOUS'
"This is a very interesting and encouraging result; however we need to be cautious for a number of reasons," UNSW's Kirby Institute director Professor Anthony Kelleher said.
"Firstly, the bone marrow transplant in both HIV cure cases were primarily used to treat cancers of the blood and were modified to enable a HIV cure. So, the cost benefit of the prognosis following a bone-marrow transplant versus that on HIV antiretroviral therapy needs serious consideration.
"Secondly, naturally resistant and compatible bone marrow donors are rare because of the need for donor recipient matching. Further, this type of procedure is not widely available in many countries.
"Finally, there is significant morbidity and mortality associated with this type of transplantation, even when conducted in the best centres, and under the best circumstances.
"While there are important limitations to applying this study to a HIV cure globally, this second documented case does reinforce the message that HIV cures are possible.
"Common to both approaches is the presence of a modified gene in our immune system (CCR5) that is necessary for HIV infection.
"This tells us that the feasibility, and importantly, the availability of delivering this approach could possibly be achieved by the rapidly accelerating field of gene editing and related gene therapies.
"However, there are still significant hurdles in this field as well."
The CCR5 gene is also associated with controversial "gene editing" by Chinese scientist He Jiankui last year, that led to the birth of the world's first gene-edited twin babies.
In Australia, about 25,000 people were living with HIV.
Worldwide about 36.9 million people are HIV positive and living with AIDS.