Speaking at the International AIDS Society Conference in Kuala Lumpur, doctors from the Brigham and Women’s Hospital in Boston announced that the two previously HIV-positive men had no detectable levels of the virus in their blood or tissue having been off anti-retroviral drugs for eight and 15 weeks respectively.
The two men both underwent bone marrow stem-cell transplants as part of cancer treatment between two and four years ago, a similar treatment to that undergone by Timothy Ray Brown, the famous “Berlin patient” who was pronounced to be cured of HIV five years ago.
However, Brown received his transplant from a donor with a rare genetic mutation that provides a heightened immunity to HIV, whereas the two Boston men received their transplants from donors with no known resistance.
One of the doctors who treated the patients, Dr Timothy Henrich, told the Conference that repeated tests of blood, tissue and cells had found no trace of the virus.
“We demonstrated at least a 1,000 to 10,000-fold reduction in the size of the HIV reservoir in the peripheral blood of these two patients, but the virus could still be present in other tissues such as the brain or gastrointestinal tract,” Henrich said.
If the virus does not resurface, the two men will join Brown and a newborn baby girl from Mississippi as the only known people to have been successfully cured of HIV. The Mississippi patient received large amounts of conventional treatment shortly after being born in July 2010.
However, researchers warned that the Boston treatment was not a viable method of combating HIV in anything but highly selective cases. Bone marrow stem-cell transplants are expensive and dangerous procedures, with up to 20 percent of patients dying within two years. A patient died of cancer after receiving the same treatment as the Boston pair.