A patient with leukaemia in the United States has become the first woman and the third person to date to be cured of HIV after receiving a stem cell transplant, researchers say.
The case, presented on Tuesday at the Conference on Retroviruses and Opportunistic Infections in the US city of Denver, was the first involving umbilical cord blood to treat acute myeloid leukaemia, which starts in blood-forming cells in the bone marrow.
Since receiving the cord blood, the middle-aged woman of mixed race has been in remission and free of HIV for 14 months, without the need for potent treatments known as antiretroviral therapy.
The donor was naturally resistant to the virus that causes AIDS.
“This is now the third report of a cure in this setting, and the first in a woman living with HIV,” Sharon Lewin, president-elect of the International AIDS Society, said in a statement.
The two prior cases occurred in males, one white and one Latino, who had received adult stem cells more frequently used in bone marrow transplants.
This new approach may make the treatment available to more people, according to researchers.
The case is part of a wider study led by the University of California, Los Angeles and Johns Hopkins University in Baltimore that follows 25 people with HIV who undergo transplants with stem cells for the treatment of cancer and other serious conditions.
Patients in the trial first undergo chemotherapy to kill off the cancerous immune cells and then receive transplant stem cells from individuals with a specific genetic mutation in which they lack receptors used by the virus to infect cells.
Scientists believe these individuals then develop an immune system resistant to HIV.
Lewin said that while bone marrow transplants are not a viable strategy to cure most people living with HIV, the report “confirms that a cure for HIV is possible and further strengthens using gene therapy as a viable strategy for an HIV cure”.
Previously, scientists believed that a common stem cell transplant side-effect called graft versus host disease – in which the donor immune system attacks the recipient’s immune system – played a role in a possible cure.
“Taken together, these three cases of a cure post stem cell transplant all help in teasing out the various components of the transplant that were absolutely key to a cure,” Lewin said.