A patient in the US has been cured of HIV after receiving a stem cell transplant from a donor who was naturally resistant to the virus that causes AIDS, researchers reported.
The middle-aged woman had the stem cell transplant because she had leukemia. The case, presented at the Denver Conference on Retroviruses and Opportunisitic Infections, is also the first to use cord blood — a newer approach that could make the treatment accessible to more people.
Since the patient received the umbilical cord blood to treat her acute myeloid leukemia – a cancer that begins in the blood-forming cells of the bone marrow – the symptoms of the disease have subsided, they say. In addition, she has been free of the HIV virus for 14 months without the need for heavy HIV treatment called antiretroviral therapy.
The two earlier cases occurred in men who had received adult stem cells, which are more commonly used in bone marrow transplants.
"This is now the third reported healing in this area and the first in a woman living with HIV," said Sharon Lewin, president-elect of the International AIDS Society, in a statement.
The case is part of a larger US-backed study led by Dr. Yvonne Bryson of the University of California Los Angeles (UCLA) and Dr. Deborah Persaud from Johns Hopkins University in Baltimore.
Stem cell transplantation as a cancer treatment
The study will follow 25 HIV-infected people who are undergoing cord blood stem cell transplants to treat cancer and other serious diseases.
The patients participating in the study are first subjected to chemotherapy to kill the cancerous immune cells. Doctors then transplant stem cells from people with a specific genetic mutation in which they lack receptors that the virus uses to infect cells.
The scientists assume that these people then develop an immune system that is resistant to HIV.
Sharon Lewin of the International AIDS Society said bone marrow transplants are not a viable solution to curing most people with HIV. But the report "confirms that a cure for HIV is possible and strengthens gene therapy as a viable strategy for an HIV cure."
The study suggests that transplantation of HIV-resistant cells is an important element for success. A common side effect of stem cell transplantation is what is known as graft-versus-host disease. The donor's immune system attacks the recipient's immune system. Until now, scientists believed that this side effect played a role in a possible cure.
"Taken together, these three cases of stem cell transplant healing help identify the various components of the transplant that were absolutely critical to healing," said Sharon Lewin.