This week a team of scientists and physicians from the U.K. published news of a second HIV positive man, in London, who is in long-term (18-month) HIV remission after undergoing treatment for Hodgkins lymphoma. The unexpected success has launched a new round of discussion about a potential cure for HIV.
Since 2008, scientists have been trying to replicate the treatment that cured the “Berlin patient” of HIV. At the time, many in the field of HIV research were excited to learn that this man, who tested positive for the human immunodeficiency virus in Berlin and had recently undergone treatment for acute myeloid leukemia, appeared to have been cured of his HIV. Until now, success in replicating that cure has been limited.
What is HIV?
HIV is the virus that causes AIDS. Since the virus was first discovered in the 1980s, more than 75 million people worldwide have been infected with HIV. Today, almost 37 million people live with HIV. Of these, about 1.1 million live in the U.S.
Infection with HIV almost always led to AIDS, which in turn was almost always fatal. The field was revolutionized in 1996 with the introduction of HIV anti-retroviral therapy medications. These drugs halt HIV from replicating and allow an infected person to regain a functioning immune system. These medications are so effective that today a person living with HIV has almost the same life expectancy of someone without HIV infection. However, these medications must be taken every day, have multiple distressing side effects, and can cost thousands of dollars each month.
Yet even with this life-extending treatment, a functional HIV cure, defined as when someone with HIV no longer tests positive for the virus and does not need to take these medications, has remained elusive.
The ‘cure’ treatment
All of that seemed to change when in 2008 at the Conference on Retrovirus and Opportunistic Infections in Boston, Massachusetts, the news broke of the Berlin patient, named Timothy Ray Brown, who seemed to have been cured of his HIV. In order to achieve that serendipitous “cure,” Brown had to undergo aggressive treatment for his acute myeloid leukemia that involved two hematopoietic stem cell transplantations – in which a patient’s bone marrow is damaged – and full body irradiation.
This complex treatment involves destroying a person’s own immune system with high doses of chemotherapy or radiation. Then the patient receives a transplant of new stem cells from either themselves or a donor.