A leukaemia patient in the US has become the first woman and the third person ever to be cured of HIV, after receiving a transplant of umbilical cord blood in a novel treatment technique, a New York Times report said Tuesday.
The previous two male patients who had been cured received expensive bone marrow transplants. Both kinds of transplants have stem cells with a mutation that blocks HIV.
The latest case was presented this week at the Conference on Retroviruses and Opportunistic Infections in Denver, Colorado.
The results show great promise in facilitating more accessible HIV treatments, especially for those who are already suffering from cancer. Cord blood is much more widely available than adult stem cells that are used in bone marrow transplants.
The middle-age woman is of mixed race and received a partial match, unlike the previous bone marrow transplants where a closer racial match is required and donors are primarily Caucasian.
Earlier, two other women had naturally cured themselves of HIV by locking away the virus in their genome in what is a ‘sterilising cure’, where the body eliminates the virus completely.
Cord blood treatment
The US mixed-race patient had been diagnosed with HIV in 2013 and had been on antiretroviral drugs. In March 2017, she was diagnosed with acute myelogenous leukaemia, and in August the same year, received the mutation-containing cord blood transplant.
She has not shown any signs of relapse since October 2020, when she received the transplant.
During and after the transplant, she also received blood for a close relative for temporary immunity, as cord blood cells can take up to six weeks to engraft. She was discharged 17 days after her transplant, and didn’t develop graft vs host disease, which was previously thought to be a step that contributed to the cure of HIV after bone marrow transplants.
Antiretroviral therapy, which typically is a drug cocktail that prevents replication and keeps viral levels low, was discontinued 37 months after the transplant, and 14 months since then, she continues to be in remission. Blood tests show no signs of both HIV and antibodies to HIV.
While the blood from her relative formed a crucial aid in keeping the immune system running until the cord blood cells took over, it is still unclear why cord cells were so effective.
However, the therapy itself is highly risky and only suitable for patients with cancer, as it destroys a large portion of the immune system using chemotherapy or radiation.
In 2008, Timothy Ray Brown from California, who came to be known as the ‘Berlin Patient’, was the first to be cured of AIDS. His identity was revealed in 2010, and he died in 2020 from leukaemia.
Adam Castillejo, who was known as the ‘London Patient’, was the second to be cured, in 2019.
Both men had painful and expensive bone marrow transplants from donors with a rare genetic mutation that is resistant to HIV. They were also on antiretroviral therapy.
Another patient, a 36-year-old man in Brazil, dubbed the Sao Paulo Patient, was temporarily able to remove the virus from his body using a drug cocktail and without surgery two years ago, but the virus rebounded with a detectable viral load 72 weeks or 15 months after he went off antiretroviral therapy.
Two women have been shown to be able to remove the disease naturally from their bodies.
In 2020, scientists announced that 66-year old Loreen Willenberg from California was able to get rid of the disease by locking the virus away inside her genome, where it would typically replicate. Her body’s defensive action was described by researchers as a “functional cure”. She had been diagnosed with HIV in 1992.
Last year, a woman from Argentina, called the Esperanza patient, was also able to naturally remove the virus from her body completely in a “sterilising cure”. She had been diagnosed in 2013 and is now disease free.
Such individuals whose bodies are able to suppress and lock away the virus, or eliminate it, are called elite controllers. It is thought that about 0.5 per cent of the 38 million HIV patients around the world make up elite controllers.
Young children have also been known to stay in remission when antiretroviral therapy is started at a very early age after birth.