A patient in the United States of America 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.
The revelation was made during the Conference on Retroviruses and Opportunistic Infections (CROI), taking place in Denver, Colorado, by scientists at the New York-Presbyterian/Weill Cornell Medical Centre.
Research that was presented at the conference on Tuesday shows that the lady had been diagnosed with HIV in 2013 and had been on antiretroviral drugs. But in 2017, she was diagnosed with acute myelogenous leukaemia. To treat the cancer, umbilical cord stem cells were used instead of the commonly used bone marrow.
The treatment involved doctors destroying the lady's immune system using chemotherapy or radiation and later rebuilding it with new cells that were donated by a blood relative and another donor who has not related to her. Medics say that cord blood is much more widely available than adult stem cells that are used in bone marrow transplants.
During and after the transplant, she received blood from 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 and has not shown any signs of relapse. 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. 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.
Scientists at the conference referred to the lady's case as a breakthrough in science since it presents new possibilities for curing HIV. They add that the results show great promise in facilitating more accessible HIV treatments, especially for those who are already suffering from cancer.
Earlier, two other women had naturally cured themselves of HIV by locking away the virus in their genome in what is a ‘sterilizing cure’, where the body eliminates the virus completely.
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.