Previous cases of HIV treatment (including definitive cures in men treated in London, Berlin and Dusseldorf, and long-term recovery in a man treated in Los Angeles) have used bone marrow stem cell transplantation as a dual treatment for both received both for cancer and for HIV (the first patient whose HIV was cured He was a man from Berlin who died in 2020 after a recurrence of cancer).
All these transplants used bone marrow stem cells from adult donors who had two copies of a rare genetic mutation called delta 32 in the CCR5 gene. This mutation changes the gateway that the HIV virus uses to enter white blood cells, thus preventing the virus from entering.
After the transplant, the donated stem cells take over the patient’s immune system and replace the old cells that are vulnerable to HIV with new cells that are resistant to HIV. Doctors use chemotherapy or radiation to destroy the population of primary immune cells to make way for new immune cells.
As in previous cases, the New York patient, who had both cancer and HIV infection, underwent chemotherapy before the transplant. However, he received stem cells taken from umbilical cord blood that contained HIV-resistant genes. Umbilical cord blood was donated by the parents of an unrelated baby at the time of delivery and was later screened for the delta 32 mutation in the CCR5 gene. To supplement the relatively low number of umbilical cord stem cells, the patient also received stem cells donated by a relative.
Since cord blood is easier to access than adult bone marrow and it is easier to find a compatible sample between donors and recipients, such procedures could become more common in the future. Although according to Dr. Bryson, stem cell transplantation is not suitable for patients who are HIV positive but do not have another serious disease such as cancer; Because it involves cleansing the immune system.