The transplantation of special stem cells from umbilical cord blood has very likely cured a New York patient of both her leukemia and her HIV disease. This is reported by US scientists in the journal "Cell". It would be the first successful treatment of a non-white woman.

So far, three cases of a cure for HIV were known: The corresponding patients in Berlin, London and Düsseldorf all received a special stem cell transplant due to a parallel cancer. Those stem cells had a specific gene mutation called CCR5Δ32. This mutation causes the absence of a docking site for HIV on the immune cells. Without this, the virus cannot find an entry point and cannot infect the cells, which makes carriers of the mutation almost resistant to the pathogen.

Transplantation of stem cells from umbilical cord blood

According to lead author Yvonne Bryson, however, only about one percent of the white population is one of these carriers, and the mutation is even rarer in other groups. In the case of a stem cell transplant, however, the closest possible match between donor and recipient is crucial, Bryson explained in a press conference on the study. "It is extremely rare for people of different skin colors or ethnicities to find a sufficiently matched, unrelated adult donor."

The team therefore decided to transplant stem cells with the rare mutation from umbilical cord blood into the non-white patient. Such cells, which come from voluntary donations and are collected in appropriate blood banks, are still very immature, which prevents the otherwise frequent rejection reactions.

The transplant took place in 2017 – in a procedure that could not be imagined as a surgical operation, but rather as a blood transfusion that takes place after chemotherapy and radiation, explained the physician Jingmei Hsu. In fact, both the patient's HIV infection and leukemia were successfully contained.

37 months after the procedure, the antiviral HIV drugs could be discontinued. "Today, the patient is doing very well, she travels, visits her family and enjoys her life," Hsu said.

Although still no virus remnants can be detected, the doctors do not yet want to speak of a complete cure. This security would only bring in the next few years. Also, due to the many risks, such a stem cell transplant is only possible in the context of the treatment of other life-threatening diseases such as cancer.

Nevertheless, the method expands the circle of potential patients, according to the study authors. They advocate building blood banks for umbilical cord blood on a large scale, encouraging donors and then testing the donated blood for the CCR5Δ32 mutation.