Cord blood stem cell transplant puts woman in HIV remission

Transplantation of stem cells from the umbilical cord led to the first HIV remission in a mixed-race woman.

Woman known as New York patient has no detectable condition HIV Since 2017, after she received HIV resistance stem cell taken from cord blood to treat her leukemiaStem cells are produced by the bone marrow and can turn into different types of blood cells.

Some people have previously been in remission from HIV after receiving Stem cells from adult donors that have two copies of the naturally occurring mutation CCR5 gene. This delta 32 mutation is virus It prevents them from entering and infecting healthy cells.

In any stem cell transplant, the recipient can only receive donations from people with matching tissue types, reducing the risks of transplantation. immune system Attack the graft.

Because tissue type is hereditary, a person’s ethnicity affects their ability to find matches.have two copies of CCR5 The mutation is rare, present in only about 1% of people of northern European ancestry, and even rarer in other populations.

To overcome the shortage of suitable adult donors, doctors conducted a study injecting cord blood into New York patients who identified as mixed race.

She also received stem cells from a relative. Because cord blood contains fewer stem cells than adult blood, mixing with stem cells from relatives can give cord blood a “kick start.” Yvonne Bryson A professor at the University of California, Los Angeles, who co-led the study, said in a statement:

Umbilical cord blood makes it easier to find transplant matches because it provides a large vault of frozen samples from people who gave birth in hospitals. Su Jinmei at New York Presbyterian Hospital. “Having a bank [of cord blood] It really opened the door for us to help more patients,” she says.

Most people with HIV can reduce the amount of virus in their blood to undetectable levels by taking antiretroviral drugs that stop the virus from replicating in the body.

Therefore, stem cell transplantation is only considered for hematologically advanced HIV-infected individuals. cancer, can be processed in steps. The New York patient no longer requires antiretroviral drugs and is in remission from his leukemia.

Transplantation uses chemotherapy and sometimes radiation to kill a person’s red blood cells before the donor’s stem cells are injected into the individual. Recipients are given immunosuppressants to reduce the risk of their immune system rejecting the transplant. Infection more likely.

It is said that it takes several months for the donor’s stem cells to repopulate the recipient’s blood cells. Mario Stevenson at the University of Miami, Florida. “That window is a very high-risk window for individuals.”

The recipient body can also reject the transplant with a complication known as graft-versus-host disease (GvHD). This is when the donated stem cell immune cells attack the recipient’s own cells.

In previous cases in which HIV-infected individuals went into remission after undergoing adult stem cell transplantation, some scientists believe that activation of dormant HIV-infected cells so that they can be eliminated more effectively requires relatively severe disease. We believed that a positive GvHD response was required.

But although the New York patient is experiencing only mild GvHD symptoms, such as gastrointestinal discomfort, HIV is still in remission, he says. Other patients had more serious complications, such as hearing loss and extreme weight loss.

According to Hsu, the New York patient’s mild symptoms were likely due to cord blood use. This blood hasn’t been exposed to many toxins or infections, she says. Low, she says.

“Success like this story opens the door for all patients in very high-risk situations,” Hsu said.