A study published in the journal “Cell” presents the case of the first cured woman with HIV. It’s about the “New York patient», a woman with leukemia and HIV who has been free of the virus since 2017.
She would be the first woman to be cured of the virus after a bone marrow transplant and joins the other three cases, men. Unlike the other patients, the patient from Düsseldorf, the late patient from Berlin and the patient from Londonin this case the healing was carried out from HIV-resistant stem cells obtained from umbilical cord blood, instead of adult cells from compatible donors.
The New York patient, a middle-aged woman with leukemia and HIV, identifies herself as mixed race. “The HIV epidemic is racially diverse, and it is extremely rare for people of color or race to find a sufficiently matched adult unrelated donor,” says Yvonne Bryson of UCLA, who co-led the study with pediatrician and infectious disease expert Deborah Persaud, of the Johns Hopkins University School of Medicine. «The use of umbilical cord blood cells expands opportunities for people of diverse ancestry living with HIV who require a transplant to cure other conditions».
Nearly 38 million people worldwide are living with HIV and antiviral treatments, while effective, must be taken for life.
The Berlin patient was the first person to be cured of HIV in 2009, and since then two other men, the London patient and the Düsseldorf patient, have also been free of the virus. All three received stem cell transplants as part of their cancer treatments, and in all cases, the donor cells came from matched adults or “paired» who carried two copies of the CCR5-delta32 mutation, a natural mutation that confers resistance to HIV by preventing the virus from entering and infecting cells.
Only about 1% of white people are homozygous for the CCR5-delta32 mutation and it is even rarer in other populations. This rarity limits the potential for transplanting stem cells carrying the beneficial mutation into patients of color because stem cell transplants generally require a strong match between donor and recipient.
Knowing that it would be nearly impossible to find the New York patient an adult donor compatible with the mutation, the team instead transplanted CCR5-delta32/32-bearing stem cells from stored umbilical cord blood to try to cure both her cancer and the HIV simultaneously.
compatible patient
Cells from the umbilical cord blood were infused together with stem cells from one of the patient’s relatives to increase the chances of success of the procedure. “With cord blood, you may not have as many cells, and they take a little longer to populate the body after infusion,” Bryson explains. Using a mixture of stem cells from a matched relative of the patient and cells from the umbilical cord blood gives the cord blood cells a good start.”
The transplant put both the patient’s HIV and leukemia into remission, and this remission has now lasted for more than four years. Thirty-seven months after the transplant, the patient was able to stop taking antiviral medication against HIV. The doctors, who continue to monitor her, say she has now been HIV-negative for more than 30 months since stopping antiviral treatment (only 18 months had passed at the time the study was written).
Marrow transplantation is only indicated because the patient has a hematological cancer that does not respond to treatment
Jose Alcamí
Virologist and director of the AIDS Immunopathology Unit (Carlos III Health Institute)
«Stem cell transplants with CCR5-delta32/32 cells offer a two-for-one cure for people living with HIV and blood cancers says Persaud. However, due to the invasiveness of the procedure, stem cell transplants (both with and without the mutation) are only being considered for people who need a transplant for other reasons, and not to cure HIV in isolation; Before a patient can undergo a stem cell transplant, he must undergo chemotherapy or radiation therapy to destroy his existing immune system.”
Jose Alcamí, virologist and director of the AIDS Immunopathology Unit (Carlos III Health Institute), in statements to the Science Media Center, highlights that the case “has some characteristics that make it different. The most important is that the transplant is not performed with stem cells from an adult donor, but obtained from the umbilical cord.
DAYS genetically
When we are born, the progenitor cells are more ‘adaptable’ to different genetic contexts. An adult stem cell marrow transplant, explains Alcamí, “requires a complete genetic identity, 100% in a series of genes that are like a genetic DNI for the transplant. However, cord cells do not require 100% identity, rather 50% identity is sufficient.”
This strategy, he says, “opens a way to find a greater number of donors per candidate patient.”
In this sense, Alcamí points out that an important aspect regarding race is that the existence of the genetic deletion that makes it resistant to HIV (the so-called delta32 in homozygosis) is low in the Caucasian population (1%) but practically non-existent in the African population. with which the chances of having a ‘two for one’ donor who cures leukemia and HIV are practically zero. Donation from cord cells is therefore an excellent strategy to overcome this obstacle.
Furthermore, adds this virologist, “a strange fact is that the cells of the transplanted patient are resistant to variants of HIV that do not use the CCR5 receptor».
Finally, Alcamí recalls that bone marrow transplantation is a risky medical intervention with high mortality (up to 40%) that is only indicated because the patient has a hematological cancer that does not respond to treatment; that is, “he is not transplanted because he is infected with HIV.”