'New York Patient' is the first mixed-race woman possibly cured of HIV
A new method to cure HIV — transplanting HIV-resistant stem cells from umbilical cord blood — helped scientists successfully treat “New York patient,” a mixed-race woman with leukemia and HIV who has been without HIV since 2017.
Previously, stem cells used for transplantation to cure HIV were obtained from compatible adult donors. However, the use of stem cells from umbilical cord blood increases the likelihood of curing HIV for people of all races, as per the press release.
“The HIV epidemic is racially diverse, and it’s exceedingly rare for persons of color or diverse race to find a sufficiently matched, unrelated adult donor,” says Yvonne Bryson, Professor, and chief ID at UCLA School of Medicine.
“Using cord blood cells broadens the opportunities for people of diverse ancestry who are living with HIV and require a transplant for other diseases to attain cures.”
Tackling an obstacle for people of color
Almost 38 million individuals globally are living with HIV. When it comes to treatment, scientists have covered a long distance. Antiviral therapies appear as an effective treatment method, but the limitation is that they must be taken for the rest of a patient's life.
In 2009, the "Berlin patient" became the first person to be cured of HIV, followed by two others: the "London patient" and the "Düsseldorf patient." All three patients received stem cell transplants for their cancer treatments. In each case, the donor cells were obtained from compatible or "matched" adults with two copies of the CCR5-delta32 mutation. This mutation is a natural occurrence that provides resistance to HIV by blocking the virus from entering and infecting cells.
But the problem is that only one percent of white people are homozygous for the CCR5-delta32 mutation, and it is even less prevalent in other populations. It comes as a limitation of the transplant stem cells carrying the advantageous mutation into people of color because stem cell transplants usually require a strong match between the donor and the recipient.
To tackle this potential obstacle for the "New York Patient," the research team transplanted CCR5-delta32/32-carrying stem cells from banked umbilical cord blood, intending to simultaneously treat the patient's cancer and HIV. The team also infused stem cells obtained from a patient's relative along with the umbilical cord blood cells to increase the chance of success.
“With cord blood, you may not have as many cells, and it takes a little longer for them to populate the body after they're infused,” says Bryson.
“Using a mixture of stem cells from a matched relative of the patient and cells from cord blood gives the cord blood cells a kick start.”
The remission of HIV and leukemia has persisted for over four years
The results have shown remission in the patient's leukemia and HIV, which have persisted for over four years. After 37 months of the transplant, the patient was able to discontinue HIV antiviral medication. The doctors, who are still monitoring the patient, report that she has been HIV-negative for over 30 months since discontinuing antiviral treatment.
“Stem cell transplants with CCR5-delta32/32 cells offer a two-for-one cure for people living with HIV and blood cancers,” says expert Deborah Persaud of the Johns Hopkins University School of Medicine.
However, the procedure's invasiveness causes stem cell transplants (both with and without the CCR5-delta32 mutation) to be only considered for people who require a transplant for other reasons and not solely to cure HIV. Before undergoing a stem cell transplant, a patient must first receive chemotherapy or radiation therapy to eliminate their existing immune system.
"This study is pointing to the really important role of having CCR5-delta32/32 cells as part of stem cell transplants for HIV patients, because all of the successful cures so far have been with this mutated cell population, and studies that transplanted new stem cells without this mutation have failed to cure HIV," says Persaud.
"If you're going to perform a transplant as a cancer treatment for someone with HIV, your priority should be to look for cells that are CCR5-delta32/32 because then you can potentially achieve remission for both their cancer and HIV."
The study was published in the journal Cell on March 16.
Study abstract:
Previously, two men were cured of HIV-1 through CCR5Δ32 homozygous (CCR5Δ32/Δ32) allogeneic adult stem cell transplant. We report the first remission and possible HIV-1 cure in a mixed-race woman who received a CCR5Δ32/Δ32 haplo-cord transplant (cord blood cells combined with haploidentical stem cells from an adult) to treat acute myeloid leukemia (AML). Peripheral blood chimerism was 100% CCR5Δ32/Δ32 cord blood by week 14 post-transplant and persisted through 4.8 years of follow-up. Immune reconstitution was associated with (1) loss of detectable replication-competent HIV-1 reservoirs, (2) loss of HIV-1-specific immune responses, (3) in vitro resistance to X4 and R5 laboratory variants, including pre-transplant autologous latent reservoir isolates, and (4) 18 months of HIV-1 control with aviremia, off antiretroviral therapy, starting at 37 months post-transplant. CCR5Δ32/Δ32 haplo-cord transplant achieved remission and a possible HIV-1 cure for a person of diverse ancestry, living with HIV-1, who required a stem cell transplant for acute leukemia.