On February 15, local time, at the Antiretroviral and Opportunistic Infection Conference (CROI), a high-level international conference in the field of HIV research held in Denver, the United States, researchers released news that after the "Berlin patient" and the "London patient", they may have successfully cured the third hive infected person, who was called the "New York patient".
The "New York Patient" is a female patient who was diagnosed with HIV in 2013 and has kept her viral levels low ongoing antiviral drugs.
Unfortunately, she was diagnosed with acute myeloid leukemia in March 2017, and in August of the same year, she underwent a stem cell transplant from an adult family member to replenish her own blood cell levels. At the same time, she receives stem cells through the umbilical cord blood of a newborn who is not related to her.
After 37 months of transplantation, the patient stopped antiretroviral therapy. After 14 months, blood tests showed no signs of HIV infection.
There have been two previous cured cases. The first case was called the "Berlin Patient". In 1995, a man named Brown was diagnosed with AIDS. Eleven years later, Brown was diagnosed with acute myeloid leukemia, and his attending physician selected one of the 60 bone marrow donors with a mutation in the CCR5-Δ32 gene. Finally, through bone marrow transplantation, not only did he cure leukemia, but he also cured AIDS.
The second so-called "London patient", a patient with both Hodgkin lymphoma and AIDS, received a bone marrow transplant from a donor with the CCR5-Δ32 mutation, and not only did Hodgkin's lymphoma recover, but there was no more HIV in the patient's blood.
The stem cell donor of the "New York Patient" is also a carrier of the CCR5-Δ32 mutation gene. Why is a bone marrow or stem cell transplant carrying the CCR5-Δ32 mutation cure AIDS? Because before the HIV virus enters the target cell, it needs to bind to the receptor on the target cell, and the receptor mediate can enter the inside of the target cell, so that the virus can survive and replicate. CCR5 has previously been shown to be the primary receptor for HIV to invade T cells. The study found that carriers of the CCR5-Δ32 mutation gene are born immune to HIV. This is also the principle of "elite controller"!
How many carriers of this homozygote defect gene are there in the population? Studies have shown that this proportion is relatively high in white European populations, with about 14% of single gene defects and about 1% of dual gene defects. In China, the proportion may be only 0.2%.
However, the difference between the "New York patient" and the first two cured patients is that the first two were cured by bone marrow transplantation, and this time it was transplanted from stem cells extracted from the donor's cord blood. Patients are first given chemotherapy, and then doctors transplant stem cells from individuals with specific genetic mutations.
The advantage of using cord blood is that cord blood stem cell transplantation is more widely used and does not need to be "closely matched" with the recipient, so some people think that curing AIDS with a new cord blood stem cell transplant may be a breakthrough, but there are still safety and other problems that need to be solved.