In May of 2016, in China, a 27-year old found out he had HIV and a couple weeks later was told he also had acute lymphoblastic leukemia. But his healthcare practitioners offered him a ray of hope. They would do a bone marrow transplant to treat his leukemia and then do an experimental treatment to get rid of the HIV in his body.
The results were published in a paper in The New England Journal of Medicine. The treatment to rid his body of HIV involved using the CRISPR-Cas9 gene editing tool – which is the same tool used by Chinese scientist, He Jiankui back in December of 2018 to modify genes in twin embryos, causing an uproar in the scientific community.
According to lead scientist of the project, Deng Hongkui, after bone marrow cells are edited, the cells and the blood cells they then produce have the ability to resist the HIV virus infection.
The treatment for the young 27-year old patient was conducted in the summer of 2017. The treatment by Peking University scientists involved the CRISPR-Cas9 gene editing tool deleting the CCR5 gene from bone marrow stem cells from a donor prior to transplanting them into the young patient.
Previously, scientists had discovered that people who were highly immune to HIV carry defective copies of the CCR5 gene. The HIV virus uses the protein, which is made by the CCR5 gene, in order to gain entry into an infected individual’s cells. There were two men, one in London and one in Berlin who were the first people to be cured of HIV after receiving bone marrow transplants by traditional surgical methods from donors who had the natural mutation of CCR5 in their bone marrow.
But for the treatment of the young Chinese patient, healthy bone marrow was taken from a donor and the CCR5 gene was deleted and then the cells were implanted into the patient. A full 19 months later after this treatment was done, in early 2019, not only was the acute lymphoblastic leukemia in complete remission but the donor cells carrying the deleted CCR5 continued to persist according to Deng’s report.
Deng said there weren’t enough of the CCR5 edited cells to get rid of all the HIV virus in the young patient’s body and that only about 5% to 8% of his bone marrow ended up with the CCR5 edited cells. Deng says that in the future, improving the efficiency of gene-editing and also optimizing the transplanting procedures will increase the transition to higher positive clinical results.