An announcement that brings hope to the scientific community and all people with HIV. On the night of Wednesday through Thursday, ahead of the International AIDS Society Conference that opens Sunday in Australia, a sixth patient referral was announced. Like the other five patients before him, he received a bone marrow transplant: present in the bones, the precious bone marrow is used to renew blood cells.
“During a bone marrow transplant, the patient’s immune cells are completely replaced by those of the donor, which makes it possible to eliminate the vast majority of infected cells,” explained virologist Asier Saez-Cirio in February.
But this time, the transplant was not like the others. And therein lies all hope. The five patients cured before him also suffered from blood cancers. To combat these diseases, the bone marrow transplant they received consisted of stem cells with a rare mutation in a gene called CCR5 delta 32. A genetic mutation known to prevent HIV from entering cells. Problem: Less than 1% of the general population carries this protective mutation, and not everyone is a match for bone marrow donation.
Stem cells that do not carry the mutation
As part of leukemia treatment, the “Geneva patient” who has had HIV since 1990 received stem cells that do not carry the mutation in 2018. Nothing in these cells was supposed to prevent the growth of HIV. However, for 20 months, and the gradual cessation of antiretroviral treatment that prevents HIV from multiplying, the virus has been undetectable in his body.
“In this specific case, perhaps the transplant made it possible to eliminate all the infected cells without the need for the famous mutation,” suggests Asier Sáez-Cirión, head of the Viral Reservoirs and Immunological Control Unit at the Pasteur Institute.
“Or perhaps his immunosuppressive treatment, necessary after the transplant, had an influence,” he adds, while pointing out that this type of operation had already been performed in the past but the virus had reappeared “after a few months.”
And even if they talk about remission, scientists point out that the virus can still persist in the patient’s body.
A complex and risky operation
Keep in mind that a bone marrow transplant is a complex and risky operation, which not all virus carriers can wait for. Side effects can be serious, notes the Canadian Cancer Society. The risk of infection is high because the number of white blood cells, which play a key role in defending the system, is very low after a transplant.
Other problems are common: bleeding problems, anemia, skin, hair and hair problems… The donor’s stem cells can also attack the recipient’s because they see them as foreign, which can finally cause “permanent organ damage.”
Source: BFM TV
