Shandong Zhanhua Yonghao pharmaceutical & Tech Co.,Ltd

While it's true that stem cell transplants have cured HIV, that doesn't mean it's always successful.

Recently, foreign researchers reported two cases in which the cure failed. The report was published on the website of the American Foundation for AIDS Research (amfAR).

At present, the only way to cure HIV completely is to transplant donor cells with the CCR5 delta32 mutation. But what is not clear is the effect of transplantation on the pool of HIV in the organ. To understand this effect, a research consortium called IciStem, funded by amfAR, has performed autopsies on deaths after failed cures.

The first case was infected for 14 years and received antiretroviral therapy (ART) throughout this period. The patient underwent an organ transplant to treat myelodysplastic syndrome (MDS). On the 36th day after surgery, he was 100% chimerism, meaning that all of his new immune cells and other blood cells were the offspring of the donor and should be resistant to HIV. However, after 29 days, 100% chimerism dropped to 85%, which may be related to the undiscovered recipient cell population, which was not destroyed during transplant preparation. The patient died of severe septicaemia, when no HIV virus was found in his blood, but samples of all organs, from the brain to the lymph nodes, showed signs of persistent infection.

The second case had been infected with HIV for 22 years and had received antiretroviral therapy for the last 19 years. He underwent two bone marrow transplants to cure acute leukemia. Although the first failed, he was 100% chimerism 29 days after the second transplant. However, he died of lung failure 8 days later. Similarly, HIV was not found in the blood at the time, but there was a reservoir of HIV in the lymph nodes and spleen.

According to the authors of the study, in order to cure HIV, not only blood but also body tissues should be examined. Because their research suggests that body tissue plays an important role in the long-term survival of viral reservoirs, routine blood sampling from HIV-infected people is not a good proxy for actual reservoir levels.