Researchers in Germany have achieved a rare and very important accomplishment: a 60-year-old man suffering from acute myeloid leukemia and HIV (human immunodeficiency virus) has reached stable remission from both diseases after a stem cell transplant. The findings were reported in an article published in Nature.

This is the seventh documented case of stable HIV remission after a stem cell transplant. The significance of this case is that the donor cells did not carry the “double” protective mutation of the CCR5 gene, as in previous successful cases, but carried only one copy of a modified version — the so-called CCR5 Δ32 mutant form, a single variant.

Until now, it was believed that for such a “cure” the donor had to have two copies of the mutation, which would deprive the virus of “access” to immune cells. However, this case shows that stable remission can occur even with a heterozygous mutation — meaning only one of the two genes is mutated. This expands the pool of potential donors and theoretically makes such transplants more accessible.

The aforesaid man was diagnosed with HIV in 2009, and with leukemia in 2015, and a bone marrow transplant was performed to save his life. In 2018, he was able to stop antiretroviral therapy, and for nearly six years — at the time of publication — no active HIV has been detected in his body.

Researchers emphasize, however, that this does not mean a “magic formula” has been found for everyone. Stem cell transplantation is a serious and dangerous procedure, not everyone can withstand it, and it carries many risks. But the fact that complete elimination of HIV is possible after such treatment even with “partial” genetic protection is encouraging. It is an important step that may change the understanding of who can become a donor and how close medicine has come to achieving stable HIV remission.