Breaking New Ground

Researchers have confirmed that a 53-year-old man in Germany has been “cured” of HIV following a stem cell transplant for acute myeloid leukemia (AML). Known as the “Düsseldorf patient,” he becomes the third person to have successfully cleared the virus following an allogeneic CCR5Δ32/Δ32 hematopoietic stem cell transplant (HSCT).

In the Nature article (1), the researchers report that the man was diagnosed with HIV-1 in 2008 but didn’t start antiretroviral therapy (ART) until 2010 because, based on national guidelines at the time, his CD4+ T cell count and HIV-1 plasma viral load did not indicate ART initiation. In 2011, he was diagnosed with AML and experienced a post-chemotherapy relapse in 2013, which was treated with an allogeneic CCR5Δ32/Δ32 HSCT. Months later, he experienced another relapse but was successfully treated without the need for another stem cell transplant.

And that’s where it gets interesting. Although he discontinued ART in November 2018 and has shown sporadic traces of HIV-1 DNA, the researchers state that he continues to show no evidence of viral rebound or immunological correlates of antigen exposure.

“Following our intensive research, we can now confirm that it is fundamentally possible to prevent the replication of HIV on a sustainable basis by combining two key methods,” said lead researcher Björn Jensen, in a press release from Heinrich Heine University Düsseldorf (2). “On the one hand, we have the extensive depletion of the virus reservoir in long-lived immune cells, and, on the other hand, the transfer of HIV resistance from the donor immune system to the recipient, ensuring that the virus has no chance to spread again. Further research is now needed into how this can be made possible outside the narrow set of framework conditions we have described.”

Although the evidence thus far surrounding HIV-1 cure after CCR5Δ32/Δ32 HSCT provides valuable insights, the researchers highlight that it has mostly been anecdotal in nature and lacks the power that controlled prospective studies would provide. Furthermore, bone marrow transplant is a high-risk procedure, making it unlikely to be offered to people living with HIV who don’t have leukemia.