Researchers Document Third Case of HIV Remission Involving Stem Cell Transplant

Scanning electron micrograph of an HIV-infected H9 T cell, colorized in purple, gold, and orange.

Photo: NIAID

A woman with HIV who received a cord blood stem cell transplant to treat acute myeloid leukemia has had no detectable levels of HIV for 14 months despite cessation of antiretroviral therapy (ART). The woman is the third known case of HIV remission following a stem cell transplant. 

The NIH-funded research was conducted by the International Maternal Pediatric Adolescent AIDS Clinical Trial Network (IMPAACT) P1107 study. Begun in 2015, the observational study was designed to describe the outcomes of up to 25 participants living with HIV who underwent a transplant with CCR5Δ32/Δ32 cord blood stem cells for treatment of cancer or other underlying disease. 

As a result of the genetic mutation CCR5Δ32/Δ32, missing cells lack CCR5 co-receptors, which is what HIV uses to infect cells. By killing off the cancerous immune cells via chemotherapy and then transplanting stem cells with the CCR5 genetic mutation, scientists theorize that people with HIV then develop an HIV-resistant immune system.

In this latest case, the woman of mixed-race ancestry had been on ART for HIV infection for 4 years at the time of her cancer diagnosis. She achieved leukemia remission after chemotherapy. Prior to the transplant, the participant’s HIV was well-controlled but detectable. At 37 months post-transplant, the patient ceased ART and, 14 months later, no HIV has been detected in the participant.

HIV remission resulting from a stem cell transplant had been previously observed in two cases. The first, the “Berlin patient” (a Caucasian male), experienced HIV remission for 12 years and was deemed cured of HIV; he died of leukemia in September 2020. The “London patient” (a Latino male) has been in HIV remission for more than 30 months. This third case suggests that CCRΔ5/Δ32 cord stem cell transplantation should be considered for people living with HIV who require such a transplant for other diseases.