amfAR, The Foundation for AIDS Research

Stem Cell Transplant Study: Researchers Report Drastic Reduction in HIV Reservoir

With the news in 2008 of “the Berlin patient”—the first and only person known to have been cured of HIV, as the result of a stem cell transplant procedure—a new horizon opened up in the field of HIV cure research.

In 2012, amfAR began discussions with a group of European researchers and two years later the consortium now known as ICISTEM was established to study and replicate the circumstances that led to the cure of Timothy Brown, “the Berlin patient.” 

 Dr. Maria Salgado and Dr. Javier Martínez-Picado, of IrsiCaixa
Dr. Maria Salgado and Dr. Javier Martínez-Picado, of IrsiCaixa

Co-led by the University Medical Center Utrecht in the Netherlands and IrsiCaixa AIDS Research Institute in Barcelona, Spain, ICISTEM researchers and cancer physicians have enrolled a cohort of more than 30 patients like Brown with cancer and HIV, who have received, or soon will receive, stem cell transplants.

Writing in the Annals of Internal Medicine, Dr. Javier Martínez-Picado of IrsiCaixa, with colleagues from the Gregorio Marañón Hospital in Madrid, report on the mechanisms contributing to a “profound” reduction in the HIV reservoir. These results may inform the design of a safer, more effective cure intervention.

In the study, five patients had undetectable HIV reservoir two years after receiving allogeneic stem cell transplants, even though the donated stem cells did not have the genetic mutation rendering HIV unable to enter and infect a cell. This mutation is widely believed to have played a key role in Timothy Brown’s cure.

Remarkably, in one of these five patients, no HIV antibodies were found seven years after the transplant, the strongest evidence of viral eradication.

While most received stem cells from adult donors, the one patient who received a cord blood transplant showed detectable HIV reservoir, and also showed delayed replacement of his cells by the donor cells. It is thought that shorter replacement time means more effective reservoir reduction. Also of note, this patient did not develop graft-versus-host disease in which donor cells attack the recipient’s cells.

“These patients all remain on antiretroviral therapy and we won’t have definitive results until therapy is withdrawn and we can observe them for signs of viral rebound,” said amfAR Vice President and Director of Research Dr. Rowena Johnston. “But these findings give us hope that Timothy Brown may soon be joined by others who have been cured of HIV.”

For more information on ICISTEM, visit