Dr. Jonah Sacha and colleagues at OHSU's Vaccine & Gene Therapy Institute are among the many scientists who are seeking to understand why the much-studied "Berlin patient" was so fortunate. Now, they've developed a new way to understand his cure. Sacha's team has shown a species of monkey called Mauritian cynomolgus macaques can successfully receive stem cell transplants.

Researchers have long used a different monkey species to research stem cell transplants, but that species' biological characteristics means it can't be reliably used to find good donor matches to mimic human stem transplants.

In a paper published Nov. 10 in the journal Nature Communications, Sacha and colleagues report they successfully performed stem transplants on two monkeys more than a year ago that continue to lead healthy lives today. The recipients did not suffer from the many common adverse effects of stem transplants, including the grueling graft-versus-host disease, which can cause severe liver damage, rashes, diarrhea and even death.

The finding provides Sacha a critical tool needed to explore how the Berlin patient was cured. As a result of the finding, researchers can also use Mauritian cynomolgus macaques to improve stem cell transplant outcomes for human patients with other blood-related conditions such as leukemia and sickle-cell disease.