Who performed the first successful human bone marrow transplant in 1956?

E. Donnall Thomas performed the first successful human bone marrow transplant in 1956.

Thomas treated a patient with leukemia by transferring bone marrow from an identical twin. Because identical twins share nearly identical tissue markers, the graft avoided the severe immune incompatibility that often causes rejection or graft-versus-host disease.

This work established the basic principle of hematopoietic stem-cell transplantation: healthy blood-forming cells can repopulate a recipient’s marrow after diseased marrow has been destroyed or suppressed. Thomas later refined transplantation using unrelated and matched donors.

Thomas received the 1990 Nobel Prize in Physiology or Medicine, shared with Joseph E. Murray, for discoveries concerning organ and cell transplantation. Bone marrow transplantation is now more broadly called hematopoietic stem-cell transplantation when the stem cells come from blood or other sources.