Bone Marrow Cells Can Travel After Transplantation

A study has found that some bone marrow cells transplanted after high-dose chemotherapy are able to relocate to other tissues throughout the body rather than being restricted to the bone marrow and blood. This information was published February 7, 2003, in the online edition of the Proceedings of the National Academy of Sciences.

Investigators from the Stanford University School of Medicine (Stanford, CA, USA) studied brain samples taken from women who were treated for leukemia with chemotherapy and then later received bone marrow transplants from male donors. These samples were ideal for this study because the donor cells contained a Y sex chromosome whereas cells in the women contained only X chromosomes.

Blood cells taken from the brains of the leukemia patients after death contained Y chromosomes, since bone marrow cells from the transplant generated them. However, five nerve cells (Purkinje cells) involved in controlling balance and movement were found to contain Y chromosomes in addition to their original X chromosomes. These out-of-place chromosomes could only have come from male cells in the bone marrow transplant. The study demonstrated that although Purkinje neurons are no longer generated after birth, cells within the bone marrow could contribute to these central system neurons even in adulthood.

Dr. Helen Blau, senior author and professor of pharmacology at the Stanford University School of Medicine, explained that the Purkinje cells may have gotten their Y chromosome from a group of traveling bone marrow cells. "I think these cells may act as a repair squad. The cells travel the bloodstream, respond to stress, and repair damaged tissues such as brain, muscle, and possibly others throughout the body,” said Dr. Blau.”



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Stanford University Medical Center