Finding a match
Challenges arise when stem cells or marrow other than the patient's own are needed for transplant. All human cells have proteins called antigens on their surfaces that are specific to each person. The introduction of cells with different antigens can send T cells, a type of invader-fighting white blood cell, into action. T-cells from donated marrow often attack the patient's own body tissue, causing graft-versus-host disease (GVHD), which can be life-threatening, as well as painful and difficult to treat.
Toni Dubeau, R.N., checks on a patient at the combined Dana-Farber/Brigham and Women's Hospital unit.
More exact antigen matching is one of the most important improvements in transplant science, according to Robert Soiffer, M.D., co-chief of the Adult Oncology Stem Cell Transplant Service and Mayberger's primary oncologist. "Graft-versus-host disease has been a devastating effect of transplant, but as matching and treatment have improved, the risk has lessened," he says.
Because antigens are determined by genes, siblings are likely to match each other. Mayberger's brother and sister were both tested. Unfortunately, neither was a close enough match to be Mayberger's donor, although they were a match for each other.
Mayberger found herself in the same position as 70 percent of patients — she had no match in the family, according to Deborah Liney, the senior unrelated bone marrow transplant search coordinator for DF/PCC. With decreasing family size, a more-mobile society, and an increasingly ethnically heterogeneous gene pool, patients more often seek help from an unrelated donor. By computer and fax, Liney sent Mayberger's blood type to registries that access about five million donors worldwide. DF/PCC is also part of the National Marrow Donor Program. As potential matches were identified, donors were asked to go through several levels of screening until the most closely matched, healthy, and willing donor was found.
"We get to know the patient extremely well. We have to be very tuned in to what is going on, from hour to hour."
— Toni Dubeau, R.N.
Once a match was found for Mayberger, her hospitalization was scheduled to begin shortly after Memorial Day in 1999. By then, she had been living with the knowledge of her disease for five months, and the greatest challenge was yet to come.
