SUNDAY, DAY 7
MEDICAL MILESTONES
Bone marrow is spongy, fatty tissue inside of bones that develops into blood cells for the rest of the body. If a person has an immune-deficiency disorder, however, or a cancer such as leukemia, bone marrow cells can become diseased or be destroyed. Such diseases are frequently fatal, which prompted researchers in the 20th century to search for ways of replacing damaged marrow.
E. Donnall Thomas (1920–), a physician at Fred Hutchinson Cancer Research Center in Seattle, was the first to demonstrate a treatment for leukemia that involved removing the diseased marrow and immediately replacing it with a transfusion of healthy marrow. He performed this procedure for the first time in 1956: A leukemia patient received bone marrow cells from his identical twin brother, and the patient’s body accepted those cells and used them to produce new, healthy blood cells.
Developments in immune-suppressing drugs, as well as techniques for identifying closely matched donors, allowed Thomas to perform the first transplant in 1969 on two relatives who were not twins. Although finding an unrelated donor wasn’t easy, it finally proved possible: In 1973, a team at Memorial Sloan-Kettering Cancer Center in New York performed a transplant on a 5-year-old patient whose donor was found in Denmark through a Copenhagen blood bank.
Today, people with leukemia, lymphoma, sickle-cell anemia, and some other diseases may be treated with bone marrow transfusions. Finding a suitable donor remains a challenge, however, and patients are known to wait years for an appropriate match. If a person has diseased bone marrow, he or she will need a donor with a matching tissue type; this type of transfusion is called allogeneic. Another type of transfusion, called autologous, may be performed if a person’s bone marrow is healthy but he or she needs to undergo a harmful procedure, such as high doses of chemotherapy or radiation for cancer. In this case, bone marrow cells are harvested beforehand and injected back into the bloodstream afterward to speed recovery.