Transplants with cord blood, collected from the umbilical cord and placenta after a baby is born, are generally done in children because of the small number of cells in a single unit of cord blood. Adults, on the other hand, need two units.
Bone marrow tissue is extracted by needle from the hip bone of donors. Marrow that is half-identical to a patient's tissue type can be obtained from parents, children and most siblings.
Results of the two trials show one-year survival rates of 54 percent for cord blood transplant and 62 percent for haploidentical marrow. Survival without disease progression at one year was 46 percent for cord blood and 48 percent for haploidentical marrow. The investigators say this is comparable to survival achieved by similar patients undergoing transplants from fully matched siblings or unrelated adult donors.
Relapse rate after one year was 45 percent for haploidentical marrow transplants and 31 percent for cord blood. No patients had severe graft versus host disease (GVHD) an attack on the patient's normal tissues by immune cells of the donor -- after bone marrow transplant.
At one year, deaths not caused by relapse occurred in seven percent of haploidentical patients and 24 percent of cord blood transplants.
Fuchs says that in the past, haploidentical transplants failed more often because the transplanted cells caused severe GVHD, especially in older patients. Half of the patients enrolled in the current trials were 50 and older.
"Ten years ago, it was unthinkable to do a haploidentical transplant," says Fuchs, who led the haploidentical transplant clinical trial.
To overcome the GVHD problems, Fuchs and colleagues at the Johns Hopkins Bon
|Contact: Vanessa Wasta|
Johns Hopkins Medical Institutions