Unless the donor is an identical twin, patients undergoing bone-
marrow transplant (also known as hematopoietic stem cell
transplant, or HSCT) must first receive powerful chemotherapy
drugs to wipe out their immune system and prevent their bodies
from rejecting the donated cells. Research from Children’s
Hospital Boston and the Dana-Farber Cancer Institute has helped
demonstrate that this punishing regimen increases the risk of
graft-versus-host disease (GVHD), in which the donor’s cells
mount an immune response against the patient. But the most
recent findings also suggest that the risk for GVHD can be
reduced by replacing a natural antibiotic protein, known as
bactericidal/permeability increasing protein (BPI), which is
depleted when patients undergo chemotherapy. Now, a multicenter
study is about to test this idea in HSCT patients, using a
manufactured form of BPI known as rBPI21 (XOMA Ltd.) Unlike
other treatments to prevent GVHD, BPI does not suppress the
immune system and has shown virtually no toxicity.