A research team from the Massachusetts General Hospital (MGH) has shown that it is possible to transplant bone marrow successfully from mismatched human donors without the usual pre-transplant destruction of the patient's own bone marrow. The report appears in the May 22 issue of The Lancet.
The scientists from the hospital's Bone Marrow Transplant Program and Transplantation Biology Research Center (TBRC) successfully induced a state of mixed chimerism - in which the immune systems from both donor and recipient are blended - in four patients with aggressive non-Hodgkins lymphomas that resisted other treatment methods. Two of those patients have achieved long-term remission without significant graft-versus-host disease, a dangerous complication of bone marrow transplantation.
"This proof-of-principal study has shown that we can achieve a lasting combination of donor and recipient immune systems without the kind of toxic treatment usually used to wipe out the recipient's bone marrow," says Megan Sykes, M.D., of the TBRC, the paper's lead author. "We are intrigued by the powerful anti-tumor effect observed in several patients."
Thomas Spitzer, M.D., director of the Bone Marrow Transplant Program and principal investigator of the study described in the Lancet paper, adds, "While it's much too early to say whether this approach will benefit and be safe for all patients with advanced blood-cell cancers, we're very encouraged by the results we've seen."
In standard bone marrow transplantation, patients undergo a pre-transplant
process called ablation in which their diseased bone marrow is destroyed by
either intense radiation or chemotherapy, essentially wiping out their immune
system. Depending on the patient's particular illness, replacement marrow may
come from a donor or may be the patient's own marrow treated to remove any
malignant cells (an autologous transplant). In the case of treatment-resistant
non-Hodgkins lymphoma, a blood-cell canc
Contact: Susan McGreevey
Massachusetts General Hospital