DONOR LYMPHOCYTE INFUSIONS TO DISPLACE RESIDUAL HOST HEMATOPOIETIC-CELLS AFTER ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR BETA-THALASSEMIA MAJOR

Purpose: Donor lymphocyte infusion (DLI) was used to reverse relapse a fter allogeneic bone marrow transplantation (BMT) in a patient with be ta-thalassemia major. Patients and Methods: The patient with unstable mixed chimerism after BMT was treated with graded increments of donor lymphocytes (10(5) T cells/kg to 5x10(7) T cells/kg) to displace resid ual hematopoietic host cells. Results: DLI resulted in complete donor- derived reconstitution of the hematopoietic compartment. The patient d eveloped mild graft-versus-host disease (GVHD) that could be controlle d by steroid treatment. Conclusions: This case report shows that DLI c an effectively eradicate host stem cells in mixed chimeras after BMT i n nonmalignant hematopoietic diseases.