Allogeneic peripheral blood progenitor cell transplantation conditioned with anti-thymocyte globulin for treatment of graft failure after allogeneic bone marrow transplantation.

A 43-year-old female with AML-M1 developed late graft failure 4 months after her first allogeneic bone marrow transplant. The patient then underwent a second transplant with peripheral blood progenitor cells obtained from the same HLA-identical brother. The donor peripheral blood progenitor cells were mobilized with granulocyte colony-stimulating factor (10 micrograms/kg daily s.c. for 6 days). The patient received horse anti-thymocyte globulin alone (15 mg/kg per day for 5 days) as the conditioning regimen. Rapid hematopoietic recovery followed a sustained engraftment. The time to reach 0.5 x 10(9)/l neutrophils and 25 x 10(9)/l platelets was 10 and 12 days, respectively. Cytogenetic analysis of bone marrow performed on day +20 demonstrated a 46XY karyotype of donor origin. There was no acute graft-versus-host disease. The patient remains in complete remission with a karnofsky score of 90% 5 months after peripheral blood progenitor cell transplantation. To treat graft failure after allogeneic bone marrow transplantation, allogeneic peripheral blood progenitor cell transplantation conditioned with anti-thymocyte globulin alone should be considered as a feasible alternative to marrow transplant.