Nonmyeloablative Peripheral Blood Stem Cell Transplantation for Chronic Myeloid Leukemia in Chronic and Advanced Phases.

Objective: To study the effect of nonmyeloablative peripheral blood stem cell transplantation(PBSCT) for chronic myelogenous leukemia(CML) in chronic phase(CML-CP) and advanced phase(CML-AP). Methods: Twenty-four CML patients, 16 in CML-CP and 4 in CML-AP underwent nonmyeloablative peripheral blood stem cell transplantation(NST). The conditioning regimen included fludarabine 30mg.m−2.d−1, intravenously(i.v.)×6d, busulphan 4mg.m−2.d−1×2d and CTX 350mg.m−2.d−1×2d combined with or without Ara-C. The donors were HLA-identical (n=20) and 5/6 antigen-matched (n=4). Results: All the patients were successfully engrafted. The mean time needed for increase of the number of neutrophils to more than 0.5×109/L and platelet more than 20×109/L were 13 days and 11.5 days respectively. Among 12 patients, 9 showed complete donor chimerism(CDC) and 3 showed mixed chimerism(MC) at +day 30. At +day 180, 18 patients still alive showed CDC and remained alive after a median follow-up of 24 months (4∼48months). 3 cases died of severe acute GVHD(aGVHD), 1 case of chronic GVHD(cGVHD), 2 cases of interstitial pneumonia(IP) and 1 case of relapse. Conclusion: Nonmyeloablative PBSCT is an effective method for CML patients in chronic phase and advanced phase. Characteristics of 24 CML patients and their donors Patient Age Gender Diagnosis Donor HLA *: unrelated donor 1 40 male CML-AP brother HLA-identical 2 32 male CML-AP brother HLA-identical 3 40 male CML-CP brother HLA-identical 4 40 male CML-CP brother HLA-identical 5 42 male CML-AP brother HLA-identical 6 24 male CML-AP sister HLA-identical 7 55 male CML-CP sister HLA-identical 8 32 male CML-CP brother HLA-identical 9 36 male CML-CP brother HLA-identical 10 46 female CML-AP sister HLA-identical 11 52 female CML-CP brother HLA-identical 12 60 male CML-CP sister HLA-identical 13 45 female CML-CP brother HLA-identical 14 48 male CML-CP brother HLA-identical 15 33 male CML-CP URD* HLA-identical 16 35 female CML-CP URD HLA-identical 17 40 male CML-CP brother HLA-identical 18 34 female CML-AP sister HLA-identical twin 19 54 female CML-CP brother HLA-identical 20 33 male CML-AP URD Subtype mismatched 21 32 male CML-CP URD Subtype mismatched 22 42 male CML-CP URD mismatched 23 50 female CML-CP URD HLA-identical 24 46 male CML-CP brother HLA-identical