Objective: To study the effects of allogeneic peripheral blood stem cell transplantation (allo-PBSCT) in high-risk leukemia.
Methods: From October 1995 to December 2000, 25 patients with high-risk leukemia (median age 34 years, range 5.5-52 years) were transplanted with peripheral blood stem cells from their HLA-identical sibling donors. Among them, 15 patients suffered from acute leukemia (ALL) (one ph+ ALL in CR1, seven in CR2 or greater, and seven in relapse, including two in relapse after the first all-BMT), four patients suffered from chronic myelocytic leukemia (CML) (in CP2, AP, BC, and relapse after BMT respecively), 6 patients suffered from myelodys plastic syndrome (MDS), including one case of refractory anemia with excess of blasts (REAB), one case of refractory anemia with excess of blasts in trransformation (REAB-T), and 4 cases of acute leukemia secondary to MDS. The graft versus host disease (GVHD) prophylaxis included administration of cyclosporine and methotrexate.
Results: All patients were successfully engrafted. The median times (range) for their neutrophil returning to > or = 0.5 x 10(9)/L and for platelet returning to > or = 20 x 10(9)/L were 14 (10-18) days and 11 (7-45) days after transplantation resprctively. Grade II acute GVHD occurred in 12 patients with an incidence rate of 48%. Grade III GVHD was found in one patient (4%). No grade IV GVHD was seen. Among the 23 evaluable patients, 16 were diagnosed as chronic GVHD (70%). The actual transplant-related mortality was 16%. Leukemia relapse occurred in 6 patients, four of them received donor lymphocyte infusion (DLI) and achieved remission again. Nineteen patients were alive and disease-free with a median follow-up time of 304 (94-1,963) days. The two-year probability of overall survival, disease-free survival (DFS), and relapse rates were 64%, 58%, and 25% respectively.
Conclusion: Allo-PBSCT decreases the relapse rate, increases the disease-free survival rate for patients with high-risk leukemia. All-PBSCT may be a better choice for patients with high-risk hematological maligmancies.