The Comparison Between Matched Related Donor and Alternative Donor for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Acquired Aplastic Anemia: KSBMT2007-02 Study

Backgound; Although allogeneic hematopoietic stem cell transplantation (alloSCT) from matched related donor (MRD) is a standard therapy for severe acquired aplastic anemia (AA), alternative donor (AD) alloSCT is increasing and the survival of alloSCT from AD improves nowadays.

Aims: We planned this study to review the recent result of alloSCT survival and to compare AD with MRD.

Methods: A retrospective study comparing MRD and AD for alloSCT in patients with AA was conducted by Korean Society of Blood and Marrow Transplantation (KSBMT2007-02 study).

Results: The patient population was AA, pure red cell aplasia, paroxysmal nocturnal hemoglobinuria, and they underwent alloHSCT from 1997 and 2007. Total 336 patients were enrolled in 24 Korean alloSCT centers. Survival analysis was done in 331 patients because data were not available in 5 patients. Two hundred five adult patients with AA were also analyzed to define the characteristics of adult AA patients. AA was 97.3% and median age at alloSCT was 20.4 (1–62) years old. Median time from diagnosis to alloSCT was 6.2 (0.2–248.4) months. Male was 48.9%. Seventy nine percent patients received bone marrow (BM) as a stem cell source. AD had longer time from diagnosis to alloSCT (p=0.049) and received more peripheral blood (PB) or cord blood (CB) as a stem cell source (16.3% vs. 31.7%, p=0.004). Univeriate analysis showed MSD (p<0.001), age less than 15 years (p=0.010), BM as stem cell source (p=0.036) and disease duration less than 12 months (p=0.007) were significant predictor for better survival. However, multivariate analysis revealed that donor type was not significant factor (p=0.087) whereas age and BM was predictors for better survival. When 205 adult AA patients were analyzed, AD had more graft failure (p=0.005), delayed neutrophil engraftment (p=0.035), more acute graft versus host disease (GvHD; p=0.009). However, there were no different between AD and MRD in terms of platelet engraftment (p=0.618), incidence of SOS (p=0.735) and relapse rate (p=0.360). MRD (p=0.011), age less than 30Y (p=0.001), disease duration less than 12M (p=0.003), no prior immune suppression therapy, (p=0.007) and platelet transfusion less than 90U (p=0.010) significantly affected survival. Only age and platelet transfusion were significant factor for better survival in multivariate analysis.

Summary: In conclusion, our study showed that donor type was not a significant factor for survival. Therefore, AD should be considered earlier when there is no MRD in patients with AA.