Matched related donor hematopoietic stem cell transplantation results in a long-term follow-up of a pediatric acquired severe aplastic anemia subset: A stem cell source perspective

HSCT has substantially improved pediatric acquired SAA patients' outcomes. Retrospectively, we attempted to assess the outcome of MRD HSCT in 65 pediatric patients referred to a single center from 1992 to 2012. We were particularly interested to find out whether source of SC (PB, n=40 and BM, n=25) significantly impacts EFS and GVHD incidence. With a median follow-up of 45months, total EFS was 87.7%; EFS for PB and BM groups was 87.5% and 88%, respectively. Acute GVHD (grades 3-4) occurred in 13 patients (PB, n=10 [25%] and BM, n=3 [12%]), acute GVHD (grades 2-4) occurred in 24 (PB, n=16 [40%] and BM, n=8 [32%]). Extensive chronic GVHD occurred in five patients (PB, n=3 [7.5%] and BM, n=2 [8%]). Cox regression revealed that elapsed time of <10months between diagnosis and HSCT is associated with improved survival (hazard ratio, 95% CI=1.204, 1.010-1.434, p=0.038). SC source did not significantly affect EFS, incidence of acute GVHD (grades 3-4), or extensive chronic GVHD (p=0.938, 0.121, and 0.487, respectively). Based on our findings, pediatric acquired SAA patients are benefitted most if MRD-HSCT is carried out early in disease process and SC source does not affect outcome of MRD-HSCT in these patients.