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 45 months, 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 <10 months 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.