Impaired hematopoiesis is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Bone marrow aplasia and peripheral cytopenias arise from primary secondary graft failure or poor function. Chimerism analysis useful to discriminate these conditions. By determining the pathogenesis of impaired hematopoiesis, timely appropriate treatment can be performed. Hemat...