LAUSR

Background: Haploidentical hematopoietic stem cell transplantation (HSCT) is a useful therapy for relapsed/refractory acute leukemia or lymphoma because of the strong graft‐vs‐leukemia (GVL) effect. However, it is often accompanied by severe acute graft‐versus‐host disease (aGVHD), which is the most serious complication after haploidentical HSCT. Thus, it is important to control the severity of aGVHD while maintaining the GVL effect. In our experience of pediatric haploidentical HSCT, it takes several days for aGVHD to become severe after the appearance of initial symptoms, mostly skin rashes. In this study, we aimed to identify useful biomarkers at the onset of aGVHD that predict subsequent development of severe aGVHD.