Prediction, management, and prognosis of mixed chimerism after hematopoietic stem cell transplantation in transfusion‐dependent pediatric thalassemia patients

Background Early‐onset mixed chimerism (MC) with a high proportion of residual host cells is considered a signal of graft rejection in patients undergoing allogenic hematopoietic stem cell transplantation for transfusion‐dependent thalassemia. In order to prevent graft rejection and minimize the risk of treatment‐related graft‐versus‐host disease (GVHD), we established a hierarchical management system based on chimerism analysis. Method This retrospective study provides a comprehensive review of the characteristics, interventions, and outcomes of the 38 patients who developed MC after transplantation among the 144 pediatric thalassemia patients between July 2007 and January 2019 at our center. Results A sibling donor, a blood type‐matched donor, conditioning regimens without fludarabine, and transplants containing