BACKGROUND Integrating evidence from randomized controlled trials (RCTs) into patient care is needed to optimize patient outcomes. Transfusion support during allogeneic hematopoietic cell transplantation (alloHCT) is a cornerstone of essential supportive care, yet optimal transfusion practices remain unclear. STUDY DESIGN AND METHODS A scoping review of RCTs in alloHCT was conducted and 14 full-length articles on transfusion practice were identified
that reported clinical outcomes after alloHCT. RESULTS Eight RCTs compared various interventions related to platelet (PLT) transfusion, addressing product storage duration, dosage, and threshold for transfusion. Restrictive prophylactic PLT transfusion strategies were successful at reducing PLT consumption without impacting clinical outcomes. One study, however, reported increased bleeding associated with a strategy whereby patients did not receive prophylactic PLT transfusions. One study of thrombopoietin was associated with reduced PLT transfusion events but no difference in clinical outcomes compared to placebo. Six RCTs examined the utility of recombinant erythropoietin (EPO) in reducing red blood cell (RBC) transfusion dependence. Four trials reported an increase in hemoglobin levels while five studies demonstrated a reduction in RBC utilization; however, clinical outcomes were variably reported and no differences were identified. There were no RCTs examining RBC transfusion strategies, plasma transfusion, or plasma-derived protein administration. CONCLUSION Prophylactic PLT transfusion when PLTs are fewer than 10 x 109 /L can prevent bleeding and is consistent with recent guidelines. Thrombopoietin and EPO can reduce transfusion requirements; however, potential safety concerns remain and the lack of improvement in clinical outcomes and high cost may limit use. Additional RCTs are needed, particularly with regard to RBC transfusion thresholds, to refine best practices after alloHCT.