Complex Transfusion Issues in Pediatric Hematopoietic Stem Cell Transplantation

•Best practices for blood product transfusion in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT) are an area of active research.•Many questions remain around safest transfusion strategies for ABO-incompatible HSCT to mitigate risks of acute or delayed hemolysis and red cell aplasia.•Strategies to prevent and treat platelet refractoriness have been extrapolated from adult transplant data, but no single solution has proven to be superior.•Further study is necessary to understand the safety and efficacy of procoagulant products and hematopoetic growth factors in the pediatric HSCT population.

Advances in the fields of pediatric transfusion medicine and hematopoietic stem cell transplant have resulted in improved outcomes but also present new questions for research. The diagnostic capabilities involved in transfusion medicine have improved in recent times, now including methods for determination of red blood cell minor antigens, detection of anti–human leukocyte antigen antibodies, and noninvasive iron quantification. At the same time, transplants are being performed for more indications including nonmalignant disease and with less intense conditioning regimens that allow some recipient blood cells to persist after transplant. We are therefore faced with new opportunities to understand the implications of transfusion medicine testing and to develop data-driven guidelines relevant to the current-day approach to transfusion and transplantation.