Allogeneic Hematopoietic Stem Cell Transplantation-Induced Anaphylaxis in 2 Pediatric Cases

Hematopoietic stem cell transplantation is a curative treatment for many malignant and nonmalignant diseases in children and adults. It is performed with peripheral blood stem cells, bone marrow, and umbilical cord blood. Anaphylaxis may occur during hematopoietic stem cell transplantation, similar to that shown with blood transfusions. In children, although a few cases of anaphylaxis have been reported with cord blood transplantation, no cases of anaphylaxis have been reported with other hematopoietic stem cell transplantations. In this case report, we present the cases of 2 children, one diagnosed with thalassemia major and the other with aplastic anemia, both of whom developed anaphylaxis associated with bone marrow transplantation products cryopreserved with dimethyl sulfoxide and hydroxyethyl starch. Hematopoietic stem cell transplantation-induced anaphylaxis could be associated with cryoprotective agents, especially dimethyl sulfoxide, and alloantigens. In both anaphy-lactic reactions, dimethyl sulfoxide was thought to be the trigger, but it could not be excluded that it was related to stem cell components, plasma, or hydroxyethyl starch.