Transfusion therapy with platelets and leukocytes.

Supportive care of the child with leukemia and solid tumors has improved dramatically due to advances in blood component preparation and use. Despite these advances, unsolved questions remain which will require research into better component preparation and randomized clinical trials. The prevention of post-transfusion graft-vs-host disease in the immunocompromised patient will require research into optimum radiation dosages for blood products and the appropriate choice of patients to receive these products. Alloimmunization to platelet concentrates will continue to be a problem as children receive more ablative cancer therapy. The use of leukocyte-poor platelets and allogeneic cryopreserved platelets may aid some of these patients, but the value of these products needs to be proven by more clinical trials. Finally, crossmatching of platelet products may become more readily available and may prove useful for more adequate selection of donors. If bone marrow transplantation becomes a therapeutic modality following remission induction for a large number of leukemic patients, the use of blood products pretransplantation will require intense investigation. Graft rejection in these children may be linked to the kind, number, and cytomegalovirus status of blood products given during their acute leukemic phase. The blood bank provides an important resource for procurement of blood products and for specialized product preparation. In addition, it should serve as a resource for new ideas and experimental blood products for use of the clinician caring for the child with cancer.