Transfusion Medicine and Hematopoietic Stem Cell Transplantation
Components
Whole blood is separated into packed red cells, platelets, and plasma. Leukoreduction reduces febrile non-hemolytic reactions, alloimmunization, and cytomegalovirus transmission. Irradiation prevents transfusion-associated graft-versus-host disease and is indicated for cellular immunodeficiencies, intrauterine transfusions, and stem cell transplant recipients. Washed products or IgA-deficient donors are used for severe IgA deficiency with anaphylaxis.
Reactions
Fever and chills suggest a febrile non-hemolytic reaction; urticaria suggests an allergic reaction; both are managed by stopping the transfusion and treating symptoms. Acute hemolytic reactions from ABO incompatibility cause fever, back pain, hemoglobinuria, and hypotension. Transfusion-associated circulatory overload shows hypertension and pulmonary edema, whereas transfusion-related acute lung injury shows hypoxemia without volume overload. Transfusion-associated graft-versus-host disease is fatal and prevented only by irradiation.
Stem cell transplantation
Autologous grafts need no HLA matching and avoid graft-versus-host disease but lack a graft-versus-tumor effect. Allogeneic grafts from matched siblings, unrelated donors, or haploidentical donors provide that effect at the cost of graft-versus-host disease. Conditioning may be myeloablative or reduced intensity. Engraftment is defined by rising neutrophil and platelet counts. Acute graft-versus-host disease affects skin, gut, and liver; chronic disease is multisystem. Sinusoidal obstruction syndrome presents with weight gain, hepatomegaly, jaundice, and ascites and is treated with defibrotide. Post-transplant lymphoproliferative disorder is usually Epstein-Barr virus driven.
Rule of thumb
In a patient with a history of transplant or immunodeficiency, cellular blood products must be both irradiated and leukoreduced.
Trap
Iron overload from chronic transfusion is assessed with ferritin plus liver iron; ferritin alone underestimates the burden during inflammation.