in case of blood transfusion is required
- to reduce the risk of anaphylaxis ↠ washed blood ( IgA deficiency , high IgA antibodies
 - to transfuse the immunocompromised ↠ CMV -ve blood.
 - to decrease GVHD ↠ Ɣ irradiated blood
 - to reduce febrile reaction, CMV transmission, Alloimmunization, possible recipient ↠ leukoreduced blood
 - to decrease Alloimmunization and delayed hemolytic reactions ↠ phenotypically matched (ABO+Rh+Kell Ag matched)
 


