C3 and acute kidney injury: Occurs during or within 24 h of cessation of transfusion with new onset of any of the following signs/symptoms: chills/rigors; fever; back/flank pain; hypotension; hematuria; epistaxis; oliguria/anuria; renal failure; disseminated intravascular coagulation (DIC); pain and/or oozing at IV site, as well as positive direct antiglobulin test (DAT) for anti-IgG or anti-C3, positive elution test with alloantibody present on the transfused red blood cells and two or more of the following: elevated LDH; elevated bilirubin; decreased haptoglobin; decreased fibrinogen; haemoglobinemia; hemoglobinuria