Acute or immediate immunological complications of blood transfusion (occur within 1-2 hours) Hemolytic transfusion reactions with symptoms (intra- or extravascular) ...

Anaphylactic transfusion reactions are much less common, occurring once per 20,000-400,000 units of blood or components transfused. The cause is generally an IgG anti-IgA in an IgA-deficient ...