Abstract
Adsorption studies are usually required to confirm or rule out the presence of underlying alloantibodies in samples containing warm autoantibody. Allogeneic adsorptions are necessary if the patient has been recently transfused. Most commonly, allogeneic adsorptions are performed using a trio of phenotyped reagent red blood cells to rule out clinically significant alloantibodies to common antigens. The adsorbing cells may be used untreated or treated with enzymes or with ZZAP before adsorption. Adsorption may also be performed using enhancement such as low-ionic strength saline or polyethylene glycol added to the mixture. Multiple adsorptions may be necessary to remove strongly reactive autoantibodies. Allogeneic adsorptions will not detect alloantibodies to high-prevalence antigens. Immunohematology2014;30:153–155.