Autoadsorption is commonly used to detect alloantibodies when the patient has not been transfused in the past 3 months. The autoantibody is removed from the patient's RBCs by heat or chemical treatment. The RBCs are then treated with an enzyme to enhance autoantibody adsorption.
Autoadsorption. (5)ZZAP Treatment:
ZZAP is the most popular technique to treat cells to be used for autoadsorption. ZZAP is a combination of dithiothreitol (DTT) and papain. The DTT removes the antibody coating the red blood cells uncovering antigens which are then enhanced by the papain to increase adsorption.
Once the cells are treated, the cells can be used to adsorb the autoantibody from the patient's plasma. This often requires several adsorptions to remove all the autoantibody, depending on the strength.
After the autoantibody has been removed, the adsorbed plasma can be used to screen and identify alloantibodies and then subsequently used for crossmatch testing, if needed.
Important note: ZZAP destroys or alters Kell, Duffy, and MNS antigens. This will need to be considered in antibody workups.
