Possible Scenarios When Transfusions are Needed in the Presence of WAIHA
- Autoantibody detectable from eluate only: If there is not a high enough titer of the autoantibody to be demonstrated in the serum/plasma of WAIHA, the antibody screen will be negative. In this situation, the autoantibody is detectable from the eluate only. Compatible crossmatches can usually be obtained in this presentation, but the survival of the transfused cells due to sensitization by the autoantibody is difficult to predict.
- Autoantibody detectable from eluate only, but the serum/plasma also demonstrates alloantibody reactivity: In this case, the serum/plasma shows a specificity (or specificities) directed against a definite pattern of cells on an antibody identification panel. The resolution would necessitate identification of the alloantibody(ies). Transfusion would require appropriate antigen-negative units, which will likely be crossmatch compatible, if the autoantibody is not detectable in the serum/plasma.
- Autoantibody reactivity in both the serum/plasma and eluate: Reactivity will likely be observed against all panel cells tested and the reactivity may mask the presence of underlying alloantibodies. Adsorption studies are the primary method of investigating this possibility. If no reactivity is present after the adsorptions, then no underlying alloantibody is present. If a transfusion is needed in this case, a common practice is to transfuse "least incompatible" units. The presence of alloantibody has been ruled out, the autoantibody is confirmed, but it is difficult to predict the efficacy of the transfusion due to the autoantibody. Special procedures/consents are usually in order to transfuse the incompatible units.
- Both autoantibody and alloantibody are demonstrated in the serum/plasma: In this case an adsorption method usually reveals the underlying alloantibody that was masked by the presence of the autoantibody. If transfusion is required, appropriate antigen-negative units must be obtained. The crossmatches will likely be incompatible due to the autoantibody, and special consents/procedures must be followed to transfuse in this situation. The survival of the transfused cells due to the demonstrable autoantibody is suspect.