Most patients with WAIHA may never need transfusion. Occasionally transfusion may be required if the anemia is severe or the patient is scheduled for a surgical procedure. The question of transfusing patients with demonstrable WAIHA cases is highly debatable. The fate of the transfused red blood cells may be the same as the patient's own cells, depending on the severity of the immune response and autoantibody production. Transfusion should occur only when clinically necessary and providing supportive therapy (oxygen and rest for example), are options. It is a clinical decision that balances the risks and clinical needs. Blood should never be withheld from a patient in a life-threatening event because of incompatibility from autoantibodies. The volume of transfusion should be the least amount to maintain adequate oxygen transportation and relieve the symptoms of anemia.
The primary goal of the blood banker is to ensure compatibility with any alloantibodies present in the serum.
- If no alloantibodies are present, random units that are ABO compatible may be selected for transfusion.
- If alloantibodies are present, antigen-negative blood must be transfused. If the specificity of the autoantibody can be determined, the appropriate antigen-negative donor blood should be selected, if possible. If transfusion is necessary, some facilities choose to transfuse units of blood that are Rh and K phenotypically matched to the patient in order to prevent alloimmunization. Due to the presence of autoantibodies where specificity cannot be determined, all crossmatches will be incompatible. The donor units with the weakest reactions in vitro are usually selected as least incompatible.