Absence of anamnestic response after transfusion of washed red blood cells in haemophilia A patients with antibody to factor VIII.

Washed red blood cells (WRC) have been used for replacing the blood loss in haemophilia A patients with antibody to Factor VIII. Levels of VIII coagulant activity (VIII:C), VIII coagulant antigen (VIII:CAg) and VIII related antigen (VIIIR:Ag) have been measured during the different steps of the preparation of WRC. The amount of VIII:CAg decreases very rapidly after washing and both are undetectable in the final product. These results were correlated with the absence of anamnestic response in 10 haemophilia A patients with inhibitor known as high responders.