Haemolytic transfusion reaction due to ABO incompatible plasma in a platelet concentrate.

A patients of blood type A1 developed brisk, but transient haemolysis after receiving a platelet transfusion derived from 4 group 0 donors. Anti-A was detected on his red cells and in his plasma. 2 of the platelet donor were found to have very high titers (1:10240) of anti-A and positive haemolysin tests. Thus, a haemolytic reaction can result from transfusion of incompatible plasma in a platelet concentrate.