The absence of the anti-B isoagglutinin in blood from a group A patient.
D000017:ABO Blood-Group System; D001803:Blood Transfusion; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000032:analysis*; D008875:Middle Aged
D000017:ABO Blood-Group System; D007518:Isoantibodies