production by an individual of antibodies against constituents of the tissues of others of his own species (as when transfused with blood from one belonging to a different blood group). In hematology, specifically implies a blood recipient who has made antibodies to a minor blood group antigen such as Kell, E or C. This can be avoided or decreased by transfusion with phenotypically- matched blood that is crossmatched for both major (A,B,O) and minor antigens.[close window

The process of making an antibody against a foreign antigen.

The process of an organism becoming immune to proteins, cells, or other antigens from members of its own species.