For yet unknown reasons, antibodies are produced (Specific IgG or IgM) which turn against the body's own structures instead of foreign matter or parasites. They are called autoantibodies. The antibody-dependant cell-mediated cytotoxicity is activated and leads to the destruction of the afftected cells. Clinical manifestations are hemolytic anemia, thrombocytopenia and neutropenia.
Examples of a type II reaction are autoimmune hemolytic anemias, idiopatic thrombocytopenic purpura or rheumatoid arthritis.