Type II hypersensitivity cytotoxic type) a Type Ii hypersensitivity reactions are mediated by igg and igm antibody binding to specific cells or tissues. The damage caused is thus restricted to the specific cells or tissues bearing the antigen. a The antibodies damage cells and tissues by activating complement and by binding and activating effector cells carrying FcyR.Type II hypersensitivity (cytotoxic type)  Type II hypersensitivity reactions are mediated by IgG and IgM antibody binding to specific cells or tissues. The damage caused is thus restricted to the specific cells or tissues bearing the antigen.  The antibodies damage cells and tissues by activating complement, and by binding and activating effector cells carrying FcR