A pharmaceutical composition suitable for administration to human beings in the prevention or treatment of immunologic disorders includes: an immune complex of an antigen and a purified antibody specific thereto, the antigen being selected from a group consisting of antigens that cause pathogenic immunologic reactions in autoimmune disease and graft rejections, and the antigen and antibody being present in a ratio whereby the antibody blocks essentially all binding sites of the antigen; and a pharmacologically acceptable carrier or diluent. The invention also provides a method of administering the composition for treatment of autoimmune disease and treatment or prevention of graft rejections.