Thymoglobulin 25mg Injection contains the active ingredient Antithymocyte Immunoglobulins. It is a purified and sterile form of gamma globulin. It is isolated from the hyperimmune plasma of horses immunized with human white blood cell components. It is used after kidney transplantation and other therapies to treat and delay organ rejection. After solid organ transplantation, the body generates an aggressive immune response because it recognizes the transplanted organ's antigens as a foreign antigen. Thus, treatment with immunosuppressive agents is necessary after an organ transplant to prevent organ rejection.