Autoantibodies to Complement Components

The purpose of the immune system is to defend the host from constantly changing microbial pathogens. Autoimmune diseases develop as a consequence of the production of antibodies and/or cells that react with self-antigens, and may recmit other effector mechanisms that result in tissue damage. Thus, in this context, autoimmunity represents an immune response to self-antigens that is sufficient to cause disease. It should not be forgotten that apparently harmless autoantibodies may also be formed following tissue damage (e.g.. antiheart antibodies, after a myocardial infarction), and the evidence that many of the autoantibodies routinely measured in the laboratory are directly pathogenic, is weak.