3.2. Stimuli for generation of autoantibody

Failure of immunologic tolerance can cause the development of autoimmunity. With a genetic background, intolerance can be triggered by environmental factors as sunlight, drugs, chemicals, and infectious agents [5].


stimulate self-reactive T cells which react with self-antigens in the tissue [4]. Some peptide antigens of microbes are similar to self-antigens, so leads to cross-reactions; called as molecular mimicry [6]. For example; the antibodies against Porphyromonas gingivalis; a periodontal pathogen were increased before RA onset and had a relation with RA [20–23].

Microorganisms related autoimmune diseases are listed in Table 2.

Sun lights can trigger lupus diseases. Many drugs as procainamide, hydrocarbon pristine, hydralazine, chlorpromazine, methyldopa, quinidine, minocycline and nitrofurantoin can trigger autoimmunity or autoimmune disease through ANAs and ANCAs. Many chemical agents include heavy metals as mercury, gold, and cadmium, pesticides, herbicides, hydrazine can trigger autoimmunity [5].

In organ-specific autoimmune diseases, such as thyroiditis, type 1 diabetes mellitus and primary biliary cirrhosis, autoantibodies can be stimulated by infection of the target organ, through molecular mimicry [16, 24]. In systemic autoimmune diseases, such as systemic lupus, autoantibodies can be triggered by genetic factors. For example; a nuclear autoantibodies produced by antigenic drive from excessive release of death cells antigens and enhanced by intrinsic abnormalities in B or T cells [16, 24].

#### 3.3. Production of autoantibody
