The develop­ment of new antigenic determinants on normal proteins may provoke formation of auto antibodies, ensuing autoimmune disease. Formation of rheumatoid factors and immunoconglutinins are the best examples for auto antibodies generated in this fashion.

Rheumatoid factors are antibodies produced by the immune system against newly exposed antigenic determinants of other immunoglobulins.

In affected people, when antigens bind to certain IgG antibodies, new antigenic determinants are exposed in the Fc region of the molecule, and these new determinants stimulate the formation of rheumatoid factors.

Most strikingly, arthritis can be transferred with serum or with purified antibody of the systemic auto antigen.