Description
Sometimes autoantibodies are produced by the human body against self antigens. The precise role that this aberrant
immunity plays in the pathogenesis of certain rheumatic diseases is unknown. However the presence of these autoantibodies
serves as credible marker of the disease.
In rheumatoid arthritis, diagnostically useful autoantibodies termed as “Rheumatoid factors” (RF) can be detected which are
immunoglobulins of the class IgM, IgG, IgA and IgE. Practically, IgM class RF with specificity to human IgG (Fc) is the most
useful prognostic marker of RA. The clinical significance of RF determinations consists in differentiation between rheumatoid
arthritis, in which RF of modified IgM class have been demonstrated in the serum of approximately 80% of the cases examined
and rheumatic fever, in which RF are almost always absent. The agglutination test is most frequently used because of its
greater sensitivity and simplicity.
