The detection of antinuclear antibodies (ANAs) by indirect immunofluorescence are nowadays predominantly tested using for screening in the patients suspected of having an autoimmune disease, particularly of the rheumatic form.

Autoantibodies against nuclear antigens occur in many disease such as systemic lupus erythematosus (SLE), Sharp's syndrome, rheumatoid arthritis, progressive systemic sclerosis, polymyositis/dermatomyositis.  The diagnosis of a systemic rheumatic disease is based primarily on the presence of compatible clinical signs and symptoms. The results of tests for autoantibodies including ANA and specific autoantibodies are ancillary. Additional diagnostic criteria include consistent histopathology or specific radiographic findings.

The frequency (prevalence) of anti-nuclear antibodies in inflammatory rheumatic disease is between 20% and 100%, the lowest occuring in rheumatoid arthritis at between 20% and 40%. Therefore, differential antibody diagnostics against nuclear antigens is indispensible for the identification of individual rheumatic diseases and their differentiation from other autoimmune disease.  At times, antibodies against nuclear antigens are detectable in subjectively healthy individuals, usually at a low titer.  This finding is more common in women than men and the frequency of a detectable ANA in healthy women over 40 years of age may approach 15% to 20%. ANA may be detectable after viral illnesses, in chronic infections, or in patients treated with some kind of medications.  A diagnosis should not be made on a single test result. The clinical symptoms of the patient should alway be taken into account along with the serological results by the physician.