an antibody showing an affinity for nuclear antigens including DNA and found in the serum of a high proportion of patients with systemic lupus erythematosus, rheumatoid arthritis, and certain collagen diseases, and in some of their healthy relatives; as well as about 1% of otherwise healthy people. Different antinuclear antibodies generate distinctive patterns on immunofluorescence staining tests. These patterns have clinical relevance and reflect which nuclear constituents (autoantigens) are generative specific antibody responses.