Abnormal Antinuclear Antibody Titers Are Less Common Than Generally Assumed in Established Cases of Systemic Lupus Erythematosus.
OBJECTIVE: To evaluate antinuclear antibody (ANA) tests in established cases of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) by indirect immunofluorescence microscopy (F-ANA) and enzyme-immunoassays detecting antinucleosomal antibodies (ANSA-EIA). METHODS: Sera from 50 patients with SLE and 65 patients with RA were analyzed regarding abnormal concentrations of F-ANA (serum dilu