Evaluation of a semiautomated prestandardized immunofluorescence test system for detection of anti-native deoxyribonucleic acid antibodies.

An immunofluorescence-native deoxyribonucleic acid (nDNA) antibody test system (Zeus Scientific, Inc.) was compared with a radioimmunoassay procedure (FARR assay) for detecting anti-nDNA antibodies in human serum. Double-blind studies of split samples obtained from 236 patients showed an 80% correlation between the immunofluorescence-nDNA antibody test system and the radioimmunoassay procedure. Studies of sera from patients with known diagnoses showed positive nDNA antibody findings in biopsy-prove n systemic lupus erythematosus only. The immunofluorescence-nDNA antibody test system provides a reliable, simple, and economically feasible alternative method for detecting nDNA antibodies that can be employed in any laboratory equipped with a fluorescence microscope.