COMPARISON OF INDIRECT IMMUNOFLUORESCENCE ON CRITHIDIA-LUCILIAE, FARR ASSAY AND NEW ELISA TECHNIQUES FOR THE DETECTION OF ANTI-NATIVE DNA ANTIBODIES

Anti-native DNA (ds DNA) antibodies were measured by the Farr assay, an indirect immunofluorescence on Crithidia luciliae (IIFCL) and a newly commercialised enzyme-linked immunosorbent assay (Elisa) in the sera of 270 patients: 73 negative controls, 67 patients with systemic lupus erythematosus (SLE), 73 with clinical symptoms of another connective tissue disease and 61 patients with liver diseases. The Farr assay remains a reliable method, IIFCL seems to be as specific but less sensitive and Elisa has a higher sensitivity but a lower specificity. Finally, 35 sera from the 270 patients were tested for anti-ds DNA antibodies using two other commercialised Elisa-related techniques. The results suggest little correlation between the three Elisa methods.