[Detection of anti-double stranded DNA antibodies of IgG, IgA and IgM classes by ELISA. Comparison with the Farr test and indirect immunofluorescence].

Anti-double stranded DNA antibodies were measured by an immunoglobulin class-specific immunoenzymatic assay (ELISA), in 450 sera from 265 patients as well as by indirect immunofluorescence using Crithidia luciliae as a substrate and, for 124 sera, by the Farr test. ELISA proved specific and reproducible and it yielded results that were well correlated with the Farr assay, with a slightly higher sensitivity of ELISA. Correlation with immunofluorescence was not as good because of the lower sensitivity of the latter method. ELISA enables the levels and isotypes of anti-DNA antibodies to be determined. Both appear to be critical parameters for a clinical interpretation of results, especially with respect to the diagnosis of systemic lupus erythematosus.