An immunoenzymatic technique for the detection of antinuclear antibodies

In the present work, we propose, for the detection of the anti-nuclear antibodies (ANA) an immunoenzymatic test in simple sandwich in heterogeneous phase (ANA-EIA) allowing the screening of the antinuclear antibodies, and its assessment in comparison with the indirect immunofluorescent assay (IFA) for 292 sera of patients affected by rheumatic diseases and 40 sera of individuals presenting no pathology. The ANA-EIA test proved to have a sensitivity of 97% and a specificity of 96%. Moreover, it gives a global concordance of 96.6% and a discordance of 3.4% compared to IFA. Also, the analysis of correlation between this test and IFA for the positive individual gives a very good concordance according to homogeneous, speckled and nucleolar aspects. On the other hand, the results obtained for cytoplasmic aspect (74%), although acceptable, needs to be confirmed a second time with a more important sampling. According to the results obtained, this test could have an interesting routine application in laboratory of immunopathology given its analytic characteristics similar to those of IFA, and its great easiness of realisation.