B-055 Comparison of two different methods for quantitation of anti-dsDNA antibody

Abstract Background Anti-dsDNA antibody is a specific marker of rheumatic disorder, primarily systemic lupus erythematosus (SLE). Early detection of these diseases is most important in treatment and prognosis. We evaluated two different quantitation systems of anti-dsDNA antibody: the BioPlex 2200 multiplex simultaneous detect system and the single detection method, which is the Phadia 250 system. Methods 53 serum samples were analyzed by two different methods, which are BioPlex 2200, Bio-Rad Laboratories, Hercules, CA, and Padia 250, Thermo Fisher Scientific, Uppsala, Sweden, respectively. The method of the BioPlex 2200 system is multiplexed bead assay, and that of Phadia 250 is Fluorescence Enzyme Immunoassay (FEIA). Results The quantitation results of BioPlexx 2200 were 1 to 126 IU/mL, and those from Phadia 250 were 0.08 to 109.53 IU/mL, respectively. These two groups of the anti-dsDNA antibody values showed excellent correlations (r=0.9036). Conclusions The quantitation of anti-dsDNA antibody were performed mainly by a single analyzing method, Phadia 250, in Korea. Bioplex 2200 system is multiplex bead assay; it can analyze eight different Extractable Nuclear Antigen Antibodies (anti-ENA) simultaneously: Anti Ribosomal P Ab, Anti SSa/Ro Ab, Anti SSb/La Ab, Anti Centromere Ab, Anti Sm Ab, Anti RNP Ab, Anti SCL-70 Ab, Anti Jo-1 Ab as well. Nevertheless, these anti-ENA results showed semiquantitative results.