Clinical performance of three anti-dsDNA antibody immunoassays in systemic lupus erythematosus.

OBJECTIVES To evaluate the clinical performance of three commercially available anti-dsDNA antibody immunoassays in Japan.

METHODS We compared the reactivity and diagnostic accuracy of three commercially available anti-dsDNA antibody immunoassays (radioimmunoassay [RIA], chemiluminescence enzyme immunoassay [CLEIA], and fluorescence enzyme immunoassay [FEIA]). We evaluated how well the three anti-dsDNA antibody immunoassays reflected disease activity and individual organ involvement in systemic lupus erythematosus (SLE).

RESULTS Three anti-dsDNA antibody immunoassays demonstrated moderate to substantial correlation and concordance, while some patients exhibited different reactivity because of assay principles and detection systems. The diagnostic accuracies of the three immunoassays were comparable based on the receiver operating characteristic analyses and optimal cutoff values. Among the three anti-dsDNA antibody immunoassays, a fully automated CLEIA-specific detection system demonstrated high sensitivity that reflects disease activity. The combined results of the titers and positivity rates of the three anti-dsDNA antibody immunoassays showed that nephritis was significantly associated with CLEIA and arthritis with RIA, and weak or no associations with other organ involvement were observed.

CONCLUSIONS We confirmed that the clinical performances of the three dsDNA immunoassays are comparable. Our findings suggest that selecting an optimal anti-dsDNA immunoassay will be useful for clinical decision-making in SLE.