Advances and pitfalls in anti-double-stranded DNA autoantibody detection and interpretation.

Anti-double-stranded DNA (anti-dsDNA) autoantibodies are detected in 20%-90% of patients with systemic lupus erythematosus (SLE), with prevalence varying according to disease activity, patient population, and assay methodology. Traditionally, four categories of anti-DNA autoantibodies have been described. The first recognizes only native dsDNA; the second recognizes both dsDNA and single-stranded DNA (ssDNA); the third reacts predominantly with denatured or ssDNA; and the fourth comprises anti-nucleosome autoantibodies, which recognize DNA-histone complexes and may yield results that differ from those obtained with assays specific for native dsDNA. Combining the Crithidia luciliae indirect immunofluorescence test with solid-phase immunoassays improves the diagnostic accuracy for anti-dsDNA antibody screening in patients with SLE. However, several limitations remain in the performance and interpretation of anti-dsDNA immassays, potentially leading to diagnostic errors. These pitfalls may arise mainly from analytical variability, assay design constraints, and a lack of standardized interpretation. Recent advances indicate a growing shift toward solid-phase multi-analyte arrays coupled with algorithm-based analysis, which may help reduce the seronegative gap in SLE while improving the harmonization of anti-dsDNA testing. This minireview critically evaluates current immunoassays for anti-dsDNA antibody testing, with particular emphasis on their analytical limitations, diagnostic pitfalls, and emerging advances.