Evaluation of method discordance in a double-stranded DNA antibody external quality assurance program

Anti-double stranded DNA (dsDNA) antibodies are examined in cases of suspected systemic lupus erythematosus (SLE) as an aid to diagnosis, classification and response to treatment. We examined anti-dsDNA results submitted between 2017 and 2021 for the RCPAQAP’s programs. Of the 40 survey cycles reviewed, 35 (87.5%) had donor history available and 15 (38.5%) of these were unable to set qualitative targets. Furthermore, this variable reporting was observed both within and between method groups. Four (16%) surveys with consensus qualitative reporting also displayed variable performance between methods, suggesting discrepancies in assay specificity and/or sensitivity.