The clinical significance of borderline results of the Elia CTD Screen assay.

Background Data on the clinical relevance of borderline results of solid-phase assays in the screening for antinuclear antibodies (ANA) are sparse. This study aimed to determine the clinical significance of borderline results of the Elia CTD Screen (ECS; Phadia/Thermo Fisher Scientific, Freiburg, Germany), a fluoroenzymeimmunoassay incorporating 17 recombinant human nuclear antigens. Methods We retrospectively examined the medical records of 143 subjects with borderline ECS results for ANA-associated autoimmune disorders (AASARD) and the association with the results of indirect immunofluorescence (IIF) and confirmatory assays for ANA.