Autoantibodies present in patient serum bind to homologous nuclear antigens in the substrate (HEp-2 cells) and are detected using fluorescein isothiocyanate (FITC)-labeled anti-human immunoglobulin antibody. A positive ANA result is associated with a variety of autoimmune disorders, including systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), rheumatoid arthritis (RA), Sjögren’s syndrome (SS), and progressive systemic sclerosis (PSS). High titers of anti–double-stranded DNA (anti-dsDNA), a specific ANA subset, are strongly associated with SLE. Anti-dsDNA titers may decrease with successful therapy and increase during disease flares. DNA–anti-DNA immune complexes contribute to SLE pathogenesis through deposition in the kidneys and other tissues. Therefore, detection and quantification of ANA and anti-dsDNA antibodies are diagnostically and therapeutically useful in patients suspected or known to have SLE or other connective tissue diseases.
Serum should not be stored in self-defrosting refrigerators or freezers.
Indirect Immunofluorescence (IF)
Negative
Positive screens will be titered and results will include titer and pattern.
Meroni P L, Schur P.H. ANA screening: an old test with new recommendations. Annals of the Rheumatic Diseases. 2010;69(8):1420–1422.