The immunofluorescence ANA assay (Antibodies, Inc) utilizes the method considered the gold standard for ANA testing by the American College of Rheumatology; circulating autoantibodies reactive with nuclear antigens of HEp-2 cells are detected. Unlike multiplex or ELISA assays, the HEp-2 cell substrate provides 100-150 possible autoantigens to detect ANAs with greater sensitivity than the solid phase assays.1, 2
The pattern and semi-quantitative titer provide useful information for both the diagnosis and the monitoring of therapy for patients with systemic lupus erythematosus (SLE) and other connective tissue diseases such as rheumatoid arthritis (RA), scleroderma, and Sjogren’s Disease.
References
1. American College of Rheumatology Position Statement, "Methodology of Testing for Antinuclear Antibodies," Approved by the Committee on Rheumatologic Care: January 2009, Approved by the Board of Directors: February 2009.
2. Fawcett, P.T., Rose, C.D., Gibney, K.M., Emerich, M.J., Athreya, B.H., and Doughty, R.A. "Use of ELISA to measure Antinuclear Antibodies (ANA) in children with Juvenile Rheumatoid Arthritis." J. Rheumatol. 26(8):1822-1826, 1999.