The Incidence of ANA and ETI-dsDNA Detected by Enzyme Immunoassays and Indirect Immunofluorescence Assay (IFA)

While the SLE (Systemic Lupus Erythematosus) specificity of ANA is low, that of anti-dsDNA autoantibodies is high. The DNA used in the assay must be double stranded: autoantibodies to single -stranded (ss) DNA exist in many diseases and specific to none. The prevalence (70%) of anti-dsDNA autoantibodies is much higher in SLE, giving a higher diagnostic sensitivity than the similarly disease-specific anti-Sm autoantibodies (30%). Anti-dsDNA autoantibodies are usually detected by very analytically sensitive techniques, such as ELISA (Enzyme Linked Immunosorbent Assay). Within SLE, ds-DNA autoantibodies tend to associate with the presence of glomerulonephritis. Their levels are used to monitor disease activity. We suggest the use of ds-DNA to find the difference between SLE patients with benign variants and classical syndrome of severe skin and renal disease.