Detection of Anti-DNA antibodies
Antibodies to DNA (anti-DNA) are prototypic autoantibodies found prominently in the sera of patients with systemic lupus erythematosus (SLE). While DNAs from various species likely differ in antigenic structure, anti-DNA antibodies in SLE sera appear to bind epitopes expressed widely on DNA, independent of its origin. Although expressed pathologically, anti-DNA antibodies nevertheless differ in their ability to mediate inflammation and tissue damage, in particular glomerulonephritis. While the role of anti-DNA in immune complex renal disease may underlie the correlation with disease activity, anti-DNA antibodies may have other functions that contribute to this association. Most clinical laboratories now perform tests that specifically detect anti-dsDNA antibodies, although anti-ssDNA can provide useful information for assessing disease activity; anti-ssDNA assays are also easier to perform. Currently, the methods available for anti-DNA include the radioimmunoassay (RIA), the Crithidia luciliae immunofluorescence (CLIF) assay, and the enzyme-linked immunosorbent assay (ELISA). The flurometric PicoGreen assay is similar to the Farr assay in principle but has the advantage of not using radiolabeled DNA. The new technology of microarrays allows the detection of several antibodies in a single experiment.
