Evaluation of an ELISA system for determination of class-specific antibodies to native and denatured DNA in XXXX .

@entity1 @entity39531 @entity1391 @entity1252
Enzyme-linked immunosorbent assays (ELISA) have been set up for determination of plasma IgG and IgM antibodies to native (n) and denatured (d) DNA. Normal male and female donors generally gave low values in the assays for IgG; IgM control values were higher, particularly in females. Mean values for @entity1 with @entity1252 ( @entity1252 ) were greatly raised in all four categories of assay in relation to the control (female) group. Levels of IgG anti-nDNA in @entity1252 correlated well with a standard diagnostic test (Farr), and this ELISA assay was more successful than Farr in discriminating between @entity1 and normal females. No such correlation with Farr was found for IgM anti-nDNA. Correlations were found in @entity1252 between levels of antibodies to nDNA and dDNA. Inhibition tests--including those with a plasmid DNA preparation containing no single-stranded regions--showed that most of the IgG antibodies determined in the 'native' assay were able to bind to nDNA and dDNA with comparable avidity, whereas most of those reacting in the 'denatured' assay could only bind dDNA. The former antibodies were probably directed against shared determinants on the @entity39531 - @entity1391 backbone and the latter against base-dependent structures not exposed in nDNA. Inhibition results for IgM assays were similar, though the predominance of antibodies specific for dDNA appeared less marked. ELISA assays could well prove more useful than established methods in diagnosis and monitoring of @entity1252 and other diseases.
