Character of anti-DNA antibodies in systemic lupus erythematosus.

Abstract

Anti-DNA antibodies in twenty-one systemic lupus erythematosus (SLE) sera were analysed by precipitation in gel, complement fixation, and the Farr globulin precipitation technique. Fifteen sera precipitated in agarose with both native and denatured DNA (Group 1) and six precipitated solely with denatured DNA (Group 2). Prior incubation of the sera with RNA or DNA digest abolished the precipitin reactions of all Group 2 sera, but had no appreciable effect on the precipitin patterns of the Group 1 sera. Molecular class of anti-DNA antibodies did not correlate with precipitation pattern. The ability of sucrose density gradient fractions of serum to fix complement with denatured DNA at 4°C did not correspond with the presence of precipitating antibodies against denatured DNA.