Immunochemical properties of anti-DNA antibodies in the sera of patients with Escherichia coli bacteremia.

To assess the role of infection in anti-DNA antibody production, the DNA-binding activity of sera from patients with Escherichia coli bacteremia was analyzed. Among 8 patients with bacteremia documented by blood culture, 5 demonstrated increased levels of antibodies to single-stranded DNA from E. coli as measured by enzyme-linked immunosorbent assay. Sera from these patients also reacted with single-stranded DNA from other bacterial and mammalian species as well as certain synthetic polynucleotides including poly-dT and poly-dC. The isotype distribution of these antibodies and their avidity as assessed by competition enzyme-linked immunosorbent assay resembled, moreover, responses of patients with systemic lupus erythematosus. These results suggest that, during the course of infection with E. coli, some patients may produce antibodies with immunochemical properties similar to those arising in systemic lupus erythematosus.