In vitro activity of anti-DNA antibodies from SLE patients in antibody-dependent cell-mediated cytotoxicity.

Peripheral blood lymphoid cells from normal individuals were cytotoxic to target cells coated with DNA when incubated with serum from patients with systemic lupus erythematosus (SLE) but not when incubated with serum from normal subjects. Sera from SLE patients with clinically acitve disease were more active than sera obtained from those patients in remission. In the absence of normal lymphocytes, SLE sera were not cytotoxic to the DNA-coated cells. The active fraction in the serum appeared to be IgG anti-DNA antibodies. These studies indicate that anti-DNA can operate through the antibody-dependent cell-mediated cytotoxicity mechanisms in vitro.