Chromosome instability in human and murine autoimmune disease: anticlastogenic effect of superoxide dismutase.

Increased chromosome breakage is observed in lymphocyte cultures from patients with so-called autoimmune diseases also in the animal model, the NZB mouse. A clastogenic agent was detected in the serum of patients and of NZB mice, that induces also chromosome breaks in cells of healthy individuals. In simultaneous cultures set up with or without superoxide dismutase in 5 patients with progressive systemic sclerosis, 5 patients with systemic lupus erythematosus and 5 patients with rheumatoid arthritis, highly significant differences in the incidence of chromosome breakage were observed. The aberration rate produced in blood cultures of healthy individuals by the breakage factor from patients was also reduced essentially to control values by addition of SOD in vitro, but were reduced also in vivo by injection of SOD in lupus patients as well as in NZB mice.