Nuclear DNA degradation in lymphocytes of patients with systemic lupus erythematosus.

The degradation of nuclear DNA in lymphocytes of patients with systemic lupus erythematosus (SLE) was analyzed. A low m.w. DNA fragment was identified in phytohemagglutinin (PHA)-stimulated lymphocytes from both healthy controls and SLE patients. The rate of appearance of low m.w. DNA was at least fourfold higher in lymphocytes from SLE patients, suggesting that DNA from SLE cells are more easily degraded than that from normal cells. PHA-stimulated lymphocytes from SLE patients were also shown to be more sensitive to UV irradiation than those of controls. These results suggest that DNA metabolism is abnormal in T cells of SLE patients.