Clinical studies on the significance of DNA:anti-DNA complexes in the systemic circulation and cerebrospinal fluid (CSF) of patients with systemic lupus erythematosus.

Evidence has gradually accumulated that DNA antibodies play a pathogenic role in SLE in combination with DNA, as DNA: anti-DNA complexes, but until recently there was no direct assay for such complexes. By measuring DNA binding before and after DN'ase digestion, an indication of the amount of DNA complexes in biological fluids was obtained. This assay was used to examine sera from patients with SLE or non-SLE nephritis. DNA:anti-DNA complexes were detectable only in the circulation of patients with SLE, almost invariably with active nephritis. When a large series (50) of SLE patients were serially examined, similar results were found. Significant amounts of DNA:anti-DNA complexes were found in the circulation only during active CNS and/or renal lupus. Persistence of the complexes was associated with treatment resistance and increased morbidity and mortality. In addition, DNA:anti-DNA complexes were found in the CSF of a patient with CNS lupus.