A new specific assay for the detection of DNA immune complexes: its relevance in SLE.

Double-stranded DNA immune complexes (DNA-ICs) were assayed by millipore filtration and deoxyribonuclease digestion in 40 patients with both active and inactive systemic lupus erythematosus (SLE). The assay is superior to the double-stranded DNA antibody (ds ADA) as an indicator of active disease, and, when combined with the total haemolytic complement (CH50) and ds ADA levels it increases the prediction of the relative risk of active disease. A good correlation between actual levels of DNA-ICs and the degree of activity was also shown. We conclude that measurement of DNA-ICs is of value as an additional monitor in the assessment of activity in SLE.