Significance of anti-cell membrane-associated DNA (mDNA) antibodies in systemic lupus erythematosus.

The aim of this study was to evaluate the value of anti-cell membrane-associated DNA (mDNA) antibodies in the diagnosis of systemic lupus erythematosus (SLE). Antibodies against mDNA were detected with indirect immunofluorescence assay in 207 SLE, 167 other rheumatic diseases, and 82 healthy controls. Association of clinical features and anti-mDNA antibodies was analyzed. The prevalence of anti-mDNA antibodies was 73.3% in SLE, 8.3% in Sjögren's syndrome, and 4.8% in rheumatoid arthritis. The incidences of anti-mDNA antibodies in SLE lacking antideoxyribonucleoprotein, antihistone antibodies, antinuclesome antibodies, anti-dsDNA, and anti-Sm antibodies were 73.8, 62.7, 65.3, 57.8 and 51.6%, respectively. Skin rash, alopecia, oral ulcer, and joint pain are more common in patients with anti-mDNA antibodies. The anti-mDNA antibody is one of the most valuable markers in SLE. It is also informative in some SLE patients lacking other autoantibodies.