Significance of anti-nucleosome antibodies in systemic lupus erythematosus

[Objective] To evaluate the clinical significance of determining serum anti-nucleosome antibodies(ANuA)in systemic lupus erythematosus(SLE) patients. [Methods] The enzyme-linked immunosorbent assay(ELISA) was used to measure the ANuA in serum of 66 SLE patients, 85 patients with other rheumatic diseases (including primary sjogren′s syndrome, dermatomyositis, polymyositis, systemic sclerosis, rheumatoid arithritis, ankylosing spondylitis, adult still disease) and 30 healthy controls. And then analyzed the relationships between ANuA and the clinical manifestations or some other laboratory results in the SLE patients. [Results] Of 66 SLE patients 65.2% were seropositive for ANuA. In contrast, only 1.2% of 85 control patients were seropositive (P 0.01) and none of the healthy controls were seropositive (P 0.01). The sensitivity and specificity of ANuA in SLE were 65.2% and 99.1% respectively. The incidences of erythra, alopecia and lupus nephritis(LN) in ANuA positive SLE patients were 90.7%, 58.1%, 69.8% respectively and significantly higher than those of ANuA negative SLE patients(34.8%,21.7%, 39.1%) (P 0.05). The positive rate of ANuA was significantly different between the active and the relieved SLE patients (P 0.01). There were no significant difference in immunoglobulins and complements between positive and negative ANuA of SLE patients (P 0.05). The positive rates of ANuA in SLE patients with negative anti-nuclear antibodies (ANA), anti-dsDNA and anti-Smith antibodies were 50.0%, 57.1%, 64.4% respectively. [Conclusion] ANuA may be a useful tool for the diagnosis and activity assessment in SLE patients, especially in the patients with negative ANA, anti-dsDNA or anti-Smith antibodies and the patients with lupus nephritis.