Abstract: Objective To investigate the correlation between the disease activity and the serum levels of anti-nuclear autoantibodies against various nuclear components in the patients with systemic lupus erythematosus (SLE). Methods Two hundred and twenty five SLE patients enrolled from 2000 to 2002 were evaluated retrospectively. All patients fulfilled the ACR 1997 diagnostic criteria for SLE. The patients were divided into three groups according to the disease activity: mild group (Group A), moderate group (Group B)and severe group (Group C), as assessed with SLEDAI score. These cases were also divided into 2 groups according to the serum levels of anti-dsDNA antibody. 52 out of 225 patients were followed up further. Results ①There was no correlation between the serum level of anti-dsDNA antibody and SLEDAI score, and between the serum level of ANA and SLEDAI score in 225 patients. ②The serum level of anti-dsDNA antibody in group C was higher than that in group A or group B (P<0.01), and without significant difference between group A and group B. And, there were no significant differences between the three groups both in the serum levels of ANA and in the positive rates of ENA antibodies (anti-Sm、anti-SSA/SSB、anti- RNP antibody). ③225 patients were divided into two groups according to the serum level of anti-dsDNA antibody: < 20% (Group 1), ≥20% (Group 2). The occurrence of renal damage in group 2 was higher than that in group 1 (P<0.05). However, there was no significant difference between these two groups in the level of proteinuria or serum creatinine. ④In the fifty-two patients followed up, 30 patients with severe disease activity, the serum level of anti-dsDNA antibody decreased after treatment (P<0.05), but no difference was shown in other 22 patients with mild to moderate disease activity (P>0.05). Conclusions A positive correlation between the anti-dsDNA antibody and the disease activity was found in the severe group of SLE, but not found in the mild or moderate group. Although the renal damage was more commonly seen in those with higher level of anti-dsDNA antibody, but there is no correlation between the level of anti-dsDNA antibody and the degree of renal lesion.

Key words: Lupus erythematosus, systemic, Antibodies, antinuclear