Abstract: Objective To detect the associations between anti-C1q antibody and systemic lupus erythematosus（SLE）and that between anti-C1q antibody and lupus nephritis（LN）．Methods The Anti-C1q antibody were measured using ELISA kit from 110 cases of SLE patients（SLE group） and 60 cases of healthy people（normal control group）. The 110 SLE patients were divided into LN group with 41 patients and non LN group with 69 patients. The serum levels of Anti-C1q,anti-dsDNA antibody and biochemical markers of the two groups were detected,and the result were analyzed. Results The serum anti-C1q antibody level of SLE group was significantly higher than that of normal control group[（11.90±23.83）U/mL vs（2.73±4.18）U/mL,P<0.05]．Serum level of anti-C1q antibody in LN group showed a strongly positive correlation with anti-dsDNA antibody and showed a negative correlation with C3 and C4 level.Conclusion Anti-C1q antibody would be helpful to characterize the disease activity of SLE,and is associated with SLE kindey damage. The combined detection of serum anti-C1q antibody,AnuA and anti-dsDNA antibody can improve LN diagnostic specificity.

Key words: Anti-C1q antibody, Systemic lupus erythematosus, Lupus nephritis