【Objective】 To investigate serum anti-Clq antibodies (Clq Ab) levels in the patients with autoimmune thyroid disease

and the correlation between serum levels of Clq Ab and thyroid function

thyroid auto-antibodies is analyzed. 【Methods】 The serum levels of Clq Ab in 28 Graves disease patients (GD group)

34 in chronic lymphocytic thyroiditis patients (CLT group) and 27 healthy subjects (CON group) were detected by enzyme-linked immunosorbent assay (ELISA). 【Results】 Serum levels of Clq Ab were 3.130 (2.773-3.833) U/mL in the CON group

4.625 (2.888-11.798) U/mL in the GD group and 3.125 (2.750-4.625) U/mL in the CLT group respectively. Patients with GD were positive more frequently for anti-C1q than controls. Absolute values of serum anti-C1q levels in the GD group were higher than that in the CON group

and correlated positively with TRAb. However

serum levels of C1q Ab in the CLT group showed a negative correlation with TT4. 【Conclusions】 Serum levels of C1q Ab in the GD group were higher than that in the CON group

and correlated positively with TRAb. And serum levels of C1q Ab in the CLT group correlated negatively with TT4.