Prevalence of thyroid autoantibodies in hepatitis C and hepatitis B infection in China.

OBJECTIVE

To explore the correlation between anti-thyroid autoantibodies and hepatitis C virus (HCV) infection.

METHODS

We collected 462 samples with positive thyroid peroxidase antibody (TPOAb) and/or thyroglobulin antibody (TgAb). Matched for age and gender, 380 subjects with negative TPOAb and TgAb were selected as controls. A third-generation enzyme linked immunosorbent assay (ELISA) was used to examine the presence of anti-HCV antibody. We also examined RNA HCV expression of subjects with positive anti-HCV antibody. Separate groups of 195 subjects with hepatitis C, 150 healthy subjects, and 150 subjects with hepatitis B were tested for thyroid-related markers.

RESULTS

The HCV infection rate was 1.30% in 462 subjects with positive thyroid autoantibodies, and 0.53% in 380 subjects who were negative for thyroid autoantibodies. There was no significant difference in the HCV infection rate between the two groups (χ(2)=1.322, p>0.05). In subjects with hepatitis C, 30.77% were TPOAb positive and 30.77% were TgAb positive; subjects with hepatitis C appeared to show significantly higher positivity of antithyroid autoantibodies when compared with healthy subjects and those with hepatitis B (χ(2)=21.496, χ(2)=30.454, p<0.01).

CONCLUSION

The HCV infection rate did not seem to be higher in subjects with abnormal thyroid autoimmunity. However, the positivity of thyroid autoantibodies appeared to be increased in subjects with hepatitis C, suggesting that thyroid-related markers should be examined in hepatitis C patients.