Serological tests were negative for human immunodeficiency virus, syphilis, hepatitis B, and hepatitis C. Thyroid function showed FT4 was 24.69 pmol/L (12.00–22.00), TSH was 9.11 mIU/L (0.27–4.20), anti-thyroid peroxidase antibody was over 600.00 IU/mL (0.00–34.00), anti-thyroglobulin antibody was 95.99 IU/mL (0.00–115.00), thyrotropin receptor antibody was 2.180 IU/L (0.000–1.750), and anti-thyroglobulin antibody was 0.41 ng/mL (3.50–77.00). Here, TG is linked to syphilis.