Abstract: Objective The study was conducted to analyze the changes of thyroid functions and their impact on response to standardized therapy in patients with autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). Methods 30 patients with AIH, 28 patients with PBC and 32 volunteers were recruited in our hospital between January 2020 and January 2022, and the patients with AIH or with PBC were treated by standardized immunosuppression or ursodeoxycholic acid therapy. Serum total-triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine T4 (FT4) and thyroid-stimulating hormone (TSH) levels were routinely detected. Serum anti-thyroglobulin antibodies (TRAb), thyroid-peroxidase antibody (TPO-Ab), anti-thyroglobulin antibodies (TGAb), thyroxine-binding globulin (TBG) and thyroglobulin (TG) were also determined by radioimmunoassay. Results Serum FT3 and FT4 levels in patients with AIH were (4.2±0.2)pmol/L and (13.8±1.9)pmol/L, and in patients with PBC were (4.3±0.3)pmol/L and (13.9±1.3)pmol/L, significantly lower than [(4.9±0.6)pmol/L and (15.9±4.2)pmol/L, respectively, P＜0.05], while serum TSH levels in patients with AIH and in with PBC were (3.8±1.2)mIU/L and (3.7±0.5)mIU/L, significantly higher than [(2.6±0.5)mIU/L, P＜0.05] in healthy volunteers; serum TPO-Ab and TG positive rates in patients with AIH were 33.3% and 26.7%, and in patients with PBC were 39.3% and 25.0%, all significantly higher than 9.4% and 3.1%(P＜0.05) in healthy individuals; at the end of one-year treatment, the response rates to treatment in patients with AIH was 66.7% and in patients with PBC was 75.0%; serum FT3 and FT4 levels in responders no matter in AIH or PBC were significantly higher than, while serum TSH levels as well as serum TPO-Ab and TG positive rates were much lower than in non-responders(P＜0.05). Conclusion The hypothyroidism could occur in patients with autoimmune liver diseases, which might influence the response to standardized therapy, and warrants clinical careful surveillance.

Key words: Autoimmune hepatitis, Primary biliary cholangitis, Thyroid functions, Anti-thyroglobulin antibodies, Therapy, Response