To evaluate the diagnostic accuracy and performance of transient elastography (TE) for liver fibrosis in autoimmune hepatitis (AIH) patients and identify factors influencing liver stiffness measurements (LSM).

We retrospectively analyzed the clinical data of 87 AIH patients who underwent both liver biopsy and TE at Tianjin Medical University General Hospital between January 2016 and December 2024. Diagnostic performance of LSM and serological models for fibrosis staging were assessed using receiver operating characteristic (ROC) curves. Independent LSM determinants were explored via multiple linear regression analysis.

LSM exhibited a significantly stronger positive correlation with histological fibrosis stage (r=0.839, P＜0.001) than the serological models. LSM demonstrated high diagnostic accuracy for significant fibrosis (≥F2; area under the curve [AUC]=0.966, 95% confidence interval [CI]: 0.925~1.000), advanced fibrosis (≥F3; AUC=0.940, 95%CI:0.887~0.993), and cirrhosis (F4; AUC=0.940, 95%CI: 0.882~0.997), with optimal cut-offs of 8.61 kPa, 10.54 kPa, and 15.62 kPa, respectively. The AUC of LSM surpassed that of the serological model across all stages. Fibrosis stage and immunoglobulin G (IgG) were independent predictors of LSM.

TE provides high diagnostic efficacy for liver fibrosis staging in AIH, outperforming serological models. Elevated IgG may influence LSM accuracy.