Inflammatory activity stratification improves liver stiffness diagnosis of fibrosis in autoimmune hepatitis

To investigate the correction value of inflammatory activity stratification on the diagnostic performance of liver stiffness measurement (LSM) for hepatic fibrosis in patients with autoimmune hepatitis (AIH), and to provide evidence for accurate fibrosis assessment in AIH patients.

Clinical data of AIH patients who underwent liver biopsy at our hospital from January 2017 to January 2026 were retrospectively analyzed. All patients underwent LSM by transient elastography within the same period. Patients were divided into the G1-G2 group (mild-to-moderate inflammation) and G3-G4 group (severe inflammation) according to the simplified Scheuer inflammatory grade. Liver pathological fibrosis staging (S0-S4) served as the gold standard. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of LSM. A correction model was constructed by multivariate logistic regression and internally validated using the Bootstrap method with 1000 resamplings.

A total of 86 AIH patients were finally enrolled, including 79 females (91.9%) with a mean age of (54.1 ± 9.1) years. There were 52 patients in the G1-G2 group and 34 in the G3-G4 group. In the overall cohort, the area under the ROC curve (AUC) of LSM for diagnosing S≥2 fibrosis was 0.73 (95% CI: 0.62-0.83), with an optimal cutoff of 8.2 kPa. After inflammation stratification, the AUC in the G1-G2 group (0.85, 95% CI: 0.76-0.94) was significantly higher than that in the G3-G4 group (0.69, 95% CI: 0.54-0.84) (Z = 2.13, P = 0.033). The optimal cutoffs were 7.8 kPa and 9.1 kPa, respectively. A correction formula was established for the G3-G4 group: corrected LSM = raw LSM - 0.4 × inflammatory grade. After correction, the AUC for S≥2 increased to 0.85 (95% CI: 0.76-0.93), sensitivity from 55.0% to 86.7%, and specificity from 88.5% to 69.2% (all P<0.05).

The diagnostic performance of LSM for fibrosis in AIH patients is affected by inflammatory activity, and severe inflammation leads to pseudo-elevation of LSM. The inflammation-stratified correction model significantly improves diagnostic accuracy and optimizes fibrosis staging in AIH patients. Further validation is required prior to clinical implementation.