Diagnostic Performance of Shear-Wave Elastography in Autoimmune Hepatitis: Evaluating Baseline Characteristics and Accuracy Across Fibrosis Stages.

Background Autoimmune hepatitis (AIH) is a chronic inflammatory condition affecting the liver, ultimately leading to fibrosis, followed by cirrhosis and liver failure. Although liver biopsy is necessary to confirm the disease and outline different stages of liver fibrosis, it is associated with several risks due to its invasiveness. Shear-wave elastography (SWE) has recently emerged as a non-invasive imaging modality, representing liver stiffness and providing additional fibrosis assessment. This study aims to validate SWE for diagnosing and discriminating liver fibrosis stage in AIH patients. Methodology This retrospective cohort study was conducted at the Sindh Institute of Urology and Transplantation, Karachi, with the enrollment of 162 patients diagnosed with AIH between March 2022 and December 2023. All participants underwent SWE and liver biopsy. The stages of fibrosis were assessed using the Metavir scoring system. Demographic, biochemical, and serological data were analyzed, including autoantibody and serum IgG levels. Diagnostic accuracy, sensitivity, and specificity of SWE were compared with histopathological findings. Results Of the 162 patients, 71 (43.8%) were males, and 91 (56.2%) were females, with a mean age of 35.8 ± 16.6 years. SWE had an overall diagnostic accuracy of 92.11%, sensitivity of 82.86%, and specificity of 98.7% in predicting fibrosis stages. SWE was effective in differentiating early fibrosis (F1-F2), while it showed reduced sensitivity for advanced fibrosis (F3-F4). Female gender (p = 0.009), elevated bilirubin (p = 0.009), autoantibody titers, and serum IgG levels (p = 0.043) were significant factors related to advanced fibrosis. Conclusions SWE has shown high diagnostic accuracy and specificity for the estimation of liver fibrosis in AIH, especially in the early stages. Sensitivity is lowered in advanced fibrosis. SWE is a very valuable non-invasive alternative to liver biopsy. Its use may decrease procedural risks, accelerate diagnosis, and improve outcomes in AIH. Further multicenter studies are recommended for confirmation and to explore the comparative performance of SWE against other non-invasive approaches.