Background and AimsLiver stiffness measurement (LSM) has been shown to adequately predict outcomes in patients with liver disease. However, the value of LSM as a predictor of disease progression in autoimmune hepatitis (AIH) remains to be determined. This study aimed to evaluate the role of LSM as a predictor of disease progression and decompensation of cirrhosis in patients with AIH. MethodsThis multicentre cohort study included 439 patients with histologically confirmed AIH and at least one LSM during follow-up. The association between the first LSM performed at least after 6 months of treatment (baseline LSM, BLSM) and cirrhosis development and poor outcomes (decompensation, liver transplantation, and/or liver-related death) was assessed using Cox regression and its discriminating capacity with a receiver operating characteristic (ROC) curve. ResultsMost patients were female (n=301, 70%), with a median age of 52 years. BLSM performed after a median time of 2.18 (1.19-4.68) years had a median value of 6 kPa (4.5-8.5). At the time of BLSM, 332 (76%) patients were in biochemical response (BR) and 57 (13%) had cirrhosis. During follow-up, 8 patients (2%) presented with poor outcomes and 26 (7%) developed cirrhosis. BLSM was higher among patients with poor outcomes (13.5 kPa vs. 6 kPa; p<0.001) and was independently associated with cirrhosis development (HR 1.300; p<0.001), irrespective of the achievement of BR. A cut-off of 8.5 kPa accurately predicted cirrhosis development and poor outcomes with an AUC of 0.859 (95%CI 0.789-0.929) and 0.900 (95%CI 0.847-0.954), respectively. ConclusionBLSM could play a significant role in predicting AIH outcomes, potentially identifying a subgroup of patients at a high risk of progressing to cirrhosis and experiencing decompensation.