Etiology-related determinants of liver stiffness values in chronic viral hepatitis B or C

Background & Aims: Transient elastography (TE) has gained popularity for the non-invasive assessment of severity of chronic viral hepatitis, but a comprehensive evaluation of the factors that might account for discrepancy in diagnostic accuracy between TE and the standard of care liver biopsy (LB) is still needed. Methods: Patients with chronic hepatitis-B (HBV, n = 104) or -C (HCV, n = 453) underwent percutaneous LB concomitantly with TE (FibroScan®; Echosens, Paris, France). Liver cell necroinflammatory activity (A) and fibrosis (F) were assessed by METAVIR. Perisinusoidal fibrosis was rated with a 0-3 score. Determinants of TE results were investigated by a linear regression model whereas discordance between TE and LB results was assessed by logistic regression. Results: Fibrosis (p <0.0001) and liver cell necroinflammatory activity (p <0.0001) were independently associated with TE results in both HBV and HCV patients, whereas steatosis (p <0.0001) was independently associated with TE in HCV only. Fibrosis overestimation was predicted by severe/moderate necroinflammatory activity in HBV and by older age (41-60 or >60 years vs. <40), >2 UNL AST and >2 UNL GGT, as well as severe/moderate necroinflammatory activity and severe/moderate steatosis in HCV. In the latter patients, however, moderate/severe necroinflammatory activity and steatosis were the only independent predictors of fibrosis overestimation. Conclusions: Fibrosis and necroinflammatory activity are the main determinants of TE in chronic viral hepatitis. Since TE staging of fibrosis is influenced by necroinflammatory activity and steatosis, a diagnostic LB is deemed necessary for a reliable intra-patient TE monitoring of the course of viral hepatitis.