It has been validated in patients with chronic hepatitis C as an accurate predictor of cirrhosis. In this issue of HEPATOLOGY, Wong and colleagues present a much anticipated study examining the accuracy of TE among patients with NAFLD.15 The study population consisted of 246 individuals originating from two
centers in France and Hong Kong who underwent liver biopsy and TE. Liver stiffness increased significantly with fibrosis and provided a high level of accuracy for detecting significant fibrosis (defined as at least perisinusoidal and portal/periportal fibrosis), advanced fibrosis (septal or bridging fibrosis) and cirrhosis, with area under the receiver operator characteristic (AUROC) curve values of 0.84, 0.92, and 0.97, respectively. Importantly, in subjects in whom a full set of 10 successful readings could be obtained, the accuracy of TE was
not affected by BMI or steatosis check details grade. Prior reports of falsely high readings due to acute hepatitis16 were not observed, with accuracy not influenced by alanine aminotransferase (ALT) levels or the histological NAFLD activity score, which reflects the relatively indolent inflammatory nature of NASH. The accuracy of TE was also compared to five clinical and biochemical noninvasive measures; aspartate aminotransferase (AST)/ALT ratio, AST-to-platelet ratio index, FIB-4, NAFLD fibrosis score, and BARD score (derived from three variables: BMI, AST/ALT ratio, diabetes). After excluding subjects with invalid learn more TE measurements, the AUROC values of TE were significantly higher than the clinical/biochemical indices for detecting advanced fibrosis and cirrhosis. However, when the diagnostic characteristics were compared using an “intention to diagnose” approach with the inclusion of subjects who had unsuccessful TE acquisition, the sensitivity diglyceride and specificity values were not dissimilar from the clinical/biochemical models, although 95% confidence intervals were not provided for statistical comparison. Therefore, when TE measurement acquisition was successful, it was
more accurate at predicting advanced fibrosis and cirrhosis than the alternative noninvasive models. Further comparative studies with models that use more direct markers of fibrogenesis such as hyaluronic acid are required before definitive conclusions can be reached regarding the relative accuracy of serum markers and TE in NAFLD. Based on the performance characteristics of TE, the authors proposed two possible algorithms for determining advanced liver fibrosis. Using a cutoff point of 8.7 kPa, those with a reading below this had a negative predictive value (NPV) of 94.6% and therefore did not require biopsy. The prevalence (or pretest probability) of advanced fibrosis in community practice is likely to be lower than in this study, and thus the NPV is likely to be even better in this setting. The positive predictive value (PPV), however, was not high at 59.5%, and these patients required biopsy for accurate staging.