Diagnostic accuracy and prognostic significance of blood fibrosis tests and liver stiffness measurement by FibroScan in non-alcoholic fatty liver disease

Background & Aims: NAFLD is highly prevalent but only a small subset of patients develop advanced liver fibrosis with impaired liver-related prognosis. We aimed to compare blood fibrosis tests and liver stiffness measurement (LSM) by FibroScan for the diagnosis of liver fibrosis and the evaluation of prognosis in NAFLD. Methods: Diagnostic accuracy was evaluated in a cross-sectional study including 452 NAFLD patients with liver biopsy (NASH-CRN fibrosis stage), LSM, and eight blood fibrosis tests (BARD, NAFLD fibrosis score, FibroMeter(NAFLD), aspartate aminotransferase to platelet ratio index (APRI), FIB4, FibroTest, Hepascore, FibroMeter(V2G)). Prognostic accuracy was evaluated in a longitudinal study including 360 NAFLD patients. Results: LSM and FibroMeterV2G were the two best-performing tests in the cross-sectional study: AUROCs for advanced fibrosis (F3/4) were, respectively, 0.831 +/- 0.019 and 0.817 +/- 0.020 (p <= 60.041 vs. other tests); rates of patients with <= 90% negative/positive predictive values for F3/4 were 56.4% and 46.7% (p < 0.001 vs. other tests); Obuchowski indexes were 0.834 +/- 0.014 and 0.798 +/- 0.016 (p <= 0.036 vs. other tests). Two fibrosis classifications were developed to precisely estimate the histological fibrosis stage from LSM or FibroMeterV2G results without liver biopsy (diagnostic accuracy, respectively: 80.8% vs. 77.4%, p = 0.190). Kaplan-Meier curves in the longitudinal study showed that both classifications categorised NAFLD patients into subgroups with significantly different prognoses (p < 0.001): the higher was the class of the fibrosis classification, the worse was the prognosis. Conclusions: LSM and FibroMeterV2G were the most accurate of nine evaluated tests for the non-invasive diagnosis of liver fibrosis in NAFLD. LSM and FibroMeterV2G fibrosis classifications help physicians estimate both fibrosis stage and patient prognosis in clinical practice. Lay summary: The amount of liver fibrosis is the main determinant of the liver-related prognosis in patients with non-alcoholic fatty liver disease (NAFLD). We evaluated eight blood tests and FibroScan in a cross-sectional diagnostic study and found that FibroScan and the blood test FibroMeterV2G were the two most accurate tests for the non-invasive evaluation of liver fibrosis in NAFLD. A longitudinal prognostic study showed these two tests initially developed for the diagnosis are also prognostic markers as they allow for the stratification of NAFLD patients in several subgroups with significantly different prognosis. (C) 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.