Noninvasive markers of fibrosis in nonalcoholic fatty liver disease: Validating the European Liver Fibrosis Panel and exploring simple markers

The detection of fibrosis within nonalcoholic fatty liver disease (NAFLD) is important for ascertaining prognosis and the stratification of patients for emerging therapeutic intervention. We validated the Original European Liver Fibrosis panel (OELF) and a simplified algorithm not containing age, the Enhanced Liver fibrosis panel (ELF), in an independent cohort of patients with NAFLD. Furthermore, we explored whether the addition of simple markers to the existing panel test could improve diagnostic performance. One hundred ninety-six consecutively recruited patients from 2 centers were included in the validation study. The diagnostic accuracy of the discriminant scores of the ELF panel, simple markers, and a combined panel were compared using receiver operator curves, predictive values, and a clinical utility model. The ELF panel had an area under the curve (AUC) of 0.90 for distinguishing severe fibrosis, 0.82 for moderate fibrosis, and 0.76 for no fibrosis. Simplification of the algorithm by removing age did not alter diagnostic performance. Addition of simple markers to the panel improved diagnostic performance with AUCs of 0.98, 0.93, and 0.84 for the detection of severe fibrosis, moderate fibrosis, and no fibrosis, respectively. The clinical utility model showed that 82% and 88% of liver biopsies could be potentially avoided for the diagnosis of severe fibrosis using ELF and the combined panel, respectively. The ELF panel has good diagnostic accuracy in an independent validation cohort of patients with NAFLD. The addition of established simple markers augments the diagnostic performance across different stages of fibrosis, which will potentially allow superior stratification of patients with NAFLD for emerging therapeutic strategies. (Hepatology 2007.)

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; AUC, area under the curve; BMI, body mass index; DS, discriminant scores; ELF, Enhanced Liver fibrosis panel; HA, hyaluronic acid; NAFLD, nonalcoholic fatty liver disease; OELF, Original European Liver Fibrosis panel; TIMP1, tissue inhibitor of matrix metalloproteinase 1.