Background: The ELF test (score calculated from markers of fibrosis: hyaluronic acid, procollagen III amino-terminal peptide, and tissue inhibitor of matrix metalloproteinase 1) is a non-invasive blood test used to estimate fibrosis stage in chronic liver disease. Since NAFLD patients with advanced fibrosis are at the highest risk for adverse long-term outcomes, the aim is to assess performance of ELF for identification of advanced fibrosis in patients with NAFLD.
Methods: Patients with biopsy-proven NAFLD were included. ELF scores were calculated using an ADVIA Centaur XP analyzer.
Results: There were 409 patients with NAFLD: 47 ± 12.9 years, 30% male, 70% white, 34% type 2 diabetes (T2DM), 56% hyperlipidemia, 54% hypertension, mean (SD) BMI 41.0 ± 10.0 kg/m2, ALT 48.4 ± 42.0 U/L, mean ELF score was 9.0 ± 1.3. Of the study cohort, 23% patients (N=93) had advanced fibrosis. Patients with advanced fibrosis had significantly higher ELF: 10.2 ± 1.3 vs. 8.6 ± 1.0, p<0.0001. There was a correlation between ELF and liver enzymes: rho=0.23 for ALT, 0.34 for AST (p<0.0001). ELF negatively correlated with BMI: rho = -0.28 (p<0.0001). Across all NAFLD patients, ELF had good performance for identifying patients with advanced fibrosis: area under curve (AUC) = 0.83 (0.79 - 0.87). The performance of ELF was similar in NAFLD patients with [AUC = 0.81 (0.73 - 0.87)] and without [AUC = 0.83 (0.77 - 0.87)] T2DM. With the commonly used cut-off of ELF ≥9.8 for prediction of advanced fibrosis, observed accuracy was as follows: sensitivity 62.4% (51.7% - 72.2%), specificity 89.6% (85.6% - 92.7%) positive predictive value (PPV) 63.7% (55.1% - 71.6%), negative predictive value (NPV) 89.0% (86.1% - 91.3%). Cut-off of 11.3 returned almost perfect specificity 99.0% (97.3% - 99.8%) with a sensitivity of 22.6% (14.6% - 32.4%), PPV 87.5% (68.1% - 95.8%), NPV 81.3% (79.6% - 82.9%).
Conclusions: ELF test performs well in identifying high risk NAFLD patients with or without T2DM.
Z. Younossi: Consultant; Self; AbbVie Inc., Bristol-Myers Squibb, Gilead Sciences, Inc., Intercept Pharmaceuticals, Inc., Novo Nordisk Inc., Terns and Viking. S. Felix: None. T. Jeffers: None. E. Younossi: None. F. Nader: None. H. Pham: None. A. Afendy: None. R. Cable: None. A. Racila: None. Z. Younoszai: None. B.P. Lam: None. P. Golabi: None. L. Henry: None. S. Clement: None. M. Stepanova: None.