Abstract
The main aim of this study was the comparative evaluation of nonalcoholic fatty liver
disease (NAFLD) fibrosis score (NFS), fibrosis 4 index (FIB-4), AST-to-Platelet Ratio
Index (APRI), and enhanced liver fibrosis (ELF) test in distinguishing none/early
(F0/F1) from significant/advanced (F2/F3) fibrosis in NAFLD patients, thereby providing
an external validation cohort. Thirty-one patients with biopsy-proven NAFLD and 10
matched controls without NAFLD were prospectively enrolled. Serum hyaluronic acid
(HA), aminoterminal propeptide of type III procollagen (PIIINP), tissue inhibitor
of metallo-proteinases (TIMP)-1, and biochemical tests were measured. NFS, FIB-4,
APRI, and ELF were calculated. ELF, FIB-4, and APRI, but not NFS, were higher in F2/F3
than F0/F1 group. Specifically, ELF [area under the ROC curve (AUROC): 0.86±0.10;
p=0.004) and APRI (AUROC: 0.86±0.07; p=0.005], but not NFS (AUROC: 0.68±0.12; p=0.16),
and FIB-4 (AUROC: 0.71±0.11; p=0.10), could similarly discriminate F0/F1 from F2/F3
stage. The sensitivity, specificity, positive predicted value (PPV), and negative
predicted value (NPV) were: a) for cut-off of APRI=0.5, 85.7%, 70.8%, 46.2%, and 94.4%,
respectively, and b) for cut-off of ELF=9.0, 85.7%, 83.3%, 60.0%, and 95.2%, respectively.
When ln(PIIINP) or TIMP-1 were combined with APRI, the combined AUROCs could distinguish
F2/F3 from F0/F1, but without significantly higher accuracy compared with APRI alone.
APRI could also distinguish patients with simple steatosis from nonalcoholic steatohepatitis,
and those with from those without lobular inflammation and ballooning, findings warranting
further research. In conclusions: The application of ELF test and APRI can distinguish
F0/F1 from F2/F3 fibrosis stages in NAFLD patients.
Key words
APRI - enhanced liver fibrosis test - FIB-4 - fibrosis - nonalcoholic fatty liver
disease fibrosis score - nonalcoholic steatohepatitis
