The combination of the enhanced liver fibrosis and FIB-4 scores to determine significant fibrosis in patients with nonalcoholic fatty liver disease

Background: The presence of fibrosis in NAFLD is the most significant risk factor for adverse outcomes. We determined the cutoff scores of two non-invasive te sts (NITs) to rule in and rule out significant fibrosis among NAFLD patients.

Methods: Clinical data and liver biopsies were used for NAFLD patients included in this analysis (2001-2020). The enhanced liver fibrosis (ELF) and FIB-4 NITs were calculated. Liver biopsies were read by a single hematopathologist and scored by the NASH CRN criteria. Significant fibrosis was defined as stage F2-F4.

Results: There were 463 NAFLD patients included: 48 ± 13 years old, 31% male, 35% type 2 diabetes; 39% had significant fibrosis; mean ELF score was 9.0 ± 1.2, mean FIB-4 score was 1.22 ± 1.05. Patients with significant fibrosis were older, more commonly male, had lower BMI but more components of metabolic syndrome, higher ELF and FIB-4 (p < 0.0001). The performance of the two NITs in identifying significant fibrosis was: AUC (95% CI) = 0.78 (0.74-0.82) for ELF, 0.79 (0.75-0.83) for FIB-4. The combination of ELF score ≥9.8 and FIB-4 ≥ 1.96 returned a positive predictive value of 95% which can reliably rule in significant fibrosis (sensitivity 22%, specificity >99%), while an ELF score ≤7.7 or FIB-4 ≤ 0.30 had a negative predictive value of 95% ruling out significant fibrosis (sensitivity 98%, specificity 22%).

Conclusions: The combination of ELF and FIB-4 may provide practitioners with easily obtained information to risk stratify patients with NAFLD who could be referred to specialists or for enrollment in clinical trials.