Liver and Bile
J Hepatol. 2023;79(2):277–86
Using the ELF test, FIB-4 and NAFLD fibrosis score to screen the population for liver disease
Background and aims: There is a need for accurate biomarkers of fibrosis for population screening of alcohol-related and non-alcoholic fatty liver disease (ALD, NAFLD). The authors compared the performance of the enhanced liver fibrosis (ELF) test to the fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS), using transient elastography (TE) as the reference standard.
Methods: They prospectively included participants from the general population, and people at risk of ALD or NAFLD. Screening positive participants (TE ≥ 8 kPa) were offered a liver biopsy. Concomitant ELF, FIB-4, and NFS were measured using validated cut-offs: ≥ 9.8, ≥ 1.3, ≥ -1.45, respectively.
Results: 3378 participants (1973 general population, 953 at risk of ALD, 452 at risk of NAFLD), with a median age of 57 years (interquartile range, 51–63 years) were included. 242 were screening positive (3.4% in the general population, 12%/14% who were at-risk of ALD/NAFLD, respectively). Most participants with TE < 8 kPa also had ELF < 9.8 (88%) despite a poor overall correlation between ELF and TE (Spearman’s rho = 0.207). ELF was associated with significantly fewer false positives (11%) than FIB-4 and NFS (35% and 45%), while retaining a low rate of false negatives (< 8%). A screening strategy of FIB-4 followed by ELF in indeterminate cases resulted in false positives in 8%, false negatives in 4% and the correct classification in 88% of cases. The authors performed a liver biopsy in 155 of 242 patients (64%) who screened positive, of whom 54 (35%) had advanced fibrosis (≥ F3). ELF diagnosed advanced fibrosis with significantly better diagnostic accuracy than FIB-4 and NFS: AUROC (area under the receiver-operating curve) 0.85 (95% confidence interval [CI]: 0.79–0.92) versus 0.73 (95% CI: 0.64–0.81) and 0.66 (95% CI: 0.57–0.76), respectively.
Conclusion: The enhanced liver fibrosis (ELF) test alone or combined with fibrosis-4 index (FIB-4) for liver fibrosis screening in the general population and at-risk groups reduces the number of futile referrals compared to FIB-4 and NAFLD fibrosis score (NFS), without overlooking true cases.