What is the Enhanced Liver Fibrosis (ELF) score?

From the Guidelines

The Enhanced Liver Fibrosis (ELF) score is a proprietary blood test that measures three elements involved in matrix turnover to assess liver fibrosis.

Key Points

• The ELF score is used to identify patients with NAFLD at increased risk of progression to cirrhosis and liver-related clinical events 1.
• It is calculated based on three proteins associated with liver fibrosis: hyaluronic acid, tissue inhibitor of metalloproteinase 1, and amino terminal peptide of procollagen III 1.
• The ELF score has been validated as a blood-based serum biomarker for detection of advanced hepatic fibrosis and "at-risk" NASH with F2 or higher 1.
• A cutoff value of 0.3576 has been proposed for the ELF score to diagnose advanced liver fibrosis, with a sensitivity of 80% and specificity of 90% 1.
• The ELF score can be used as a secondary risk assessment when elastography is not available, and it has been recommended as a non-invasive test for evaluating liver disease severity and prognosis in patients with NAFLD 1.

Clinical Use

• The ELF score can be used to rule out advanced fibrosis in clinical practice, with a cutoff value of <9.8 1.
• It can be used in combination with other non-invasive tests, such as liver stiffness measurement (LSM) by transient elastography (TE), to refine the stratification of risk of liver-related events in patients with NAFLD 1.
• The ELF score has been shown to have good accuracy for predicting liver-related events and overall mortality in patients with NAFLD, with an area under the receiver operating characteristic curve (AUROC) of 0.90 1.

From the Research

Definition of Enhanced Liver Fibrosis (ELF) Score

• The Enhanced Liver Fibrosis (ELF) score is a blood test that combines three markers linked to liver fibrosis 2.
• It is a non-invasive test used to diagnose and predict the severity of liver fibrosis in patients with chronic liver disease 3, 4.

Components and Calculation of ELF Score

• The ELF test comprises a logarithmic algorithm combining three serum markers of hepatic extracellular matrix metabolism 3.
• The exact formula for calculating the ELF score is not provided in the studies, but it is mentioned that the score increases with increasing liver fibrosis stage 2.

Diagnostic Accuracy of ELF Score

• The ELF score has high diagnostic accuracy for liver fibrosis, with an area under the receiver operating characteristic curve (AUROC) of 0.81 for advanced fibrosis 3.
• The diagnostic accuracy of the ELF score is comparable to that of liver stiffness measurement (LSM) by FibroScan 3.
• The ELF score can predict clinical outcomes in patients with chronic liver disease, with a unit change in ELF associated with a doubling of risk of liver-related outcome 4.

Comparison with Other Diagnostic Tests

• The ELF score is less discriminative in low and moderate fibrosis stages compared to transient elastography, and is more strongly influenced by inflammatory liver injury 5.
• The ELF score can be used for estimating the severity of fibrosis, but it is inferior to transient elastography (TE) in estimating liver fibrosis severity 6.
• A combination of ELF and other non-invasive tests, such as LSM or the Fibrosis-4 index, can increase the diagnostic accuracy and specificity for advanced fibrosis 3.