What does an elevated Enhanced Liver Fibrosis test result indicate for a patient with fatty liver disease?

From the Guidelines

An elevated Enhanced Liver Fibrosis (ELF) test result indicates that a patient with fatty liver disease is at increased risk of progression to cirrhosis and liver-related clinical events.

Key Points

• The ELF test is a validated blood-based serum biomarker for detecting advanced hepatic fibrosis and "at-risk" nonalcoholic steatohepatitis (NASH) with F2 or higher fibrosis 1.
• An ELF score can identify patients with NAFLD at increased risk of progression to cirrhosis and liver-related clinical events 1.
• The ELF test measures three liver fibrosis-related matrix proteins: hyaluronic acid, tissue inhibitor of metalloproteinase 1, and aminoterminal peptide of procollagen III 1.
• A cutoff value of 0.3576 for the ELF test has been proposed, with a sensitivity of 80% and specificity of 90% for advanced liver fibrosis 1.
• The ELF test can be used as a secondary risk assessment when elastography is not available 1.

Clinical Implications

• Patients with elevated ELF test results should be monitored closely for signs of liver disease progression and considered for liver biopsy if necessary 1.
• The ELF test can be used in conjunction with other non-invasive tests, such as the Fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS), to assess liver fibrosis severity 1.
• The ELF test is a useful tool in the management of patients with fatty liver disease, particularly in those with advanced fibrosis or cirrhosis 1.

From the Research

Elevated Enhanced Liver Fibrosis Test Result Indication

An elevated Enhanced Liver Fibrosis (ELF) test result in a patient with fatty liver disease indicates a higher likelihood of advanced liver fibrosis. The ELF test is a non-invasive blood test that measures three molecules involved in liver matrix metabolism to give a score reflecting the severity of liver fibrosis 2.

Diagnostic Performance of ELF Test

The diagnostic performance of the ELF test varies depending on the threshold used. A study found that the ELF test had a sensitivity of >0.90 for excluding fibrosis at a threshold of 7.7, but its specificity and positive predictive value were limited at high thresholds, especially in low-prevalence settings 3. Another study found that the ELF test had an area under the receiver operating characteristic curve of 0.81 for the diagnosis of advanced fibrosis, with a cut-off value of 9.34 achieving 90.4% sensitivity and 10.83 achieving 90.6% specificity 4.

Comparison with Other Non-Invasive Tests

The ELF test has been compared with other non-invasive tests, such as liver stiffness measurement (LSM) by FibroScan, and found to have comparable diagnostic accuracy 4. A combination of ELF and LSM or sequential use of the Fibrosis-4 index and ELF can increase the specificity and positive predictive value of the test 4, 5.

Key Points

• An elevated ELF test result indicates a higher likelihood of advanced liver fibrosis in patients with fatty liver disease.
• The diagnostic performance of the ELF test varies depending on the threshold used and the prevalence of disease in the population.
• The ELF test has comparable diagnostic accuracy to other non-invasive tests, such as LSM by FibroScan.
• Combination or sequential use of ELF with other non-invasive tests can improve its diagnostic performance.

ELF Test Thresholds

Some key ELF test thresholds to note are:

• 7.7: sensitivity of >0.90 for excluding fibrosis 3
• 9.34: 90.4% sensitivity and 10.83: 90.6% specificity for advanced fibrosis 4
• 9.8: defined as elevated ELF (eELF) in a study of the general population 6