Is FIB-4 the right tool for screening for liver fibrosis?

Area of Science:

• Hepatology
• Non-invasive liver disease diagnostics
• Metabolic dysfunction-associated steatotic liver disease (MASLD) research

Background:

• Accurate staging of liver fibrosis is crucial for managing MASLD.
• Non-invasive tests, such as the FIB-4 index, are increasingly used but their accuracy in MASLD requires further evaluation.
• Vibration-controlled transient elastography (VCTE) is a reliable method for assessing liver stiffness.

Purpose of the Study:

• To assess the agreement between the FIB-4 index and VCTE in patients with MASLD.
• To identify and validate new FIB-4 cut-off values for different age groups to improve fibrosis detection.
• To evaluate the diagnostic performance of FIB-4 using standard and proposed cut-offs.

Main Methods:

• A prospective cohort study involving primary care patients in Belgium and the Netherlands.
• VCTE (FibroScan®) was used to measure liver stiffness, with FIB-4 calculated from patient data and blood samples.
• Agreement was assessed using Weighted Cohen's kappa; new cut-offs were determined and validated in independent cohorts.

Main Results:

• FIB-4 demonstrated poor agreement with VCTE (κ=0.138) in the primary cohort.
• Proposed FIB-4 cut-offs of 1.29 (≤65 years) and 1.72 (>65 years) were identified.
• The 1.72 cut-off showed improved sensitivity but lower specificity in validation cohorts compared to the standard cut-off of 2.0.

Conclusions:

• The FIB-4 index, using standard cut-offs, is an unreliable tool for diagnosing liver fibrosis in MASLD patients.
• Current FIB-4 thresholds show poor agreement with VCTE, necessitating alternative non-invasive tests or optimized cut-off values.
• Further research is needed to establish reliable non-invasive methods for fibrosis assessment in MASLD.