FIB-4 Test
The non-invasive FIB-4 (Fibrosis-4) test is an index used to assess the extent of liver fibrosis, particularly in patients with liver diseases such as hepatitis C or metabolic-associated steatotic (fatty) liver disease (MASLD, formerly NAFLD). It is calculated from common clinical data, including the patient’s age, liver enzyme levels (ALT and AST), and platelet count. The calculation formula is as follows:
FIB-4 = Age (years) x AST (IU/L) / platelets (109/L) x √ ALT (IU/L)
The test requires a simple blood sample to obtain these values. It is a well-validated score for classifying risk in patients, including patients with MASLD or hepatitis C, categorizing them into high, intermediate, and low risk of developing cirrhosis within the next 10 years. FIB-4 can be a key step in primary care pathways for both these conditions.
It is recommended that FIB-4 be used to evaluate liver fibrosis in patients with risk factors for chronic liver diseases, such as diabetes, obesity, or excessive alcohol consumption.
For patients suspected of having MASLD, a FIB-4 score below 1.30 indicates a low risk of developing significant fibrosis. A score between 1.30 and 2.67 corresponds to intermediate risk, while a score above 2.67 signals high risk.
Biron performs the necessary tests and automatically calculates the FIB-4 index when it has been ordered.