Echosens FibroMeter (Liver Fibrosis, Chronic Viral Hepatitis)

FibroMeter is a blood test used to aid in the evaluation and management of liver fibrosis. This test was specifically designed for patients with chronic viral hepatitis (with or without HIV coinfection). This noninvasive blood analysis is from the creators of the FibroScan instrument.

Features and Benefits

Noninvasive diagnostic test that evaluates the level of fibrosis in the liver from blood biomarkers and patient demographic information
High diagnostic accuracy confirmed by a rules-based system
No interference from patients with Gilbert disease or hemolysis (e.g., induced by ribavirin)
An economic alternative to FibroSURE
Enhanced graphical reports available

Education Resource

Non-invasive Assessment of Liver Fibrosis
by Patricia R. Slev, PhD

Test Details

Scores are algorithmically calculated from values of blood biomarkers, platelet count, and demographic information.

Measurements Performed by ARUP	Alpha-2-macroglobulin, ALT, AST, GGT, prothrombin index, urea
Information Provided by Client	Patient’s platelet count, age, sex
Calculated Scores	Score ranges from 0 to 1, 1 being the most severe stage: Fibrosis score (FibroMeter) Cirrhosis score (CirrhoMeter) Necroinflammatory activity score (InflaMeter)
Metavir Classifications	Corresponding classifications are reported together with the scores: F0–F4 for fibrosis/cirrhosis A0–A3 for activity grade
ALT, alanine aminotransferase; AST, aspartate aminotransferase; GGT, gamma-glutamyl transpeptidase

Comparison between liver biopsy and the noninvasive FibroMeter test:

	FibroMeter	Liver Biopsy
Nature of test	Noninvasive	Invasive
Advantages	Measurement of global fibrosis, suitable for serial observations	Direct, evaluation of coexisiting pathologies
Limitations	Indirect measurement of functional changes of the liver	Sampling error, inter-observer variability, possible hospitalization
Risks	Very little risk	Pain, bleeding, pneumothorax, hemothorax, infection
Cost	Less expensive than biopsy	Expensive
Contradictions	None known	Uncooperative patient, severe coagulopathy, extrahepatic biliary obstruction, ascites, morbid obesity

Ordering Information

How to Order

Please contact your hospital or reference laboratory to inquire about pricing, test-request forms, and billing for this test.

Test Information

Test Name	Liver Fibrosis, Chronic Viral Hepatitis (Echosens FibroMeter)
Test Code	2005661
Mnemonic	FIBRO V
Method	Quantitative nephelometry, enzymatic, spectrophotometric, and electromagnetic mechanical clot detection
Specimen Information	3 mL serum AND 1 mL citrated plasma. Must supply patient platelet count performed on EDTA whole blood (ordered separately through client institution)

Specimen Collection Requirements

Collection	Lavender (EDTA) or pink (K2EDTA) tube, serum separator tube, and light blue (sodium citrate) tube
Preparation	Separate serum and citrated plasma from cells as soon as possible or within two hours of collection. Transfer 3 mL serum to an ARUP standard transport tube (min: 1.2 mL). Transfer 1 mL platelet-poor citrated plasma to the ARUP standard transport tube (min: 0.5 mL).
Transport Temperature	Serum and citrated plasma should be shipped frozen; do not send the EDTA whole blood to ARUP.
Remarks	Separately arrange for on-site automated platelet count on the EDTA whole blood sample. Include patient platelet count with test submission information.
Specimen Stability	From the time of collection to initiation of testing: Serum: refrigerated: unacceptable; frozen: 2 weeks Plasma: refrigerated: unacceptable; frozen: 2 weeks

Frequently Asked Questions

Does it matter which instrument is used to generate the platelet count?

No. Many hematology analyzers are available and are suitable for the FibroMeter test.

Why is urea used in FibroMeter?

Each of the individual analytes in the algorithm have been shown to be a marker for liver function. This includes urea, which decreases with impaired liver function and advanced liver disease. However, the accuracy of using the FibroMeter test to assess fibrosis is based on a proprietary algorithm that evaluates and weighs the concentration of each analyte along with demographic data to provide a score.

Test Interpretation and Strategy

The result states that "FibroMeter and CirrhoMeter scores are modified by the rules-based algorithm." What does this mean?

To reduce misclassification, test scores are evaluated by a rule-based algorithm to detect anomalous profile results, which may modify test scores as needed.

Can this test be used if a patient has a coinfection of HCV/HIV or HBV/HIV?

Yes.

Performance and Limitations

Can this test be used on patients receiving ribavirin therapy?

Yes.

What is the clinical performance of this test?

Metavir Classification	FibroMeter
Metavir Classification	≥F2	F4
AUROC	0.85–0.89	0.91
Sensitivity (%)	80.5–89.0	94.1
Specificity (%)	84.1–89.9	87.6
PPV (%)	82.0–86.3	68.0
NPV (%)	77.6–82.5	94.7

Can this test be run without the platelet count?

No. The platelet count is necessary for the score calculation. If necessary, platelet count values from an earlier or later draw can be used. However, the date of platelet count must be within three days from the collection of the other blood samples submitted to ARUP for the FibroMeter test.

Can this test be used on a pediatric patient?

The FibroMeter test was validated on patients age 18 or older. Pediatric specimens will not be rejected, but results should be interpreted with caution.