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Test ID FIBRO FibroTest-ActiTest, Serum

Shipping Instructions


Necessary Information

Age and sex are required.

Specimen Required

Supplies: Amber Frosted Tube, 5 mL (T192)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Amber vial (T192)

Specimen Volume: 3 mL

Collection Instructions:

1. Centrifuge and aliquot within 2 hours of collection.

2. Centrifuged serum must be light protected within 4 hours of collection. It is acceptable to draw the blood and then protect it from light after centrifugation as long as it is within 4 hours of collection.

Secondary ID


Useful For

Evaluating hepatic fibrosis in chronic hepatitis C patients


Diagnosing fibrosis in carriers of chronic hepatitis B virus


Evaluating hepatic fibrosis in co-infected HIV carriers


Providing access to new-generation noninterferon treatment for hepatitis


Evaluating fibrosis in patients suffering from metabolic conditions (nonalcoholic fatty liver disease) and patients who consume excess alcohol

Profile Information

Test ID Reporting Name Available Separately Always Performed
INTF FibroTest-ActiTest, Interpretation No Yes
APOAF Apolipoprotein A1, S No Yes
A2MF Alpha-2-Macroglobulin, S Yes, (Order A2M) Yes
HAPTF Haptoglobin, S Yes, (Order HAPT) Yes
ALTF Alanine Aminotransferase (ALT), S Yes, (Order ALT) Yes
GGTF Gamma Glutamyltransferase (GGT), S Yes, (Order GGT) Yes
TBILF Bilirubin, Total, S Yes, (Order BILIT) Yes

Testing Algorithm

This test is a patented test algorithm developed by BioPredictive. FibroTest combines 5 standard biomarkers (gamma-glutamyltransferase, total bilirubin, alpha-2-macroglobulin, apolipoprotein A1, and haptoglobin). The ActiTest adds a marker for inflammatory activity (alanine aminotransferase: ALT). These markers are weighted depending on the patient's age and gender.


Testing is compliant with BioPredictive's technical recommendations and approvals.

Method Name

INTF: Algorithm and interpretation provided through BioPredictive.

APOAF: Automated Turbidimetric Immunoassay

A2MF: Nephelometry

HAPTF: Nephelometry

ALTF: Photometric Rate, L-Alanine with Pyridoxal-5-Phosphate

GGTF: Photometric Rate

TBILF: Photometric, Diazonium Salt (DPD)

Reporting Name

FibroTest-ActiTest, S

Specimen Type


Specimen Minimum Volume

1.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  14 days
  Ambient  24 hours

Reject Due To


Mild OK; Gross reject


Mild OK; Gross reject


Mild OK; Gross reject


Patients <2 years of age, not light protected

Clinical Information

Fibrosis and inflammatory activity are the 2 main causes of liver disease.


FibroTest-ActiTest estimates the levels of fibrosis and cirrhosis in the liver as well as the level of necroinflammatory activity. The estimation is made by measuring 6 standard serum biomarkers (gamma-glutamyl transferase, total bilirubin, alpha-2-macroglobulin, apolipoprotein A1, haptoglobin, and alanine aminotransferase). The activity score is a measure of liver inflammation caused by disease. Results from these tests are combined with the patient’s age and sex to estimate hepatic fibrosis and inflammatory activity scores.


Hepatic fibrosis is typically compared to a form of scar tissue that progresses throughout the liver. The most serious stage of fibrosis is known as cirrhosis.

Reference Values

FibroTest-ActiTest, Interpretation


FibroTest Score





No fibrosis



No fibrosis



Minimal fibrosis



Minimal fibrosis



Moderate fibrosis



Advanced fibrosis



Advanced fibrosis



Severe fibrosis (Cirrhosis)

*Boundary values can apply to 2 stages based on rounding. For example, a FibroTest score of 0.305 will round up to 0.31 and be staged F1. A FibroTest score of 0.314 will round down to 0.31 and be staged F1-F2.


ActiTest Score





No activity



No activity



Minimal activity



Minimal activity



Significant activity



Significant activity



Severe activity

*Boundary values can apply to 2 grades based on rounding. For example, an ActiTest score of 0.285 will round up to 0.29 and be graded A0-A1. An ActiTest score of 0.294 will round down to 0.29 be graded A1.



100-280 mg/dL




<12 months: No established reference values

≥1 year: 7-55 U/L



<12 months: No established reference values

≥1 year: 7-45 U/L




<24 months: No established reference values

2-17 years:

Low: <115 mg/dL

Borderline low: 115-120 mg/dL

Acceptable: >120 mg/dL

≥18 years: ≥120 mg/dL



<24 months: No established reference values

2-17 years:

Low: <115 mg/dL

Borderline low: 115-120 mg/dL

Acceptable: >120 mg/dL

≥18 years: ≥140 mg/dL




0-11 months: <178 U/L

12 months-6 years: <21 U/L

7-12 years: <24 U/L

13-17 years: <43 U/L

≥18 years: 8-61 U/L



0-11 months: <178 U/L

12 months-6 years: <21 U/L

7-12 years: <24 U/L

13-17 years: <26 U/L

≥18 years: 5-36 U/L



30-200 mg/dL



0-6 days: Refer to for information on age-specific (postnatal hour of life) serum bilirubin values.

7-14 days: <15.0 mg/dL

15 days to 17 years: ≤1.0 mg/dL

≥18 years: ≤1.2 mg/dL


FibroTest-ActiTest provides a score that assesses hepatic fibrosis (F0-F4) and a score that assesses hepatic inflammatory activity (A0-A3). Interpretation of the score is provided in the report. Individual results from the 6 component tests are also provided with institution-specific reference intervals.


Fibrosis is reported relative to a scale ranging from F0-F4 (F0=no fibrosis, F1=minimal fibrosis, F2=moderate fibrosis, F3=advanced fibrosis, F4=severe fibrosis). Fibrosis scores may overlap (eg, F0/F1, F1/F2).


Activity is reported relative to a scale ranging from A0-A3 (A0=no activity, A1=minimal activity, A2=significant activity, A3=severe activity). Activity scores may overlap (eg, A0/A1, A1/A2).


Defer the test in transient situations that could modify the components of FibroTest-ActiTest, such as:

-Acute hemolysis which could decrease haptoglobin and increase unconjugated bilirubin.

-Acute hepatitis, whether drug-induced, viral (superinfection by hepatitis a virus: HAV, hepatitis B virus: HBV, Epstein-Barr virus: EBV), or autoimmune. Massive hepatic necrosis leads to a large increase of transaminases and total bilirubin.

-Acute inflammation, as with concomitant bacterial or acute viral infection: bronchopulmonary or urinary tract infection. The large increase of haptoglobin can lead to false-negative results.

-Extrahepatic cholestasis, such as gallstones.


The advice of a liver disease specialist should be sought for interpretation in chronic states in which the components of the test could be modified, such as chronic hemolysis, particularly in patients with a cardiac valvular prosthesis; Gilbert disease; protease inhibitors used in HIV treatment, which can increase unconjugated bilirubin (Indinavir, Atazanavir); or gamma glutamyltransferase (GGT) and alanine aminotransferase (Ritonavir).


The interpretation of FibroTest has been validated in renal transplant patients. In patients with renal insufficiency or who are on dialysis, FibroTest had an acceptable diagnostic value, though lower than in transplanted patients.


As a general rule, isolated extreme values of 1 of the 6 components should signal caution in interpreting the results, particularly in the following cases:

-Haptoglobin below 12 mg/dL, in which hemolysis or anhaptoglobinemia (more frequent in western African patients) must be ruled out.

-Haptoglobin above 320 mg/dL, in which acute inflammation must be ruled out.

-Transaminases above 622 IU/L, in which acute hepatitis must be ruled out.

-Bilirubin above 1.75 mg/dL and GGT below 50 IU/L, in which Gilbert syndrome must be suspected.

-Alpha2-macroglobulin above 590 mg/dL.


In case of discordance between a biopsy result and a FibroTest result, it is advisable to seek the advice of a liver disease specialist.


Haptoglobin is an acute-phase reactant and increases with inflammation or tissue necrosis. Low haptoglobin is normal for the first 3 to 6 months of life; testing is not performed on patients younger than 2 years-old per BioPredictive.


GGT activity is inducible by drugs such as phenytoin and phenobarbital and, therefore, elevations should not be considered indicative of liver disease until drug use is ruled out. Elevations are also seen after ingestion of alcoholic beverages. In very rare cases, gammopathy, in particular, type IgM (Waldenstrom macroglobinemia) may cause unreliable results.


Bilirubin specimens should be protected from light and analyzed as soon as possible. Grossly hemolyzed specimens should be rejected because hemoglobin inhibits the diazo reaction and falsely decreased results may be seen. Compounds that compete for binding sites on serum albumin contribute to lower serum bilirubin levels (eg, penicillin, sulfisoxazole, acetylsalicylic acid).

Clinical Reference

1. BioPredictive: Technical Recommendations for FibroTest and FibroMax assays, Bio Predictive, Saint Germain, Paris, France. Accessed 2/2018. Available at

2. Halfon P, Bourliere M, Deydier R, et al: Independent prospective mulitcenter validation of biochemical markers (FibroTest-ActiTest) for the prediction of liver fibrosis and activity in patients with chronic hepatitis C: the fibropaca study. Am J Gastroenterol 2006 Mar;101(3):547-555

3. Houot M, Ngo Y, Munteanu M, et al: Systematic review with meta-analysis: direct comparisons of biomarkers for the diagnosis of fibrosis in chronic hepatitis C and B. Aliment Pharmacol Thera 2016;43:16-29

4. Anastasiou J, Alisa A, Virtue S, et al: Noninvasive markers of fibrosis and inflammation in clinical practice: prospective comparison with liver biopsy. Eur J Gastroenterol Hepatol 2010 Apr;22(4):474-480

5. Martinez SM, Crespo G, Navasa M, Forns X: Noninvasive assessment of liver fibrosis. Hepatology 2011 Jan;53(1):325-335

Day(s) and Time(s) Performed

HAPTF, A2MF: Monday through Saturday; 3 p.m.

ALTF, GGTF, TBILF: Monday through Sunday; Continuously

APOAF: Monday through Saturday; Continuously

Analytic Time

1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information










LOINC Code Information

Test ID Test Order Name Order LOINC Value
FIBRO FibroTest-ActiTest, S In Process


Result ID Test Result Name Result LOINC Value
TBILF Bilirubin, Total, S 1975-2
ALTF Alanine Aminotransferase (ALT), S 1743-4
A2MF Alpha-2-Macroglobulin, S 1835-8
APOAF Apolipoprotein A1, S 1869-7
GGTF Gamma Glutamyltransferase (GGT), S 2324-2
HAPTF Haptoglobin, S 46127-7
SCRF FibroTest Score In Process
STGF FibroTest Stage In Process
INTEF FibroTest Interpretation In Process
SCRA ActiTest Score In Process
STGA ActiTest Grade In Process
INTEA ActiTest Interpretation In Process
CMMF FibroTest-ActiTest Comment 48767-8
NUM BioPredictive Serial Number In Process

NY State Approved



If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Gastroenterology and Hepatology Client Test Request (T728)