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Test Code LAB20954 FibroTest-ActiTest, Serum


Necessary Information


Age and sex are required.



Specimen Required


Supplies: Amber Frosted Tube, 5 mL (T915)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Amber vial

Specimen Volume: 3 mL

Collection Instructions:

1. Centrifuge and aliquot serum into an amber vial 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

38292

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 non-interferon 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, HAPTF: Nephelometry

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

GGTF: Photometric Rate

TBILF: Photometric, Diazonium Salt

Reporting Name

FibroTest-ActiTest, S

Specimen Type

Serum

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Patients <2 years of age Reject

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

Stage

Interpretation

0.00-0.21*

F0

No fibrosis

0.21-0.27*

F0-F1

No fibrosis

0.27-0.31*

F1

Minimal fibrosis

0.31-0.48*

F1-F2

Minimal fibrosis

0.48-0.58*

F2

Moderate fibrosis

0.58-0.72*

F3

Advanced fibrosis

0.72-0.74*

F3-F4

Advanced fibrosis

0.74-1.00

F4

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

Grade

Interpretation

0.00-0.17*

A0

No activity

0.17-0.29*

A0-A1

No activity

0.29-0.36*

A1

Minimal activity

0.36-0.52*

A1-A2

Minimal activity

0.52-0.60*

A2

Significant activity

0.60-0.62*

A2-A3

Significant activity

0.62-0.100

A3

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.

 

ALPHA-2-MACROGLOBULIN

≤18 years: 178-495 mg/dL

>18 years: 100-280 mg/dL

 

ALANINE AMINOTRANSFERASE (ALT)

Males

<12 months: Not established

≥1 year: 7-55 U/L

 

Females

<12 months: Not established

≥1 year: 7-45 U/L

 

APOLIPOPROTEIN A1

Males

<24 months: Not established

2-17 years

Low: <115 mg/dL

Borderline low: 115-120 mg/dL

Acceptable: >120 mg/dL

≥18 years: ≥120 mg/dL

 

Females

<24 months: Not established

2-17 years

Low: <115 mg/dL

Borderline low: 115-120 mg/dL

Acceptable: >120 mg/dL

≥18 years: ≥140 mg/dL

 

GAMMA-GLUTAMYLTRANSFERASE (GGT)

Males

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

 

Females

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

 

HAPTOGLOBIN

30-200 mg/dL

 

BILIRUBIN, TOTAL

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

7-14 days: 0.0-14.9 mg/dL

15 days-17 years: 0.0-1.0mg/dL

≥18 years: 0.0-1.2 mg/dL

Interpretation

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).

Method Description

FibroTest-ActiTest, Interpretation:

Proprietary algorithm owned by BioPredictive.

 

Alpha-2-Macroglobulin and Haptoglobin:

In this method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.

 

A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light-emitting diode, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.

 

The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Unpublished Mayo method; Instruction manual: Siemens Nephelometer II, Siemens, Inc; Version 2.3. 2008; Addendum to the Instruction Manual 2.3, 08/2017)

 

Alanine Aminotransferase (ALT):

Alanine a minotransferase (ALT) activity is determined by a kinetic method using a coupled enzyme reaction where the rate of NADH consumption is measured at 340 nm. The NADH decrease is directly proportional to the ALT activity.(Package insert: Roche ALT reagent. Roche Diagnostics; 2018)

 

Apolipoprotein A1:

Anti-apolipoprotein A-1 antibodies react with the antigen in the sample to form antigen/antibody complexes which, following agglutination, can be measured turbidimetrically.(Package insert: Tina-quant Apolipoprotein A-1. Roche Diagnostics; 2019)

 

Gamma-Glutamyltransferase (GGT):

This is an enzyme colorimetric method (rate method) where gamma-glutamyltransferase (GGT) transfers the gamma-glutamyl group of the substrate (L-gamma-glutamyl-3-carboxy-4-nitroanilide) to glycylglycine. The amount of 5-amino-2-nitrobenzoate liberated is proportional to the GGT activity and can be determined photometrically.(Package insert: Boehringer Mannheim GGT reagent. Boehringer Mannheim; 2017)

 

Bilirubin, Total:

Total bilirubin, in the presence of a suitable solubilizing agent, is coupled with 3,5-dichlorophenyl diazonium in a strongly acidic medium. The color intensity of the red azo dye formed is directly proportional to the total bilirubin and can be determined photometrically.(Package insert: Bilirubin Total Gen. 3. Roche Diagnostics; 2019)

Day(s) Performed

HAPTF, A2MF: Monday through Saturday

ALTF, GGTF, TBILF: Monday through Sunday

APOAF: Monday through Saturday

Report Available

2 to 5 days

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. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

81596

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FIBRO FibroTest-ActiTest, S 48796-7

 

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 48795-9
STGF FibroTest Stage 48794-2
INTEF FibroTest Interpretation 88447-8
SCRA ActiTest Score 48792-6
STGA ActiTest Grade 48793-4
INTEA ActiTest Interpretation 88448-6
CMMF FibroTest-ActiTest Comment 48767-8
NUM BioPredictive Serial Number 74715-4

Forms

If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen