Hep C Discussion Forum

FibroTest (known as FibroSure in the USA) is a non-invasive test measuring liverscarring in hepatitis C (or B), resulting in scores which correspond to the 0-4 point METAVIR Fibrosis (scarring) scale. FibroTest is the most frequently used serum fibrosis marker and consists of an algorithm of five fibrosis markers (alfa2-macroglobulin [g/l], apolipoproteinA1 [g/l], total bilirubin [micromoles/l], haptoglobin [g/l], Gamma GT [IU/l]). Below left, see how it compares to the METAVIR scarring scale.

ActiTest, another non-invasive test, measuring liver inflammation in chronic viral hepatitis C (or B),  resulting in scores which correspond to the 0-3 point METAVIR Activity (inflammation/necrosis) scale. It requires the FibroTest scores from tests above, plus it requires an ALT score. Below right, see how it compares to the METAVIR Activity (inflammation/necrosis) scale.

For great interactive patient information on FibroTest and ActiTest and a letter to request testing from your doctor, see this webpage (http://www.biopredictive.com/intl/patient/home-patients/hcv).

Information for doctors about FibroTest and ActiTest is found on this webpage (http://www.biopredictive.com/intl/physician/physicians/fibrotest-for-hcv/)

Correlation with Metavir Scales: FibroTest (Fibrosis) and ActiTest (Inflammation):

NOTE: The above graphs resulted from this data:
Gender=Male
Birthdate=15/12/1971
Sample date=22/04/2007 (subject therefore is 35.3 yrs)
alfa2-macroglobulin [g/l]= 2.44
apolipoproteinA1 [g/l]=1.71
bilirubin [micromoles/l]=16.70 (also called total bilirubin)
haptoglobin [g/l]=0.74
GammaGT [IU/l]=66 (also called GGT)
ALT [IU/l]=211

How to Get Tested:

With referrals from a physician, you may be able to get the tests paid by your insurance. However, incorporating the test results into the algorithm of this test, done by BioPredictive company,  is at present seldom covered by medical insurance, so you would have to pay for this part yourself.
Wikipedia provides the following equation for calculating the FibroTest score regression coefficient:

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WARNING:  Do NOT use APRI alone as its accuracy rate is not sufficient to do so; experts recommend using a combination of two or  all three of the non-invasive liver tests (APRI, FibroSure/FibroTest, or FibroScan).

Using the results of APRI, a non-invasive test, one can very roughly determine whether one has a high risk of having advanced liver damage. It is not particularly useful in telling the exact Metavir stage; it simply provides 'one piece of the puzzle'. To compute APRI one only needs to know the most current AST score and PLATELET Count, both of which are on most blood panels regularly given to HCV+ patients.

SOURCE: "A Simple Noninvasive Index Can Predict Both Significant Fibrosis and Cirrhosis in Patients with Chronic Hepatitis C" by Chu-Tao Wai, Joel K. Greeson, et al, HEPATOLOGY Vol. 38, #2, 2003, pp 518-526. 

APRI formula:

• Divide the AST by 35*.
• Divide that number by the PLATELET count (this should be in the range 0 to 500 or so - if there are extra zeros, delete these before computing).
• Multiply this number by 100.
• If this number is greater than 0.5, there is a good chance they have some liver damage. If greater than 1.5, the person very likely has cirrhosis. One can say APRI scores between 0.5 to 1.5 VERY LOOSELY correspond to Metavir Stages 1-3, and above 1.5 corresponds (again, very loosely) to Metavir Stage 4.

 *Why divide by 35??

You are supposed to divide the AST by the "Upper Limit of Normal" AST.  This number is sometimes disputed, and varies from lab to lab. Most seem to be in the range of 35-45.

 Sample APRI Computations of three HCV+ individuals:

DONALD:
From a recent blood test, Donald got these scores
- AST= 232
- Blood Platelet count= 94
Donald's APRI =(232/35)/94*100=7.05
Conclusion: Donald likely has advanced liver damage, and is probably cirrhotic.

LINDA:
From a recent blood test, Linda got these scores
- AST=35
- Blood Platelet count=150
Linda's APRI=35/35/150*100=0.67
Conclusion: Linda probably has some liver damage, but it is likely not very advanced yet.

ROBERT:
- AST=20
- Blood Platelet count=250
Robert's APRI=20/35/250*100=0.23
Conclusion: Robert probably does not have any serious liver damage yet