FibroTest, known as FibroSure in the US, is a patented biomarker blood test that measures the results of six blood serum tests [naturally occurring substances in the blood] to generate a score that is correlated with the degree of liver damage in people with a variety of liver diseases.
FibroTest has been evaluated in relation to liver biopsy (the current reference standard in liver disease assessment) in a large number of patients with hepatitis C, hepatitis B, alcoholic liver disease, Non-alcoholic fatty liver disease and in the general population. FibroTest has the same prognostic value as a liver biopsy.
The Fibrosure blood test measures the amount of the following substances in your blood:
- Alpha 2 macroglobulins (normal range = 110 to 276 mg/dL)
- Haptoglobulin (normal range = 34 to 200 mg/dL)
- Apolipoprotein A-1 (normal range = 110 to 205 mg/dL)
- Bilirubin total (normal range = 0 to 1.2 mg/dL)
- GGT (normal range = 0 to 60 IU/L)
- ALT (normal range = 0 to 40 IU/L)
No need for you to remember these parameters, they are just included in case you want to research them further. The important thing is that these values are combined mathematically to create a score for you which will determine the following –
- Fibrosis Score (normal range = 0 to 0.21) – you want this to be low
- Fibrosis stage from 1 to 4 – you want this to be low
- Necro-inflammatory activity score (normal range = 0 to 0.17) – you want this to be low
- Necro-inflammatory activity grade – this is graded from mild to severe – you want this to be mild
The Fibrosis score and stage determine the amount of scarring in your liver.
The Necro-inflammatory activity score and grade determine the amount of inflammation in your liver and this is important because chronic inflammation in the liver causes the scar tissue to build up and destroys healthy liver cells.
The FIBROSpect II is a commercially available test that combines hyaluronic acid, tissue inhibitor of a metalloproteinase-1 (TIMP-1), and alpha-2-macroglobulin in a predictive algorithm for fibrosis stages (F2 to F4). An index score of greater than 0.42 is classified with the presence of stage F2 to F4 fibrosis. Based on data from the test manufacturer involving 696 chronic HCV-infected patients, the overall sensitivity at this cutoff is 80.6% and the specificity 71.4%. Overall, this is a good test for determining presence or absence of significant fibrosis but not useful in differentiating intermediate stages of fibrosis. It would serve as a good surrogate for determining the presence or absence of cirrhosis in those patients who have a contraindication to liver biopsy, or those who refused it.