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FibroSure Fibrosis Score

A 0 to 1 score from blood tests that estimates how much scarring (fibrosis) the liver has, without a biopsy. FibroSure is Labcorp's brand name for it.

AI-verified against cited sources. Awaiting expert reviewAlso called FibroTestLOINC 48795-9

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What it is

FibroSure, also sold as FibroTest, combines several routine blood results with your age and sex using a patented formula. The result is a number from 0.00 to 1.00. The lab matches it to a stage on the METAVIR scale, from F0 (no scarring) to F4 (cirrhosis). The score is an estimate made from blood, and it does not look at liver tissue. FibroSure and FibroTest are brand names of the companies that sell the test.

Why it matters

Scarring of the liver (fibrosis) often causes no symptoms until it is advanced, and how much there is helps guide follow-up. FibroSure is used in people with long-term liver conditions, such as hepatitis B or C, fatty liver disease or alcohol-related liver disease, as a blood-based way to estimate scarring when a biopsy is not wanted. It is read together with your history and other tests.

If it’s low

A low score goes with little or no scarring. A score of 0.21 or lower matches stage F0. It is an estimate and cannot rule out scarring completely.

Common causes

  • No or minimal scarring in the liver

What can help

  • Ask how often your clinician would like to repeat it, based on your liver condition and risk factors

If it’s high

A higher score goes with more scarring, and 0.48 or higher matches stage F2 or above. It is an estimate, not a diagnosis, and neighboring stages overlap. Some conditions that are not scarring can push the score up, so your clinician will read it in context.

Common causes

  • Gilbert syndrome, a harmless condition that raises bilirubin
  • Breakdown of red blood cells (hemolysis), which can change the blood tests the score uses
  • Acute hepatitis or a blocked bile duct, which can disturb the inputs
  • Kidney problems or a liver transplant, where the score may be less accurate
  • Scarring from chronic hepatitis B or C
  • Scarring from fatty liver disease
  • Scarring from long-term alcohol-related liver disease

What can help

  • Ask whether another test, such as elastography or the ELF blood test, would help confirm the result
  • Ask whether anything in your health history could be distorting the score
  • Talk with your clinician about managing the underlying liver condition, including weight, physical activity and alcohol

Usual ranges

What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.

For adults: 0–0.21 score. Source: Labcorp, Mayo Clinic Laboratories.

FibroSure / FibroTest score to METAVIR stage (Labcorp and Mayo; boundary values can fall in either stage)

  • F0, no fibrosisbelow 0.21 score
  • F0-F10.21 to under 0.27 score
  • F1, portal fibrosis0.27 to under 0.31 score
  • F1-F20.31 to under 0.48 score
  • F2, bridging fibrosis with few septa0.48 to under 0.58 score
  • F3, bridging fibrosis with many septa0.58 to under 0.72 score
  • F3-F40.72 to under 0.74 score
  • F4, cirrhosis0.74 and above score

What can affect your result

  • Age and sex, which are part of the formula
  • Gilbert syndrome, which raises bilirubin
  • Hemolysis, which lowers haptoglobin
  • Acute hepatitis and bile duct blockage
  • Kidney problems and liver transplant
  • Fasting, for the NASH versions that use glucose and triglycerides
  • Light exposure of the sample, which breaks down bilirubin
  • Labcorp says the test is not recommended in people with Gilbert syndrome, acute hemolysis (for example from some hepatitis C treatments), acute hepatitis, bile duct blockage (extra-hepatic cholestasis), a liver transplant or kidney insufficiency, because the score can be inaccurate.
  • Mayo asks for the serum to be separated within 2 hours and protected from light within 4 hours, because bilirubin is light-sensitive.
  • The NASH versions also use glucose and triglycerides. Mayo requires a 12-hour fast for its NASH-FibroTest and lists no fasting rule for the standard FibroTest-ActiTest, so follow your lab's instructions.

The score follows scarring that builds over years, so it is not meant for frequent rechecks.

When to talk to a clinician

There is no urgent FibroSure value. Talk with a clinician about a score of 0.48 or higher (stage F2 or above) so they can decide on follow-up. Get prompt care for yellow skin or eyes, vomiting blood, black or tarry stools, a swollen belly, or new confusion or drowsiness, and call 911 or your local emergency number if these are severe.

Questions you could ask

  • Which score and stage matter most for my situation?
  • How does this fit with my FIB-4 and other liver tests?
  • Could Gilbert syndrome, hemolysis or another condition be distorting this score?
  • Would an elastography scan or the ELF blood test help confirm the stage?
  • What follow-up do you suggest for my liver condition?
  • How often should this be repeated, given my liver condition?

Questions people ask

What do the stages F0 to F4 mean?

They come from the METAVIR scale used by pathologists. F0 means no scarring, F1 is mild scarring around the portal areas, F2 and F3 are scarring that forms bridges between areas, and F4 is cirrhosis. FibroSure estimates the stage from blood; it does not look at tissue.

Is FibroSure as accurate as a biopsy?

No. It is an estimate, and its accuracy varies by score and by the liver condition. Labcorp's report notes that a score below 0.31 had a negative predictive value of 85% against biopsy in people with hepatitis C. Your clinician may use another test to confirm.

Is FibroSure the same as FibroTest?

They are the same kind of test. Labcorp sells FibroSure, its report refers to the FibroTest score, and Mayo Clinic Laboratories offers FibroTest. Both labs print the same score-to-stage table.

Show the science and sources

For clinicians and researchers

FibroTest is a patented algorithm developed by BioPredictive and offered by Mayo; Labcorp sells it as FibroSure and its reports refer to the FibroTest score. Mayo describes it as combining five markers (gamma-glutamyltransferase, total bilirubin, alpha-2-macroglobulin, apolipoprotein A1 and haptoglobin), weighted by age and sex; ActiTest adds ALT to give a necroinflammatory activity score. Labcorp's HCV FibroSure analyzes six tests. Its NASH FibroSure uses 10 biochemicals with age, sex, height and weight to give fibrosis, steatosis and NASH scores. The score is mapped to METAVIR stages with overlapping boundary bins (0.21, 0.27, 0.31, 0.48, 0.58, 0.72, 0.74); Mayo notes that boundary values can belong to two stages depending on rounding. Imbert-Bismut et al. (Lancet 2001), in 339 patients with hepatitis C, reported areas under the ROC curve of 0.84 and 0.87, with scores of 0 to 0.10 excluding F2 to F4 with certainty and scores of 0.60 to 1.00 giving more than 90% certainty of F2 to F4. Labcorp reports a negative predictive value of 85% for a score below 0.31 against biopsy in 1,270 patients with hepatitis C (38% with significant fibrosis) and a positive predictive value of 61% above 0.48. In 171 patients with NAFLD, a score above 0.3 had 83% sensitivity and 78% specificity for significant fibrosis. Both Labcorp and Mayo state the test was developed by and validated at the lab and is not FDA-cleared. Results are not interchangeable with FIB-4, ELF or elastography.

LOINC 48795-9 (primary). Specimen: calculated.

Sources

  1. HCV FibroSure (test 550123) sample report, Labcorp (2023)
  2. NASH FibroSure (test 550140) sample report, Labcorp (2022)
  3. FibroTest-ActiTest, Serum (Test ID FIBRO), Mayo Clinic Laboratories
  4. Nonalcoholic Steatohepatitis (NASH)-FibroTest, Serum and Plasma (Test ID NSFIB), Mayo Clinic Laboratories
  5. Biochemical markers of liver fibrosis in patients with hepatitis C virus infection: a prospective study, The Lancet (2001)
  6. LOINC 48795-9 (NLM Clinical Tables), National Library of Medicine

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.

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