What Is the METAVIR Score?

What to expect

Show Article Table of Contents

The METAVIR score is a tool used to evaluate the severity of fibrosis seen on a liver biopsy sample from a person who has hepatitis C. The grade indicates the amount of inflammation in the liver and the stage represents the amount of scarring or fibrosis. Since symptoms, blood tests, and calculations are unable to define the degree of fibrosis, tests such as the METAVIR score and others are used to determine who should be treated and when, to monitor the progression of chronic liver disease, and more.

what a METAVIR score measures
Illustration by Emily Roberts, Verywell

Purpose

The purpose of the METAVIR score is to determine the level of fibrosis (scarring) of the liver. When a liver biopsy is performed, the METAVIR score provides a way to quantify what is seen under the microscope. The score takes into account both the degree of inflammation in the liver and the degree of fibrosis already present to give doctors an indication of how advanced the disease is, its prognosis, and when treatment should be considered.

This is often done for people with hepatitis C, but may be used for people with chronic hepatitis B, alcoholic liver disease, non-alcoholic fatty liver disease, primary biliary cirrhosis, autoimmune hepatitis, or metabolic diseases of the liver.

Scores such as the METAVIR score may also predict who may be at risk of liver cancer (hepatocellular carcinoma) related to hepatitis C, as well as those with liver cancer who are more likely to have a recurrence after hepatitis C treatment.

Understanding Liver Fibrosis

There is a continuum of scarring (fibrosis) that may occur with chronic liver disease. Inflammation of the liver, due to infection and other causes, results in the production of the collagen and proteins. When the build-up of this material surrounding cells (extracellular matrix) surpasses that of repair, fibrosis occurs, the most advanced stage being cirrhosis. There are many complications of cirrhosis that lead to much of the illness and death related to chronic liver disease.

Tests to assess fibrosis are important as everyone progresses to and through the stages of fibrosis at a different rate. Some people with hepatitis C develop fibrosis rapidly and may progress to cirrhosis in 20 years, whereas with others, the progression is much more gradual.

Since fibrosis is a form of scarring, it's been thought that the main goal of treatment is to prevent further fibrosis (progression). Regression of fibrosis (a lower METAVIR score) has now been seen with some people after treatment for hepatitis C or hepatitis B.

Complementary Tests

There are a number of different tests that are looked at when evaluating liver disease, but they fail to provide an adequate measure of fibrosis alone. These tests, however, are an important adjunct in the evaluation treatment of the disease. Some tests that may also be ordered for people with hepatitis C include:

  • Tests for concurrent conditions: Certainly, conditions that can make chronic hepatitis C worse are important. Some of these include chronic hepatitis B infection, non-alcoholic fatty liver disease, and iron overload,
  • Blood tests: Blood tests such as liver enzymes (AST, ALT, bilirubin, and albumin) and platelet count are monitored.
  • Calculations: Ratios, such as the ratio of a liver function tests (aminotransferase) to platelet count (APRI) and fibrosis-4 (FIB-4), may be looked at as well.
  • Serum markers: Markers that may indicate a higher chance of fibrosis include serum hyaluronic acid, alpha-2-macroglobulin, and matrix metalloproteinase-1.

Similar Tests

Since a METAVIR score requires a liver biopsy, an invasive procedure, other less-invasive methods of determining the level of fibrosis are desired.

One of these, transient elastography (Fibroscan), uses either an ultrasound or magnetic resonance imaging (MRI) to look at the elasticity or stiffness of the liver. Just as the METAVIR score has limitations (see below), Fibroscan results are not always accurate, as the degree of stiffness of the liver doesn't always reflect the degree of fibrosis. Radiological tests on the whole are limited in their ability to evaluate liver fibrosis.

Other Scoring Systems

In addition to the METAVIR score, there are other scoring systems that may be used to predict the degree of fibrosis seen on a liver biopsy sample. These include the Batts and Ludwig system, the Knodell score (the histological activity index or HAI), the Ishak score (modified Knodell score), and the International Association for Study of the Liver system.

Limitations

Like most evaluations, the METAVIR score has its strengths and weaknesses.

Small biopsy specimens may not allow physicians to adequately determine a score representative of the whole. There can also be significant heterogenicity or variability of inflammation and fibrosis in different regions of the liver; the score will only reflect that of the sample. In this way, the score may either overestimate or underestimate the amount of inflammation or fibrosis present.

For example, the METAVIR score may indicate significant activity, but this may not mean that severe disease is present.

Furthermore, different people with the same METAVIR score may have different treatment needs and prognoses, and treatment cannot be dictated by the score alone.

Liver Biopsy

The METAVIR score uses two measurements that are made from the appearance of a sample obtained from a liver biopsy—the fibrosis score and the activity score. Doctors use these scores together to estimate the degree of fibrosis of the liver and the chance that further fibrosis will develop.

A percutaneous liver biopsy is a procedure in which a long thin needle is inserted into the liver and a piece of tissue removed. In some cases, a liver biopsy may be done via laparoscopy (a surgical procedure in which small incisions are made in the abdomen), or by threading a needle through the jugular vein into the liver (a transvenous biopsy).

Biopsy can cause issues such as bleeding, damage (via penetration of the wrong organ) to the lung, kidney, gallbladder, or intestine, or rarely, death, but most procedures are done without consequence.

Pre-Test

Performed in a hospital or specialty clinic, you will be asked to lie flat on an exam table after changing into a hospital gown. Your nurse will insert an IV and give you a sedative before the procedure begins. After cleaning the skin overlying the liver (the right upper abdomen) with an antiseptic, the skin is then numbed with a local anesthetic.

Throughout the Test

Using ultrasound guidance, a long, thin needle with a hollow center is inserted into the area of the liver the physician wishes to biopsy. The actual biopsy takes only a minute or so using a special instrument on the end of the needle, and then the needle is withdrawn. When the procedure is done, your nurse will monitor your vital signs and make sure you aren't experiencing any pain or other symptoms for around four hours.

Post-Test

When you're given the all clear, you will be allowed to return home; you will need someone to drive you. You will be advised to avoid excessive activity or heavy lifting for the next week.

The sample from your liver will be sent to the pathologist, who will look at the tissue under the microscope and use special stains that provide more information about your liver cells and how they are functioning.

Interpreting Results

The pathologist will determine the METAVIR score of the sample evaluated. As noted, this is one of many "tools" a doctor can use to help monitor the progress of liver disease.

Fibrosis Score

The fibrosis score is used to describe the amount of inflammation (the intensity of inflammation/breakdown of tissue) in the liver:

  • F0: No fibrosis
  • F1: Portal fibrosis without septa
  • F2: Portal fibrosis with few septa
  • F3: Numerous septa without cirrhosis
  • F4: Cirrhosis

Activity Score

The activity score is a prediction about how rapidly the degree of fibrosis is progressing:

  • A0: No activity
  • A1: Mild activity
  • A2: Moderate activity
  • A3: Severe activity

In general, a fibrosis score of F0 or F1 means that no significant fibrosis is present, while a score of greater than or equal to F2 indicates significant fibrosis and suggests that treatment should be started.

With hepatitis C, it's now recommended that everyone receive treatment regardless of their METAVIR score, but this isn't always practical and isn't a one-size-fits-all approach. Studies suggest that the 15-year survival rate for hepatitis C is better when people are treated beginning with stage F0 or F1 disease, but if fibrosis progresses slowly, it may be preferable to wait before starting treatment with antiviral therapy. The METAVIR score can help doctors gain insight and make an estimation about when cirrhosis may develop.

In addition to suggesting when treatment should be initiated, the level of fibrosis can indicate the likelihood of treatment response (more advanced cases will usually have a poorer response to treatment).

In contrast, the risk of complications for those who have F3 or F4 disease is substantial, and treatment should be started right away.

Follow-Up

Depending on your results, a repeat liver biopsy and METAVIR score may be recommended at some time, but the timing of further testing will depend on your specific disease, any treatments you receive, and more.

Understanding your METAVIR score can not only help you make more educated decisions about hepatitis C treatment, but guide you to make changes that may reduce the rate of fibrosis. Factors that increase the rate of progression include smoking, alcohol intake, obesity, elevated cholesterol, and having poorly controlled diabetes. Quitting smoking, maintaining a healthy weight, avoiding alcohol, and carefully managing conditions such as diabetes and hyperlipidemia are important measures people can take themselves to protect their liver.

A Word From Verywell

The METAVIR score, while having limitations, is a common way to detect and monitor the progression of fibrosis in people with chronic liver disease. While less is heard about liver disease than some other conditions, the importance of reducing fibrosis can't be underestimated. At the current time, cirrhosis is the twelfth leading cause of death in the United States and a major concern globally as well.

If you're living with chronic hepatitis C, take the time to learn about your disease and be your own advocate in your care. In addition to seeking medical treatment, there are things you can do on your own that may improve your outcome. Attention to risk factors that may worsen the disease and seeking out excellent medical care may not only reduce the progression of fibrosis, but in some cases, could even result in a regression in the level of fibrosis present.

Was this page helpful?
Article Sources