HBV: Grading and Staging a Liver Biopsy

Christine M. Kukka
HBV Project Manager
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The liver biopsy is the best test we have today for finding out if the liver is healthy or damaged. After the biopsy is performed, a medical expert will review the tiny piece of liver tissue and write a report on the health of the liver.

Grading and Staging

There are a couple of ways to read a liver biopsy. The most common scoring methods are known as the Metavir and the Knodell Score. It is important to remember that the size of the piece of liver taken at biopsy can affect the report. The knowledge of the doctor reading the biopsy is also important.

Metavir
The Metavir scoring system was set up just for patients with hepatitis B. The scoring uses both a grade and a stage system. The grade tells you about the activity or amount of swelling and irritation (inflammation). The stage tells you the amount of fibrosis or scarring. The grade is given a number based on the amount of inflammation.

The grade is usually scored from 0-4. A 0 is no activity and 3 or 4 is severe activity. Knowing the amount of inflammation is important because inflammation may lead to eventual scarring or damage.
The fibrosis score is also assigned a number from 0-4:

0 = no scarring
1 = minimal scarring
2 = scarring has occurred and is outside the areas of the liver which include blood vessels
3 = bridging fibrosis (the fibrosis is spreading and connecting to other areas that contain fibrosis)
4 = cirrhosis or advanced scarring of the liver

Knodell
The Knodell score or HAI (histologic activity index) is also commonly used to stage liver disease. It is a bit more complex a process than using the Metavir score. But some experts believe that it is a better at finding how much liver inflammation and damage are present. It has four different numbers that make up a single score.

The addition of these numbers reveals the amount of inflammation in the liver:

0 = no inflammation
1-4 = minimal inflammation
5-8 = mild inflammation
9-12 = moderate inflammation
13-18 = marked inflammation

The fourth part of the score deals with the amount of scarring in the liver and is scored from 0 (no scarring) to 4 (extensive scarring or cirrhosis). The report will be sent to the doctor to review and discuss with a patient to help make the best possible healthcare decisions.

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