Liver biopsy
A liver biopsy is where small sample of liver tissue is taken, and examined later under a microscope.
A liver biopsy is considered the best way to assess liver disease. It provides information about both the stage (the amount of scarring) and the grade (amount of inflammation, which drives future scarring) of liver disease. It can also identify other causes of liver disease.
A liver biopsy involves having a needle inserted between the ribs, and into the liver. This then clips and removes a small sample of liver tissue. The procedure can be painful, and carries a small risk of complications (1-3%), such as puncturing other organs or bleeding, and a much, much smaller risk of death (0.1% to 0.01%).
Biopsy is not perfect because there can be errors in sampling and in reviewing. Results may be inaccurate when a sample is too small, or it comes from an area in the liver that is more or less damaged than the rest. Samples also need to be reviewed by a specialist. In addition, the cost of a biopsy may limit how easy this is to access. Despite this it is still the ‘gold standard’.
Because a biopsy is not pleasant, many people with HCV are reluctant to take part. Still, many doctors think they offer the best and most reliable way to know the level of liver damage. Luckily, reliance on biopsy as a requirement for HCV treatment is an area that is changing.
Some experts think that if you have a high chance of response to treatment (people with genotype 2 or 3, and with lower HCV viral load) you do not need a biopsy before HCV treatment. A biopsy may be most useful for informing treatment decisions in people with harder-to-treat HCV (genotypes 1 and 4) who may be able to wait for newer therapies if they do not have serious liver damage.
One of the main obstacles to HCV treatment is the liver biopsy. So, right now I am considering treatment, because I see a lot of people dying from hep C and I’ve had it for a long time. My viral load is OK, my liver enzymes are OK, but we know that the only way to know the real situation is a liver biopsy. To be honest, I am ready to start treatment tomorrow, but I don’t want a doctor to put a needle in my liver.
A biopsy should only be performed by an experienced doctor, who has a good record of successful biopsies.
The doctor should guide the needle with an ultrasound scan to reduce the chance of puncturing another organ, and to pinpoint areas of damaged liver tissue for sampling. If you are concerned about the pain, ask your doctor about options for pain management during and after the procedure. Ask other people about their experiences. It may be easier to find a good doctor by talking with people who have had a biopsy.
Recent research is looking at less invasive alternatives to biopsy (see Measuring liver stiffness).
When is a biopsy important?
Having a biopsy can help you make a treatment decision by showing how damaged your liver is.
Despite the discomfort, and risk of complications, it is an important test for monitoring HCV disease over time. It is therefore recommended during chronic infection, and especially recommended before starting treatment.
In untreated, HIV-positive people, a followup biopsy is recommended every 2-3 years.
UK guidelines say that the risks versus benefits should be weighed for each individual. Many centres feel that the risk of a liver biopsy outweighs the benefit in men with haemophilia.
One doctor said: ‘I tell people who really don’t want a biopsy, that they are important in order to make treatment decisions, and they may needtto get one in the future. For example, if someone isn’t responding to HCV treatment after 12 weeks, we need to decide whether or not to stop treatment altogether, or to continue with maintenance treatment.’
Interpreting biopsy results
There are different systems for measuring liver inflammation and fibrosis.All go from zero to a maximum score; the higher the number the more inflammation or fibrosis.
- Ishak: inflammation 0-18, fibrosis 0-6
- Metavir: inflammation A0-A3, fibrosis F0-F4
- Knodell: inflammation 0-18, fibrosis 0-4
UK (BHIVA) guidelines define mild liver damage as a modified Ishak score of 3 or less and a fibrosis score of 2 or less, and moderate liver damage has an inflammatory score of 4 or more and/or a fibrosis score of 3 to 5.
However, these scoring systems are not used in every hospital and some clinics prefer to just stage biopsies as mild, moderate or cirrhosis.