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Liver biopsy in chronic hepatitis – why do it?
Dr P Scheuer, London, UK, provided strong arguments for the continued
use of liver biopsy in diagnosis, pre- and post-treatment assessment,
follow up, and research, in chronic hepatitis.
Biopsy adds much to liver function tests in diagnosis, and is essential
for total assessment. Although HCV RNA in serum is now often used for
diagnosis of Hepatitis C, biopsy can give more insight into the nature
of disease, showing extent of inflammation and cirrhosis. Biopsy can also
illustrate which disease is responsible for liver damage in cases of e.g.
hepatitis plus thalassaemia.
In assessing patients’ need for treatment, biopsy is also useful.
Originally, pathologists had difficulty in classifying hepatitis by histology
alone, but a number of grading and staging systems have been used over
the years. Clinicians require a numerical evaluation to assist their decisions
to treat, and the simple algorithm of the METAVIR group has been very
useful. This has a range of 0-3, and does not detect minor histological
changes. On the other hand, the Knodell updated scoring allows a cumulative
grading of 0-18, and a staging of 0-6. However, a ‘grading total’
figure should not be used to assume the need for therapy, since these
numbers are not true measurements, but a hierarchy of gradings.
Although largely unnecessary for detecting cirrhosis nowadays, biopsy
is still often used to do so. Pathology is also useful in identifying
hepatocellular carcinoma when there is not obvious tumour mass, and negative
serum alpha-fetoprotein.
Liver tissue is essential to cell-based research studies, such as analysis
of cytotoxic lymphocytes in a diseased organ. Various in situ staining
techniques obviously need tissue sections to be useful. As a concluding
note, Dr Scheuer referred to a study which had shown that progression
of fibrosis is related to age of the patient at infection, duration of
disease, high alcohol intake, and male sex – purely derived by a
sophisticated scoring system of biopsy pathology.
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