Page 209 - Medicine and Surgery

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Chapter 5: Disorders of the liver 205

Clinical features bylightmicroscopy.Alcoholmayalterand/orenhance
HEV causes acute hepatitis, with a prodromal phase of the effects of other chemicals on the liver, including
a‘flu-like’ illness, followed by jaundice. Generally there other hepatotoxins and carcinogens.
is a 1% risk of fulminant liver failure, except in women Alcohol increases lactate and fatty acid accumulation
in the last trimester of pregnancy where there is a 25% resulting in fatty liver.
risk. Chronic alcohol use activates the microsomal oxidis-
ingsystem,whichincreasesmetabolismofalcoholand
Management other drugs (see Fig. 5.9). Cirrhosis may result from
Supportive care may be required. fibroblast proliferation and collagen synthesis. Liver
cell membranes may become immunogenic resulting
in a lymphocyte-mediated cytotoxic response against
Other liver diseases the liver cells.

Alcohol-induced liver disease
Clinical features
Definition Differing patterns are seen:
Liver disease caused by alcohol range from a fatty liver Acute alcoholic hepatitis resembles acute viral hepati-
to hepatitis and cirrhosis. tis, (malaise, anorexia, jaundice, abdominal pain and
fever).
Incidence/prevalence Fatty liver is asymptomatic, it may be detected with
Alcohol is the most common cause of liver disease in the abnormal liver function tests.
West. Chronic alcohol-induced liver damage may present
with signs of chronic liver damage or with complica-
tions of cirrhosis.
Geography
Increasing importance in developing countries.
Microscopy
Aetiology There are three main patterns of liver damage:
The risk of developing chronic disease is related to quan- Alcoholic hepatitis is focal necrosis of hepatocytes,
tity, types of beverage, drinking pattern (see page 521), with neutrophil infiltration. Fibrosis around the cen-
nutrition and genetic susceptibility. tral veins is present in later cases. Characteristically
Mallory’s bodies composed of cytoskeletal fragments
Pathophysiology andubiquitin,aheatshockproteinthatlabelsproteins
Any alcohol ingestion causes changes in liver cells, as being damaged and targets them for breakdown.

which can be seen by electron microscopy. Alcoholic It appears as bright eosinophilic amorphous globules
hepatitis refers to alcohol-induced liver injury visible within hepatocytes.

Alcohol NAD + H+
alcohol dehydrogenase
Lactate and fatty acid
Acetaldehyde NAD + H+ produced
acetaldehyde dehydrogenase Increased in alcohol-
induced liver damage
Acetate + NADH
Increased metabolism of
alcohol and other drugs
Figure 5.9 Alcohol metabolism.