People with chronic hepatitis B have a
significantly higher risk of developing cirrhosis in subsequent decades. The
risk of developing cirrhosis depends, among other things, on disease activity
and disease duration. Factors which may accelerate the development of cirrhosis
include the presence of other chronic liver disease, such as infection with other hepatitis viruses (such
as co-infection with hepatitis C virus) and exposure to substances that damage
the liver. Alcohol is the key cause of this additional damage.
Cirrhosis is defined as a state in which a large part
of the liver tissue has been replaced by connective (scar) tissue. This
destroys the normal liver tissue structure and affects the blood supply,
causing high blood pressure in the portal vein (the vein between the intestine
and liver). Backflow of blood may cause dilated veins (varices) to develop in
the oesophagus (food tube) and stomach. If these veins burst, severe gastrointestinal
bleeding may occur. The risk of bleeding is increased because the blood's ability to clot is impaired by the reduced synthesis of protein in the
liver and a reduction in the number of blood platelets.
Accumulation of body fluids (ascites) in the
abdominal cavity may occur. One reason for this is the high blood pressure to the
If cirrhosis is present, the liver may be unable to
break down some of the toxins entering the blood from the gastrointestinal
tract, allowing these toxins to enter the main circulation. These toxins may
cause increased fatigue and poor concentration (hepatic encephalopathy
[encephalon = brain]).
Reduced protein production in the cirrhotic liver
impairs blood coagulation and results in an undersupply of substances needed by
the immune system. As a result, the patient is more prone to infections.
Retention of bile in people with
severe liver disease commonly causes yellowness of the eyes and skin
(jaundice). This may be accompanied by itching. Dark urine may be produced.
People with a long history
of chronic hepatitis B are also at greater risk of developing liver cancer
(hepatocellular carcinoma). The risk seems to be greatest for people with a
high viral load (HBV DNA). In most cases the hepatocellular carcinoma is
secondary to cirrhosis, but there are reports of liver cancer occurring in
people with chronic hepatitis B who had no history of cirrhosis. People
with low-replicative chronic hepatitis B (HBs antigen carriers) are also at
greater risk of developing liver cancer. Therefore, these patients also require
regular ultrasound scans and blood tests for monitoring purposes. In some
patients, chronic hepatitis B is severe enough to warrant a liver transplant.