Symptoms of uncomplicated chronic hepatitis B
Failure to clear the virus may lead to chronic infection. Chronic hepatitis B is defined as persistence of HBsAg in the circulation for more than six months.
The disease may cause mild liver damage as well as active hepatitis, cirrhosis and primary liver cancer. Some patients with acute hepatitis B do not recover normally (between five and ten per cent) and will progress to chronic hepatitis.
The earlier the disease is acquired in life the greater the chance of developing chronic infection. Chronic hepatitis B is more likely to follow infections acquired in childhood than those acquired in adult life. 90 per cent of neonates infected at birth will develop chronic hepatitis B unless vaccination is given.
The persistence of abnormal alanine aminotransferase activity for more than six months after the onset of acute hepatitis B indicates disease progression and is usually accompanied by serological evidence of continued infection.
Only a small percentage of patients with chronic infection give a history of acute hepatitis or jaundice. Physical examination in chronic hepatitis B may show no physical abnormalities.
With more advanced disease there may be spider naevi and hepatomegaly (enlarged liver). Wasting, ascites, oedema, palmar erythema and bruising suggest advanced disease with cirrhosis. The features of portal hypertension, such as ascites and bleeding oesophageal varices, are late features of hepatitis B and cirrhosis.
Many patients show no symptoms of liver disease. If symptoms are present, they are usually non-specific and mild.
There are several signs to look out for:
- Fatigue is the most common symptom, variously described as a lack of energy, lassitude or the feeling that one is ageing.
- With the development of cirrhosis, weight loss, weakness, wasting, abdominal swelling, oedema, dark urine and jaundice may become progressive problems. Many carriers may be detected through routine screening for HBsAg.
- Older patients may present with complications of active hepatitis and cirrhosis or with HCC.
- A small proportion of patients may present with extrahepatic manifestations of HBV infection – glomerulonephritis, vasculitis, or polyarteritis, for example.
The following liver function tests (LFTs) are used to determine the presence of liver disease.
- ALT – tests usually show an increase in ALT although young carriers with high levels of hepatitis B may have normal ALT levels. Recording single measures of ALT will be less useful in a disease as dynamic as hepatitis B as aminotransferases may fluctuate over time.
- AST – tests will usually show an increase in AST.
- Serum bilirubin and albumin tests – usually normal unless the disease is severe and advanced.
- Prothrombin time – usually normal length unless the disease is severe and advanced.
The utility of HBV genotypes is still being determined but there is a suggestion that response to interferon is higher in genotypes A and B versus genotypes C and D. In comparison with genotype C, genotype B is associated with spontaneous HBeAg seroconversion at a younger age, less active liver disease, slower progression to cirrhosis and less frequent development of HCC. Genotype D is associated with HBeAg negative chronic hepatitis B.
The terms used to describe the pathology of chronic hepatitis are being reappraised. More emphasis is now placed on grading the degree of inflammation and staging the extent of fibrosis.