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Liver

i. Hepatitis B virus

Hepatitis B virus (HBV) is a highly infectious virus that can cause either an acute hepatitis or chronic infection. It primarily affects liver, but can be found elsewhere in the body. There is a wide spectrum of disease in chronic infection, from a mild inactive state to a progressive hepatitis. In certain individuals the infection more rapidly causes complications.

HBV can be transmitted in several ways:

  1. Around the time of birth from an infected mother ("perinatal")
  2. By exposure to infected blood e.g. blood transfusion, sharing needles, open wounds
  3. Sexual transmission

Chronic HBV infection usually occurs in individuals exposed to the virus early in life or in individuals with weakened immune systems.

Symptoms

  • Patients with acute hepatitis often have jaundice and are very unwell.
  • Chronic infection is usually asymptomatic until complications arise. The infection may only be detected when donating blood or when abnormal liver results are found on blood tests.

Complications:

  • Liver fibrosis and cirrhosis
  • Liver failure
  • Liver cancer
  • Kidney disease

Treatment

  • Acute HBV infection – Usually self-limited and resolves with supportive management only. Bed rest is crucial for faster recovery.
  • Chronic HBV infection – Infection is not curable yet. Treatment is aimed at suppressing replication of the virus using oral antiviral agents, thus preventing damage to the liver and the development of complications.

Immunization and prevention of infection

HBV infection can be prevented by vaccination. Since 1995 HBV vaccination has been part of the South African program for immunization. Transmission of HBV perinatally can also be prevented by using the correct therapy. It is advised that all adults who are at an increased risk of infection or are at risk of more severe infection should also receive vaccination. This includes patients receiving immunosuppressant drugs.

ii. Hepatitis C virus

Hepatitis C virus (HCV) is a virus that exclusively infects the liver and can cause chronic infection. Like Hepatitis B virus, it can cause an acute hepatitis. However, this is usually mild and may go unnoticed.

HCV can be transmitted in several ways:

  1. Around the time of birth from an infected mother (“perinatal”)
  2. By exposure to infected blood e.g. blood transfusion, sharing needles, open wounds
  3. Sexual transmission

 

Symptoms

  • Individuals with acute hepatitis C virus infection may have flu-like symptoms, such as fatigue, muscle aches and nausea. Jaundice may be present. However, the majority of cases are aymptomatic.
  • Chronic hepatitis is also usually asymptomatic before the onset of cirrhosis. Many non-specific symptoms may be experienced, including fatigue and depression.

Diagnosis

The diagnosis of HCV infection is done using blood tests. If the blood test for antibodies is positive, this is usually confirmed with a test for HCV DNA in the blood. It may be necessary to perform a liver biopsy to assess the degree of damage to the liver.

Treatment

Until recently, the treatment of HCV was unpleasant and often unsuccessful. However, a new class of antiviral agents for the treatment of HCV was approved in 2011, and since then significant advances have been made. Treatment for most strains of HCV is now safe, easy and highly effective. Unfortunately, the therapy is very expensive and this can hamper treatment.

iii. Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is due to the accumulation of fat in liver cells and the absence of excessive alcohol intake. It is the most common cause of liver disease in Western countries. It is associated with many conditions, the most important being:

  • Obesity
  • Diabetes mellitus
  • Malnutrition or rapid weight loss
  • Certain medications and toxins

 

The severity NAFLD varies significantly:

  • Isolated fatty liver – Minor abnormalities in liver tests with no impairment of liver function.
  • Non-alcoholic steatohepatitis (NASH) – Significant abnormalities in liver tests, with inflammation in the liver caused by the excess fat. Damage to the liver from inflammation may cause fibrosis and cirrhosis.
  • Liver cirrhosis – Untreated NASH may lead to liver cirrhosis and, ultimately, failure.

 

Diagnosis

If the condition is recognised and managed properly, progression of disease can be prevented. Diagnosis can be made with compatible blood results and radiological imaging. Non-invasive tests have been developed to determine the presence and degree of fatty infiltration and cirrhosis (e.g. Fibroscan). However, it may be necessary for a liver biopsy to be performed to assist with diagnosis.

Treatment

The mainstay of treatment for NAFLD is lifestyle modification i.e. dietary changes, weight loss and exercise. Responses to various drug therapies have been disappointing, but there is much ongoing research into other possible treatment options.