Hepatitis

What is hepatitis

Hepatitis is an inflammation of the liver that is most commonly caused by viruses but may also be due to chemicals, drugs, alcohol, inherited diseases, or autoimmune disease. The inflammation can be acute, flaring up and then resolving within a few weeks to months, or chronic, enduring over many years. Chronic hepatitis may persist for 20 years or more before causing significant symptoms related to progressive liver damage such as cirrhosis, liver cancer, or death.

The liver is a vital organ located in the upper right-hand side of the abdomen. It performs many functions in the body, including processing the body's nutrients, manufacturing bile to help digest fats, synthesising many important proteins, regulating blood clotting, and breaking down potentially toxic substances into harmless ones that the body can use or excrete. Inflammation may (in severe cases) interfere with these processes and allow potentially toxic substances to accumulate. The following table summarizes some common types of hepatitis.

Type of HepatitisDescriptionExamples of Causes
ViralInfection with one of the hepatitis viruses causes inflammation; may be acute or chronic depending on the virus.In the UK, most common causes are hepatitis A, B and C viruses.
Chemical or drug inducedThe liver processes many substances for the body to use and/or then eliminate. Some of these substances are toxic to the liver and can result in hepatitis.Acute or chronic exposure to alcohol, acetaminophen
InheritedCertain gene mutations that are passed from one generation to the next can result in a disease that damages the liver, causing hepatitis.Wilson's disease, hemochromatosis, alpha-1 antitrypsin deficiency
Non-alcoholic Fatty LiverFat deposited in the liver in increasing amounts can lead to decreased amount of healthy liver tissue.Associated with metabolic syndrome
AutoimmuneThe body's immune system inappropriately produces antibodies directed against liver tissue.Associated with type I diabetes, Sjorgren's syndrome
Signs and Symptoms

The signs and symptoms of hepatitis are the same, regardless of the cause, but vary from person to person and may vary over time. Many people have few, mild, and/or vague symptoms that may be mistaken for flu. Some of the more common signs and symptoms include:

  • Fatigue
  • Nausea
  • Abdominal pain
  • Joint aches
  • Itching
  • Jaundice

Some may experience additional symptoms such as loss of appetite, dark coloured urine, or light coloured stools. More serious complications can involve accumulation of fluid in the abdomen (ascites) and mental confusion.

A physical examination may reveal a liver that is tender and enlarged. Chronic hepatitis usually causes no symptoms or may be noticeable as only a loss of energy and tiredness. In some people, chronic hepatitis can gradually damage the liver and, after many years, cause liver failure. The chronic form typically lasts for many years and only rarely goes away without treatment.

Laboratory Tests

There are several laboratory tests that may be used in cases of known or suspected hepatitis. These tests may be used for various reasons and may fall into one or more of these categories:

  • General chemistry tests used to detect liver inflammation and/or damage
  • Screening tests used to detect Viral Hepatitis; for example, screening for exposure to hepatitis B or hepatitis C may be done because of increased risk of the disease (use of illegal drugs, multiple sex partners) or at the time of blood donation.
  • Tests used to help diagnose the underlying cause
  • Follow-up tests used to monitor progression of hepatitis and/or help guide treatment

Acute hepatitis is often suspected and tested for because of the appearance of symptoms such as fever, loss of appetite, and nausea, often accompanied by dark urine, pale stools, and yellow discolouration of the skin and the whites of the eyes (jaundice or icterus).

Chronic hepatitis is more commonly detected as a result of abnormal routine test results. In a patient who is having no, few, or vague symptoms, hepatitis may be first discovered during routine blood testing.

Tests may be used both to detect liver injury and to give an indication of how severe it may be. Some of these are listed below:

  • Alanine aminotransferase (ALT) - an enzyme found mainly in the liver; the best test for detecting hepatitis
  • Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other places, particularly the heart and other muscles
  • Alkaline phosphatase (ALP) – an enzyme related to the bile ducts; often increased when they are blocked, but may also be increased with bone disorders
  • Gamma-glutamyl transpeptidase (GGT) - an enzyme found in the liver that is very sensitive to changes in liver function; helps to differentiate between the causes of an elevated ALP; if GGT is increased, then the elevated ALP is due to liver, not bone disease.
  • Bilirubin - a waste product made from the breakdown of old blood cells; it is a yellow compound that causes jaundice and dark urine when present in increased amounts.
  • Albumin - measures the main protein made by the liver and tells how well the liver is making this protein
  • Total Protein - measures albumin and all other proteins in blood, including antibodies made to help fight off infections
  • Prothrombin time (PT). This test may be requested in a person with hepatitis or suspected hepatitis. Proteins used in the formation of a blood clot (coagulation factors) are mostly produced by the liver, and prolonged PT may indicate the severity of liver damage.
  • A liver biopsy, in which a needle is inserted into the liver to withdraw a small amount of cells that are examined under a microscope by a Histopathologist, is the most definitive way to diagnose the disease. Since this is an invasive procedure, it is used primarily when other tests are inconclusive or to determine how much damage to the liver has occurred.

For information on laboratory tests used for specific types of hepatitis, click on the links found in the Table on the Overview page.

Imaging tests such as ultrasound and specialized X-rays may be used to evaluate the liver, detect hepatitis, help make a diagnosis, and help determine a cause of liver injury.

Viral Hepatitis

A common cause of hepatitis is an infection with a virus. The five viruses primarily associated with hepatitis are named in the order of their discovery: A, B, C, D, and E. In the UK, acute viral hepatitis is most commonly caused by hepatitis A (HAV), hepatitis B (HBV), and hepatitis C (HCV), while only HBV and HCV cause chronic hepatitis.

Hepatitis A is spread through water and food that have been contaminated with the virus derived from human faeces and urine. Rates of hepatitis A have been dropping and are the lowest in 40 years due to a vaccine introduced in 1995. Hepatitis A causes an acute infection but not a chronic form of the disease. Treatment usually involves only supportive therapy, and most patients recover fully within about six months. Persons who have been in recent close contact with a known case of hepatitis A can benefit from prompt administration of prophylactic hepatitis A vaccine or human normal immunoglobulin.

Hepatitis B (HBV) can be spread by exposure to contaminated blood or needles, through unprotected sex with an infected person, and from an infected mother to baby. It is the most common cause of acute viral hepatitis. All pregnant women in the UK are offered hepatitis B screening and newborns of infected mothers areroutinely vaccinated which dramatically reduces the risk of them becoming infected.

Most adults with HBV will get better without any intervention, but about 1-3% become carriers - chronically infected and able to spread the disease to others. Up to 90% of newborns and 25-50% of children 1 to 5 years old who are infected with hepatitis B virus develop a chronic infection. With the advent of screening pregnant women for hepatitis B and the vaccination of newborns, the number of infected babies has fallen. Most chronic hepatitis B infections are now seen in people born in parts of the world (particularly southern and eastern Asia, southern Europe, and Africa) where infection among newborns still remains common. An estimated 350 million people around the world are chronically infected with HBV.

Hepatitis C (HCV) is spread by exposure to contaminated blood. The most common mechanism of exposure is the sharing of needles or other "works" used in injecting drugs of abuse such as cocaine or heroin. Other means of becoming infected include occupational exposure of health care workers to used needles or other sharp objects, through sexual activity that results in tissue tears, from mother to baby during childbirth, and sharing personal items contaminated with blood such as razors and toothbrushes.

HCV is less common than hepatitis B as a cause of acute hepatitis but is the most common cause of chronic hepatitis. About 75% to 85% of those exposed to the virus develop chronic hepatitis C infection. In addition, about 60% to 70% develop chronic liver disease, roughly 5% to 20% will develop cirrhosis over many years, and 1% to 5% are estimated to die from a condition that results from chronic infection such as cirrhosis and liver cancer.

There is no vaccine available to prevent hepatitis C, but research is in progress to develop one. Currently, the best way to avoid getting infected is to limit exposure to possible sources of the virus, especially avoiding the sharing of needles to inject drugs.

Hepatitis D and E are rare. Hepatitis D only causes an infection when hepatitis B is present and can make that infection more severe. It is usually spread by exposure to blood or infected needles. Hepatitis E is spread in a similar fashion to hepatitis A and is found primarily in Asia, Africa, and South America.

Signs and Symptoms of viral hepatitis correspond to those of hepatitis in general. See the section on Signs and Symptoms for detailed information.

Laboratory Tests
There are a variety of antibody and antigen tests that are available to help diagnose and/or monitor hepatitis caused by the specific hepatitis viruses.

Prevention
The incidence of new cases of viral hepatitis has decreased due to use of safe injection and safe sex practices (important in preventing hepatitis B and C) and the availability of vaccines for hepatitis A and hepatitis B (there is currently no vaccine available for hepatitis C). Screening units of blood for hepatitis B and C has virtually eliminated infections through blood transfusions. A systematic programme to screen pregnant mothers for hepatitis B and to vaccinate all newborns with infected mothers has greatly decreased new cases of hepatitis B.

Treatment
Support and symptom relief are frequently the only treatments required for acute viral hepatitis A, B, and C. This usually involves plenty of rest, fluids, and nutritious food. With hepatitis A, most people recover without any complications. With hepatitis B and C, some people may develop chronic forms of the disease. The goal with chronic forms is to minimise further damage to the liver, to treat underlying conditions that are causing or exacerbating the condition, and to prevent transmission of viral hepatitis to others. There are medications available to treat chronic hepatitis B and C, but not all people need to be treated. The antiviral drugs that are given can have serious side effects. Often, people with chronic hepatitis will be closely monitored to see if they develop cirrhosis or liver cancer. New treatments, vaccines, and prevention strategies for viral hepatitis continue to emerge. It is important to talk to your doctor about the risks and benefits of currently available options.

Toxic, Drug or Chemically-Induced Hepatitis

The liver is responsible for the metabolism of alcohol, drugs, and environmental toxins. It breaks them down into substances that can be used and/or then eliminated from the body. Certain drugs, chemicals, and toxins can cause liver damage whenever a person is exposed to them. At times, the symptoms of toxic hepatitis can appear quickly, within hours or days of exposure to the substance, or sometimes develop slowly over time after repeated use of a drug or exposure to a chemical.

Paracetamol which is found in numerous over-the-counter and prescription medications, is an example of a drug that can cause toxic hepatitis. In therapeutic doses, it is a useful pain reliever, but in very high dosages or in combination with alcohol, it has the potential to cause life-threatening acute liver failure.

Excessive consumption of alcohol is a common cause of this type of hepatitis. According to the National Institute on Alcohol Abuse and Alcoholism, about 10% of heavy drinkers develop this disease. It may be chronic yet mild, lasting for years but with no specific symptoms. However, over time, the liver may sustain more and more damage. The damage may be reversed if alcohol consumption is stopped. A more dangerous form can be acute with symptoms that appear quickly after binge drinking and may result in severe complications possibly resulting in death.

Many drugs have the potential to cause hepatitis in a few people, in a seemingly random fashion. Their effect cannot be foreseen and appears to be related to an allergic reaction to the medication. Drugs that have had this affect in some people include anaesthetics, antibiotics, anabolic steroids, and seizure medications.

Signs and Symptoms of toxic hepatitis vary depending on the cause. They may appear suddenly or may develop gradually over time with prolonged exposure to the drug or toxin. When present, they often correspond to the signs and symptoms of hepatitis in general. See the section on Signs and Symptoms for detailed information.

Laboratory Tests
Drug, alcohol, and chemical hepatitis are not typically tested for directly with laboratory tests. The diagnosis is often arrived at by examining the patient, getting a full medical history, especially about previous ingestion of chemicals, drugs, alcohol, and, where applicable, evaluating hazards the patient may have been exposed to in the workplace, such as industrial solvents. There are some tests that may be performed to help evaluate someone with toxic hepatitis:

  • Liver function tests - to detect and/or determine the extent of liver damage
  • Ethanol- if alcohol is suspected to be a cause
  • Emergency and overdose drug testing - including tests for drugs of abuse, paracetamol, and therapeutic drugs to help determine the cause of hepatitis and guide treatment

Treatment
There is no specific treatment for most kinds of toxic hepatitis. Usually discontinuing the medication that is causing the liver damage or avoiding exposure to toxins is the first step. Many people fully recover from this type of hepatitis if this is done soon enough, although it may sometimes take months for the liver to heal. Occasionally, there is lasting damage such as cirrhosis and even liver failure. If the liver is irreversibly damaged, then a liver transplant may be an option.

There is treatment available for an overdose of paracetamol that can minimise damage to the liver. N-acetylcysteine (NAC) may be given as an antidote within 24 hours of ingestion. It is most effective as an antidote if given within 8 hours of ingestion, so it is important to identify and treat this condition as soon as possible.

Inherited Forms of Hepatitis

Several inherited diseases affecting the liver can become apparent, primarily by causing symptoms of acute or chronic hepatitis. Some examples include:

  • Haemochromatosis is the most common form of inherited hepatitis and is associated with absorption and accumulation of too much iron in the body. The liver is one of the principal organs damaged, and chronic hepatitis may be due to iron overload.
  • Alpha-1-antitrypsin deficiency is also a relatively common inherited disease, and in children who have this deficiency state, both acute and chronic hepatitis are common. In adults, the liver involvement is often hard to detect, but cirrhosis and liver cancer are both more common in those with alpha-1-antitrypsin deficiency.
  • Wilson’s disease is a rare form of inherited hepatitis and is associated with an accumulation of excess copper in the liver, brain, and in other tissues. This disease may cause both acute and chronic hepatitis. Unless Wilson’s disease is treated, it becomes progressively worse and is eventually fatal.

Click on the links above to read more about the specific conditions listed.

Signs and Symptoms of inherited forms of hepatitis are varied and specific for the individual diseases. Click on the links above to find out more about them. Signs and symptoms of the liver involvement in these conditions correspond to those of hepatitis in general. See the section on Signs and Symptoms for detailed information on those.

Laboratory Tests
Inherited hepatitis may be suspected if there is a family history of liver disease. Some common tests to look for the presence of inherited liver diseases include:

  • Iron tests such as serum iron, total iron binding capacity, transferrin saturation and ferritin to help diagnose haemochromatosis
  • Alpha-1-antitrypsin level to look for alpha-1-antitrypsin deficiency
  • Caeruloplasmin and copper tests can help diagnose Wilson’s disease.
  • Genetic testing - these tests may be used to detect mutations in certain genes that can lead to inherited types of hepatitis. Tests for mutations in the HFE gene, for example, can help diagnose haemochromatosis.
  • Liver biopsy - microscopic examination of a sample of liver tissue can help make a diagnosis.

Treatment
There is no cure for genetic diseases that affect the liver. Treatments depend on the cause and are as varied as the conditions. For example, hereditary haemochromatosis treatment usually involves periodic phlebotomy where a pint of blood is removed from the affected person to decrease the amount of iron in the body. Those affected by Wilson’s disease may be put on a low copper diet and treated with drugs to help eliminate copper from the body or prevent its absorption from the diet.