Overview of Chronic Hepatitis

The most common causes of chronic hepatitis are

• Hepatitis C virus

• Hepatitis B virus

• Fatty liver not due to alcohol use

• Alcohol-related liver disease

Hepatitis C virus causes about 60 to 70% of cases of chronic hepatitis, and at least 75% of acute hepatitis C cases become chronic.

About 5 to 10% of hepatitis B cases in adults become chronic, sometimes with hepatitis D coinfection. (Hepatitis D does not occur by itself. It occurs only as a coinfection with hepatitis B.) Acute hepatitis B becomes chronic in up to 90% of infected newborns and in 25 to 50% of young children.

Rarely, hepatitis E virus causes chronic hepatitis in people with a weakened immune system, such as those who are taking drugs to suppress the immune system after an organ transplant, who are taking drugs to treat cancer, or who have HIV infection.

Hepatitis A virus does not cause chronic hepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) (a type of chronic inflammation of the liver; formerly called nonalcoholic steatohepatitis [NASH]) usually occurs in people with excess body weight (obesity), diabetes, and/or abnormal levels of cholesterol and other fats (lipids) in the blood. All of these conditions cause the body to synthesize more fat or process (metabolize) and excrete fat more slowly. As a result, fat accumulates and is then stored inside liver cells (called fatty liver). Fatty liver can lead to chronic inflammation and eventually progress to cirrhosis. (Fatty liver due to any condition other than excessive consumption of alcohol is called metabolic dysfunction-associated steatotic liver disease [MASLD], which was formerly called nonalcoholic fatty liver disease [NAFLD].)

Alcohol, after being absorbed in the digestive tract, is usually processed (metabolized) in the liver. As alcohol is processed, substances that can damage the liver are produced. Alcohol-related liver disease typically occurs in people who drink heavily for many months or years. Alcohol-related liver disease is characterized by fatty liver and widespread liver inflammation that can result in the death of liver cells. If people continue drinking, scar tissue can form in the liver and may eventually replace a large amount of normal liver tissue, resulting in cirrhosis.

Less often, chronic hepatitis results from

• Autoimmune hepatitis

• Medications

• Alpha-1 antitrypsin deficiency (a hereditary disorder)

• Celiac disease

• Hemochromatosis (a hereditary disorder that causes the body to absorb too much iron)

• Primary biliary cholangitis

• A thyroid disorder

• In children and young adults, Wilson disease

In autoimmune hepatitis, the chronic inflammation resembles inflammation caused by the body attacking its own tissues (an autoimmune reaction). Autoimmune hepatitis is more common among women than men.

Certain medications

Overview of Autoimmune Hepatit...

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No one knows exactly why a particular virus or medication causes chronic hepatitis in some people but not in others or why the degree of severity varies.

In about two-thirds of people, chronic hepatitis develops gradually, often without causing any symptoms of a liver disorder until cirrhosis occurs. In the remaining one-third, it develops after a bout of acute viral hepatitis that persists or returns (often several weeks later).

Chronic hepatitis often causes general symptoms, such as a vague feeling of illness (malaise), poor appetite, and fatigue. Sometimes affected people also have a low-grade fever and some discomfort in the upper abdomen. Jaundice (a yellow discoloration of the skin and whites of the eyes caused by deposits of excess bilirubin) is rare unless liver failure develops. Many people with chronic hepatitis have no symptoms.

Often, the first specific symptoms occur when liver disease has progressed and there is evidence of cirrhosis. Symptoms can include

• An enlarged spleen

• Small spiderlike blood vessels visible in the skin (called spider angiomas)

• Redness of the palms

• Accumulation of fluid within the abdomen (ascites)

• A tendency to bleed (coagulopathy)

• Bleeding in the digestive tract due to esophageal varices

• Jaundice

• Deterioration of brain function (hepatic encephalopathy)

• Liver cancer

Brain function deteriorates because the badly damaged liver cannot remove toxic substances from the blood as it normally does. These substances then build up in the blood and reach the brain. Normally, the liver removes them from the blood, breaks them down, then excretes them as harmless by-products into the bile (the greenish yellow fluid that aids in digestion) or blood (see Functions of the Liver). Treatment of hepatic encephalopathy can prevent the deterioration of brain function from becoming permanent.

Blood cannot clot as it normally does because the damaged liver can no longer synthesize enough of the proteins that help blood clot.

A few people have jaundice, itchiness, and light-colored stools. Jaundice and itchiness develop because the damaged liver cannot remove bilirubin from the blood as it normally does. Bilirubin then builds up in the blood and is deposited in the skin. Bilirubin is a yellow pigment produced as a waste product during the normal breakdown of red blood cells. Stool is light-colored because the flow of bile out of the liver is blocked and less bilirubin is eliminated in stool. Bilirubin is what gives stool its typical brown color.

Autoimmune hepatitis may cause other symptoms that involve other body systems. Symptoms can include cessation of menstrual periods, joint pain and swelling, loss of appetite, and nausea. People with autoimmune hepatitis may also have other autoimmune disorders such as type 1 diabetes mellitus, ulcerative colitis, celiac disease, or autoimmune disorders that cause anemia or inflammation of the thyroid gland or kidneys.

In many people, chronic hepatitis does not progress for years. In others, it gradually worsens. The outlook depends partly on which virus is the cause and whether treatment is available:

• Chronic hepatitis C, if untreated, causes cirrhosis in about 20 to 30% of people. However, cirrhosis may take decades to develop. The risk of liver cancer is increased usually only if cirrhosis is present.

• Chronic hepatitis B tends to worsen, sometimes rapidly but sometimes over decades, leading to cirrhosis. Chronic hepatitis B also increases the risk of liver cancer whether cirrhosis develops or not. (In people with liver disease caused by other conditions, liver cancer is usually a risk only if cirrhosis develops.) Rarely, chronic hepatitis B resolves on its own, without treatment.

• Chronic coinfection with both hepatitis B and D viruses, if untreated, causes cirrhosis in up to 70%.

• Autoimmune hepatitis can be effectively treated in most people, but some develop cirrhosis.

• Chronic hepatitis caused by a medication often completely resolves once the medication is stopped.

• Blood tests

• Occasionally a biopsy

Doctors may suspect chronic hepatitis when

• People have typical symptoms.

• Blood tests (done for other reasons) detect elevated liver enzymes.

• People have had acute hepatitis before.

Also, everyone aged 18 or over, regardless of whether symptoms are present, should be tested at least once for hepatitis C. Such testing is recommended because hepatitis C is often unrecognized.

Testing for chronic hepatitis usually begins with blood tests to measure the levels of liver enzymes and other substances produced by the liver (liver tests). These tests may help establish or exclude the diagnosis of hepatitis, identify the cause, and determine the severity of liver damage.

Blood tests are also done to help doctors identify whether a hepatitis virus is causing the infection. If no virus is identified, other blood tests are needed to check for other causes, such as autoimmune hepatitis.

A liver biopsy is sometimes done to confirm the diagnosis. The liver biopsy also enables a doctor to do the following:

• Determine how severe the inflammation is

• Determine whether any scarring (fibrosis) or cirrhosis has developed

• Possibly help identify the cause of hepatitis

However, liver biopsy is being done less frequently as new technologies continue to develop. For example, tests done to determine how badly the liver is damaged and to check for other liver problems may include

• Specialized imaging tests, such as ultrasound elastography and magnetic resonance elastography

• Blood tests to measure substances (called markers) that indicate whether and how much fibrosis is present

Ultrasound elastography and magnetic resonance elastography use sound waves, applied to the abdomen, to determine how stiff the liver tissue is.

• Treatment of the cause (such as antiviral medications for hepatitis B or C)

• Treatment of complications

Treatment of chronic hepatitis focuses on treating the cause and managing the complications, such as ascites and hepatic encephalopathy, in people with cirrhosis.

If a medication or other substance is the cause, its use is stopped. If another disorder is the cause, it is treated. If the cause is alcohol-related liver disease, doctors recommend changes in lifestyle, mainly abstinence from alcohol.