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Fibrosis of the Liver

By

Jesse M. Civan

, MD, Thomas Jefferson University Hospital

Last full review/revision Dec 2019| Content last modified Dec 2019
Click here for the Professional Version
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Fibrosis is the formation of an abnormally large amount of scar tissue in the liver. It occurs when the liver attempts to repair and replace damaged cells.

Scar tissue replaces the liver cells and, unlike liver cells, performs no function. Scar tissue can distort the liver's internal structure and interfere with blood flow to and in the liver, limiting the blood supply for the liver cells. Without enough blood, these cells die, and more scar tissue is formed. Also, blood pressure in the vein that carries blood from the intestine to the liver (portal vein) increases—a condition called portal hypertension Portal Hypertension Portal hypertension is abnormally high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches. Cirrhosis (scarring that distorts... read more .

Fibrosis can sometimes be reversed if the cause is identified promptly and corrected. However, after months or years of repeated or continual damage, fibrosis becomes widespread and permanent. The scar tissue can form bands throughout the liver, destroying the liver’s internal structure and impairing the liver’s ability to regenerate itself and to function. Such severe scarring is called cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more Cirrhosis of the Liver .

Causes of Liver Fibrosis

The most common causes in the United States are

Nonalcoholic fatty liver usually occurs in people who have excess body weight Obesity Obesity is excess body weight. Obesity is influenced by a combination of factors, which usually results in consuming more calories than the body needs. These factors may include physical inactivity... read more Obesity , diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more or prediabetes, and/or high levels of fats (lipids) and cholesterol Overview of Cholesterol and Lipid Disorders The body needs fats for growth and energy. It also uses them to synthesize hormones and other substances needed for the body’s activities. The body may deposit excess fat in blood vessels and... read more in the blood. This combination of risk factors for fatty liver disease is often referred to as metabolic syndrome. Metabolic Syndrome Metabolic syndrome is characterized by a large waist circumference (due to excess abdominal fat), high blood pressure, resistance to the effects of insulin (insulin resistance) or diabetes,... read more Over recent years, metabolic syndrome leading to nonalcoholic fatty liver has become increasingly common in the United States. Worldwide, viral hepatitis B (see table The Hepatitis Viruses) The Hepatitis Viruses Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more is a common cause. Sometimes the cause of fibrosis is not known.

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Symptoms of Liver Fibrosis

Diagnosis of Liver Fibrosis

  • A doctor's evaluation

  • Sometimes blood tests, imaging tests, or both

  • Sometimes liver biopsy

Doctors suspect fibrosis when people have a disorder or take a drug that could cause fibrosis or when routine blood tests to evaluate the liver Liver Blood Tests Liver tests are blood tests that represent a noninvasive way to screen for the presence of liver disease (for example, hepatitis in donated blood) and to measure the severity and progress of... read more indicate that the liver is damaged or is malfunctioning. Tests are then done to confirm the diagnosis, and if fibrosis is present, tests are done to determine its severity. These tests can include imaging tests, blood tests, liver biopsy, and sometimes specialized imaging tests to determine how stiff the liver is.

Certain combinations of blood tests can distinguish between two levels of fibrosis:

  • Absent or mild

  • Moderate to severe

These tests cannot reliably differentiate between degrees of moderate or severe fibrosis. The severity of fibrosis helps indicate the prognosis in people who have chronic viral hepatitis.

Liver biopsy Biopsy of the Liver Doctors can obtain a sample of liver tissue during exploratory surgery, but more often they obtain a sample by inserting a hollow needle through the person's skin and into the liver. This type... read more is the most reliable way to detect and stage (determine the amount of) fibrosis and to identify the disorder causing fibrosis. Biopsy is often done when the diagnosis is unclear. It is also done to determine whether fibrosis has progressed to cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more Cirrhosis of the Liver (for example, in people with hepatitis C). Because liver biopsy is invasive and can cause complications, doctors may first do blood tests to determine the level of fibrosis and then do a liver biopsy only if blood tests indicate that fibrosis is moderate or severe. Doctors are increasingly relying on certain specialized imaging tests as noninvasive alternatives to biopsy.

Specialized imaging tests can determine how stiff the liver is. The stiffer liver tissue is, the more severe fibrosis is likely to be. These tests (ultrasound elastography, magnetic resonance elastography, and acoustic radiation force impulse imaging) use sound waves, applied to the abdomen, to determine how stiff the liver tissue is. Unlike liver biopsy, these tests are not invasive and thus have some advantage. Ultrasound elastography and magnetic resonance elastography are being used in people with viral hepatitis C to diagnose fibrosis. Additionally, these tests are used in people with fatty liver disease. Although conventional ultrasonography can be unreliable in extremely overweight people (who are at risk of fatty liver disease Fatty Liver Fatty liver is an abnormal accumulation of certain fats (triglycerides) inside liver cells. People with fatty liver may feel tired or have mild abdominal discomfort but otherwise have no symptoms... read more ), specialized attachments are available to allow reliable ultrasound elastography measurements in obese people.

Treatment of Liver Fibrosis

Doctors focus on treating the cause, which often stops or slows further scarring of the liver and sometimes results in improvement. Such treatment may include

No available drug stops the formation of scar tissue effectively and safely. However, drugs that may reduce fibrosis are under study. Silymarin, a powerful antioxidant present in the medicinal herb called milk thistle Milk Thistle Milk thistle is a purple-flowered plant. Its sap and seeds contain the active ingredient silymarin, a potent antioxidant and a term often used interchangeably with milk thistle. (See also Overview... read more , is sometimes used to treat fibrosis. It appears to be safe (except when combined with certain drugs to treat hepatitis C), but it does not appear to be effective. Drinking coffee may help protect the liver against fibrosis.

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