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Cirrhosis

Description

An in-depth report on the causes, diagnosis, treatment, and prevention of cirrhosis

Alternative Names

Alcoholism; Liver Transportation; Primary Billing Cirrhosis

Causes

There are several processes that can lead to cirrhosis.

Alcoholism

The liver is particularly endangered by alcoholism. Alcoholic cirrhosis (also sometimes referred to as portal, Laennecs, nutritional, or micronodular cirrhosis) is the primary cause of cirrhosis in the US. It is estimated to be responsible for 44% of deaths from cirrhosis in North America. Some experts believe this estimate is low; one Canadian study found alcohol to be the major contributor to 80% of all cirrhosis deaths.

The relationship between alcohol and cirrhosis is generally as follows:

  • Alcohol is absorbed from the small intestine, and the blood carries it directly into the liver, where it becomes the preferred energy source.
  • In the liver, alcohol converts to toxic chemicals, such as acetaldehyde (AcH), which trigger the production of powerful immune factors called cytokines. These molecules in large amounts can cause inflammation and tissue injury and are proving to be major culprits in the destructive process in the liver. AcH is particularly being researched because it plays a role in most actions of alcohol, including damaging effects on the liver that may lead to cirrhosis.
  • The injured liver eventually is unable to breakdown fatty acids, compounds that make up fat. Over time, then, fat accumulates, further impairing the livers ability to absorb oxygen and increasing its susceptibility to injury. During the initial phase, the fat-laden liver becomes greatly enlarged, but it eventually shrinks as cirrhosis develops.

Chronic Hepatitis

The second leading cause of cirrhosis in the US is chronic hepatitis, either hepatitis B or hepatitis C. Chronic hepatitis C is the more dangerous form and accounts for one-third of all cirrhosis cases. Overall, between 10% and 15% of patients with chronic hepatitis C develop cirrhosis. The risk varies widely, however. About 5% to 10% of hepatitis B patients eventually develop cirrhosis. Viruses or other mechanisms that cause hepatitis produce inflammation in liver cells, resulting in their injury or destruction. If the condition is severe enough, the cell damage becomes progressive, building a layer of scar tissue over the liver. In advanced cases, as with alcoholic cirrhosis, the liver shrivels in size, a condition called postnecrotic or posthepatic cirrhosis.

Hepatitis C
Hepatitis C is a virus-caused liver inflammation which may cause jaundice, fever and cirrhosis. Persons who are most at risk for contracting and spreading hepatitis C are those who share needles for injecting drugs and health care workers or emergency workers who may be exposed to contaminated blood.

Autoimmune Liver Disease

Autoimmune liver diseases include autoimmune hepatitis and primary biliary cirrhosis. Like other autoimmune disorders, these conditions most likely develop because a genetically defective immune system attacks the body's own cells and organs. People who have one of these liver diseases also often have other autoimmune conditions, including systemic lupus erythematosus, rheumatoid arthritis, Sjgren's syndrome, scleroderma, inflammatory bowel disease, glomerulonephritis, and hemolytic anemia.

Autoimmune Hepatitis. Autoimmune chronic hepatitis occurs when an abnormal immune response causes an attack on the liver cells. It accounts for about 20% of all chronic hepatitis cases. Autoimmune chronic hepatitis typically occurs in women between the ages of 20 and 40 who have other autoimmune diseases. Some research indicates that the postmenopausal period may be another peak in incidence of AIH among women. About 30% of patients are men, however, and in both genders there is often no relationship to another autoimmune disease. In general, no major risk factors have been discovered for this condition.

Suspects for triggering this hepatitis include the measles virus, a hepatitis virus, or the Epstein-Barr virus, which causes mononucleosis. It is also possible that a reaction to a drug or other toxin that affects the liver also triggers an autoimmune response in susceptible individuals.

Infectious mononucleosis Click the icon to see an image of mononucleosis.

Primary Biliary Cirrhosis. Up to 95% of primary biliary cirrhosis cases occur in women, usually around age 50. In the case of primary biliary cirrhosis, the cells under attack from the aberrant immune system are in the bile ducts. Liver cells are destroyed as the disease progresses. In some cases, the disease also has features that resemble autoimmune hepatitis, but these features do not appear to affect the long-term outlook.

Some research indicates that this autoimmune process may be triggered by a virus or an unknown intestinal microorganism. People with celiac sprue appear to have a higher risk. This is an intestinal disorder associated with an inability to metabolize gluten, which is found in wheat and other common grains. Genetic factors are involved, but the inheritance pattern is unclear. A 1999 English study suggested that the disease is on the rise, although it is unclear if this reflects an actual increase or simply a greater awareness of the disorder.

Celiac sprue - foods to avoid Click the icon to see an image of the types of food that contain gluten.

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease, also called nonalcoholic steatohepatitis (NASH), has features similar to alcohol-induced hepatitis, particularly a fatty liver, but it occurs in individuals who do not consume significant amounts of alcohol. Severe obesity and type 2 diabetes are the major risk factors for NASH, as well as for complications from NASH. NASH may occur in about half of people with diabetes and up to 75% of obese people, depending on how severe the obesity is. (It can occur in overweight children as well as adults.) Some evidence suggests that insulin resistance (the primary problem in type 2 diabetes) is a major factor in development of a fatty liver in the first place. Although NASH is generally considered to be a benign and slowly progressive disorder, the fatty liver is vulnerable to injury from oxidants (damaging particles produced by chemical processes in the body). Excessive oxidation can lead to progression to advanced liver disease. In one study of patients with NASH, about 20% had some liver damage over a period of 3.5 to 11 years, with only about 6% of all patients showing severe liver damage. Another study reported that eventually 15% to 20% of patients develop advanced liver disease.

Hemochromatosis and Iron Overload

Hemochromatosis is a disorder of iron metabolism that is characterized by excess iron deposits throughout the body, including the liver, where they can cause cirrhosis. Once believed to be rare, hereditary hemochromatosis is now considered to be one the most common genetic diseases among Caucasians. Between 2% and 4% of people of European ancestry are believed to carry the gene, and the disease itself is estimated to occur in between 1.5 and three Caucasians per 1,000. Early symptoms of hemochromatosis include:

  • Fatigue.
  • Joint pain (arthralgia).
  • Impotence in men.
  • Arthritis.

A 2000 study further suggested that both hemochromatosis patients and their relatives who carry the trait are at higher risk for cirrhosis. Elevated iron levels, even in the absence of this disease, have been associated with liver scarring, particularly when accompanied by other risk factors for cirrhosis, including hepatitis, NASH, and alcoholism.

Other Causes of Cirrhosis

Inherited Diseases. Cirrhosis can be caused by a number of inherited diseases including:

  • Cystic fibrosis.
  • Alpha-1 antitrypsin deficiency.
  • Galactosemia.
  • Glycogen storage diseases.
  • Wilsons disease.

Other Rare Causes. Rare causes of cirrhosis include:

  • Schistosomiasis, caused by a parasite found in the Far East, Africa, and South America.
  • Small intestine bypass surgery (rarely, if ever, performed anymore).
  • Long-term or high level exposure to certain chemicals and drugs can cause cirrhosis, including arsenic, methotrexate, and toxic doses of vitamin A.

Changes That Resemble Cirrhosis

Cancers that have metastasized to the liver, blood clots in the hepatic or portal vein, or obstructions in the bile duct can cause changes that resemble cirrhosis.

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