What are the main fibrogenic pathologies of the liver?
About 10% of the US population has some form of liver disease. There are many diseases that can cause the gradual development liver fibrosis, that in turn, may develop into cirrhosis. The most common cause of cirrhosis in in the United States is Non-Alcoholic Liver Disease (NASH). Alcoholic liver disease is the second most common cause at 36%, followed by Chronic viral hepatitis (B and C) combined causes 15% of liver disease, and other diseases including auto-immune diseases (primary biliary cirrhosis and auto-immune hepatitis), accounting for only 3% of liver disease.
Non-alcoholic steatohepatitis (NASH): is defined histologically by the combination of a buildup of fat (steatosis) and liver inflammation. It is estimated one in four Americans, or about 60 million suffer from simple fatty liver disease (Non-Alcoholic Fatty Liver Disease or NAFLD). Of these patients with NAFLD, about 10% or 6 million develop will develop NASH. It is expected that NASH will continue grow at the rate of Type 2 diabetes in the US, or at about 1.2% per year.
Alcohol: In the US, excessive alcohol consumption is a common cause of liver disease. It is estimated that 8% to 10% of Americans are at risk of Alcoholic Liver Disease (ALD), and approximately 10% to 15% of those at risk will develop alcoholic related cirrhosis over a 5 year period. Abstinence can reverse alcoholic induced liver inflammation and mild injury.
Viral Hepatitis C: This is an RNA virus transmitted primarily through blood contact While many were infected through blood transfusions, today most transmissions are secondary via intravenous drug use (needle sharing), but the origin is unidentified in 30% of cases. The Hepatitis C virus is spontaneously cured in only 10% of cases, and 90% of cases therefore develop into a chronic form. These chronic forms cause fibrosis damage. While no vaccine exists to prevent infection, therapies are available that can kill the virus.
Viral Hepatitis B: This is a DNA virus whose main contamination mode is still via blood (intravenous drug use, tattoos, piercing), as well as sexual contact and vertical transmission during birth. Transmission via blood transfusions or blood products or unsterilized medical equipment. The Hepatitis B virus is cured spontaneously in 90% of cases. In 10% of cases, Hepatitis B develops into a chronic form. These chronic forms cause fibrosis damage. Unlike Hepatitis C, there are effective vaccines available to prevent infection.
Other Causes of Chronic Liver Disease
Primary biliary cirrhosis (PBC): This is an inflammatory disease of the small intrahepatic bile ducts. It is most often found in women over 40, and its cause is unknown. The term 'cirrhosis' is inappropriate, because cirrhosis is present only in the advanced forms. The presence of anti-mitochondrial antibodies is observed in most patients.
Auto-immune hepatitis: This is an inflammatory disease of the small intrahepatic bile ducts. It is most often found in women over 40, and its cause is unknown. The term 'cirrhosis' is inappropriate, because cirrhosis is present only in the advanced forms. The presence of anti-mitochondrial antibodies is observed in most patients. Auto-immune hepatitis: This is an inflammatory disease of the liver, which can occur at any age, characterized by elevated liver enzymes and gammaglobulin levels (immunoglobulin G) as well as the presence of autoantibodies (antinuclear antibodies, anti-smooth muscle antibodies, anti-LKM antibodies). It more often affects women.
Genetic haemochromatosis: This is a genetic condition caused by deficient regulation of the intestinal absorption of iron. Iron accumulates in the tissues, and particularly in the liver, causing fibrosis and then cirrhosis. This disease is ten times more common in men than women (because of the loss of iron during menstruation), and is recognized in the 40-60 age range. The treatment for haemochromatosis involves performing repeated bleeding to reduce the iron deposits in tissues.
Wilson's disease: This is a genetic disease caused by the accumulation of copper in the liver. The cornea and the central nervous system can also be affected. This is unusual.
Alcohol consumption can increase the risk of progression to fibrosis and cirrhosis in patients with chronic liver disease. Talk to your doctor if you have a chronic liver disease.