Introduction
Adult bile ductopenia is a rare and severe cause of cholestatic diseases. Adult bile ductopenia (also called Idiopathic adult ductopenia) is a rare, progressive chronic liver disease whose etiology(cause) is unknown.
What Is Adult Bile Ductopenia?
It is an inflammatory bowel disease that lacks autoantibodies. It is usually seen in young adults. In most reported cases, adult bile ductopenia progresses to liver cirrhosis (a chronic disease of the liver causing inflammation, degeneration of cells, and fibrosis of the tissues in the liver) and liver failure. It is said to be associated with chronic cholestasis of the liver. The course of the condition is variable. Some follow a benign course, while others progress to biliary cirrhosis requiring a liver transplant. A maximum of a hundred cases have been reported in the literature. No specific diagnostic tests are available for the condition.
What Is Bile Duct?
A bile duct is a tube through which bile is transported to and from the liver. There are intrahepatic and extrahepatic bile ducts. A small network of tubes that transport bile within the liver is called the intrahepatic bile ducts. Extrahepatic bile ducts transport bile from the liver and gallbladder to the small intestine. Bile is made in the liver and stored in the gallbladder. Then, it is transported through the bile ducts to the small intestine to digest the fat in food.
Many diseases may obstruct the flow of bile or reduce the bile flow. Some of them include gallstones (stones in the gallbladder), cancer, infections, developmental defects like biliary atresia, and inflammation. Routine liver function tests are usually done to diagnose bile duct diseases. In addition, imaging tests like magnetic resonance imaging (MRI) and computed tomography also help diagnose the condition.
A few changes in our lives can reduce the risk of biliary obstruction. They include:
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A diet rich in fiber.
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Avoid or limit the intake of sugar and other saturated fats (sugars and saturated fats can increase the risk of developing gallstones).
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Try to maintain an ideal body weight.
What Is the History of Adult Bile Ductopenia?
Adult bile ductopenia was first described by Ludwig et al. in 1988. Since then, less than a hundred cases have been recorded in literature.
What Are the Types of Adult Bile Ductopenia?
Two distinct types of adult bile ductopenia are noticed, showing histological and prognosis variation. Type 1 adult bile ductopenia shows less than fifty percent biliary duct loss on biopsy, a more benign clinical course, and a better prognosis. Type 2 adult bile ductopenia is more widespread and progresses to decompensated biliary cirrhosis.
What Are the Causes of Adult Bile Ductopenia?
The exact etiology of adult bile ductopenia has yet to be discovered. However, several possible causes have been put forward, which include the following:
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Late-onset non-syndromic paucity of the intrahepatic bile ducts.
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Small duct PSC (primary sclerosing cholangitis) without the involvement of a large duct and no evidence of inflammatory bowel disease.
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Non-suppurative viral cholangitis (a condition where the ducts are proliferated with bile plugs).
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Hepatitis C virus.
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Autoimmune cholangitis (chronic inflammation of the liver, a variant of autoimmune hepatitis).
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Cholangitis in autoimmune hepatitis (similar to autoimmune cholangitis).
Typically, adult bile ductopenia is more common in males than females. The common ages at which the condition is diagnosed are young or middle-aged adults.
What Are the Symptoms of Adult Bile Ductopenia?
Most patients have been reported to be asymptomatic at diagnosis. Some patients exhibited symptoms of other liver diseases, like cholestatic liver disease (an abnormal condition where bile is not formed properly, or its transportation is hindered), primary biliary cirrhosis (a chronic condition in which the bile ducts are impaired), etc. Commonly presented signs include:
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Pruritus (itching of the skin).
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Jaundice (yellowish discoloration of the skin).
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Fatigue.
Approximately one-third of the patients reported repeated episodes of jaundice and pruritus, gradually worsening. In addition, liver function tests were also abnormal in most cases. Therefore, laboratory tests include liver function tests like an alkaline phosphatase test, bilirubin in the blood, GGt (gamma-glutamyl transferase) test, etc.
How Is Adult Bile Ductopenia Diagnosed?
In most cases, the laboratory findings of adult bile ductopenia were comparable to those of chronic cholestasis. Direct bilirubin levels are found to be elevated. ALP (alkaline phosphatase) and GGT (Gamma Glutamyl Transferase) levels were three times higher than the normal values.
Transaminase levels may vary from normal to a ten-fold rise in value in different patients. Antimitochondrial antibodies were absent in most cases. Viral hepatitis markers and autoantibodies were absent.
The liver would appear normal in most imaging techniques like computed tomography and magnetic resonance imaging. However, histological examination shows less than fifty percent lesser biliary ducts.
How Is Adult Bile Ductopenia Distinguished From Other Cholestatic Liver Diseases?
Primary biliary cholangitis ( a type of disease that affects the bile ducts)is ruled out using its specific serological markers(a diagnostic tool used to identify conditions or diseases based on antibodies in the serum). These antimitochondrial antibodies are absent in adult bile ductopenia. Chronic destructive cholangitis(a chronic condition of the bile duct where bile flow is impaired) can be ruled out using histological examinations. Sarcoidosis(a condition where inflammatory cells get collected in some part of the body) can be ruled out by checking for extrahepatic manifestations, which are absent in adult bile ductopenia. Further, no granulomas are seen histologically in adult bile ductopenia, which is present in sarcoidosis. Primary sclerosing cholangitis9 a condition causing impairment in the functions of the bile duct) shows the involvement of intrahepatic and extrahepatic biliary trees, while extrahepatic involvement is absent in adult bile ductopenia.
What Are the Diagnosis Options for Adult Bile Ductopenia?
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Acalculous cholecystography (a condition caused when the gallbladder fails to empty properly).
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Bile duct tumors.
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Biliary cirrhosis (a rare type of liver disease caused by defective bile ducts; it is progressive and tends to worsen if not treated).
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Biliary colic (abdominal pain caused by gallstones' obstruction in the bile duct).
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Biliary obstruction.
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Budd-Chiari syndrome (a condition where the drainage by the veins is obstructed, causing the blood to pile up in the liver, thereby enlargement).
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Cholangiocarcinoma (cancer of the bile duct).
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Gall bladder tumors.
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Viral hepatitis.
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Autoimmune cholangitis.
Conclusion
Adult bileductopenia is a rare and severe cause of cholestatic diseases. The exact cause of the condition is still unknown, and the clinical presentation varies from person to person, which makes it difficult to diagnose the condition properly. Adult bile ductopenia should also be considered a differential diagnosis in patients with chronic cholestasis.
