Hello and welcome to the zero to finals podcast. My name is Tom and in this episode I'm going to be

talking to you about primary bilory colangitis. And you can find written notes on this topic at

zero to finals.com slash primary billory colangitis or in the gastroenterology section of the second edition

of the zero definals medicine book. So let's get straight into it. Primary billory colangitis is an

autoimmune condition where the immune system attacks the small bile ducts in the liver, resulting in

obstructive jaundice and liver disease. It was previously known as primary bilary cirrhosis.

Let's talk about the pathophysiology. Primary bilary colangitis affects the small bile ducts inside the liver, the intra-hypatic ducts.

There is inflammation and damage to the epithelial cells of the bile ducts, which are the

colangiosites. These are the cells that line the inside of the ducts.

Over time, this can lead to obstruction of the flow of bile through the ducts. Reduced bile flow

is called colistasis. The back pressure of bile and the overall disease process ultimately leads to liver fibrosis

or scarring, cirrhosis and then liver failure. Normally, bile acids, bilirubin and cholesterol

are excreted through the bi bile ducts into the intestines.

When obstruction to the outflow of these chemicals means that they're not excreted,

they build up in the blood.

Raised bile acids cause itching and raised bilirubin causes jaundice.

Raised cholesterol causes cholesterol deposits in the skin, which are called xanthalasma.

Xanthomas are larger nodular deposits of cholesterol in the skin and the tendons.

Raised cholesterol increases the risk of atherosclerosis and cardiovascular disease.

Bile acids help with the digestion of fats when they're in the intestine.

Reduced or absent bile acids in the gastrointestinal tract causes abdominal symptoms,

malabsorption of fat and fat soluble vitamins, and greasy stools.

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