Diseases of the Biliary Tract and Liver

Question 1

What are the common causes of liver cirrhosis in the UK?

Answer 1

The common causes of liver cirrhosis in the UK include alcohol abuse, obesity, and hepatitis B and C infections.

Question 2

What are some acute causes of liver cirrhosis?

Answer 2

Acute causes of liver cirrhosis include drug-induced liver injury (e.g., paracetamol, penicillins), alcohol consumption, viral infections (such as Hepatitis A, B, E, CMV, EBV, and COVID-19), vascular disorders (hepatic vein thrombosis, Budd-Chiari syndrome), ischaemic liver disease, and Wilson’s disease.

Question 3

What are some chronic causes of liver cirrhosis?

Answer 3

Chronic causes of liver cirrhosis include alcohol abuse, fatty liver disease, autoimmune diseases (such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis), viral infections (Hepatitis B, C), and inherited conditions like haemochromatosis or Wilson’s disease and A1AT deficiency.

Question 4

What is liver failure characterized by?

Answer 4

Liver failure is characterized by jaundice (failure to clear bilirubin), coagulopathy (raised INR due to failure to produce clotting factors), hypoalbuminemia (failure to produce protein), encephalopathy (failure to eliminate toxins like ammonia), and ascites.

Question 5

What is ascites?

Answer 5

Ascites is the accumulation of fluid in the peritoneal cavity, resulting from leakage of fluid out of the portal blood vessels.

Question 6

What is portal hypertension?

Answer 6

Portal hypertension is an increase in blood pressure within the portal vein system. It can lead to complications such as hepatorenal failure, a progressive cause of kidney failure due to constriction of renal vessels.

Question 7

What are varices?

Answer 7

Varices are abnormal dilated blood vessels that can develop in the esophagus or stomach.

Question 8

What are the common presentations of varices?

Answer 8

Varices can present with symptoms such as haematemesis (vomiting of blood) or melaena (passing of altered blood in the stool).

Question 9

What is the underlying cause of varices?

Answer 9

Varices are secondary to portal hypertension, which leads to the formation of venous collaterals in the esophagus or stomach.

Question 10

How are varices treated?

Answer 10

Varices are typically treated with endoscopic banding, where bands are placed around the varices to prevent bleeding. Additionally, beta blockers may be prescribed to reduce portal hypertension. If these measures fail, interventions such as TIPSS (Trans Intrahepatic Portosystemic Shunt) or surgery (venous shunts) may be considered.

Question 11

How is bilirubin metabolized in the body?

Answer 11

Unconjugated bilirubin is formed from the breakdown of heme in red blood cells. It is then transported to the liver bound to albumin and undergoes conjugation by UDP glucuronyltransferase to form bilirubin glucuronide. This conjugated bilirubin is excreted via the bile ducts to the bowel, where it can be converted by bacteria and excreted in feces as stercobilin or reabsorbed back into the blood and excreted in urine as urobilin.

Question 12

What are the causes of jaundice?

Answer 12

The causes of jaundice can be categorized as prehepatic (raised unconjugated bilirubin), intrahepatic (the liver itself not clearing bile), or posthepatic.

Question 13

What are the causes of intrahepatic jaundice?

Answer 13

Intrahepatic jaundice can be hepatocellular or cholestatic. Hepatocellular jaundice is characterized by inflammation of hepatocytes and elevated transaminases (ALT/AST). Causes can include viral hepatitis, fatty liver disease, alcohol-related liver disease, drug-induced liver injury, ischemia, and inherited conditions. Cholestatic jaundice is characterized by inflammation of cholangiocytes and elevated alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT). Causes can include primary biliary cirrhosis, primary sclerosing cholangitis, drug-induced cholestasis, and conditions like sarcoidosis.

Question 14

What are the liver histology basics?

Answer 14

Liver histology basics refer to the study of liver tissue under a microscope to examine its cellular structure and identify any pathological changes. This can provide insights into the cause and severity of liver diseases.

Question 15

What is post-hepatic jaundice, also known as obstructive jaundice?

Answer 15

Post-hepatic jaundice, or obstructive jaundice, occurs when there is an obstruction in the bile ducts, preventing the normal flow of bile from the liver to the intestine.

Question 16

What are some causes of post-hepatic jaundice?

Answer 16

Causes of post-hepatic jaundice include gallstones, strictures (e.g., primary sclerosing cholangitis), worms, pancreatic cancer, gallbladder cancer, and cholangiocarcinomas.

Question 17

What is primary sclerosing cholangitis (PSC)?

Answer 17

Primary sclerosing cholangitis is a condition characterized by inflammation and scarring of the bile ducts, leading to cholestasis and obstruction. It is often associated with ulcerative colitis, with approximately 80% of PSC patients having ulcerative colitis, and about 5% of ulcerative colitis patients having PSC.

Question 18

What are the liver function tests (LFTs) used to assess liver function?

Answer 18

The commonly measured liver function tests include alanine transaminase (ALT) and aspartate transaminase (AST), which reflect hepatocyte function, and alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT), which reflect cholangiocyte function.

Question 19

How are abnormal liver function tests (LFTs) patterns classified?

Answer 19

Abnormal LFT patterns can be classified as hepatocellular (or hepatitis) or cholestatic. In hepatocellular pattern, ALT/AST levels are elevated compared to ALP/GGT. In cholestatic pattern, ALP/GGT levels are elevated compared to ALT/AST.

Question 20

What are some possible causes of elevated ALT (1500 IU/L)?

Answer 20

An elevated ALT level of 1500 IU/L suggests possible viral infection, drug-induced liver injury, or liver ischemia.

Question 21

What could be the cause of an isolated raised ALP (normal GGT and transaminases)?

Answer 21

An isolated raised ALP with normal GGT and transaminases may suggest a bone-related cause. Further investigations such as checking ALP isoenzymes, bone profile, and vitamin D levels or considering pregnancy may be necessary.

Question 22

What could be the cause of elevated AST (300 IU/L) and ALT (200 IU/L) levels with normal ALP?

Answer 22

Elevated AST and ALT levels with normal ALP may suggest alcohol-related liver injury.

Question 23

What conditions should be considered in the case of isolated raised bilirubin?

Answer 23

In the case of isolated raised bilirubin, conditions such as Gilbert’s syndrome or hemolysis should be considered.

Question 24

What is the significance of abnormal liver function tests (LFTs) in the general population?

Answer 24

Approximately one-third of the population may have at least one abnormal LFT, but only 4% of them have significant liver disease. Early detection of liver disease is important as 50% of patients with significant liver disease are not detected early enough.

Question 25

What does a full liver screen typically involve?

Answer 25

A full liver screen may include serology for hepatitis A, B, C, and E viruses, autoimmune markers such as antimitochondrial antibodies (for primary biliary cirrhosis) and anti-smooth muscle antibodies (for autoimmune hepatitis), immunoglobulin levels, copper studies (for Wilson’s disease), alpha 1 antitrypsin levels (for A1 AT deficiency), ferritin levels (for hemochromatosis), and an ultrasound of the liver.

Question 26

When should a patient be referred to a specialist regarding abnormal liver function tests?

Answer 26

Referral to a specialist may be warranted based on the magnitude of the rise (>2x ULN), rate of change over time, abnormal liver screen, elevated FIB-4 score with a risk of significant fibrosis, suggestions of liver failure (raised bilirubin, raised INR, low albumin), or if the patient clinically has ascites.