Liver Dysfunction

Question 1

What are the main physiological functions of the liver?

Answer 1

1. Bile secretion (digestion & waste elimination).
2. Metabolic functions (regulation of carbohydrates, lipids, proteins, vitamins, iron).
3. Detoxification & purification (ureogenesis, xenobiotic metabolism).
4. Endocrine function (IGF-1 secretion, vitamin D activation).
5. Immune function (Kupffer cells remove endotoxins, viruses, and particles).

Question 2

What are the main disorders affecting liver function?

Answer 2

• Cholestasis (bile flow obstruction).
• Hepatitis (inflammation, acute/chronic).
• Liver failure (impaired synthetic/catabolic functions).
• Liver cancer (hepatocellular carcinoma, HCC).

Question 3

What are the key enzymatic markers of liver function?

Answer 3

1. Transaminases (ALT, AST) – Indicators of hepatocellular injury.
2. Alkaline Phosphatase (ALP), Gamma-Glutamyl Transferase (GGT) – Indicators of cholestasis.
3. Lactate Dehydrogenase (LDH) – Marker of hepatocyte necrosis.
4. Coagulation factors (Prothrombin Time, Factor V) – Assess synthetic liver function.

Question 4

How do ALT (ALAT) and AST (ASAT) levels change in liver disease?

Answer 4

• ALT (ALAT) is more liver-specific → High in viral, toxic, or ischemic hepatitis.
• AST (ASAT) also found in muscle & heart → High in alcoholic hepatitis (AST > ALT ratio >2).

Question 5

What does an increase in GGT and ALP indicate?

Answer 5

• GGT elevation → Alcoholic liver disease, bile duct obstruction.
• ALP elevation → Cholestasis, bile duct disease, or bone disease.

Question 6

What is the significance of LDH in liver disease?

Answer 6

• LDH5 (Lactate Dehydrogenase 5) is liver-specific.
• Increases in LDH → Hepatocyte necrosis (e.g., viral hepatitis).

Question 7

What are the non-enzymatic markers of liver function?

Answer 7

1. Bilirubin (Total, Direct, Indirect) – Indicator of jaundice.
2. Albumin – Reflects synthetic liver function.
3. Ammonia (NH₃) – Increased in liver failure (hepatic encephalopathy).
4. Blood urea nitrogen (BUN) – Decreased in liver failure (impaired ureogenesis).
5. Cholesterol levels – Altered in liver disease (low in cirrhosis, high in cholestasis).

Question 8

What are the normal bilirubin levels in adults?

Answer 8

• Total Bilirubin (BT): 6-10 mg/L.
• Conjugated Bilirubin (BC): <2 mg/L.

Question 9

What is cytolytic hepatitis?

Answer 9

It is the destruction of hepatocytes, leading to the release of intracellular enzymes (ALT, AST, LDH).

Question 10

What are the main causes of cytolytic hepatitis?

Answer 10

• Viral Hepatitis (A, B, C, D, E).
• Autoimmune hepatitis.
• Toxic Hepatitis (drugs, alcohol, toxins).

Question 11

How do ALT & AST levels change in acute viral hepatitis?

Answer 11

• ALT & AST increase 10-100× normal levels before jaundice appears.
• ALT rises before AST.

Question 12

What are the laboratory findings in alcoholic hepatitis?

Answer 12

• AST/ALT ratio >2 (AST predominates).
• GGT is significantly elevated.

Question 13

What is liver cirrhosis?

Answer 13

A chronic, progressive liver disease characterized by fibrosis and loss of function.

Question 14

What are the types of cirrhosis and their markers?

Answer 14

• Alcoholic Cirrhosis → ↑ GGT, GLD.
• Biliary Cirrhosis → ↑ ALP, GGT, 5’-Nucleotidase.

Question 15

How does cirrhosis affect enzyme levels in later stages?

Answer 15

• Enzymes stabilize in late-stage cirrhosis despite ongoing damage.
• Coagulation factors & albumin decrease (synthetic function failure).

Question 16

What are the causes of liver failure (hepatocellular insufficiency)?

Answer 16

• Acute causes: Viral hepatitis, drug toxicity, ischemic injury.
• Chronic causes: Cirrhosis, autoimmune disease, Wilson’s disease.

Question 17

How does liver failure affect protein metabolism?

Answer 17

• ↓ Albumin → Edema, ascites.
• ↓ Ureogenesis → Hyperammonemia (hepatic encephalopathy).
• ↓ Coagulation factors → Bleeding risk.

Question 18

What are the metabolic consequences of liver failure?

Answer 18

• Hypoglycemia (impaired glycogen storage).
• Hypocholesterolemia (impaired lipid synthesis)

Question 19

What is jaundice (icterus)?

Answer 19

A condition where bilirubin accumulates in the blood, causing yellowing of skin & eyes.

Question 20

What are the three types of jaundice?

Answer 20

1. Pre-hepatic (hemolytic jaundice) → ↑ Unconjugated bilirubin (due to hemolysis).
2. Hepatic jaundice → Mixed bilirubin increase (due to liver dysfunction).
3. Post-hepatic (obstructive jaundice) → ↑ Conjugated bilirubin (due to bile duct obstruction).

Question 21

What enzymes are elevated in cholestasis (biliary obstruction)?

Answer 21

• ALP (Alkaline Phosphatase).
• GGT (Gamma-Glutamyl Transferase).
• 5’-Nucleotidase

Question 22

What is Lipoprotein X (LpX), and why is it important?

Answer 22

• Abnormal lipoprotein found in cholestasis.
• Highly specific for bile flow obstruction.

Question 23

A patient has high ALT, AST, low albumin, and prolonged PT. What is the likely diagnosis?

Answer 23

Acute liver failure (viral hepatitis, toxic injury).

Question 24

A patient with jaundice and high ALP, GGT, 5’-Nucleotidase likely has?

Answer 24

Cholestasis (biliary obstruction, liver tumor, or gallstones).

Question 25

A patient with hypoglycemia, low cholesterol, and hyperammonemia likely has?

Answer 25

Liver failure (cirrhosis, end-stage liver disease).