DSA: Liver enzymes

Question 1

Liver function tests (LFTs), a misnomer, include what tests?

Answer 1

1. AST/ALT (transaminases)
   
   1. aspartate aminotransferase (AST)
   2. Alanine aminotransferase (ALT
2. ALP (alkaline phosphatase)
3. Bilirubin
4. LDH and GGT

Question 2

TRUE liver function tests include:

Answer 2

1. PT/INR (tests coag factors)
2. Albumin
3. Cholesterol
4. Ammonia

Question 3

• In hepatocellular injury => _______ in _________ enzymes
  
  • ____ is MORE specific for liver injury

Answer 3

1. ↑ AST/ALT
   
   1. ALT is MORE specific for liver injury

Question 4

In cholestatic injury (injury to bile ducts) => _______ in _________ enzymes

Answer 4

• ↑ ALP and bilirubin

Question 5

In __________, bile cannot reach duodenum.

Answer 5

Cholestatic injury

Question 6

Signs of cholestatic injury

Answer 6

1. Jaundice
2. Pruritis (very itchy)
3. Pure cholestasis (no signs of hepatocellular necrosis)

Question 7

On labs, if we see ↑ ALP, indicates problems with _________ or _______.

How do we differentiate?

Answer 7

• Bone or liver (cholestasis)
• To differentiate, measure GGT
  
  • NL GGT = bone
  • ↑ GGT = liver (cholestatic)

Question 8

↑ ALP in NL in _____________.

Answer 8

Childhood, as we are growing and pregnancy

Question 9

When is ↑ INR problematic?

Answer 9

If a patient is NOT on coumadin/warfarin, then they can have liver disease.

Question 10

________ is the best test to measure acute hepatic functioning (acute liver failure).

Answer 10

INR

Question 11

INR measures what?

Answer 11

Deficiency of all cloting factors except factor 8 => liver disease, hepatitis, toxic injury, cirrohosis.

Question 12

PT prolongation due to fat malasbsoprtion can be distinguished from liver disease by _____________.

Answer 12

Rapid and complete response to vitamin K.

Question 13

Albumin tests the ________ of the liver.

↓ serum albumin often occurs due to?

Answer 13

• Function of the liver (degree of hypoalbuminia = severity of liver dysfunction)
• ↓ in patients with chronic liver disease

Question 14

Ammonia tests the ________ of the liver.

↑ blood ammonia often occurs due to?

Answer 14

• Function of the liver
• Hepatic detoxification is not working or acute encephalopthy

Question 15

↑ indirect-reacting bilirubin, with all other enzymes NL) can be due to __________________.

Answer 15

1. Hemolysis (↑ = more than 90% of total bilirubin)
2. Gilbert’s syndrome (↑ = more than 90% of total bilirubin)

Question 16

Associated features with hemolysis (↑ isolated indirect-acting bilrubin)

Answer 16

• Anemia
• ↑ reticulocyte count
• NL enzyme levels (LDH may be ↑)

Question 17

Associated features with Gilberts (↑ isolated indirect-acting bilrubin)

Answer 17

• Benign course that beings in late adolescence that occurs during fasting
• No abnormal liver tests
• No anemia

Question 18

Many types of liver disease will have ↑ ___________.

Answer 18

Direct-reacting bilirubin

Question 19

Non-hepatic reasons for ↑ bilirubin

Answer 19

• RBC (hemolysis, intra-abdominal bleeding, hematoma)

Question 20

Non-hepatic reasons for ↑ AST

Answer 20

• Skeletal muscle
• Cardiac muscle
• RBC

Question 21

Non-hepatic reasons for ↑ ALT

Answer 21

• Skeletal muscle
• Cardiac muscle
• Kidneys

Question 22

Non-hepatic reasons for ↑ LDH

Answer 22

• Heart
• RBC (hemolysis)

Question 23

Acute (<6 months) abnormal liver ezymes tests that indicate hepatic injury => check for?

Answer 23

• 1. IgM Anti-HAV, [HBsAg & IgM Anti- Hbc], Anti-HCV => Hep A, B, C
• 2. SMA => autoimmune hepatitis
• 3. Mono heterphile => Mono
• 4. Ceruloplasm => Wilsons disease
• 5. Alcohol history => alcoholic hepatitis
• 6. Drug history

Question 24

Small elevation of AST/ALT => mostly due to _______

Answer 24

nonalcoholic fatty liver disease

Question 25

**Acute (\< 6 months)** abnormal liver ezymes tests that indicate **cholestatic injury** =\> check for?

Answer 25

1. AMA =\> primary biliary cirrhosis 2. Drug history 3. US/MRI =\> structural problems, hepatic vein thrombosis 4. MRCP/ECRP

Question 26

**Chronic (\> 6 months)** abnormal liver ezymes tests that indicate **hepatitic injury** =\> check for?

Answer 26

1. HbsAg and Anti-HCV =\> Hep B and C 2. Fe saturation, ferritan 3. Ceruloplasm 4. a-AT1 5. ANA, SMA =\> AI hepatitis 6. US 7. Alcohol history

Question 27

**Chronic (\> 6 months)** abnormal liver ezymes tests that indicate **cholestatic injury** =\> check for?

Answer 27

1. **Meds** 2. **AMA** 3. **p-ACNA** 4. **US** 5. **MRCP/ERCP**