1. Interpretation of Liver Function Test
Dr. Wongsakorn Boonkarn Medicine

2. Liver Function Test Total / Direct bilirubin SGOT (AST), SGPT (ALT)
Alkaline phosphatase
GGT
Albumin/ Globulin

3. Hyperbilirubinemia TB ≥ 2-3 mg/dl = Jaundice
Elevated Bilirubin
Hyperbilirubinemia
TB ≥ 2-3 mg/dl = Jaundice

4. Types of Hyperbilirubinemia
Indirect Hyperbilirubinemia
( IB > 80% )
Direct Hyperbilirubinemia
( DB > 50% )

5. Heme Biliverdin Indirect bilirubin
Bilirubin Metabolism
Heme
Biliverdin
Indirect bilirubin
Indirect hyperbilirubinemia
Direct bilirubin
UDP-GT
hepatocyte
Enterohapatic
circulation
Bile duct
UDP glucuronosyltransferase
Intestine
Bacteria
Urobilinogen
urine

6. Heme Biliverdin Indirect bilirubin
Bilirubin Metabolism
Heme
Biliverdin
Indirect bilirubin
UDP-GT
Direct bilirubin
hepatocyte
Direct hyperbilirubinemia
Enterohapatic
circulation
Bile duct
Intestine
Bacteria
Urobilinogen
urine

7. Jaundice & Hyperbilirubinemia
Indirect
IB > 80%
Direct
DB > 50%
Mild jaundice
Normal urine color
(may be dark in intravascular hemolysis)
- Urine bile -ve
Mild to marked jaundice
Dark urine
- Urine bile +ve

8. Causes of Indirect Hyperbilirubinemia
RBC
Hemolytic jaundice
Liver
Inherited disorder
(Gilbert’s disease)
Congested liver (CHF)
Thyrotoxicosis

9. Causes of direct Hyperbilirubinemia
Liver
Hepatocellular jaundice
Intrahepatic cholestasis
(medical cholestasis)
Biliary tract
Obstructive jaundice
(extrahepatic cholestasis

10. Hepatocellular Jaundice
Key Features
Symptoms & sign
- Malaise, weakness, anorexia
and N-V
- Degree of jaundice varies
- Dark urine
- Normal-colored stool
LFT
- TB varies
- DB > 50% of TB
- ↑ SGOT/SGPT > 5X
- ALP < 3X
Urine
- Urine bile +ve

11. Hepatocellular Jaundice
Common Causes of
Hepatocellular Jaundice
Alcohol
Viral hepatitis
Drug & Herb

12. Hepatocellular Jaundice
Less Common Causes of
Hepatocellular Jaundice
Ischemic hepatitis
Systemic infection (DHF, typhoid, typhus)
HSV, CMV, EBV
Autoimmune hepatitis
Wilson’s disease
Acute fatty liver of pregnancy
Acute CBD obstruction
Acute Budd-Chiari syndrome

13. Acute viral Hepatitis HAV, HBV
Prodomal symptomes: flu-like, malaise, N-V before the onset of jaundice
Fever disappears after jaundice begins
AST/ALT level usually < 2000 U/L
AST < ALT
Serology
- Anti HAV igM
- HBsAg, anti HBc IgM

14. Alcoholic Hepatitis Heavy, continued drinking
Fever, jaundice, malaise, N-V
AST/ALT level usually < 300 U/L
AST > ALT (usually > 2x)
- Alcohol induces release of mitochondrial AST from cells
without visible cell damage
- Pyridoxine deficiency decreases hepatic ALT activity

15. Drug-Induced Hepatitis
Both modern drugs and herbs can cause hepatitis
Onset of exposure usually within 1 mo
( but can be to 3 mo )
Mechanisms
Direct toxic effect : Paracetamol
Idiosyncrasy : sulfa, phynytoin, CBZ, PTU, anti TB, etc
Patterns of LFT vary
Diagnosis by exclusion of other causes

16. LFT clues in Acute Hepatocellular injury
Level of aminotranferase
Predominant AST or ALT
Rate of aminotransferase declination

17. Level of Aminotransferase
Mild ALT elevation (1-2 xULN) is non-specific
and usually normal when repeated
Alcoholic hepatitis : < 300 U/L
Viral hepatitis : Rarely > 2,000 U/L
Marked ALT elevation ( > xULN)
- Ischemic hepatitis
- Acute BCS
- Drug & toxin : particularly PCM & mushroom
ALT level poorly correlated with the extent of hepatocellular injury

18. Rate of Aminotrasferase Declination
Rapid ALT declination
- Ischemic hepatitis
- Acute CBD obsteruction
- Acute BCS
Slow ALT declination
- Viral hepatitis : 10% /day or 50% /week
- Drug-induced (varies)
- Autoimmune and metabolic disease

19. Predominant AST (AST/ALT ratio > 1)
Alcoholic hepatitis
- AST/ALT ratio usually > 2
Wilson’s disease
Any hepatitis flare in cirrhosis
Ischemic hepatitis
Some drug

20. Cholestasis Jaundice Key Features
Symptoms & sign
- Jaundice
- Pruritus
- Dark urine
- Pale stool
LFT
- TB varies
- DB > 50% of TB
- ↑ SGOT/SGPT < 5X
- ALP > 3X
Urine
- Urine bile +ve

21. Causes of Elevated ALP (+ GGT)
Liver
Intrahepatic cholestasis
(medical cholestasis)
SOL
Infiltrative liver disease
Biliary tract
Obstructive jaundice
(extrahepatic cholestasis

22. Common Causes of Extrahepatic Cholestasis
Extrinsic cancer
Fixing and compressing duct
intrinsic cancer
Impacted stone
Stricture

23. Common Causes of Intrahepatic Cholestasis
Drugs (phenothiazines, estrogen, anabolic hormones, erythromycin, arsenic, ect
Sepsis
Congested liver (from RHF)
Thyrotoxicosis
Primary biliary cirrhosis
Benign post-operative cholestasis
ICU jaundice

24. Differentiate Causes of Elevated ALP
Obstructive Jaundice
IHC
ILD
SOL
Pruritus,
Pale stool
Yes (may be absent in first few weeks)
Yes or No
Rare
TB level
< mg/dl
(except in the presence of ARF or hemolysis)
Up to 50-60
mg/dl
Less prominent
Than ALP and
Occurs late
ALP
level
Almost always
Elevated
CBD stone <500
Malignancy varies
3x to > 10x
Varies, but
May be
normal
Varies from
3x to >10x US
Dilated IHD ± CBD
(esp. TB > 12 mg/dl)
Normal
Mass

25. ϒ-Glutamyl Transpepetidase (GGT)
Usefulness of GGT
Exclusion elevated ALP from bone
Elevated GGT without elevated ALP
Physiology
-- infant < 1 yr and after 60 yr
Others
-- DM, acute pancreatitis, MI
-- Alcohol
-- Drug : phenytoin, phenobarb, CBZ, rifampicin
antidepressants
-- Hyperthyroidism
-- Obesity, anorexia nervosa

26. Alumin / Globulin Albumin Hypoalumin Globulin Hyperglobulinemia
Liver synthesis
half life day
Hypoalumin
- liver disease
Malnutrition NS
Protein loosing enteropathy
Chronic disease
Globulin
WBC synthesis
inflammation
Hyperglobulinemia
Cirrhosis
Chronic infection
Auto immune liver disease MM