The document discusses liver function tests. It outlines the various functions of the liver including metabolic, synthetic, secretory, excretory, storage, detoxification and haemopoietic functions. It then describes different types of liver function tests that can indicate hepatocellular damage, biliary obstruction, synthetic function, excretory function, metabolic function and detoxification function. Normal ranges are provided for various enzymes and proteins. Causes and biochemical differences between pre-hepatic, hepatic and post-hepatic jaundice are also summarized.

1. Liver function test
Dr. Mohammad Shiblee Zaman
Lecturer (Biochemistry)
Dhaka Medical College

2. Functions of liver
1. Metabolic function
2. Synthetic function – synthesis of plasma
proteins, clotting factors, lipoproteins, primary
bile acids etc.
3. Secretory function – secretion of bile
4. Excretory function – excretion of bile pigments,
bile salts, drugs, steroid, heavy metals etc.

3. Functions of liver
5. Storage function – storage of glycogen, fat
soluble vitamins, vitamin B12, folic acid, iron
etc.
6. Detoxification function
7. In embryonic life, haemopoietic function

4. Liver function tests
Indications:
• Diagnosis of liver disease
• Assessment of severity of liver disease
• Assessment of prognosis of liver disease
• Treatment monitoring
• Differential diagnosis of jaundice

5. A. Test to detect hepatocellular damage
• Alanine aminotransferase (ALT)/Serum glutamate
pyruvate transaminase (SGPT) – in hepatic cytosol
• Aspartate aminotransferase (AST)/Serum
glutamate oxaloacetate transaminase (SGOT) – in
hepatic mitochondria & cytosol
• Gamma glutamyl transferase (GGT) – in cytoplasm
of hepatocyte & epithelial lining of bile duct

6. B. Test to detect biliary obstruction or cholestasis
• Alkaline phosphatase (ALP)
– in membrane of bile
canaliculi & hepatic sinusoid
• GGT
• 5′–nucleosidase

7. Normal values in plasma/serum
Enzyme Reference range
SGPT 5 – 40 IU/L
SGOT 10 – 40 IU/L
ALP 25 – 85 IU/L
GGT Male: 10 – 55 IU/L
Female: 5 – 35 IU/L

8. C. Test to assess synthetic function
• Serum total protein (STP)
• Serum albumin
• Serum albumin to globulin
ratio (A:G ratio)
• Prothrombin time (PT)

9. Normal values in plasma/serum
Markers Reference range
STP 6 – 8 gm/dL
S albumin 3.5 – 5 gm/dL
S globulin 1.8 – 3.6 gm/dL
A:G ratio 25 – 85 IU/L
PT 12 – 14 sec

10. PT is more sensitive and early
marker........
Prothrombin time
Proteins Half life
Albumin 20 days
Prothrombin Hrs to days
Serum albumin

11. D. Test to assess excretory or conjugating function
• Serum bilirubin (total, direct and indirect)
– Direct or conjugated bilirubin increases in
obstructive jaundice and
– Indirect or unconjugated bilirubin increases in
hemolytic jaundice

12. Normal values in plasma/serum
Bilirubin variants Reference range
Total bilirubin 0.2 – 1.0 mg%
Direct bilirubin 0.1 – 0.2 mg%
Indirect bilirubin 0.2 – 0.7 mg%

13. E. Test to assess metabolic function
• Galactose tolerance test – Orally administered
galactose is supposed to convert into glucose in
liver. In liver disease, failure of conversion leads
to increase blood galactose, thereby leads to
galactosuria.

14. F. Test to assess detoxification function
• Hippuric acid test – liver is supposed to
remove orally or intravenously administered
sodium benzoate from blood by conjugating with
glycine, in the form of urinary hippuric acid.
Decrease urinary excretion suggest liver
disease.

15. G. Special tests
• Antibody detection test
Antimitochondrial Ab...1⁰ biliary cirrhosis
Antinuclear Ab...in chronic active hepatits
• Antigen detection test
HBsAg...in hepatitis B infection
• α1–antitrypsin (AAT)...in juvenile liver cirrhosis
• Ceruloplasmin...in Wilson’s disease
• α–fetoprotein (AFP)...in hepatocellular carcinoma

16. JAUNDICE
↑ bilirubin >3mg% in body fluid (clinical jaundice)
Yellow coloration of skin, sclera & mucous membrane
Latent jaundice: Bilirubin concentration 1-3mg%

17. Fig: Bilirubin metabolism

18. Biochemical differences among jaundice
Biochemical test Pre-hepatic
(Hemolytic)
Hepatic
(Hepatocellular)
Post-hepatic
(Obstructive)
S Bilirubin ↑ unconjugated
(3-5mg%)
↑↑ Both
(<20mg%)
↑↑↑ conjugated
(<50mg%)
VD (van den)
Bergh reaction
Indirect Biphasic Direct
Urinary
urobilinogen
↑↑ Normal or ↓ Absent
Urinary Bilirubin Not present Present (+) Present (++)

19. Biochemical differences among jaundice
Biochemical test Pre-hepatic
(Hemolytic)
Hepatic
(Hepatocellular)
Post-hepatic
(Obstructive)
Bile salts in urine Not present Not present Present
Faecal
stercobilnogen
↑ (++) ↓ Absent
Faeces colour Dark brown Varies (pale yellow) Clay coloured
Prothrombin time Normal Prolonged; does not
return to normal after
administration of
vitamin K
Prolonged; returns
to normal after
administration of
vitamin K

20. Biochemical differences among jaundice
Biochemical test Pre-hepatic
(Hemolytic)
Hepatic
(Hepatocellular)
Post-hepatic
(Obstructive)
SGPT Normal ↑ (++++) ↑ (+ to ++)
Serum ALP Normal ↑ (+) ↑ (++ to +++)
Serum 5-nucleotidase Normal ↑ (+) ↑ (++ to +++)
Serum GGT Normal ↑ (+) ↑ (++ to +++)
Serum total
cholesterol
Normal ↓ ↑

21. • Viral hepatitis
• Toxic hepatitis
• Autoimmune hepatitis
• Metastatic liver disease
• Hepatocellular carcinoma
• Wilson’s disease &
• Haemochromatosis
Causes of hepatocellular jaundice

22. Causes of obstructive jaundice
Intrahepatic cause
• Primary biliary atresia
• Primary sclerosing cholangitis
• Alcohol & drugs
• Viral/autoimmune hepatitis
• Cystic fibrosis
• Severe bacterial infection
• Hodgkin’s lymphoma
• Pregnancy
Extrahepatic cause
• Choledocholithiasis
• Ca pancreas
• Ca bile duct
• Traumatic biliary stricture
• Parasitic biliary obstruction

23. Hyperbilirubinemia in new born
A. Early within 10days
• Within 1st 2 days – hemolytic disease of
newborn, Rh incompatibility
• Within 3-10days – physiological, prematurity,
hypoglycaemia, acidosis, sepsis etc.

24. Hyperbilirubinemia in new born
B. Prolonged i.e. more than 10days
• Unconjugated – hemolytic anemia,
hypothyroidism, sepsis, Gilbert’s syndrome,
Crigler-Najjar syndrome
• Conjugated – hepatitis, biliary atresia, α1 -
antitrypsin deficiency, cystic fibrosis, Dubin-
Johnson syndrome, Rotor syndrome

25. Physiological jaundice
• Neonatal jaundice
• Appears usually 3rd day onwards
• Results from accelerated destruction of RBC
with aim to replacing HbF with HbA along with
reduced clearance due to hepatic immaturity
• Exposure to sunlight or phototherapy causes
isomerisation of bilirubin to lumirubin, thus
facilitate urinary excretion

26. Kernicterus
Deposition of unconjugated bilirubin in basal
ganglia in infants & neonates due to immaturity
of BBB

27. Thank you.