contains liver function test overall description in clinical scenario.Contains adequate information on anatomy of liver,functions, classifications of LFT , indications,bilirubin metabolism,Van den berg reaction,liver enzyme panel,special tests. #LFT

1. LIVER FUNCTION TEST
Sujata jha
Bsc nursing

2. Outline
• Anatomy
• Biochemical Functions
• Classification of LFT
• Bilirubin metabolism
• Van den Bergh’s reaction
• Clinical significance

3. Clinical Case study
• Comment on the following laboratory results obtained in a patient
and give your probable diagnosis.
• Serum bilirubin – 9.0 mg/dl
• Conjugated bilirubin – 7.5 mg/dl
• Unconjugated bilirubin – 1.5 mg/dl
• SGOT – 80 U/L
• SGPT – 90 U/L
• ALP – 140 KA Units
• Urine bile salts – positive(++), Bile pigments – positive(++),
Urobilinogen – negative , feces stercobilinogen – negative.

4. Anatomy
 Largest parenchymal organ
 Essential and has central role in metabolisms
 Weight- 1-1.5Kg, Wedge shaped
 Location - Right upper quadrant below
diaphragm extending upto left upper
quadrant.
 Blood supply - 20%-hepatic artery and 80%
portal vein.
 Nerve supply - Vagus and phrenic nerve

5. Biochemical Functions
• Excretory function
I. Substances detoxified by liver are excreted through bile.
II. Daily 1 Liter bile excreted
III. Bile contains bile salts, bilirubin, phospholipids, cholesterol .
IV. Bile facilitates digestion & absorption of lipid and fat soluble vitamins.

6. Synthetic function
– plasma proteins
– carrier proteins
– hormonal factors
– growth factors
– bile acids, cholesterol and phospholipids.

7. Metabolic function
• Carbohydrate metabolism:
– Glycolysis , TCA , ETC to yield energy if the cells are in need of ATP.
If not, glucose can be stored as glycogen & TG.
• Protein catabolism :
- Dietary proteins → amino acids → proteins of different kinds.
• Lipid metabolism:
Fatty acids →Acetyl CoA
TCA ETC fatty acid cholesterol ketone body

8. Detoxification Function:
• Exogenous toxins Endogenous substances
Enter from - ammonia , bilirubin
Gut & parenteral route
detoxified by Urea conjugated bilirubin
Hydrolysis, hydroxylation, oxidation,
Carboxylation, reduction, demethylation &
conjugation
water soluble products → urine

9. Classification of liver function tests
• Tests of hepatic excretory function.
 Serum– Bilirubin, total, conjugated and Unconjugated
 Urine – bile pigments, bile salts and urobilinogen
• Liver enzyme panel
 Alanine transaminase (ALT)
 Aspartate transaminase(AST)
 Alkaline phosphatase(ALP)
 Gamma glutamyl transpeptidase (GGT)
 5’-Nucleotidase

10. Contd……
• Tests for synthetic function of liver.
I. Total proteins
II. Serum albumin, globulins, A/G ratio
III. Prothrombin time
• Special tests
I. Ceruloplasmin
II. α1 antitrypsin
III. α fetoprotein
IV. Haptoglobin
• Test for detoxification function of liver - Hippuric acid test

11. Indications for liver function tests
– Jaundice
– Suspected liver metastasis
– Alcoholic liver disease
– Any undiagnosed chronic illness
– Annual checkup of diabetic patients
– Coagulation disorders
– Therapy with statins to checks hepatotoxicity

12. Tests of hepatic excretory function.
• Serum–Total bilirubin, conjugated and Unconjugated bilirubin
• Urine – bile pigments, bile salts and urobilinogen.

13. Bilirubin metabolism

15. Van den Bergh reaction
• Diazotized sulfanilic acid reacts with bilirubin to form Azobilirubin (purple
colored complex).
• For conjugated bilirubin, purple color produce immediately. Said to be V.D.B
direct positive.
• If both conjugated & Unconjugated bilirubin are present then purple color
produce immediately and the color intensified on adding methanol. The
reaction is called biphasic.

16. Urinary Bilirubin
• Only conjugated bilirubin - soluble in water
• Acholuric jaundice.
• In obstructive jaundice – Regurgitation of conjugated bilirubin back
into the blood.
• Choluric jaundice

17. Urinary urobilinogen
• In cases of obstruction – urobilinogen decreased or absent in urine.
• In hepatic jaundice – Normal or decreased
• In hemolytic anemia – urobilinogen increased
• Reappearance of urobilinogen in urine is first indication of recovery
of obstruction.
• Urobilinogen is detected by Ehrlich’s test.

18. Urine bile salts
• Normally (sodium salts of taurocholic acid & Glycocholic acid) are
present in bile, but not in urine.
• Present in obstruction of biliary passages cause regurgitation in blood
& excretion in urine.
• Absent in hepatic & pre-hepatic jaundice .
• Detected by Hay’s test.

19. Liver enzyme panel
 Alanine amino transaminase (ALT)
 Aspartate amino transaminase(AST)
 Alkaline phosphatase(ALP)
 Gamma glutamyl transpeptidase (GGT)
 5’-Nucleotidase

20. Alanine amino transferase (ALT)/ SGPT
• Normal serum level = < 45 U/L
• High value (300-1000 U/L) in acute hepatitis (viral or toxin).
• Both ALT & AST increase in liver disease, but ALT > AST.
• ALT is specific for liver but AST widely present in myocardium ,
skeletal muscle , brain , kidney.
• In obstructive jaundice ↑ to 200 – 300 U/L.
• In hemolytic - normal

21. Aspartate amino transferage(AST)/SGOT
• Normal level = < 35 U/L
• Elevated in MI.
• Marked ↑ AST seen in primary hepatoma.
• In alcoholic hepatitis AST may more than ALT values elevates mild but
AST/ALT ratio more than two.
• Normal in hemolytic jaundice.
• Normal value need not rule out minor liver disease.

22. Clinical significance of AST/ALT ratio
• Normal AST : ALT ratio is 0.8.
• A ratio >2 is seen in
– Alcoholic hepatitis
– Hepatitis with cirrhosis
– Liver metastasis
– MI
– Erythromycin treatment
• A low ratio ( ALT higher) is seen in
– Acute hepatocellular injury
– Toxic exposure
– Extrahepatic obstruction

23. Alkaline phosphatase (ALP)
• Produced by liver, bone, intestine, placenta
• Excreted in bile
• Serum level 40 -125 U/L
• Mild ↑ in parenchymal diseases.
• Moderate (2-3 times) ↑ in hepatic disease.
• Very high (10 – 12 times) ↑ in obstructive jaundice.
• Drastically high (10 – 25 times) in bone disease.
• normal in hemolytic jaundice.

24. Gamma glutamyl transferase (GGT)
• Sensitive to detect alcohol abuse.
• GGT level is parallel to alcohol intake in alcoholic.
• Elevated GGT seen in chronic alcoholism, pancreatic disease, MI,
Renal failure , COPD & DM.

25. 5’-Nucleotidase
• Serum level increase in hepatobiliary disease
• Closely parallel to ALP.
• Specific for obstructive liver disease.

26. Algorithm for diagnosis of liver diseases
Abnormal liver enzyme profile
ALT or AST >3 Times &
ALP <2 times
Hepatocellular disease
Albumin normal
Acute hepatitis
Albumin low
Chronic hepatitis
ALT or AST < 3 times &
ALP > 2 times
Cholestatic disease
Albumin normal
Acute cholestasis
High GGT
Intrahepatic
cholestasis
Mild increase in GGT
Extrahepatic
cholestasis
Albumin low
Chronic
cholestasis

27. Tests based on synthetic function
• All plasma proteins (except Ỳ-globins) and clotting factors
synthesized in liver.
• In all chronic diseases albumin level decreased
• A/G ratio reverse in cirrhosis.
• Serum albumin = 3.5 – 5.5 gm/dl
• Serum globulin = 2.5 – 3.5 gm/dl
• A/G ratio = 1.2:1 – 2.5:1

28. Prothrombin time
• Clotting factors I, II, V, VII, IX & X synthesized in liver.
• Vit k is essential for II , VII , IX & X.
• if any one factor deficient , prolonged PT.
• Prolonged PT indicates 80% hepatocytes damage.
• Vit k cause also PT prolonged,
• After vit k administration PT remains prolonged indicates liver
damage.

29. Special tests
Alpha fetoprotein:
• Normal in fetal blood, disappear after birth
• It is tumor marker
• Mild elevation suggest chronic hepatitis or cirrhosis
• Drastic increase in hepatocellular carcinoma & germ cell tumors.
• Elevated AFP in maternal serum indicates open neural tube defects,
multiple fetuses & fetal death.
• Low maternal serum AFP indicates fetal down syndrome.

30. Ceruloplasmin(cp)
• Mainly synthesized in liver & small part by lymphocytes.
• Cp increased in active hepatitis, biliary cirrhosis, hemochromatosis
and obstructive biliary disease.
• Decrease in Wilson’s hepatolenticular degeneration

31. Alpha antitrypsin (AAT)
• Glycoprotein , mol wt. 50 KD.
• Synthesized & secreted by liver.
• Also called Alpha-anti protease inhibitor.
• Has multiple alleles.
• Individuals possessing PiZZ allele is prone for develop liver cirrhosis.
• Normal serum level = 75 – 200 mg/dl
• AAT deficiency cause Emphysema.

32. Haptoglobin
• Synthesized in liver.
• It bound with Hb in plasma and transport to RE system.
• Normal level = 30 – 200 mg/dl
• Serum level ↓ in hepatocellular liver disease. (deficient synthesis)
and hemolytic disease ( ↑ degradation rate).
• ↑ in inflammatory processes, trauma, infection & MI.
• Early marker.

33. Test for detoxification function of liver
• Hippuric acid test:
– After light breakfast (usually 2 hrs later) & after emptying bladder.
– About 6 g of Na benzoate + 250 ml water is orally given
– Urine collected in next 4 hrs & amount of Hippuric acid excreted is
estimated.
– Theoretically, 6 g of Na benzoate should yield 7.5 g Hippuric acid .
– In normal person, 4.5 g (i.e 60%) is excreted in urine.
– Decrease hippuric acid excretion (<3g) indicate hepatic damage.

34. Clinical significance
Jaundice
• Yellowish discoloration of sclera, skin, mucus membrane.
• It characteristic of liver diseases.
• Hemolytic jaundice;
– Increase unconjugated bilirubin
– Absence of bilirubinuria
– Excessive excretion of UBG in urine & SBG in feces.

35. Hepatocellular jaundice
– Both bilirubin increase
– UBG in urine may normal or decrease
Causes of Hepatocellular damage
– Viruses
– Alcohol
– Toxins
– Immunological
– Bacterial infections
– Parasites
– drugs

36. Obstructive jaundice
– Conjugated bilirubin increased in serum
– UBG will decrease or absent in urine
– Clay colored stool
• Causes of cholestasis
Intrahepatic cholestasis
– Alcoholic cirrhosis
– Chronic active hepatitis
– Biliary cirrhosis
– Primary hepatoma

37. Extra hepatic obstruction
– Gall stone
– Carcinoma head of pancreas
– Enlarged lymph glands in porta hepatis
– Biliary stricture
– Parasites(liver flukes)

38. Distinguish different type of jaundice
Condition S. bil.
conjugated
S. bil.
unconj
ugated
Urine
urobilinogen
Urine
bilirubin
Faecal
urobilin
ogen
ALT AST ALP
Normal 0.1–0.4
mg/dl
0.2-0.7
mg/dl
0.4 mg/24 h Absent 40-280
mg/24h
<45
IU/L
<35
IU/L
40-1 25
IU/L
Haemolytic
jaundice
N ↑ ↑ Absent ↑ N N N
Hepatic
jaundice
↑ ↑ ↓if micro
obstruction
to bile
ductules
Present if
micro
obstruction
to bile
ductules
↓ ↑↑ ↑↑ N or
mild
↑
Obstructive
jaundice
Increased Normal Absent present Trace to
absent
mild
↑
Mild
↑
↑↑

39. Crigler – Najjar syndrome
• Congenital non hemolytic jaundice
• Defect in conjugation.
• Deficiency of UDP glucuronyl transferase due to gene encoding this
enzyme in chromosome no. 2 is defective.
• Unconjugated bilirubin level increases > 20 mg/dl hence kernicterus
results.
• Children die before 2 years.

40. Gilbert’s Disease
• Inherited an autosomal dominant trait.
• Defective uptake of bilirubin by liver
• Bilirubin level – 3mg/dl
• Asymptomatic

41. Dubin – Johnson syndrome
• Autosomal recessive disorder , leading to defective excretion of
conjugated bilirubin;
• due to mutation in MRP-2 protein which is responsible for transport
of conjugated bilirubin.
• Conjugated bilirubin increase in blood.
• Bilirubin get deposited in liver so liver appears black called Black liver
jaundice.

42. Clinical Case study
• Comment on the following laboratory results obtained in a patient
and give your probable diagnosis.
• Serum bilirubin – 9.0 mg/dl
• Conjugated bilirubin – 7.5 mg/dl
• Unconjugated bilirubin – 1.5 mg/dl
• SGOT – 80 U/L
• SGPT – 90 U/L
• ALP – 140 KA Units
• Urine bile salts – positive(++), Bile pigments – positive(++),
Urobilinogen – negative , feces stercobilinogen – negative.

43. Answer
• Obstructive jaundice

44. THANK YOU