This document discusses liver function tests and how to evaluate liver disease patterns. It outlines the clinical presentation of hepatocellular and cholestatic liver disease. Key investigations covered include liver enzymes, bilirubin, albumin, clotting factors and their significance. Imaging modalities like ultrasound, CT and MRI are described for assessing liver abnormalities. The patterns of hepatocellular versus obstructive liver disease are contrasted based on symptoms, enzyme levels and imaging findings.

1. LFT
Liver function tests

2. Liver disease patterns
Hepatocellular
or
Cholestatic

3. Clinical
 History-
 RUQ pain- persistent dull ache or colicky
 Jaundice, anorexia, fever, pruritis, easy bruisability
 Color of stool & urine
 Personal & family history
 Examination-
 Pallor, jaundice, purpura
 Signs of CLD
 Liver, gall bladder, spleen, ascitis

4. Investigations-Ix-1
Bilirubin- a product of Hb metabolism
Indirect- lipid soluble
Direct- water soluble

5. Ix-2
 Aminotransferases- hepatocellular damage
 ALT/SGPT- found mainly in liver, more specific
 AST/SGOT- found in liver/muscle/heart/kidney; less specific
 Usually parallel rise/fall, exception being alcoholic
liver disease where AST >> ALT due to deficiency of
cofactor pyridoxine-5- phosphate
 Serial measurements more important
 Persistent elevation needs evaluation

6. Ix-3
 Alkaline phosphatase-
 Present in liver, bone, intestine, placenta
 In liver, mainly in biliary tract epithelium
 Marker of cholestasis/obstruction of biliary tract
 5’ nucleotidase-
 To confirm liver origin of alkaline phosphatase
 γ-glutamyl transpeptidase-
 Most sensitive indicator of biliary tract disease
 A marker of alcoholism

7. Ix-4
 Albumin-
 Half-life ~2-3 weeks
 Good marker of CLD
 Levels influenced by nutritional status, GI/renal loss,
redistribution in acute illness
 Clotting factors-
 Liver synthesizes factors I, II, V, VII, IX, X
 Need vitamin K- II, VII, IX, X
 Clotting impaired in acute or CLD
 Measured by elevated PT/INR
 Elevation a poor prognostic marker in liver disease

8. Ix-5
Ammonia- a product of urea cycle
Levels suggest hepatocellular function
Marker for hepatic encephalopathy

9. Ix-6
 Other-
 Markers for viral hepatitis
 Immunological-
Autoimmune hepatitis- ANA, LKM-1 Ab
PBC- anti-mitochondrial Ab
 AFP- Hepatocellular carcinoma
 Ferritin- hemochromatosis
 Ceruloplasmin- Wilson’s disease
 Liver biopsy

10. Radiological investigations
 Ultrasound- low cost, safe, portable
 CT scan- better anatomic definition
 MRI- no radiation, infiltrative diseases
 ERCP- biliary pathology, Dx & Rx
 PTC- dilated biliary tree, proximal disease
 HIDA scan- Dx of acute cholecystitis
 Angiography- Dx, resectability, palliation of
hepatic tumors or vascular lesions

11. Patterns of liver disease
 Hepatocellular
 Dull RUQ pain
 No steatorrhea
 ALT markedly elevated
 Alk. phos mildly elevated
 Albumin decreased
 INR increased,
not correctable
 US- liver enlarged/shrunken,
± splenomegaly
 Obstructive
 Colicky RUQ pain
 Steatorrhea present
 ALT mildly elevated
 Alk. phos markedly elevated
 Albumin unchanged
 INR- may be elevated,
correctable with vit. K
 US/CT- cholelithiasis, dilated
biliary tree, SOL