Lab Evaluation of Liver Cell Injury

Question 1

What is the source of unconjugated bilirubin?

Answer 1

End product of heme metabolism in splenic macrophages

Question 2

Is unconjugated bilirubin lipid or water soluble?

Answer 2

Lipid

Question 3

What enzyme conjugates bilirubin?

Answer 3

UGT

Question 4

Is conjugated bilirubin lipid or water soluble?

Answer 4

Water

Question 5

What causes jaundice?

Answer 5

Increase in unconjugated or conjugated bilirubin

Question 6

Where is jaundice first noticed?

Answer 6

Sclera (ictrerus)

Question 7

What is the most common cause of jaundice?

Answer 7

Viral hepatitis

Question 8

What is the second most common cause of jaundice?

Answer 8

Gilbert DZ- impaired UGT function

Question 9

What are the types of hyperbilirubinemia?

Answer 9

Unconjugated: CB less than 20%.
Mixed: CB 20-50%
Conjugated: CB>50%

Question 10

What liver enzyme is specific for liver cell necrosis?

Answer 10

ALT

Question 11

Increased GGT indicates what pathology?

Answer 11

Intrahepatic or extrahepatic obstruction to bile flow

Question 12

An increase in ALP, but not GGT indicated what pathology?

Answer 12

Source of ALP is not liver (i.e. bone)

Question 13

An increase in GGT and ALP indicated what?

Answer 13

Cholestasis

Question 14

PT and INR may be increased in severe liver disease, why?

Answer 14

Liver synthesizes clotting factors and uptakes Vitamin K

Question 15

What tumor marker is used to detect hepatocellular carcinoma?

Answer 15

AFP- alpha fetoprotein

Question 16

What lab findings indicate a viral hepatitis?

Answer 16

Mixed hyperbilirubinemia, ALT>AST, increased urine bilirubin/urobilinogen

Question 17

What lab findings indicate an alcoholic hepatitis?

Answer 17

Mixed hyperbilirubinemia, AST>ALT, increased GGT, increased urine bilirubin/urobilinogen

Question 18

What lab findings indicate cholestasis?

Answer 18

Conjugated hyperbilirubinemia, increased ALP/GGT, increased urine bilirubin

Question 19

What lab findings indicate extravascular hemolysis?

Answer 19

Unconjugated hyperbilirubinemia, increased AST (RBCs)

Question 20

What conditions lead to unconjugated hyperbilirubinemia?

Answer 20

Extravascular hemolytic anemias, Gilbert syndrome, Crigler-Najjar syndrome, physiologic jaundice in newborn

Question 21

What conditions lead to conjugated hyperbilirubinemia?

Answer 21

Obstruction. Drugs, primary biliary cirrhosis, Dubin-Johnson syndrome, Rotor syndrome, gallstones, cancer