MCQ on Liver Function Test

Mr. Joydeb Pradhan & Mrs. Tanusri Bera Pradhan
4.8
(4562)

1. Which of the following is NOT part of a routine liver function test (LFT) panel?

  • A) Serum bilirubin
  • B) Alanine aminotransferase (ALT)
  • C) Serum creatinine
  • D) Alkaline phosphatase (ALP)

Answer: C) Serum creatinine
Explanation: Routine LFTs include bilirubin, ALT, AST, ALP, GGT, albumin, and total protein. Serum creatinine is primarily a renal function marker. LFTs assess liver cell integrity, cholestasis, and synthetic capacity. Thus, creatinine does not reflect hepatic function.

2. Which enzyme is most specific for hepatocellular injury?

  • A) ALT (Alanine aminotransferase)
  • B) AST (Aspartate aminotransferase)
  • C) ALP (Alkaline phosphatase)
  • D) LDH (Lactate dehydrogenase)

Answer: A) ALT (Alanine aminotransferase)
Explanation: ALT is more specific to the liver compared to AST, which is also found in muscle, heart, and kidney. Elevated ALT strongly indicates hepatocellular damage such as viral hepatitis or toxic injury. AST/ALT ratio is also clinically important in chronic liver disease.

3. Which test best reflects the liver’s synthetic function?

  • A) Serum bilirubin
  • B) Prothrombin time (PT)
  • C) Serum ALP
  • D) Serum GGT

Answer: B) Prothrombin time (PT)
Explanation: The liver synthesizes clotting factors II, V, VII, IX, and X. Prolonged prothrombin time indicates impaired hepatic protein synthesis. Unlike albumin (which has a long half-life), PT reflects acute hepatic failure quickly. Thus, PT is a sensitive test of synthetic capacity.

4. Conjugated (direct) hyperbilirubinemia usually indicates:

Answer: B) Hepatocellular dysfunction or cholestasis
Explanation: Conjugated bilirubin increases in hepatocellular dysfunction (e.g., hepatitis, cirrhosis) or cholestasis (e.g., gallstones, bile duct obstruction). Unconjugated hyperbilirubinemia occurs in hemolysis or impaired conjugation (e.g., Gilbert’s syndrome). Measuring direct and indirect fractions helps identify underlying causes of jaundice.

5. An elevated alkaline phosphatase (ALP) with high gamma-glutamyl transferase (GGT) suggests:

Answer: B) Cholestatic liver disease
Explanation: ALP is elevated in both liver and bone disorders. GGT is more specific for liver origin. Thus, ALP + GGT elevation suggests cholestasis (obstructive jaundice, primary biliary cholangitis). If ALP is high but GGT normal, bone disease is more likely.

6. Which LFT parameter is decreased in advanced chronic liver disease?

  • A) Serum ALT
  • B) Serum bilirubin
  • C) Serum albumin
  • D) Serum ALP

Answer: C) Serum albumin
Explanation: Albumin is synthesized in the liver. In chronic liver disease (e.g., cirrhosis), albumin synthesis decreases, causing hypoalbuminemia and edema/ascites. In acute liver disease, albumin remains normal due to its long half-life (20 days). Thus, albumin indicates chronic hepatic synthetic failure.

7. The AST/ALT ratio >2 is most suggestive of:

Answer: B) Alcoholic liver disease
Explanation: AST/ALT ratio >2 strongly suggests alcoholic liver disease because alcohol reduces pyridoxal phosphate (a coenzyme needed for ALT activity), leading to disproportionately higher AST. In viral hepatitis, ALT is usually higher than AST (ratio <1). This ratio helps differential diagnosis.

8. Which enzyme is the most sensitive indicator of alcohol-induced liver damage?

  • A) ALT
  • B) AST
  • C) ALP
  • D) GGT

Answer: D) GGT
Explanation: Gamma-glutamyl transferase (GGT) is induced by alcohol and certain drugs. It is highly sensitive but not specific, as it rises in many liver conditions. Elevated GGT with high ALP indicates hepatic cholestasis. In isolation, elevated GGT strongly suggests chronic alcohol consumption.

9. Unconjugated hyperbilirubinemia without liver enzyme elevation suggests:

  • A) Viral hepatitis
  • B) Gallstone obstruction
  • C) Hemolytic anemia
  • D) Cirrhosis

Answer: C) Hemolytic anemia
Explanation: In hemolysis, excessive breakdown of red blood cells leads to unconjugated hyperbilirubinemia. Liver enzymes (ALT, AST, ALP) remain normal as the liver itself is not damaged. This helps differentiate hemolytic jaundice from hepatocellular or cholestatic jaundice.

10. Which of the following is true about serum alkaline phosphatase (ALP)?

  • A) ALP is exclusively produced by the liver
  • B) ALP is elevated in bone and liver diseases
  • C) ALP is specific for hepatocellular injury
  • D) ALP decreases in cholestasis

Answer: B) ALP is elevated in bone and liver diseases
Explanation: ALP originates from liver, bone, intestine, and placenta. Elevated ALP is seen in cholestasis and bone disorders (rickets, Paget’s disease). GGT helps confirm hepatic origin. Thus, ALP is sensitive but not specific for liver pathology.

11. Which form of bilirubin is water-soluble and excreted in urine?

Answer: B) Conjugated bilirubin
Explanation: Conjugated bilirubin is bound to glucuronic acid in the liver, making it water-soluble. It can pass through the kidney and appear in urine (bilirubinuria), commonly seen in obstructive and hepatocellular jaundice. Unconjugated bilirubin is albumin-bound, water-insoluble, and never excreted in urine.

12. Which test is most reliable for assessing acute liver failure?

  • A) Serum albumin
  • B) Prothrombin time (PT/INR)
  • C) Serum ALT
  • D) Serum bilirubin

Answer: B) Prothrombin time (PT/INR)
Explanation: In acute liver failure, PT/INR prolongation is the earliest and most reliable indicator of impaired liver synthetic function. Albumin is not sensitive due to its long half-life. Bilirubin and ALT rise but are less predictive of prognosis. Hence, PT/INR is the best marker.

13. Which of the following is a feature of Gilbert’s syndrome?

Answer: B) Unconjugated hyperbilirubinemia
Explanation: Gilbert’s syndrome is a benign inherited condition with reduced UDP-glucuronyl transferase activity, causing mild unconjugated hyperbilirubinemia, especially during fasting or stress. Liver enzymes and other LFT parameters remain normal. It is often discovered incidentally during routine testing.

14. Which of the following indicates obstructive jaundice in LFTs?

  • A) High unconjugated bilirubin with normal ALP
  • B) High conjugated bilirubin with elevated ALP and GGT
  • C) High ALT and AST with low albumin
  • D) Isolated unconjugated hyperbilirubinemia

Answer: B) High conjugated bilirubin with elevated ALP and GGT
Explanation: Obstructive jaundice (e.g., gallstones, biliary obstruction) causes conjugated hyperbilirubinemia and cholestatic enzyme elevation (ALP, GGT). ALT and AST may rise secondarily, but the predominant pattern is cholestasis. Differentiation from hepatocellular jaundice relies on enzyme pattern.

15. Which protein decreases earliest in liver disease due to its short half-life?

  • A) Albumin
  • B) Prothrombin
  • C) Fibrinogen
  • D) Ceruloplasmin

Answer: B) Prothrombin
Explanation: Prothrombin has a very short half-life (~6 hours). Hence, PT prolongation due to reduced prothrombin synthesis occurs rapidly in acute liver damage. Albumin has a longer half-life (~20 days), so it reflects chronic rather than acute liver failure.

16. In hepatocellular jaundice, the predominant LFT pattern is:

  • A) High ALP with normal ALT/AST
  • B) High conjugated bilirubin with high ALP
  • C) Markedly elevated ALT and AST
  • D) Isolated increase in unconjugated bilirubin

Answer: C) Markedly elevated ALT and AST
Explanation: Hepatocellular jaundice (viral hepatitis, drug-induced injury) shows significant elevations in ALT and AST, often >10 times normal. Bilirubin may be elevated but enzyme rise predominates. In contrast, cholestatic jaundice shows disproportionately higher ALP and GGT.

17. Which LFT abnormality is most characteristic of primary biliary cholangitis (PBC)?

  • A) Elevated ALT and AST
  • B) Elevated ALP and GGT
  • C) Low bilirubin
  • D) Low ALP

Answer: B) Elevated ALP and GGT
Explanation: PBC is an autoimmune cholestatic liver disease affecting intrahepatic bile ducts. It shows high ALP and GGT as hallmark findings. Bilirubin rises later in disease progression. ALT and AST are usually only mildly elevated compared to cholestatic enzymes.

18. Which LFT marker best indicates chronic alcohol consumption?

Answer: C) GGT
Explanation: GGT is highly sensitive to alcohol-induced liver injury and enzyme induction. Chronic alcohol consumption disproportionately elevates GGT. When combined with high MCV in CBC, it supports alcohol abuse diagnosis. However, GGT alone is not specific, as it rises in many hepatic disorders.

19. Which of the following is true about AST (Aspartate aminotransferase)?

  • A) Found only in the liver
  • B) Elevated in myocardial infarction and muscle disease
  • C) More specific to liver than ALT
  • D) Decreases in hepatitis

Answer: B) Elevated in myocardial infarction and muscle disease
Explanation: AST is present in liver, heart, skeletal muscle, kidney, and brain. Thus, elevated AST can occur in myocardial infarction and muscular disorders. ALT is more liver-specific. In hepatitis, AST increases significantly, though ALT usually rises more prominently.

20. Which LFT abnormality is expected in advanced cirrhosis?

  • A) Elevated albumin
  • B) Decreased albumin
  • C) Elevated ALT
  • D) Decreased bilirubin

Answer: B) Decreased albumin
Explanation: Cirrhosis impairs hepatic protein synthesis, leading to hypoalbuminemia, ascites, and edema. ALT and AST may normalize in end-stage cirrhosis due to loss of hepatocytes. Bilirubin often increases due to impaired excretion. Thus, decreased albumin is a hallmark of chronic advanced liver disease.

21. Which fraction of bilirubin increases in hemolytic jaundice?

Answer: B) Unconjugated bilirubin
Explanation: Hemolysis releases excessive heme from red blood cells. The liver cannot conjugate all bilirubin, leading to elevated unconjugated bilirubin. Liver enzymes remain normal, and no bilirubin is found in urine since unconjugated bilirubin is not water-soluble. This pattern distinguishes hemolytic from hepatocellular or obstructive jaundice.

22. Which test differentiates hepatic jaundice from hemolytic jaundice?

  • A) Serum albumin
  • B) AST/ALT ratio
  • C) Urinary bilirubin and urobilinogen
  • D) Serum ALP

Answer: C) Urinary bilirubin and urobilinogen
Explanation: In hemolytic jaundice, unconjugated bilirubin is high but absent in urine; urinary urobilinogen increases due to excess bilirubin breakdown. In hepatic or obstructive jaundice, conjugated bilirubin appears in urine, while urobilinogen may decrease in complete obstruction. Thus, urine analysis helps differentiation.

23. In which condition is alkaline phosphatase (ALP) normal but bilirubin high?

Answer: B) Viral hepatitis
Explanation: In viral hepatitis, hepatocellular injury causes elevated ALT and AST, with increased bilirubin. ALP remains within normal or only mildly elevated. In contrast, in obstructive or cholestatic conditions, ALP is markedly increased. This distinction helps classify jaundice as hepatocellular or cholestatic.

24. Which liver enzyme is mitochondrial and often elevated in alcoholic hepatitis?

  • A) ALT
  • B) AST
  • C) GGT
  • D) ALP

Answer: B) AST
Explanation: AST has both cytosolic and mitochondrial isoenzymes. Alcoholic hepatitis preferentially damages mitochondria, raising AST more than ALT. Hence, the AST/ALT ratio >2 strongly suggests alcoholic liver disease. ALT, being cytosolic, is less elevated in alcohol-related injury compared to viral hepatitis.

25. Which parameter best monitors progression in chronic liver disease?

  • A) ALT
  • B) Serum albumin
  • C) Bilirubin
  • D) GGT

Answer: B) Serum albumin
Explanation: Albumin synthesis reflects long-term hepatic protein production. In chronic liver disease (e.g., cirrhosis), albumin progressively decreases. ALT may normalize in end-stage cirrhosis due to reduced hepatocyte mass. Thus, serum albumin is the most reliable marker for chronic progression.

26. Which test is most useful to distinguish liver from bone ALP elevation?

Answer: B) GGT
Explanation: GGT is present in liver but absent in bone. If both ALP and GGT are elevated, the origin is hepatic. If ALP is high but GGT is normal, the source is likely bone (Paget’s disease, rickets). Hence, GGT helps differentiate ALP sources.

27. Which of the following conditions shows an isolated rise in unconjugated bilirubin with normal liver enzymes?

  • A) Viral hepatitis
  • B) Gilbert’s syndrome
  • C) Cholestasis
  • D) Cirrhosis

Answer: B) Gilbert’s syndrome
Explanation: Gilbert’s syndrome is a benign inherited condition with reduced bilirubin conjugation. It presents as isolated unconjugated hyperbilirubinemia, often discovered incidentally. ALT, AST, ALP, and albumin remain normal. It is precipitated by fasting, illness, or stress but requires no treatment.

28. Which laboratory marker rises earliest in obstructive jaundice?

Answer: B) ALP
Explanation: In obstructive jaundice, ALP rises earliest due to cholestasis-induced enzyme induction in bile canalicular membranes. GGT also rises but ALP elevation is more prominent. Bilirubin increases later as bile flow obstruction persists. ALT/AST may rise mildly but not as predominantly as ALP.

29. Which parameter is most important in assessing prognosis in fulminant hepatic failure?

  • A) ALT level
  • B) Albumin level
  • C) Prothrombin time (PT/INR)
  • D) Serum bilirubin

Answer: C) Prothrombin time (PT/INR)
Explanation: In acute fulminant hepatic failure, PT prolongation (due to rapid fall in clotting factor synthesis) reflects prognosis more reliably than ALT or bilirubin. Albumin is less useful acutely due to its long half-life. A rapidly increasing INR is an ominous sign requiring urgent intervention.

30. Which LFT abnormality is typical in extrahepatic bile duct obstruction?

  • A) High ALT and AST
  • B) Low albumin
  • C) High conjugated bilirubin with markedly elevated ALP
  • D) Isolated unconjugated hyperbilirubinemia

Answer: C) High conjugated bilirubin with markedly elevated ALP
Explanation: Extrahepatic biliary obstruction (e.g., gallstones, pancreatic carcinoma) causes conjugated hyperbilirubinemia and prominent cholestatic enzyme elevation (ALP, GGT). ALT/AST may rise modestly but the dominant pattern is cholestatic. This helps differentiate from hepatocellular injury where ALT/AST predominate.

31. Which test best reflects chronic hepatic protein synthesis impairment?

  • A) Serum albumin
  • B) ALT
  • C) AST
  • D) ALP

Answer: A) Serum albumin
Explanation: Albumin is synthesized exclusively in the liver. A persistently low albumin indicates chronic liver failure such as cirrhosis. Since albumin has a long half-life (~20 days), it is not useful in acute failure but reflects long-standing impaired hepatic protein synthesis in chronic conditions.

32. Which of the following enzymes is most sensitive to bile duct obstruction?

  • A) ALT
  • B) AST
  • C) ALP
  • D) LDH

Answer: C) ALP
Explanation: Alkaline phosphatase (ALP) rises markedly in biliary obstruction due to increased synthesis in bile duct epithelium. GGT rises as well but ALP shows the greatest proportional increase. ALT and AST are only mildly elevated in cholestatic disorders compared with hepatocellular damage.

33. Delta bilirubin is defined as:

Answer: A) Bilirubin bound to albumin
Explanation: Delta bilirubin refers to conjugated bilirubin covalently bound to albumin in plasma. It appears in prolonged cholestasis and persists longer than unconjugated or free conjugated bilirubin because it remains in circulation until albumin is degraded. Its detection suggests longstanding obstructive jaundice.

34. Which test distinguishes between hepatocellular and cholestatic jaundice?

  • A) Prothrombin time
  • B) AST/ALT ratio
  • C) ALP and GGT pattern
  • D) Albumin

Answer: C) ALP and GGT pattern
Explanation: In hepatocellular jaundice (e.g., viral hepatitis), ALT and AST rise significantly. In cholestatic jaundice (e.g., bile duct obstruction), ALP and GGT show disproportionately higher elevations. Thus, evaluating enzyme patterns helps differentiate hepatocellular versus cholestatic causes of jaundice.

35. Which urine finding is typical of conjugated hyperbilirubinemia?

  • A) Increased urobilinogen only
  • B) Bilirubinuria
  • C) Absent bilirubin and urobilinogen
  • D) Crystals

Answer: B) Bilirubinuria
Explanation: Conjugated bilirubin is water-soluble and appears in urine in hepatocellular or obstructive jaundice. Unconjugated bilirubin is albumin-bound, water-insoluble, and never excreted in urine. Hence, bilirubinuria always indicates conjugated hyperbilirubinemia and points toward hepatic or obstructive pathology.

36. In which condition is unconjugated bilirubin elevated with normal LFT enzymes?

Answer: A) Hemolysis
Explanation: Hemolysis causes excessive breakdown of red cells, producing increased unconjugated bilirubin. Since the liver is not injured, ALT, AST, ALP, and albumin remain normal. Urine bilirubin is absent, but urinary urobilinogen increases. This pattern indicates pre-hepatic jaundice.

37. Which LFT result is commonly altered in neonatal jaundice?

  • A) Increased unconjugated bilirubin
  • B) Increased conjugated bilirubin
  • C) Elevated ALT and AST
  • D) Elevated ALP

Answer: A) Increased unconjugated bilirubin
Explanation: Neonatal jaundice is usually due to immature glucuronyl transferase activity in the liver, leading to unconjugated hyperbilirubinemia. It is physiologic in most newborns but may become pathological if bilirubin levels are very high, risking kernicterus. Liver enzymes are usually normal.

38. Which of the following tests indicates liver excretory function?

  • A) Serum bilirubin
  • B) Albumin
  • C) PT/INR
  • D) ALT

Answer: A) Serum bilirubin
Explanation: Serum bilirubin reflects the liver’s ability to conjugate and excrete bile pigments. Elevated conjugated bilirubin suggests defective excretion or obstruction. Albumin and PT assess synthesis, while ALT indicates hepatocellular integrity. Thus, bilirubin specifically reflects hepatic excretory function.

39. Which of the following suggests intrahepatic cholestasis rather than extrahepatic obstruction?

  • A) Isolated ALP elevation
  • B) ALP + GGT elevation with mild ALT rise
  • C) Markedly elevated ALT and AST
  • D) Normal bilirubin

Answer: B) ALP + GGT elevation with mild ALT rise
Explanation: Intrahepatic cholestasis (e.g., primary biliary cholangitis, drug-induced cholestasis) shows elevated cholestatic enzymes (ALP, GGT) with mild transaminase rise. In extrahepatic obstruction, conjugated bilirubin is also high with more severe cholestatic pattern. Enzyme pattern helps localization of cholestasis.

40. Which enzyme remains elevated longest after acute viral hepatitis?

  • A) ALT
  • B) AST
  • C) ALP
  • D) GGT

Answer: A) ALT
Explanation: In acute viral hepatitis, ALT rises early, peaks, and remains elevated longer than AST, reflecting ongoing hepatocellular injury. AST usually declines faster. ALP and GGT may be mildly increased but normalize earlier. Thus, ALT persistence indicates prolonged hepatic injury or chronicity.

41. Which test is most useful in assessing synthetic liver function in acute liver failure?

  • A) ALT
  • B) Prothrombin time (PT/INR)
  • C) Albumin
  • D) Serum bilirubin

Answer: B) Prothrombin time (PT/INR)
Explanation: PT/INR reflects synthesis of clotting factors (II, VII, IX, X) with short half-lives. In acute liver failure, PT/INR rises rapidly, making it a sensitive indicator of hepatic synthetic dysfunction. Albumin changes slowly and bilirubin indicates excretory function, not immediate synthetic activity.

42. Which condition shows markedly elevated ALT and AST with minimal ALP elevation?

Answer: A) Viral hepatitis
Explanation: In viral hepatitis, hepatocellular injury predominates, releasing large amounts of ALT and AST into circulation. ALP is only mildly elevated. In biliary obstruction or cholestasis, ALP is disproportionately increased. Hence, the transaminase-predominant pattern suggests hepatocellular pathology like hepatitis.

43. Which of the following can falsely elevate ALP levels?

  • A) Pregnancy
  • B) Rickets
  • C) Bone growth in children
  • D) All of the above

Answer: D) All of the above
Explanation: ALP is present in liver, bone, placenta, and intestine. Physiological causes like pregnancy (placental ALP), growing children (bone ALP), and bone diseases like rickets elevate ALP. Therefore, isoenzyme studies or GGT testing is essential to confirm hepatic origin.

44. Which test best differentiates between hepatic and bone sources of ALP?

  • A) ALT
  • B) GGT
  • C) AST
  • D) Albumin

Answer: B) GGT
Explanation: Gamma-glutamyl transferase (GGT) is elevated in hepatobiliary disease but not in bone disorders. If both ALP and GGT are elevated, the source is hepatic. If ALP is elevated with normal GGT, bone disease is suspected. This combination helps pinpoint the source of raised ALP.

45. Which parameter is most sensitive to alcohol-induced liver injury?

  • A) ALT
  • B) AST
  • C) AST/ALT ratio
  • D) GGT

Answer: C) AST/ALT ratio
Explanation: In alcoholic liver disease, AST:ALT ratio >2:1 is typical. ALT is lower due to pyridoxal phosphate deficiency in alcoholics. GGT is also raised with chronic alcohol intake but the AST/ALT ratio is most characteristic of alcoholic hepatitis.

46. Which liver test abnormality is most characteristic of obstructive jaundice?

  • A) Elevated unconjugated bilirubin
  • B) Increased ALP and conjugated bilirubin
  • C) Low albumin
  • D) Elevated LDH

Answer: B) Increased ALP and conjugated bilirubin
Explanation: In obstructive jaundice, conjugated bilirubin accumulates due to impaired bile flow and is excreted in urine. ALP rises significantly due to bile duct epithelial enzyme induction. Albumin reduction occurs in chronic liver disease, not early obstruction.

47. Which test is used to detect early hepatic encephalopathy in liver failure?

  • A) Serum ammonia
  • B) Albumin
  • C) PT/INR
  • D) ALT

Answer: A) Serum ammonia
Explanation: In liver failure, impaired urea cycle leads to ammonia accumulation. Elevated serum ammonia levels contribute to hepatic encephalopathy. PT/INR and albumin reflect synthetic function, but ammonia directly correlates with neurological manifestations of hepatic encephalopathy, making it a useful early marker.

48. Which fraction of bilirubin is elevated in Gilbert’s syndrome?

Answer: C) Unconjugated bilirubin
Explanation: Gilbert’s syndrome is a benign hereditary condition due to reduced activity of UDP-glucuronyl transferase. It leads to mild unconjugated hyperbilirubinemia, especially during fasting, stress, or illness. Liver enzymes, albumin, and PT remain normal. It does not progress to chronic liver disease.

49. Which test best indicates hepatic fibrosis and cirrhosis chronically?

  • A) ALT
  • B) Albumin
  • C) ALP
  • D) Conjugated bilirubin

Answer: B) Albumin
Explanation: Chronic liver disease such as cirrhosis impairs albumin synthesis, leading to hypoalbuminemia. Since albumin has a long half-life, it reflects long-term hepatic dysfunction rather than acute changes. PT and bilirubin reflect acute dysfunction, while enzymes are markers of damage, not fibrosis.

50. Which laboratory finding is characteristic of Dubin-Johnson syndrome?

  • A) Elevated unconjugated bilirubin
  • B) Elevated conjugated bilirubin with black liver
  • C) Elevated ALT and AST
  • D) Elevated ALP

Answer: B) Elevated conjugated bilirubin with black liver
Explanation: Dubin-Johnson syndrome is a rare hereditary condition with defective excretion of conjugated bilirubin. Patients have chronic conjugated hyperbilirubinemia but normal liver enzymes. Grossly, the liver appears black due to pigment deposition. It is usually benign without progression to cirrhosis.

51. Which bilirubin fraction is water-soluble and excreted in urine?

Answer: B) Conjugated bilirubin
Explanation: Conjugated bilirubin is water-soluble because it is bound to glucuronic acid in the liver. In obstructive jaundice, conjugated bilirubin leaks into the blood and is excreted in urine, giving it a dark color. Unconjugated bilirubin is fat-soluble and cannot appear in urine.

52. Which test is most reliable for monitoring chronic liver synthetic capacity?

  • A) ALT
  • B) Albumin
  • C) ALP
  • D) GGT

Answer: B) Albumin
Explanation: Albumin is synthesized exclusively in the liver and has a long half-life (~20 days). Decreased serum albumin reflects chronic liver synthetic impairment, as seen in cirrhosis or chronic hepatitis. Transaminases (ALT, AST) reflect hepatocellular injury, not synthetic capacity.

53. Which enzyme rises first after acute hepatocellular injury?

  • A) ALT
  • B) AST
  • C) ALP
  • D) LDH

Answer: B) AST
Explanation: AST is released early from mitochondria and cytoplasm after acute hepatocyte injury, while ALT follows later. However, ALT is more specific for liver disease. In myocardial infarction, AST also rises, but LDH and CK are better cardiac markers.

54. Which LFT abnormality is typical in hemolytic jaundice?

  • A) Elevated unconjugated bilirubin
  • B) Elevated conjugated bilirubin
  • C) Elevated ALP
  • D) Elevated GGT

Answer: A) Elevated unconjugated bilirubin
Explanation: Hemolysis increases bilirubin production beyond the liver’s conjugation capacity, leading to unconjugated hyperbilirubinemia. Conjugated bilirubin, ALP, and GGT remain normal since hepatocytes and bile ducts are unaffected. No bilirubinuria occurs because unconjugated bilirubin is not water-soluble.

55. Which marker best reflects biliary epithelial injury or obstruction?

  • A) ALT
  • B) AST
  • C) ALP
  • D) LDH

Answer: C) ALP
Explanation: Alkaline phosphatase (ALP) is abundant in bile duct epithelium. In cholestasis or biliary obstruction, ALP is induced and markedly elevated. To confirm hepatic source, GGT or 5’-nucleotidase should also be measured, since ALP can also rise in bone disease.

56. Which enzyme is most specific for liver disease among aminotransferases?

  • A) ALT
  • B) AST
  • C) ALP
  • D) LDH

Answer: A) ALT
Explanation: ALT (alanine aminotransferase) is localized mainly in hepatocytes, making it a specific indicator of liver injury. AST is also present in muscle, heart, and kidneys, hence less specific. ALT elevation strongly suggests hepatocellular damage, such as viral hepatitis or drug-induced liver injury.

57. Which test helps distinguish conjugated hyperbilirubinemia from unconjugated type?

Answer: A) Urine bilirubin test
Explanation: Conjugated bilirubin is water-soluble and appears in urine, giving it a dark color. Unconjugated bilirubin is not excreted in urine. Thus, the presence of bilirubinuria indicates conjugated hyperbilirubinemia, seen in obstructive or hepatocellular jaundice.

58. Which is the earliest indicator of hepatic synthetic failure in acute liver disease?

Answer: B) PT/INR
Explanation: PT/INR rises quickly because clotting factors II, VII, IX, and X have short half-lives (hours to days). Albumin decreases slowly due to a long half-life, while bilirubin reflects excretory function, not synthetic failure. Thus, PT/INR is the earliest indicator of impaired hepatic synthesis.

59. Which test best indicates cholestasis due to intrahepatic obstruction?

  • A) ALT
  • B) GGT
  • C) LDH
  • D) Serum iron

Answer: B) GGT
Explanation: Gamma-glutamyl transferase (GGT) is elevated in cholestasis and alcohol-related liver disease. When elevated along with ALP, it confirms hepatic cholestasis. Isolated ALP elevation suggests a non-hepatic cause, such as bone disease. Hence, GGT is a confirmatory marker for intrahepatic biliary obstruction.

60. Which finding is typical of Crigler–Najjar syndrome type I?

Answer: B) Unconjugated hyperbilirubinemia with absent UGT enzyme
Explanation: Crigler–Najjar syndrome type I is a rare hereditary disorder with complete absence of UDP-glucuronyl transferase (UGT). This prevents conjugation of bilirubin, causing severe unconjugated hyperbilirubinemia, kernicterus, and often fatal outcomes. Type II is less severe, with partial enzyme activity.

61. Which test best evaluates the liver’s ability to detoxify ammonia?

  • A) PT/INR
  • B) Serum albumin
  • C) Serum ammonia
  • D) ALT

Answer: C) Serum ammonia
Explanation: The liver detoxifies ammonia by converting it into urea via the urea cycle. In advanced liver failure or portosystemic shunting, serum ammonia levels rise, leading to hepatic encephalopathy. ALT and PT reflect hepatocellular injury and synthesis, not detoxification capacity.

62. In Gilbert’s syndrome, which LFT abnormality is seen?

Answer: A) Mild unconjugated hyperbilirubinemia
Explanation: Gilbert’s syndrome is a benign inherited disorder due to reduced activity of UDP-glucuronyl transferase. It leads to mild, fluctuating unconjugated hyperbilirubinemia, often triggered by fasting, stress, or illness. Other LFTs remain normal. No treatment is usually required as prognosis is excellent.

63. Which test is most useful to differentiate hepatocellular from cholestatic jaundice?

  • A) Serum bilirubin
  • B) ALT/AST ratio
  • C) ALP and GGT levels
  • D) Albumin

Answer: C) ALP and GGT levels
Explanation: ALP and GGT are markedly elevated in cholestatic jaundice due to bile duct obstruction, while ALT/AST predominate in hepatocellular injury. Bilirubin alone does not differentiate the type. Albumin reflects chronic liver function, not the pattern of jaundice.

64. Which marker is elevated earliest in alcoholic liver disease?

  • A) ALT
  • B) AST
  • C) ALP
  • D) GGT

Answer: D) GGT
Explanation: GGT is highly sensitive to alcohol intake and rises early in alcoholic liver disease. AST may also increase (with AST:ALT ratio >2 suggestive of alcoholic hepatitis), but GGT is the most sensitive early biomarker of alcohol-induced hepatotoxicity.

65. Which protein decreases in advanced cirrhosis leading to edema and ascites?

  • A) Transferrin
  • B) Albumin
  • C) Ferritin
  • D) Ceruloplasmin

Answer: B) Albumin
Explanation: Hypoalbuminemia is a hallmark of chronic liver failure. Albumin maintains plasma oncotic pressure; its deficiency causes fluid shift into interstitial and peritoneal spaces, producing edema and ascites. Transferrin and ceruloplasmin may decrease but albumin has the most clinical relevance in cirrhosis.

66. Which test reflects the liver’s ability to conjugate bilirubin?

Answer: A) Direct bilirubin
Explanation: Direct (conjugated) bilirubin reflects the liver’s ability to conjugate bilirubin via UDP-glucuronyl transferase. Increased direct bilirubin suggests impaired excretion (cholestasis, obstruction, hepatocellular dysfunction). Indirect bilirubin indicates pre-hepatic or conjugation defects. PT/INR measures clotting, not conjugation.

67. Which test is most useful to detect drug-induced hepatocellular injury?

  • A) ALP
  • B) GGT
  • C) ALT
  • D) PT

Answer: C) ALT
Explanation: ALT is the most specific indicator of hepatocellular injury, especially in drug-induced hepatitis caused by acetaminophen, isoniazid, or anti-TB drugs. ALP and GGT are more useful in cholestatic or alcohol-related liver injury. PT reflects synthetic capacity but not direct hepatocyte necrosis.

68. Which test is most specific for cholestasis confirmation when ALP is elevated?

  • A) ALT
  • B) AST
  • C) GGT
  • D) Albumin

Answer: C) GGT
Explanation: GGT elevation confirms hepatic origin of elevated ALP. If ALP is high but GGT normal, the cause may be bone disease. Elevated ALP with elevated GGT strongly indicates cholestasis or bile duct obstruction. Albumin does not help in this differentiation.

69. Which inherited liver disorder presents with conjugated hyperbilirubinemia and dark urine?

  • A) Gilbert’s syndrome
  • B) Crigler–Najjar syndrome
  • C) Dubin–Johnson syndrome
  • D) Hemolysis

Answer: C) Dubin–Johnson syndrome
Explanation: Dubin–Johnson syndrome is a benign hereditary disorder due to defective bilirubin excretion into bile. This causes conjugated hyperbilirubinemia and dark urine. The liver may appear grossly pigmented. In contrast, Gilbert’s and Crigler–Najjar syndromes cause unconjugated hyperbilirubinemia.

70. Which test is considered the most sensitive indicator of early hepatic dysfunction?

  • A) PT/INR
  • B) Serum albumin
  • C) ALT
  • D) Bilirubin

Answer: A) PT/INR
Explanation: PT/INR reflects synthesis of clotting factors with short half-lives, making it the earliest indicator of hepatic dysfunction. Albumin falls late due to long half-life. ALT reflects hepatocyte injury, not function. Bilirubin reflects excretion, not early synthetic capacity.

71. Which enzyme is more specific for liver disease than ALP?

  • A) LDH
  • B) CK
  • C) GGT
  • D) Amylase

Answer: C) GGT
Explanation: Gamma-glutamyl transferase (GGT) is highly specific for hepatobiliary disease. ALP may increase in bone disorders, but GGT helps confirm hepatic origin. LDH rises in hemolysis, CK in muscle injury, and amylase in pancreatitis. Thus, GGT is the best differentiator when ALP is elevated.

72. Which LFT is most affected in acute fulminant hepatic failure?

  • A) Serum albumin
  • B) PT/INR
  • C) ALP
  • D) GGT

Answer: B) PT/INR
Explanation: PT/INR rises earliest and most markedly in acute fulminant hepatic failure due to impaired synthesis of clotting factors. Serum albumin takes longer to decline. ALP and GGT reflect cholestasis, not fulminant necrosis. Thus, PT/INR is the most critical test in prognosis.

73. Which bilirubin fraction is water-soluble and excreted in urine?

Answer: B) Conjugated bilirubin
Explanation: Conjugated bilirubin is water-soluble, excreted in urine, and gives dark-colored urine in obstructive or hepatocellular jaundice. Unconjugated bilirubin is bound to albumin, insoluble in water, and not excreted in urine. Urobilinogen is formed in the intestine from conjugated bilirubin breakdown.

74. Which test differentiates hemolytic jaundice from hepatic jaundice?

  • A) Serum albumin
  • B) Serum unconjugated bilirubin
  • C) PT/INR
  • D) ALP

Answer: B) Serum unconjugated bilirubin
Explanation: Hemolytic jaundice is characterized by markedly elevated unconjugated bilirubin due to excessive hemolysis, with normal ALT, ALP, and PT. In hepatic jaundice, both conjugated and unconjugated bilirubin may rise. Thus, isolated elevation of unconjugated bilirubin indicates hemolytic jaundice.

75. Which LFT abnormality suggests advanced cirrhosis with portal hypertension?

  • A) High ALT
  • B) High ALP
  • C) Low albumin
  • D) High GGT

Answer: C) Low albumin
Explanation: Hypoalbuminemia is a feature of advanced cirrhosis, reflecting poor protein synthesis. It contributes to ascites and edema, often associated with portal hypertension. ALT and ALP may normalize in cirrhosis due to “burnt-out” liver. Low albumin indicates poor prognosis.

76. Which LFT marker is useful in monitoring hepatotoxicity from methotrexate?

Answer: B) ALT
Explanation: ALT is the most specific marker for hepatocellular injury, including drug-induced hepatotoxicity such as methotrexate, isoniazid, or acetaminophen. ALP indicates cholestasis, LDH is nonspecific, and bilirubin rises later. Monitoring ALT helps detect toxicity early before irreversible damage occurs.

77. Which condition shows disproportionately high ALP compared to ALT/AST?

Answer: C) Obstructive jaundice
Explanation: In obstructive jaundice, bile duct obstruction leads to marked elevation of ALP, often out of proportion to ALT/AST. Viral and drug-induced hepatitis mainly raise ALT/AST, while alcoholic liver disease elevates AST > ALT. Thus, ALP dominance suggests cholestasis.

78. Which test best reflects long-term synthetic function of the liver?

  • A) Serum albumin
  • B) PT/INR
  • C) ALT
  • D) Bilirubin

Answer: A) Serum albumin
Explanation: Albumin has a half-life of about 20 days, making it a reliable indicator of long-term synthetic function. PT/INR reflects short-term function. ALT indicates hepatocyte injury, while bilirubin reflects excretory function. Chronic hypoalbuminemia signifies advanced liver disease and poor prognosis.

79. Which urinary test supports the diagnosis of obstructive jaundice?

  • A) Urinary ketones
  • B) Urinary conjugated bilirubin
  • C) Urinary urobilinogen
  • D) Urinary proteins

Answer: B) Urinary conjugated bilirubin
Explanation: In obstructive jaundice, conjugated bilirubin (water-soluble) regurgitates into blood and appears in urine, causing dark urine. Urobilinogen is absent in complete obstruction. In hemolysis, urinary bilirubin is absent but urobilinogen is increased. Proteinuria is unrelated.

80. Which LFT is most useful in assessing prognosis of chronic liver disease?

  • A) ALT
  • B) Serum bilirubin
  • C) PT/INR
  • D) Serum albumin

Answer: D) Serum albumin
Explanation: Chronic liver disease prognosis depends largely on long-term protein synthesis, reflected by serum albumin levels. Persistent hypoalbuminemia indicates severe impairment. PT/INR is more relevant in acute settings. ALT and bilirubin fluctuate and do not consistently reflect prognosis.

81. Which test is included in the Child-Pugh score for cirrhosis prognosis?

  • A) ALT
  • B) Serum sodium
  • C) Serum albumin
  • D) GGT

Answer: C) Serum albumin
Explanation: The Child-Pugh score uses bilirubin, albumin, PT/INR, ascites, and encephalopathy for prognosis in cirrhosis. Low albumin reflects impaired protein synthesis and worse prognosis. ALT and GGT are not included. Serum sodium is used in MELD-Na, not Child-Pugh.

82. Which condition shows decreased serum ceruloplasmin with abnormal LFTs?

  • A) Hemochromatosis
  • B) Wilson’s disease
  • C) Alcoholic hepatitis
  • D) Viral hepatitis

Answer: B) Wilson’s disease
Explanation: Wilson’s disease, a copper metabolism disorder, shows low serum ceruloplasmin, elevated liver enzymes, and copper deposition in tissues. Hemochromatosis shows high ferritin and transferrin saturation. Alcoholic and viral hepatitis do not affect ceruloplasmin. Ceruloplasmin helps differentiate Wilson’s from other hepatic conditions.

83. Which test distinguishes hepatic from pre-hepatic jaundice?

  • A) Serum LDH
  • B) PT/INR
  • C) Serum conjugated bilirubin
  • D) ALP

Answer: C) Serum conjugated bilirubin
Explanation: In pre-hepatic (hemolytic) jaundice, unconjugated bilirubin predominates with no bilirubinuria. In hepatic jaundice, both conjugated and unconjugated fractions rise, often with bilirubinuria. PT and ALP are nonspecific. Conjugated bilirubin levels are crucial to differentiate intra-hepatic from pre-hepatic jaundice.

84. Which test is most sensitive to detect early cholestasis?

  • A) ALT
  • B) AST
  • C) ALP
  • D) GGT

Answer: D) GGT
Explanation: GGT rises earliest and most sensitively in cholestasis, drug-induced liver injury, or alcohol abuse. ALP also rises but later, and it can be increased in bone disease. ALT and AST primarily reflect hepatocellular injury, not cholestasis.

85. Which finding is typical of alcoholic liver disease in LFTs?

  • A) ALT > AST
  • B) AST > ALT (usually ratio > 2:1)
  • C) Very high ALP
  • D) High serum albumin

Answer: B) AST > ALT (usually ratio > 2:1)
Explanation: In alcoholic liver disease, AST rises more than ALT, with a ratio greater than 2:1. This occurs because ALT depends on vitamin B6, which is deficient in alcoholics. ALP is mildly raised; albumin is often low in chronic cases.

86. Which test is elevated in bone and liver disease, making GGT important?

Answer: B) ALP
Explanation: Alkaline phosphatase is elevated in both liver cholestasis and bone diseases (like Paget’s, rickets). GGT is added to distinguish liver origin (elevated in hepatobiliary disease). ALT and bilirubin are more liver-specific. LDH is nonspecific.

87. Which test reflects acute changes in liver protein synthesis?

  • A) Albumin
  • B) PT/INR
  • C) Globulin
  • D) Bilirubin

Answer: B) PT/INR
Explanation: PT/INR rises rapidly in acute liver failure because clotting factors have short half-lives (especially factor VII). Albumin changes slowly (half-life ~20 days). Globulins are more affected in chronic disease. Bilirubin reflects excretory, not synthetic, function.

88. Which serum enzyme is elevated in hepatocellular carcinoma?

  • A) ALT
  • B) AST
  • C) AFP
  • D) ALP

Answer: C) AFP
Explanation: Alpha-fetoprotein (AFP) is a tumor marker elevated in hepatocellular carcinoma (HCC). ALT and AST may be mildly raised but nonspecific. ALP can rise in bone metastasis. AFP helps differentiate HCC from benign hepatic injury.

89. Which LFT is commonly prolonged in vitamin K deficiency?

Answer: A) PT
Explanation: Vitamin K deficiency impairs synthesis of clotting factors II, VII, IX, and X, causing prolonged PT. Albumin is unaffected. ALT and bilirubin do not reflect coagulation. PT helps assess vitamin K deficiency, cholestasis, or warfarin effect.

90. Which LFT finding is common in sepsis-induced cholestasis?

  • A) ALT predominance
  • B) ALP and bilirubin elevation
  • C) Isolated albumin drop
  • D) Normal LFTs

Answer: B) ALP and bilirubin elevation
Explanation: Sepsis-induced cholestasis typically presents with elevated conjugated bilirubin and ALP due to impaired bile excretion. ALT may be normal or mildly elevated. Albumin decreases in chronic illness, not acutely. Recognizing this pattern prevents misdiagnosis of obstructive jaundice.

91. Which enzyme rises earliest in acute viral hepatitis?

  • A) ALP
  • B) GGT
  • C) ALT
  • D) LDH

Answer: C) ALT
Explanation: ALT is highly specific to hepatocytes and rises earliest and highest in acute viral hepatitis, sometimes reaching >1000 IU/L. AST also rises but is less specific. ALP and GGT are usually normal or mildly increased unless cholestasis is present.

92. Which test best indicates chronic liver failure prognosis?

  • A) Serum bilirubin
  • B) PT/INR
  • C) Serum albumin
  • D) ALT

Answer: B) PT/INR
Explanation: PT/INR is the most reliable indicator of hepatic synthetic capacity in chronic liver failure. Albumin decreases slowly and bilirubin may fluctuate. ALT is a marker of hepatocyte injury, not prognosis. A persistently prolonged PT/INR predicts poor outcome in chronic liver disease.

93. Which LFT abnormality is typical of intrahepatic cholestasis of pregnancy?

  • A) ALT > 1000 IU/L
  • B) Isolated rise of unconjugated bilirubin
  • C) Elevated ALP and bile acids
  • D) High AFP

Answer: C) Elevated ALP and bile acids
Explanation: In intrahepatic cholestasis of pregnancy, elevated bile acids and ALP are characteristic, with mild bilirubin increase. ALT is usually normal or mildly raised. AFP rises in HCC, not cholestasis. Recognition is important due to fetal complications.

94. Which LFT pattern suggests hemolytic jaundice?

  • A) Elevated unconjugated bilirubin, normal ALT, ALP
  • B) High conjugated bilirubin, raised ALP
  • C) ALT and AST very high
  • D) PT prolonged with low albumin

Answer: A) Elevated unconjugated bilirubin, normal ALT, ALP
Explanation: In hemolytic jaundice, unconjugated bilirubin is elevated due to excessive RBC breakdown. ALT, AST, and ALP remain normal since the liver is not directly damaged. Conjugated bilirubin and PT remain normal.

95. Which enzyme is most liver-specific?

  • A) AST
  • B) ALT
  • C) ALP
  • D) GGT

Answer: B) ALT
Explanation: ALT (alanine aminotransferase) is almost exclusively found in the liver, making it highly specific for hepatocellular injury. AST is also in heart and muscle. ALP and GGT are present in other tissues. Thus, ALT is the most specific enzyme for liver injury.

96. Which test helps differentiate obstructive from hepatocellular jaundice?

  • A) ALT/AST ratio
  • B) ALP levels
  • C) LDH activity
  • D) Serum uric acid

Answer: B) ALP levels
Explanation: In obstructive jaundice, ALP rises markedly due to impaired bile flow, often with elevated GGT. In hepatocellular jaundice, ALT/AST dominate. LDH is nonspecific. Serum uric acid is not relevant. ALP is a key discriminator.

97. Which condition shows disproportionately high ALP compared to ALT/AST?

Answer: C) Biliary obstruction
Explanation: In biliary obstruction, ALP increases disproportionately compared to aminotransferases, sometimes >3–4 times the upper limit. Viral and alcoholic hepatitis show high ALT/AST. Wilson’s disease typically shows modest transaminase elevation with low ceruloplasmin, not isolated ALP rise.

98. Which test is useful to monitor hepatotoxicity of methotrexate?

Answer: A) ALT
Explanation: ALT is the best marker for detecting hepatocellular injury due to methotrexate, isoniazid, or other hepatotoxic drugs. ALP reflects cholestasis. PT/INR indicates liver failure, not early damage. Bilirubin rises late. Regular ALT monitoring is recommended during long-term methotrexate therapy.

99. Which serum finding is suggestive of Gilbert’s syndrome?

  • A) High conjugated bilirubin
  • B) Elevated unconjugated bilirubin with normal LFTs
  • C) ALT and AST > 1000 IU/L
  • D) Very high ALP

Answer: B) Elevated unconjugated bilirubin with normal LFTs
Explanation: Gilbert’s syndrome is a benign hereditary disorder of bilirubin conjugation, leading to mild unconjugated hyperbilirubinemia, often triggered by fasting or stress. ALT, AST, ALP, and PT remain normal. It is important to distinguish from hemolysis or hepatic jaundice.

100. Which test is used in diagnosing primary biliary cholangitis (PBC)?

  • A) High ALT
  • B) Anti-mitochondrial antibody (AMA) with raised ALP
  • C) Low ceruloplasmin
  • D) AFP elevation

Answer: B) Anti-mitochondrial antibody (AMA) with raised ALP
Explanation: Primary biliary cholangitis shows markedly elevated ALP and GGT with positive AMA (90–95% of cases). ALT and AST are mildly raised. Low ceruloplasmin is seen in Wilson’s disease. AFP elevation suggests hepatocellular carcinoma. AMA and ALP combination confirms PBC.

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