LIVER DISEASES PATTERN Flashcards
In which of the following conditions would you most likely observe an isolated elevation of unconjugated bilirubin?
A. Viral hepatitis
B. Gilbert’s syndrome
C. Obstructive jaundice
D. Alcoholic hepatitis
Correct Answer: B
Rationale: Isolated unconjugated hyperbilirubinemia is characteristic of genetic conditions like Gilbert’s syndrome and Crigler-Najjar syndrome. It is not commonly associated with liver disease, as both bilirubin fractions are typically elevated in liver conditions.
- Which of the following is the primary difference between conjugated (direct) and unconjugated (indirect) bilirubin?
A. Conjugated bilirubin is bound to albumin, while unconjugated bilirubin is water-soluble.
B. Conjugated bilirubin is water-soluble, while unconjugated bilirubin is bound to albumin.
C. Both conjugated and unconjugated bilirubin are water-insoluble.
D. Both conjugated and unconjugated bilirubin can be excreted by the kidney.
Correct Answer: B
Rationale: Conjugated bilirubin is water-soluble and can be excreted by the kidneys, while unconjugated bilirubin is bound to albumin in the blood and is insoluble in water. Understanding the solubility differences is key to interpreting bilirubin metabolism and excretion.
Why is fractionation of bilirubin rarely helpful in determining the cause of jaundice?
A. Both conjugated and unconjugated bilirubin are elevated in most liver diseases.
B. Fractionation is not accurate in distinguishing liver from biliary diseases.
C. Fractionation results do not correlate with clinical outcomes.
D. Fractionation cannot be performed using current diagnostic tests.
Correct Answer: A
Rationale: In most liver diseases, both conjugated and unconjugated bilirubin fractions are elevated. Hence, fractionation does not often provide additional diagnostic information except in isolated unconjugated hyperbilirubinemia.
Which of the following statements best describes the difference between AST and ALT as markers of liver injury?
A. AST is more specific to the liver than ALT.
B. ALT is more specific to the liver than AST.
C. AST is only found in the liver, while ALT is found in other tissues.
D. Both AST and ALT are equally specific to the liver.
Correct Answer: B
Rationale: ALT is primarily found in the liver, making it a more specific marker of liver injury. AST, on the other hand, is present in several other tissues, including cardiac muscle, skeletal muscle, and the kidneys.
Which of the following conditions is most likely to cause aminotransferase levels greater than 1000 IU/L?
A. Chronic viral hepatitis
B. Nonalcoholic fatty liver disease
C. Alcoholic liver disease
D. Ischemic liver injury
Correct Answer: D
Rationale: Striking elevations of aminotransferases (>1000 IU/L) occur in conditions associated with extensive hepatocellular injury, such as ischemic liver injury, viral hepatitis, or toxin-/drug-induced liver injury. Chronic or alcoholic liver diseases typically have lower aminotransferase levels.
aminotransferases >1000 IU/L—occur almost
exclusively in disorders associated with extensive hepatocellular injury
such as (1) viral hepatitis, (2) ischemic liver injury (prolonged hypotension
or acute heart failure), or (3) toxin- or drug-induced liver injury.
An AST:ALT ratio >2:1 is most suggestive of which condition?
A. Viral hepatitis
B. Alcoholic liver disease
C. Ischemic liver injury
D. Obstructive jaundice
Correct Answer: B
Rationale: An AST:ALT ratio >2:1 is suggestive of alcoholic liver disease, and a ratio >3:1 is highly suggestive. This pattern occurs due to an alcohol-induced deficiency of pyridoxal phosphate, which is required for ALT synthesis.
In most acute hepatocellular disorders, which of the following patterns of aminotransferase elevation is typically observed?
A. AST > ALT
B. ALT > AST
C. AST = ALT
D. Both AST and ALT remain normal
Correct Answer: B
Rationale: In most acute hepatocellular disorders, ALT levels are higher than or equal to AST levels, reflecting ALT’s greater specificity to liver injury.
Why is serum albumin not a reliable marker for acute liver dysfunction?
A. Serum albumin is degraded too quickly to reflect acute changes.
B. The liver produces less albumin during acute liver injury.
C. Serum albumin has a long half-life and slow turnover.
D. Albumin synthesis ceases completely during acute liver disease.
Correct Answer: C
Rationale: Serum albumin has a long half-life of 18–20 days, with only about 4% degraded per day. This slow turnover makes it an unreliable marker for acute liver dysfunction, as changes in albumin levels occur gradually.
What cytokines are associated with decreased albumin synthesis in chronic infections?
A. Interleukin 1 and tumor necrosis factor
B. Interleukin 6 and interferon-gamma
C. Tumor necrosis factor and interleukin 10
D. Interleukin 12 and interleukin 18
Correct Answer: A
Rationale: Chronic infections can lead to prolonged increases in cytokines such as interleukin 1 and tumor necrosis factor, which inhibit albumin synthesis and contribute to hypoalbuminemia.
What is the primary reason serum albumin levels are reduced in chronic liver diseases such as cirrhosis?
A. Increased albumin degradation
B. Decreased hepatic synthesis of albumin
C. Increased renal clearance of albumin
D. Loss of albumin through the gastrointestinal tract
Correct Answer: B
Rationale: In chronic liver diseases like cirrhosis, severe hepatic damage leads to reduced synthesis of albumin, contributing to hypoalbuminemia.
Which specific immunoglobulin is most commonly elevated in autoimmune hepatitis?
A. IgA
B. IgG
C. IgM
D. IgE
Correct Answer: B
Rationale: In autoimmune hepatitis, there is a diffuse polyclonal increase in IgG levels, often exceeding 100%. This is a key marker for recognizing the condition.
Elevated levels of IgM are commonly associated with which chronic liver disease?
A. Chronic hepatitis
B. Primary biliary cholangitis
C. Cirrhosis
D. Alcoholic liver disease
Correct Answer: B
Rationale: Increased levels of IgM are commonly seen in primary biliary cholangitis (PBC), a chronic autoimmune liver disease affecting the bile ducts.
Why do γ globulin levels increase in cirrhosis?
A. The liver becomes overactive in antibody synthesis.
B. There is impaired clearance of bacterial antigens from the bloodstream.
C. There is a decrease in the synthesis of α and β globulins.
D. The liver fails to produce immunoglobulins.
Correct Answer: B
Rationale: In cirrhosis, the liver’s inability to clear bacterial antigens leads to increased synthesis of γ globulins (antibodies), particularly those directed against intestinal bacteria.
What is the next step in evaluating isolated elevation of bilirubin if the direct fraction is <15%?
A. Check for Dubin-Johnson or Rotor syndrome
B. Perform evaluation for hemolysis
C. Check antinuclear antibodies (ANA)
D. Order a liver biopsy
Correct Answer: B
Rationale: If the direct bilirubin is <15%, it is primarily an indirect hyperbilirubinemia. This should prompt an evaluation for hemolysis to determine the underlying cause.
If a patient has isolated indirect hyperbilirubinemia and the workup for hemolysis is negative, the likely diagnosis is:
A. Gilbert’s syndrome
B. Hemolytic anemia
C. Primary biliary cholangitis
D. Autoimmune hepatitis
Correct Answer: A
Rationale: In the absence of hemolysis, isolated indirect hyperbilirubinemia in an otherwise healthy patient is typically due to Gilbert’s syndrome, which requires no further evaluation.
