Clinical biochemistry: jaundice work-up: practice question

A Biochemistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Biochemistry · Clinical biochemistry: jaundice work-up

Sample item

A 55-year-old man has progressive jaundice, itching, dark urine and pale stools. Which pattern of laboratory findings is expected?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Conjugated hyperbilirubinaemia, bilirubinuria, absent urine urobilinogen and raised ALP

In obstructive jaundice conjugated bilirubin regurgitates into blood and, being water-soluble, appears in urine, giving dark urine. Bile cannot reach the gut, so stercobilin is lacking (pale stools) and urobilinogen is absent from urine. Cholestasis raises ALP and GGT. Haemolytic jaundice has the opposite pattern: unconjugated bilirubin, no bilirubinuria and increased urobilinogen.

Option by option

  • A. Normal bilirubin and normal ALP with raised urine urobilinogen

    Normal bilirubin and ALP would not explain jaundice.

  • B. Unconjugated hyperbilirubinaemia, no bilirubinuria and raised urine urobilinogen

    This is the pattern of haemolytic jaundice, with no obstruction.

  • C. Conjugated hyperbilirubinaemia, bilirubinuria, absent urine urobilinogen and raised ALP (correct)

    Correct. Conjugated bilirubin spills into urine while urobilinogen is absent from the lack of bile in the gut.

  • D. Unconjugated hyperbilirubinaemia with raised ALP and absent bilirubinuria

    Unconjugated bilirubin does not pass into urine, and raised ALP with absent bilirubinuria does not fit obstruction.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is C, Conjugated hyperbilirubinaemia, bilirubinuria, absent urine urobilinogen and raised ALP. In obstructive jaundice conjugated bilirubin regurgitates into blood and, being water-soluble, appears in urine, giving dark urine.

Why is "Normal bilirubin and normal ALP with raised urine urobilinogen" not the answer?

Normal bilirubin and ALP would not explain jaundice.

Why is "Unconjugated hyperbilirubinaemia, no bilirubinuria and raised urine u…" not the answer?

This is the pattern of haemolytic jaundice, with no obstruction.

Why is "Unconjugated hyperbilirubinaemia with raised ALP and absent bilirubin…" not the answer?

Unconjugated bilirubin does not pass into urine, and raised ALP with absent bilirubinuria does not fit obstruction.

What concept does this question test?

It tests Clinical biochemistry: jaundice work-up in Biochemistry. Bile cannot reach the gut, so stercobilin is lacking (pale stools) and urobilinogen is absent from urine. Cholestasis raises ALP and GGT. Haemolytic jaundice has the opposite pattern: unconjugated bilirubin, no bilirubinuria and increased urobilinogen.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Clinical biochemistry: jaundice work-up?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.