Iron metabolism: 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 · Iron metabolism

Sample item

A man with long-standing rheumatoid arthritis has anaemia with low serum iron, low transferrin saturation and a raised ferritin. Which mechanism best explains the low serum iron?

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

The answer and the reasoning

C. Interleukin-6-driven rise in hepcidin, degrading ferroportin and trapping iron in macrophages

Inflammation raises interleukin-6, which stimulates hepatic hepcidin. Hepcidin binds ferroportin and causes its degradation, so iron is not released from macrophages or absorbed from the gut. This gives anaemia of chronic disease with low serum iron but adequate stores and high ferritin.

Option by option

  • A. Loss of intrinsic factor impairs iron absorption

    Intrinsic factor is needed for vitamin B12 absorption, not iron absorption.

  • B. Decreased hepcidin increases ferroportin and iron absorption

    Low hepcidin would raise serum iron, as in haemochromatosis, which is the opposite of this picture.

  • C. Interleukin-6-driven rise in hepcidin, degrading ferroportin and trapping iron in macrophages (correct)

    Correct. High hepcidin removes ferroportin, locking iron in stores and lowering serum iron.

  • D. Increased transferrin synthesis binds more iron

    Transferrin is low or normal in chronic disease rather than raised, and transferrin synthesis does not trap iron in macrophages.

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, Interleukin-6-driven rise in hepcidin, degrading ferroportin and trapping iron in macrophages. Inflammation raises interleukin-6, which stimulates hepatic hepcidin.

Why is "Loss of intrinsic factor impairs iron absorption" not the answer?

Intrinsic factor is needed for vitamin B12 absorption, not iron absorption.

Why is "Decreased hepcidin increases ferroportin and iron absorption" not the answer?

Low hepcidin would raise serum iron, as in haemochromatosis, which is the opposite of this picture.

Why is "Increased transferrin synthesis binds more iron" not the answer?

Transferrin is low or normal in chronic disease rather than raised, and transferrin synthesis does not trap iron in macrophages.

What concept does this question test?

It tests Iron metabolism in Biochemistry. Hepcidin binds ferroportin and causes its degradation, so iron is not released from macrophages or absorbed from the gut. This gives anaemia of chronic disease with low serum iron but adequate stores and high ferritin.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Iron metabolism?

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.