Rheumatology: serology of active lupus nephritis: practice question

A General Medicine 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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General Medicine · Rheumatology: serology of active lupus nephritis

Sample item

A patient with lupus has haematuria, rising creatinine and new oedema. Which laboratory pattern best indicates active lupus nephritis?

AHigh C3 and C4 with falling anti-dsDNA titreBLow C3 and C4 with raised anti-dsDNA titreCNormal complement with positive anti-histoneDLow C3 with positive anti-centromere

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

The answer and the reasoning

B. Low C3 and C4 with raised anti-dsDNA titre

Active immune-complex disease consumes complement, so C3 and C4 fall while anti-dsDNA antibody titres rise. These two markers are followed to judge lupus flares, especially nephritis.

Option by option

A. High C3 and C4 with falling anti-dsDNA titre
Rising complement with falling anti-dsDNA suggests remission.
B. Low C3 and C4 with raised anti-dsDNA titre (correct)
Correct. Complement consumption with rising anti-dsDNA marks a renal flare.
C. Normal complement with positive anti-histone
Anti-histone positivity points to drug-induced lupus, which spares the kidney.
D. Low C3 with positive anti-centromere
Anti-centromere belongs to limited systemic sclerosis and does not track lupus nephritis.

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.

Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is B, Low C3 and C4 with raised anti-dsDNA titre. Active immune-complex disease consumes complement, so C3 and C4 fall while anti-dsDNA antibody titres rise.

Why is "High C3 and C4 with falling anti-dsDNA titre" not the answer?

Rising complement with falling anti-dsDNA suggests remission.

Why is "Normal complement with positive anti-histone" not the answer?

Anti-histone positivity points to drug-induced lupus, which spares the kidney.

Why is "Low C3 with positive anti-centromere" not the answer?

Anti-centromere belongs to limited systemic sclerosis and does not track lupus nephritis.

What concept does this question test?

It tests Rheumatology: serology of active lupus nephritis in General Medicine. These two markers are followed to judge lupus flares, especially nephritis.

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 Rheumatology: serology of active lupus nephritis?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.