Renal: IgA nephropathy: practice question

A Pathology 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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Pathology · Renal: IgA nephropathy

Sample item

A 20-year-old man has recurrent episodes of macroscopic haematuria one to two days after each sore throat. Serum C3 and C4 are normal. What would immunofluorescence of his renal biopsy show?

ANo immune deposits on stainingBMesangial deposits dominated by IgA with C3CLinear IgG staining along the glomerular basement membraneDGranular IgG and C3 along the capillary loops

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

The answer and the reasoning

B. Mesangial deposits dominated by IgA with C3

IgA nephropathy is the commonest primary glomerulonephritis worldwide. Galactose-deficient IgA1 forms immune complexes that deposit in the mesangium, and flares of haematuria typically follow mucosal infection within one to two days, unlike the two-week latent period of post-streptococcal disease. Complement levels are normal.

Option by option

A. No immune deposits on staining
Absence of deposits characterises pauci-immune ANCA vasculitis.
B. Mesangial deposits dominated by IgA with C3 (correct)
Correct. Mesangial IgA deposition defines the disease.
C. Linear IgG staining along the glomerular basement membrane
Linear IgG staining defines anti-GBM disease, which gives rapidly progressive glomerulonephritis with haemoptysis.
D. Granular IgG and C3 along the capillary loops
Granular capillary-loop staining describes membranous nephropathy or immune complex disease and is not the pattern here.

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 Pathology question

What is the answer to this Pathology question?

The best answer is B, Mesangial deposits dominated by IgA with C3. IgA nephropathy is the commonest primary glomerulonephritis worldwide.

Why is "No immune deposits on staining" not the answer?

Absence of deposits characterises pauci-immune ANCA vasculitis.

Why is "Linear IgG staining along the glomerular basement membrane" not the answer?

Linear IgG staining defines anti-GBM disease, which gives rapidly progressive glomerulonephritis with haemoptysis.

Why is "Granular IgG and C3 along the capillary loops" not the answer?

Granular capillary-loop staining describes membranous nephropathy or immune complex disease and is not the pattern here.

What concept does this question test?

It tests Renal: IgA nephropathy in Pathology. Galactose-deficient IgA1 forms immune complexes that deposit in the mesangium, and flares of haematuria typically follow mucosal infection within one to two days, unlike the two-week latent period of post-streptococcal disease. Complement levels are normal.

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 Renal: IgA nephropathy?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology 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.