Immunology: hyper IgE syndrome: practice question

A Microbiology 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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Microbiology · Immunology: hyper IgE syndrome

Sample item

A 10-year-old boy has eczema, recurrent staphylococcal skin and lung abscesses with little warmth or inflammation, pneumatoceles, retained primary teeth and fractures after minor trauma. Serum IgE is above 2000 IU/mL. What is the underlying immune defect?

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

The answer and the reasoning

C. Impaired Th17 differentiation due to STAT3 mutation

Autosomal dominant hyper IgE (Job) syndrome results from dominant-negative STAT3 mutations. Th17 cells and IL-17 are needed for recruitment of neutrophils to skin and lung, so staphylococcal abscesses form without usual inflammation (cold abscesses). Connective tissue features include retained primary teeth, scoliosis and fractures.

Option by option

  • A. Defective integrin-mediated leukocyte adhesion

    Adhesion molecule defects cause leukocyte adhesion deficiency with absent pus formation and delayed cord separation.

  • B. Defective lysosomal trafficking regulator

    A lysosomal trafficking defect causes Chediak-Higashi syndrome with partial albinism and giant granules.

  • C. Impaired Th17 differentiation due to STAT3 mutation (correct)

    STAT3 mutation prevents Th17 differentiation and explains the cold abscesses and skeletal features.

  • D. Defective phagocyte NADPH oxidase

    NADPH oxidase deficiency causes chronic granulomatous disease with catalase-positive infections but not these skeletal features.

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 Microbiology question

What is the answer to this Microbiology question?

The best answer is C, Impaired Th17 differentiation due to STAT3 mutation. Autosomal dominant hyper IgE (Job) syndrome results from dominant-negative STAT3 mutations.

Why is "Defective integrin-mediated leukocyte adhesion" not the answer?

Adhesion molecule defects cause leukocyte adhesion deficiency with absent pus formation and delayed cord separation.

Why is "Defective lysosomal trafficking regulator" not the answer?

A lysosomal trafficking defect causes Chediak-Higashi syndrome with partial albinism and giant granules.

Why is "Defective phagocyte NADPH oxidase" not the answer?

NADPH oxidase deficiency causes chronic granulomatous disease with catalase-positive infections but not these skeletal features.

What concept does this question test?

It tests Immunology: hyper IgE syndrome in Microbiology. Th17 cells and IL-17 are needed for recruitment of neutrophils to skin and lung, so staphylococcal abscesses form without usual inflammation (cold abscesses). Connective tissue features include retained primary teeth, scoliosis and fractures.

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 Immunology: hyper IgE syndrome?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology 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.