Inflammation: myeloperoxidase deficiency: 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 · Inflammation: myeloperoxidase deficiency

Sample item

A 55-year-old man with poorly controlled diabetes has had recurrent Candida infections. A nitroblue tetrazolium test is normal, but his neutrophils fail to generate hypochlorous acid from hydrogen peroxide. Which disorder is this?

ALeukocyte adhesion deficiency type 1BMyeloperoxidase deficiencyCChronic granulomatous diseaseDChediak-Higashi syndrome

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

The answer and the reasoning

B. Myeloperoxidase deficiency

Myeloperoxidase converts hydrogen peroxide and chloride into hypochlorous acid, a major microbicidal product. Its deficiency is the commonest inherited phagocyte disorder and is usually asymptomatic, though Candida infection may occur, particularly in diabetics. The oxidative burst itself, and so the nitroblue tetrazolium test, is normal.

Option by option

A. Leukocyte adhesion deficiency type 1
Leukocyte adhesion deficiency type 1 impairs adhesion and gives neutrophilia without pus.
B. Myeloperoxidase deficiency (correct)
Correct. A normal respiratory burst with failure of hypochlorous acid formation is typical of this enzyme defect.
C. Chronic granulomatous disease
Chronic granulomatous disease has a failed burst and an abnormal nitroblue tetrazolium test.
D. Chediak-Higashi syndrome
Chediak-Higashi syndrome shows giant granules and albinism, not isolated failure of hypochlorous acid formation.

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, Myeloperoxidase deficiency. Myeloperoxidase converts hydrogen peroxide and chloride into hypochlorous acid, a major microbicidal product.

Why is "Leukocyte adhesion deficiency type 1" not the answer?

Leukocyte adhesion deficiency type 1 impairs adhesion and gives neutrophilia without pus.

Why is "Chronic granulomatous disease" not the answer?

Chronic granulomatous disease has a failed burst and an abnormal nitroblue tetrazolium test.

Why is "Chediak-Higashi syndrome" not the answer?

Chediak-Higashi syndrome shows giant granules and albinism, not isolated failure of hypochlorous acid formation.

What concept does this question test?

It tests Inflammation: myeloperoxidase deficiency in Pathology. Its deficiency is the commonest inherited phagocyte disorder and is usually asymptomatic, though Candida infection may occur, particularly in diabetics. The oxidative burst itself, and so the nitroblue tetrazolium test, is 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 Inflammation: myeloperoxidase deficiency?

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.