Immunology: severe combined immunodeficiency: 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.

Try it

Microbiology · Immunology: severe combined immunodeficiency

Sample item

A 4-month-old infant has persistent oral thrush, chronic diarrhoea, failure to thrive and profound lymphopenia, and developed disseminated disease after BCG vaccination. What is the definitive treatment?

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

The answer and the reasoning

B. Early allogeneic haematopoietic stem cell transplantation

Severe combined immunodeficiency involves absent T cell function, with B or NK cell defects depending on the gene, and is fatal in infancy without correction. Live vaccines are contraindicated. Definitive treatment is haematopoietic stem cell transplant, ideally before infections develop, with gene therapy for selected types.

Option by option

  • A. Monthly intravenous immunoglobulin alone

    Immunoglobulin replacement corrects antibody deficiency only, not the T cell defect.

  • B. Early allogeneic haematopoietic stem cell transplantation (correct)

    Correct. Transplant reconstitutes the missing lymphocyte compartment.

  • C. Long-term antifungal prophylaxis alone

    Antifungals treat infection but do not correct the underlying immune failure.

  • D. Recombinant G-CSF

    G-CSF raises neutrophil counts and does not restore lymphocyte function.

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.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is B, Early allogeneic haematopoietic stem cell transplantation. Severe combined immunodeficiency involves absent T cell function, with B or NK cell defects depending on the gene, and is fatal in infancy without correction.

Why is "Monthly intravenous immunoglobulin alone" not the answer?

Immunoglobulin replacement corrects antibody deficiency only, not the T cell defect.

Why is "Long-term antifungal prophylaxis alone" not the answer?

Antifungals treat infection but do not correct the underlying immune failure.

Why is "Recombinant G-CSF" not the answer?

G-CSF raises neutrophil counts and does not restore lymphocyte function.

What concept does this question test?

It tests Immunology: severe combined immunodeficiency in Microbiology. Live vaccines are contraindicated. Definitive treatment is haematopoietic stem cell transplant, ideally before infections develop, with gene therapy for selected types.

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: severe combined immunodeficiency?

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.