Immunology: HLA and drug hypersensitivity: 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: HLA and drug hypersensitivity

Sample item

Before prescribing abacavir to a patient with HIV, which test is advised to prevent a potentially fatal systemic hypersensitivity reaction?

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

The answer and the reasoning

A. HLA-B*57:01 genotyping

Abacavir hypersensitivity, with fever, rash, gastrointestinal and respiratory symptoms, is strongly associated with HLA-B*57:01, which presents the drug-altered peptide repertoire to T cells. Screening before therapy and avoiding the drug in carriers essentially prevents the reaction.

Option by option

  • A. HLA-B*57:01 genotyping (correct)

    Correct. Carriers of HLA-B*57:01 should not receive abacavir.

  • B. HLA-B*27 typing

    HLA-B27 is associated with ankylosing spondylitis and reactive arthritis.

  • C. HLA-DR3 typing

    HLA-DR3 is associated with conditions such as Graves disease and type 1 diabetes.

  • D. HLA-DQ2 typing

    HLA-DQ2 is associated with coeliac disease.

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 A, HLA-B*57:01 genotyping. Abacavir hypersensitivity, with fever, rash, gastrointestinal and respiratory symptoms, is strongly associated with HLA-B*57:01, which presents the drug-altered peptide repertoire to T cells.

Why is "HLA-B*27 typing" not the answer?

HLA-B27 is associated with ankylosing spondylitis and reactive arthritis.

Why is "HLA-DR3 typing" not the answer?

HLA-DR3 is associated with conditions such as Graves disease and type 1 diabetes.

Why is "HLA-DQ2 typing" not the answer?

HLA-DQ2 is associated with coeliac disease.

What concept does this question test?

It tests Immunology: HLA and drug hypersensitivity in Microbiology. Screening before therapy and avoiding the drug in carriers essentially prevents the reaction.

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: HLA and drug hypersensitivity?

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.