Chemotherapy: abatacept mechanism: practice question

A Pharmacology 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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Pharmacology · Chemotherapy: abatacept mechanism

Sample item

A patient with rheumatoid arthritis not controlled by methotrexate is started on abatacept, a fusion protein of CTLA-4 and the Fc portion of IgG1. How does it work?

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

The answer and the reasoning

C. Binding CD80 and CD86, blocking T-cell co-stimulation

Abatacept binds CD80 and CD86 on antigen-presenting cells, so they cannot engage CD28 on T cells and the co-stimulatory signal for T-cell activation is lost. Rituximab depletes CD20-positive B cells, tocilizumab blocks the IL-6 receptor, and tofacitinib inhibits JAK enzymes.

Option by option

  • A. Inhibition of Janus kinases in lymphocytes

    JAK inhibition is the action of tofacitinib.

  • B. Depletion of B cells by binding CD20

    B-cell depletion through CD20 is the action of rituximab.

  • C. Binding CD80 and CD86, blocking T-cell co-stimulation (correct)

    Correct. Abatacept blocks CD28 co-stimulation by binding CD80 and CD86.

  • D. Blockade of the interleukin-6 receptor

    IL-6 receptor blockade is the action of tocilizumab.

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 Pharmacology questions

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is C, Binding CD80 and CD86, blocking T-cell co-stimulation. Abatacept binds CD80 and CD86 on antigen-presenting cells, so they cannot engage CD28 on T cells and the co-stimulatory signal for T-cell activation is lost.

Why is "Inhibition of Janus kinases in lymphocytes" not the answer?

JAK inhibition is the action of tofacitinib.

Why is "Depletion of B cells by binding CD20" not the answer?

B-cell depletion through CD20 is the action of rituximab.

Why is "Blockade of the interleukin-6 receptor" not the answer?

IL-6 receptor blockade is the action of tocilizumab.

What concept does this question test?

It tests Chemotherapy: abatacept mechanism in Pharmacology. Rituximab depletes CD20-positive B cells, tocilizumab blocks the IL-6 receptor, and tofacitinib inhibits JAK enzymes.

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 Chemotherapy: abatacept mechanism?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology 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.