Immunology: crossmatch before transplantation: 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: crossmatch before transplantation

Sample item

Before a renal transplant, the laboratory mixes the potential recipient's serum with donor lymphocytes in the presence of complement. Which risk does a positive result predict?

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

The answer and the reasoning

B. Hyperacute rejection due to preformed anti-donor antibody

The complement-dependent cytotoxicity crossmatch detects preformed recipient antibodies against donor HLA antigens. A positive result means the graft would be attacked within minutes to hours of reperfusion, with thrombosis and necrosis, so transplantation is avoided. Preformed antibodies arise from previous transfusions, pregnancies or grafts.

Option by option

  • A. Graft-versus-host disease

    Graft-versus-host disease is mediated by donor T cells and relates to haematopoietic transplantation.

  • B. Hyperacute rejection due to preformed anti-donor antibody (correct)

    Correct. Lysis of donor cells shows preformed antibody and predicts hyperacute rejection.

  • C. Chronic graft vasculopathy years later

    Chronic vasculopathy develops slowly and is not predicted by a crossmatch.

  • D. Cytomegalovirus reactivation

    Cytomegalovirus reactivation depends on immunosuppression and serostatus, not on the crossmatch.

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, Hyperacute rejection due to preformed anti-donor antibody. The complement-dependent cytotoxicity crossmatch detects preformed recipient antibodies against donor HLA antigens.

Why is "Graft-versus-host disease" not the answer?

Graft-versus-host disease is mediated by donor T cells and relates to haematopoietic transplantation.

Why is "Chronic graft vasculopathy years later" not the answer?

Chronic vasculopathy develops slowly and is not predicted by a crossmatch.

Why is "Cytomegalovirus reactivation" not the answer?

Cytomegalovirus reactivation depends on immunosuppression and serostatus, not on the crossmatch.

What concept does this question test?

It tests Immunology: crossmatch before transplantation in Microbiology. A positive result means the graft would be attacked within minutes to hours of reperfusion, with thrombosis and necrosis, so transplantation is avoided. Preformed antibodies arise from previous transfusions, pregnancies or grafts.

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: crossmatch before transplantation?

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.