Transplant Immunology Flashcards
6 cards from real CHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Transplant Immunology flashcards as text
What is a 'virtual crossmatch' in transplantation?
Answer: Predicting crossmatch outcome by comparing recipient DSA specificities to donor HLA typing without a physical test
Virtual crossmatch uses recipient antibody specificity data (SAB testing) and donor HLA typing to predict whether a physical crossmatch would be positive, enabling faster organ allocation.
Which immunosuppressive drug class specifically inhibits calcineurin to block IL-2 production and T cell activation?
Answer: Calcineurin inhibitors (cyclosporine, tacrolimus)
Cyclosporine and tacrolimus bind cyclophilin and FKBP12 respectively, forming complexes that inhibit calcineurin and block NFAT-mediated IL-2 gene transcription.
In the context of sensitization, what does a high Calculated Panel Reactive Antibody (cPRA) value indicate?
Answer: The patient has antibodies reactive to a large proportion of the donor pool, making compatible donors rare
A high cPRA (e.g., 90%+) means the recipient has HLA antibodies that would react with most potential donors, significantly limiting compatible organ availability.
Which test is used to measure the strength of donor-specific antibodies in mean fluorescence intensity (MFI) units?
Answer: Single Antigen Bead (SAB) assay
SAB assays use Luminex-based beads coated with single HLA antigens to detect and quantify DSA by measuring MFI, providing antibody specificity and relative strength.
What is the significance of 'de novo' donor-specific antibodies (dnDSA) post-transplant?
Answer: They are strongly associated with late antibody-mediated rejection and graft loss
De novo DSA developing after transplantation are a major risk factor for chronic antibody-mediated rejection and long-term graft failure.
Which phenomenon describes the situation where a transplant recipient becomes unresponsive to donor alloantigens without chronic immunosuppression?
Answer: Operational tolerance
Operational tolerance is a rare state in which a transplant recipient maintains stable graft function without immunosuppression due to active regulation of the immune response.