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
Which type of rejection occurs within minutes to hours after transplantation and is mediated by preformed donor-specific antibodies?
Answer: Hyperacute rejection
Hyperacute rejection is caused by preformed donor-specific antibodies that immediately activate complement and cause thrombosis of graft vasculature.
Which immune cells are primarily responsible for acute cellular rejection?
Answer: CD4+ and CD8+ T lymphocytes
Acute cellular rejection is driven predominantly by host CD4+ and CD8+ T cells that recognize donor alloantigens as foreign.
What is the 'indirect pathway' of allorecognition?
Answer: Host T cells recognize donor peptides presented by self HLA on host APCs
In the indirect pathway, donor HLA proteins are processed into peptides and presented by recipient APCs on self-HLA molecules to recipient T cells.
Chronic allograft nephropathy is most closely associated with which long-term immunological mechanism?
Answer: Persistent donor-specific antibody (DSA)-mediated injury
Chronic antibody-mediated rejection driven by DSA leads to progressive microvascular injury, transplant glomerulopathy, and eventual graft loss.
Which complement pathway is most directly activated by donor-specific antibodies (DSA) bound to graft endothelium?
Answer: Classical complement pathway
DSA bound to donor endothelial HLA antigens activate the classical complement pathway via C1q, leading to C4d deposition.
What does a positive C4d staining on peritubular capillaries in a kidney biopsy indicate in the transplant setting?
Answer: Antibody-mediated rejection (AMR)
Peritubular capillary C4d deposition is a marker of complement activation by DSA and is a diagnostic criterion for antibody-mediated rejection.