CHT Transplant Immunology

Question 1

Which type of rejection occurs within minutes to hours after transplantation and is mediated by preformed donor-specific antibodies?

Accepted Answer

Hyperacute rejection

Answer

Acute cellular rejection

Answer

Chronic rejection

Answer

Accelerated acute rejection

Question 2

Which immune cells are primarily responsible for acute cellular rejection?

Accepted Answer

CD4+ and CD8+ T lymphocytes

Answer

B cells and plasma cells

Answer

NK cells and mast cells

Answer

Neutrophils and eosinophils

Question 3

What is the 'indirect pathway' of allorecognition?

Accepted Answer

Host T cells recognize donor peptides presented by self HLA on host APCs

Answer

Host T cells directly recognize intact donor HLA molecules on donor cells

Answer

NK cells recognize missing self HLA on donor cells

Answer

B cells produce antibodies against donor blood group antigens

Question 4

Chronic allograft nephropathy is most closely associated with which long-term immunological mechanism?

Accepted Answer

Persistent donor-specific antibody (DSA)-mediated injury

Answer

Recurrent hyperacute rejection episodes

Answer

Autoimmune anti-tubular basement membrane antibodies

Answer

NK cell cytotoxicity only

Question 5

Which complement pathway is most directly activated by donor-specific antibodies (DSA) bound to graft endothelium?

Accepted Answer

Classical complement pathway

Answer

Alternative complement pathway

Answer

Lectin (MBL) complement pathway

Answer

Terminal pathway only without upstream activation

Question 6

What does a positive C4d staining on peritubular capillaries in a kidney biopsy indicate in the transplant setting?

Accepted Answer

Antibody-mediated rejection (AMR)

Answer

Acute cellular rejection only

Answer

Calcineurin inhibitor toxicity

Answer

Viral nephropathy