Hyperacute transplant rejection occurs within minutes d/t pre-existing recipient antibodies that react to donor antigen (type II hypersensitivity reaction), activate complement.

Transplant Rejections (p.119)

• Hyperacute - Minutes pre-existing Ab attack new organ Ag + activate complement T2
• Acute - Weeks CD8 +/- CD4 bind organ MHC. T4
• Chronic - Months/years CD4s can activate macrophages and mediate damage T4, or activate B cells --> Ab --> damage graft. T2 or T4
• GVH - Time varies, organ with T-cells grow and reject foreign host. T4

Transplant Types

• Autologous Self skin grafts
• Allogenic Normal organ transplant
• syngeneic graft (isograft) Monozygotic twins
• xenograft animal to human heart valves

ABCD Hypersensitivity (p.112 FA2020)

• T1 : Anaphylactic & Atopic
• T2: (anti)Body-mediated
• T3: Complex (Immune)
• T4: Delayed Cell Mediated

Per First Aid: antibodies against ABO blood types tend to be IgM or IgG, which is why the answer is IgG + complement and not IgA + complement