Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Aug 16 2024

Transplant

Snapshot
  • A 55-year-old-woman presents with nausea and yellowing of the skin to her primary care physician. Medical history is significant for a liver transplantation approximately 1.5 weeks prior to presentation. On physical examination there is scleral icterus and mild ascites. A liver biopsy shows lymphocytic infiltrates in the interstitium. (Acute rejection)
Introduction
  • Transplantation is a process by which
    • cells, tissues, or organs (graft) from the donor are transplanted into a host (or recipient)
  • The immune system's ability to recognize and respond to foreign antigens bring challenges to transplantation
    • all transplant patients or on immunosuppressive agents which increases their risk of infection 
  • There are several types of grafts
    • autograft
      • tissue is moved from one location to another in the same person
        • e.g., skin graft and using the saphenous vein to replace a coronary artery
      • the graft will not be considered foreign and will not require lifelong immunosuppresion
    • syngeneic graft (isograft)
      • tissue is transplanted from one genetically identical donor to the host
        • e.g., transplantation between monozygotic twins
    • allograft
      • tissue is transplanted from one genetically different donor of the same species to the host
        • e.g., kidney transplant
    • xenograft
      • tissue is transplanted from a donor of a different species to the host
        • e.g., porcine heart valve
Transplant Rejection
 
Transplant Rejection
Rejection Type
Pathogenesis
Comments
Hyperacute 
  • Type II hypersensitivity reaction where 
    • pre-existing recipient antibodies attack the donor antigen resulting in
      • complement activation
      • endothelial damage
      • inflammation
      • thrombosis
  • Time
    • minutes to hours
  • Findings
    • capillary thrombosis which
      • prevents graft vascularization
Acute
  • Cellular rejection
    • type IV hypersensitivity reaction where
      • recipient CD8+ T-cells react to donor antigens after activation by antigen presenting cells 
  • Humoral rejection
    • just like in hyperacute rejection; however,
      • the antibodies are formed after transplantation occured
  • Time
    • weeks to months
  • Findings
    • graft vessel vasculitis with
      • lymphocytic infiltrates
  • Treatment
    • Renal 
      • Continue calcineurin inhibitors (i.e., tacrolimus, cyclosporine) and add IV steroids
Chronic 
  • Type II and IV hypersensitivity reaction secondary to
    • CD4+ T-cells responding to the host's antigen presenting cells
  • Time
    • months to years
  • Findings
    • cytokine secretion after T-cell activation leads to
      • smooth muscle proliferation
      • interstitial fibrosis
      • parenchymal atrophy
Graft-versus-host disease
  • Type IV hypersensitivity reaction secondary to
    • the donor's T-cells attacking the recipient's cells leading to 
      • organ dysfunction
  • Time
    • variable
  • Findings
    • maculopapular rash
    • jaundice
    • diarrhea
    • hepatosplenomegaly
 
Tissue Compatibility Testing
  • ABO blood typing
  • Tissue typing
    • used to see if HLA antigens match and subtypes include
      • HLA-A
      • HLA-B
      • HLA-DR

References

Question
1 of 2
Private Note