Organ Transplant Rejection Flashcards
What are 3 fundamental problems in organ transplantation?
1-Transplant must perform its function
2-Transplant and recipient health must be maintained
3-Recipient immune system must not reject the transplant
What are 2 Transplantation types?
1-Solid organ
2-Blood (bone marrow or transfusion)
When a donor and recipient are the same individual it is called?
Autologous
When the donor and recipient are genetically identical (twins) it is called?
Syngeneic
When the donor and recipient are genetically different but of the same species it is called what?
Allogeneic
When the donor and recipient are of different species it is called?
Xenogeneic
What are the 3 types of Organ rejection?
1-Hyperacute
2-Acute
3-Chronic
Which type of organ rejection is type II hypersensitivity, happens in minutes to hours of which alloantibodies are a problem?
Hyperacute
Which type of organ rejection is Type IV hypersensitivity involving CD4 and CD8 T cells and have HLA mismatches?
Acute
Which type of Organ rejection is Type III hypersensitivity, is caused by antibodies against transplant MHC I and is associated with long term organ transplant inflammation?
Chronic
What is the most common transplant?
Blood transfusion
*no MHC I or II so no HLA matching, leukocytes are removed
What are the three fractions of blood that are commonly transfused?
1-Erythrocytes
2-Plasma
3-Platelets
ABO antigens dictate blood type and transfusion success, when the blood is rejected it is what type of hypersensitivity?
Type II
*oligosaccharides on erythrocytes. Gut express similar A and B antigen.
Which blood type is the universal donor?
Type O- (no surface A/B protein or Rh factor)
Which blood type is the universal recipient?
AB+ (No antibodies against A,B or Rh factor)
What needs to match for a success cornea, liver or kidney transplant respectively?
Cornea: No matching needed
Liver: Only blood type
Kidney: HLA and blood type
Direct and Indirect allorecognition leads to what?
Graft rejection
What type of rejection is caused by transplant dendritic cells activating recipient T cells though direct MHC interaction, independent of peptide and happens in days to weeks?
Direct allorecognition causing acute rejection
*Type IV sensitivity
How do you reset the blood system?
Bone marrow/Hematopoietic stem cell transplantation
*used for blood diseases (myeloid and lymphoid cancers) also causes graft Versus host disease (GVHD)
What must the donor and recipient share some of in order to mount an adaptive immune response?
HLA class I and II haplotypes
What disease results when the transplant adaptive immune cells target and kill recipient tissues?
Graft versus host disease
*most pronounced in GI, liver and skin
Alloreactive NK cells can kill what?
Leukemia in recipient
What drugs suppress NF-kB transcriptional activity by increasing IkBa production?
Corticosteroids
*Prednisolone is the active compound
Immunosuppression targets what?
T cell activation signals
1-Activation
2-Survival
3-Proliferation
