Tolerance and Transplantation Flashcards
What are the 3 fundamental problems when considering transplantations?
- Transplant must perform its functions
- Transplant and recipient health must be maintained
- Recipient immune system must not reject the transplant
Name the two transplantation types
- Solid organ
2. Blood
What are the two types of blood transplants?
- Bone marrow/hematopoitic stem cell
2. Transfusion
T/F Transplants are permanent solutions
False
What is the most common organ transplant?
Kidney
Name the 4 types of transplants
- Autologous
- Syngeneic
- Allogeneic
- Xenogenic
Define autologous
Donor and recipient are the same individual
Define syngeneic
Donor and recipient are genetically identical
Define allogeneic
Donor and recipient are genetically different but of the same species
Define Xenogenic
Donor and recipient are of a different species
Name the 3 types of organ rejection
- Hyperacute
- Acute
- Chronic
What type of organ rejections are associated with type III hypersensitivity?
Chronic
Which type of organ rejection is associated with type IV hypersensitivity?
Acute
Which type of organ rejection is associated with type II hypersensitivity?
Hyperacute
The time frame for hyperacute organ rejection is what?
minutes to hours
Which organ rejection is associated with blood type alloantibodies?
Hyperacute
What type of cells are involved in Acute organ rejection?
CD4 and CD8 T cells
Which type of rejection is associated with HLA mismatches?
Acute
Which rejection is chronic transplant inflammation?
chronic
Most transplants are ______
Allogeneic
What is the biggest predictor of transplant success?
Histocompatibility between donor and recipient
What three things affect the histocompatibility of donor and recipient?
- Blood type
- Major HLA genes
- Minor HLA genes
What two things improve survival rates?
- Donor matching
2. Immunosuppressants
What is the most common transplantation?
Blood transfusions
When was the first blood transfusion/transplant performed?
1812
T/F blood transfusions are a transient transplant
True
How often can you donate blood?
Whole blood: every 56 days
Plasma: every 28 days
Platelets: Every 15 days
What are the 3 blood fractions most commonly transfused?
- Erythrocytes
- Plasma
- Platelets
What are some things that make a blood transfusion easier than a organ transfusion
- Readily donated by healthy individuals
- Simple and inexpensive compared to solid organ transplant
- Erythrocytes do not express MHC 1 an 2
- no HLA matching
What type of antigens dictate blood type transfusion success?
ABO antigens
T/F ABO antigens are oligosaccharides
true
What express antigens similar to A and B?
Gut bacteria
What type of hypersensitivity do we need to be worried about with a blood transfusion?
Type II
Which Solid organ transplants can be done from live, healthy donors?
- Kidney
2. Liver
T/F you can get transplants from cadavers
True
T/F Transplant tissues must be alive and healthy
True
The transplant recipient is in a state of ______
inflammation
T/F the degree of match between donor and recipient varies with tissue type
True
What type of match do you need for a cornea transplant?
No matching or immunosuppression
What type of match do you need for a Liver transplant?
Only blood type match
What type of match do you need for a kidney transplant?
HLA and blood type match
ABO and rhesus incompatibility would lead to what type of rejection?
Hyperacute
Pre-existing anti-HLA class I antibodies would lead to which type of rejection?
Hyperacute
T/F Hyperacute rejection leads to reversible organ loss
False, irreversible organ loss
How would you prevent a hyperacute reaction?
compatibility assessment
Direct and indirect ______ leads to graft rejection
Allorecognition
Acute rejection would be associated with what type of Allorecognition?
Direct
Chronic rejection would be associated with what type of allorecognition?
Indirect
What antigens are involved in Allorecognition?
HLA class I and II antigens
Minor HLA antigens
How would direct allorecognition cause acute rejection?
Transplant dendritic cells activate recipient T cells
In Direct allorecognition that causes acute rejection you have direct ____ Interaction, independent of _______
- MHC
2. Peptide
What is the time frame for Acute rejection due to Direct allorecognition?
Days to weeks
________ Activates T cells directly
Allogeneic
Activated transplant dendritic cells express ___ which lead to activating a _______ response
- B7
2. CD8 and CD4 Th1
Antibodies against transplant MHC I cause _________
Chronic rejection
Progressive loss of blood and nutrient supply would be indicative of what kind of rejection?
Chronic rejection from antibodies against transplant MHC I
What type of transplantations Could be said to reset the blood system?
Bone marrow/hematopoietic stem cells
T/F Donor and recipient must share some HLA class I and II haplotypes
True
Hematopoietic transplants cause what type of disease?
Graft-Versus-Host Disease
Define graft versus host disease?
Transplant adaptive immune cells target and kill recipient tissues
What are the most pronounced problems in GVHD?
- GI
- Liver
- Skin problems
GVHD can be beneficial in what way?
For fighting cancer
Donor T cells cause
Acute DVHD
Alloreactive _______ cells can kill recipient _______
- Natural killer cells
2. Leukemia
What suppresses NF-kB transcriptional activity?
Corticosteroids
Immunosuppression targets what ?
T cell activation
Name two drugs that inhibit T cell activation?
- Cyclosporin
2. Tacrolimus
Name two drugs that prevent T cell survival and proliferation?
- Belatacept
2. Anti-CD25
