Lecture 20 - Immunology of transplantation Flashcards
What are the two major advancements with transplantations? [2]
- Surgery
- Immune suppression
What happens to a transplant if the antigens are recognised as foreign?
The transplant is rejected
What are the two challenges that restrict the advancement of transplants? [2]
- Managing Organ rejection
- Organ supply
What are the types of transplant that can be performed?
- Solid organ
- Stem cell transfer
- Others
What does Autograft refer to?
Using tissues from a patient for a transplant to the same patient
What does Isograft refer to?
Using tissues/organs from an identical twin
What does Allograft refer to?
Using tissues/organs from a non-identical donor
What does Xenograft refer to?
Using tissues/organs from animals
What does it mean if a transplant is Histocompatible?
- No immune response
- Accepted
What does it mean if a transplant is HistoIncompatible?
- Immune response
- Rejected
What kind of response do MAJOR histocompatibility antigens cause?
Strong responses
What kind of response do MINOR histocompatibility antigens cause?
Weaker response
Where is the loaction of the gene loci that are responsible for the most vigorous graft rejections?
In the major histocompatibility complex
How are the alleles in the MHC genes expressed?
Co-dominantly
What does MINOR histocompatability antigen incompatibility cause?
Slow graft rejections
What are the three types of graft rejection? [3]
- Hyperacute (minutes)
- Acute (days to weeks)
- Chronic (months to years)
How does hyperactive rejection occur?
- Patient has pre-formed anti-donor antibodies
- Activates immune system
What are the stages of rejection during an Acute rejection?
- Allo-recognition and activation of CD4+ Th cells
- Generation of efectors cells
- Attack on graft
How does chronic rejection occur?
- Slow and progressive loff of graft function
- Leads to bloackage of vessels
How can you avoid graft rejection?
- Organ retrieval
- Pre-screening and matching
How can you prevent graft rejection?
Immune suppression
How can you minimise the damage to donated organs before a transplant?
- Optimal donor management
- Organ preservation
What are the drawbacks to using immune supression?
- Increases risk of infections and malignancy
- Drug associated toxicities
