Transplantation Flashcards
1
Q
Transplantation
A
Used to replace tissues/organs that have undergone an irreversible pathological process
2
Q
Transplantation criteria
A
- Irreversible damage
- No alternative treatments
- No reoccurrence
3
Q
Autologous (autograft)
A
Tissue returning to same individual
4
Q
Syngeneic (isograft)
A
Tissue from identical twin
5
Q
Allogeneic (allograft)
A
Tissue between humans (same species)
6
Q
Xenogeneic (xenograft)
A
Tissue between different species
7
Q
Cadaveric
A
Tissue from dead donor
8
Q
Privileged sites
A
Anatomical region that are naturally less subject to immune responses
- Cornea
- CNS
- Testes
9
Q
Transplantation Complications
A
- REJECTION
- GVHD
- Infection
- Neoplasia
- Drug side effects
- Recurrence of disease
- Ethical, surgical issues
10
Q
Hyperacute rejection
A
- Within hours
1. Preformed antibodies bind to ABO blood group or HLA class I antigens on graft.
2. Hypersensitivity type II reaction
3. Vascular thrombosis
11
Q
Acute rejection
A
- Days or weeks
1. Allorecognition: donor dendritic cells (APCs) stimulate response - HLA mismatch
2. T cells migrate and recruit other cells (macrophages, NK cells, B lymphocytes)
12
Q
Chronic rejection
A
- Months or years
- Allogeneic reaction often mediated by T cells - repeated acute rejection
- Multifactorial
13
Q
Stem cell transplant (SCT)
A
Haematopoetic stem cells used to restore myeloid and lymphoid cells
- Autologous: returned to same patient
- Allogenic: high risk (GVHD)
- Sources - bone marrow, peripheral blood, umbilical cord blood
- Conditioning prior to SCT
14
Q
Graft versus Host Disease (GVHD)
A
Donor T cells respond to allogeneic recipient antigens
- Acute: 4 weeks (skin, gut, liver, lung)
- Chronic: skin and liver
- Treatment: Immunosuppressive drugs
15
Q
Prevent graft rejection
A
- ABO compatibility
- HLA compatibility (typing and cross-matching)
- Absence of anti-donor HLA
- Immunosuppressive Tx
