Transplant Immunology Flashcards
graft
cells, tissues, or organs that are transplanted
____ is the major barrier to transplantation medicine
Organ availability is the major barrier to transplantation medicine
Most common transplants (top 3)
- Kidney
- Liver
- Heart
___ are a common transplant that do not have the immunological barriers that are common to almost all other allografts. They are removed from all deceased donors.
Corneal transplants are a common transplant that do not have the immunological barriers that are common to almost all other allografts. They are removed from all deceased donors.
Living vs deceased donors
- Living donors have better outcomes than deceased donors on average
- Living donors may provide kidney; lobe of a lung; partial liver, pancreas or intestine
- Deceased donors may provide any organ
- Brain dead donors best outcomes on average among all deceased donors
- Circulatory death donors second best outcomes among all deceased donors
Organs derived from deceased donors are sometimes referred to as ___.
Organs derived from deceased donors are sometimes referred to as cadaveric.
Circulatory death donors
Died recently, usually from trauma, opiate overdose, or terminally ill donors after voluntary cessation of life support
Factors in matching: Kidney
Factors in matching: Liver
Factors in matching: Lung
Factors in matching: Heart
Some transplant criteria applied to several different organs
- Height and weight of donor/recipient (to ensure physiologic/metabolic compatibility)
- Immunocompatibility
- Blood group
- Presence of antibodies for donor cells
Since patients with no renal function can be kept alive by dialysis until a kidney becomes available, one criteria for waiting list placement of these patients is . . .
Since patients with no renal function can be kept alive by dialysis until a kidney becomes available, one criteria for waiting list placement of these patients is the time they have been dialysis‐dependent
Types of living donation: Related
Blood relatives of transplant candidates including brothers, sisters, parents, children (over 18 years of age), aunts, uncles, cousins, half brothers & sisters, nieces and nephews
Types of living donation: Non-related
Individuals emotionally close to, but not related by blood to transplant candidates, including spouses, in-law relatives, close friends, coworkers, neighbors or other acquaintances.
Types of living donation: Non-directed
Individuals who are not related to or known by the recipient, but make their donation purely out of selfless motives. This type of donation is also referred to as anonymous, altruistic stranger, and stranger-to-stranger living donation
Types of living donation: Paired
Consists of two kidney donor/recipient pairs whose blood types are not compatible. The two recipients trade donors so that each recipient can receive a kidney with a compatible blood type
Even without the advantage of shared MHC alleles, organs removed from living donors . . .
Even without the advantage of shared MHC alleles, organs removed from living donors are in better condition, that is suffered less ischemic damage, then those removed from cadavers, and therefore also do better in the recipients
Ethical and Social Considerations of Transplantation
- Risk to donor
- Compensation for donors
- “Transplantation tourism”
- Waiting lists and triage
- Racial/ethnic minority donor shortages
- Consent for deceased organ donation
- Definitions of death for deceased donors
- Expense/resources
Transplantation tourism
The phenomenon of patients in need of organs traveling to countries where there are more organs available
Rejection
An inflammatory reaction which a recipient mounts against a graft, which can cause graft injury and failure. Mediated by adaptive immunity.
autologous graft
A graft transplanted from one individual to the same individual
syngeneic graft
A graft transplanted between two genetically identical individuals
allogeneic graft (or allograft)
A graft transplanted between two genetically different individuals of the same species
xenogeneic graft (or xenograft)
A graft transplanted between individuals of different species
alloantigens
The molecules that are recognized as foreign on allografts
xenoantigens
The molecules that are recognized as foreign on xenografts