Transplantation 1 Flashcards
what is transplantation
the act of transferring cells, tissues, or organs from one
site to another
when did joseph Murray perform his first successful kidney
transplant from living donor
1954
what did Dr Christian Barnard carry out in 1967
the 1st human heart
transplant
Autograft
Tissue is derived from ‘self’, and can be transplanted back
to the same place or another site (same one body)
isograft e.g. first human kidney transplant in 1954
tissue transplanted between genetically identical twins
whats the most common transplant type
Allograft e.g kidney, heart, pancreas, lung, liver, bowel, bone, skin
whats an allograft
Tissue transferred from one individual to another
Xenograft e.g.
Tissue transferred from one species to another (eg.
Heart valves)
why is whole organ xenografting limited
due to the potential for hyperacute rejection
what are immunologically privileged sites e.g.
sites where grafts aren’t rejected e.g cornea, brain, testis, uterus (fetus)
what do corneal allograft transplants not require as they are immunologically privileged sites
no assessment of HLA type and no administration of immunosuppressive drugs
what is the major barrier to overcome in transplantation
Human Leucocyte Antigens (HLA)
how many classical HLA loci are there, each encoded by seperate genes
name them
6
Class I (A,B,C)
Class II (DR, DQ,DP)
Why do HLA’s determine histocompatibility
as they allow tissue to be recognised as ‘self’ or ‘non-self’ by the host IS
what is the primary function of HLA’s, making them very polymorphic
to serve as
recognition molecules in the initiation of an immune
response
what do HLA’s present to effector cells of IS (T cells)
peptides from foreign substances
What cells are HLA class I expressed on
what pathogens do they recognise
on nearly all cells (nucleated)
pathogens that reside inside cells e.g. viruses
What cells are HLA class II expressed on
what pathogens do they recognise
immune cells - antigen presenting
pathogens that reside outside the cells e.g. bacteria
what do HLA-A define
the locus
what does HLA-A24 show
the serologically defined antigen
what does asterisk mean in HLA-A*24
that the allele has been defined by molecular methods (low resolution)
what resolution does HLA-A*24:01 show
where is this required
higher resolution, specific allele
required for haematopoietic stem cell transplant
what do father and mother produce when looking at HLA inheritance
4 haplotypes (sets of DNA variants along single chm)
what must be determined for all organ recipients and donors to minimise chance of rejection
major HLA loci
