organ transplantation Flashcards
(25 cards)
life saving vs life enhancing transplants
liver, heart and bowel vs kidney and pancreas
define allografts
transplants between different individuals of same species
define autografts
transplants from within same individual (eg stem cells)
types of donor
mostly deceased, but also living
types of deceased donors
DBD (after brainstem death) or DCD (after circulatory death)
transplant selection vs allocation
selection is whether someone is eligible to be on the waiting list, allocation is who on the waiting list gets the organ
what allocation is dependent on
waiting time, how genetically close they are, and age difference between donor and recipient
how to increase transplantation activity
more deceased donation eg more elderly/DCD donor, more living donation, and more stem cell research for future (autografts)
problem with DCD donors
unlike DBD donors, organs less useful
problem with organ transplantation and solution
antibodies against blood group antigens- to solve, the antibodies are removed by plasma exchange
DIAGRAM other problem and how this occurs
HLA differences- recipient APC takes off MHC molecules from DONOR cells, and presents these to T cells
most polymorphic HLA types and what this means
HLA-A, HLA-B, HLA-DR, meaning most likely to cause immune reaction
DIAGRAM how to calculate mismatches
in first column, only one mismatch
diagnosis and treatment of immune rejection
histological biopsy ie look for lots of inflammatory cells- treatment involves immunosurpression
types of rejection
either T cell mediated/antibody-mediated, or acute/chronic rejection
T cell mediated
APC removes MHC from donor cells (see before)- T cells then go to organ
DIAGRAM how T cells attack kidney and how to tell they are T cells
can see T cells infiltrate interstitial space, they rupture the BM, and they affect the actual tubules (tubulitis)- they all have CD3
types of antibody-mediated rejection
either against HLA or AB antigens- either pre-transplant (SENSITISED PEOPLE already have antibodies) or post
how antibody-mediated rejection occurs
antibody binds on surface of ENDOTHELIAL cells and recruits complement OR macrophages= endothelial death death
antibody rejection vs T cell rejection
intravascular (eg glomerulonephritis) vs interstitium+tubule
post transplant monitoring for rejection
look at if organ deteriorating eg look at kidney function
post transplant prevention and treatment
prevent HLA differences, and give immunosuppressive drugs
main immunosuppressive drugs against T cells
azothrioprine, steroids and calcineurin inhibitor
main immunosuppressive drugs against B ells
retuxinab (anti-CD20), and proteosome inhibitors
