Transplant Immunity Flashcards
1
Q
transplant rejection
A
-when a kidney is transplanted and the recipients T cells attack the transplant
2
Q
graft versus host disease
A
-bone marrow is transplanted and the T cells in the transplant attack the recipients tissue
3
Q
MHC
A
- class I and class II genes
- antibodies against class I were easy to if
- tasmanian devil tumors wouldn’t transfer if there was an MHC barrier-there isn’t
- class I and class II isotypes range from monomorphic to highly polymorphic
- hard to get HLA match
4
Q
blood group antigens
A
- blood is most common transplant
- blood groups are antigens of the surface of most cells in the body
- most people have natural antibodies against other blood groups
- IgM antibodies
5
Q
o antigen
A
-mostly naked
6
Q
a antigen
A
-galnAc
7
Q
b antigen
A
gal
8
Q
Rh factor
A
- if neg, only have anti Rh after exposed to Rh-like mom giving birth to Rh pos baby
- if pos, don’t have anti Rh
9
Q
blood types and transplantation
A
- ABO, method agglutination
- AB patient has no anti A or B
- a patient has anti B
- B patient has anti A
- O patient has anti A and B
10
Q
hyperacture rejection
A
- most severe and immediate
- caused by preformed antibodies that react to the transplanted organ
- most common antigen would be a blood group antigen
- under some conditions, can have pre-existing antibodies to HLA antigens
- minutes to hours
11
Q
example of hyperacute
A
- healthy kidney grafted into patient with defective kidney and pre-existing antibodies against donor blood group antigens
- antibodies against donor blood group antigens bind vascular endothelium of graft, initiating IF response that occludes blood vessels
- graft becomes engorged and purple colored because of hemorrhage
- usually IgM against blood group but can be IgG against HLA
12
Q
cross match
A
- preformed antibodies to HLA
- IgG
- previous surgeries/transplants and could be exposed to HLA
- blood transfusions- exposed to B and T cells
- women giving birth-mom becomes sensitized to babies (dads) HLA
13
Q
panel reactive antibody
A
- serum of a recipient is tested against a panel of leukocytes from many individuals
- detection of the presence of antibodies to HLA
- presented as a percentage from 0-100%
- have to consider past medical history-25yo w/ tetrology of fallot may not be as good as 65yo with no previous surgery
14
Q
acute rejection
A
- process in which T cells from recipient become reactive against the transplant
- days to weeks
- stronger response is donor MHC II in the graft eliciting a response (DCs in kidney- kidney cells wouldn’t normally have MHCII)-direct- DCs go to spleen and activate T cells that go back to kidney and kill it–>
- weaker response is indirect presentation of dying donor cells by APCs-indirect
- most immune suppression therapies are directed toward inhibiting acute rejection
15
Q
allorecognition
A
-same species, different MHC