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Flashcards in MHC and transplanatation Deck (26):
1

In what types of cells is blood group substance found

all vascular endothelial cells.

2

what 2 types of isoagglutinins do all individuals have

anti A and anti B

3

what are isoagglutinins

Antibodies produced by an individual that cause agglutination of red blood cells in other individuals.

4

what happens when a donor is mismatched for the second time

necrosis is much faster.
• This is because the immune system has formed a memory
• 2nd response is more vigorous.

5

What is MHC

set of genes found in all vertebrate species.

6

What are the key roles of MHC

immune function- present ‘self’ and ‘nonself’ antigens for inspection by T cell antigen receptors.
disease susceptibility
reproductive success.

7

what chromosome is MHC found on

6 (short arm)

8

how many classes of MHC are there

3

9

which classes of MHC are involved in transplant

class I and class II (encode antigens)

10

what cell are class I expressed on

all nucleated cells.

11

What cells are class II antigens expressed on

B lymphocytes and expression can be indued on T lymphocytes

12

what type of biochemical molecules are MHC/HLA

glycoproteins.

13

How is MHC inherited

mendelian inheritance
each individual inherits 2 antigens at a given locus.
co-dominant expression. All inherited antigens are displayed on the cell surface.

14

what type os blood cell has lots of HLA'a

WBC

15

Is HLA highly polymorphic

Yes large number of allelic variants at each locus.

16

why is the advantage of having so many types of HLA

survival advantage
– as everyone in the population will have developed resistance and immunity against certain pathogens, overall as a population we have immense immunity to lots of pathogens.

17

How do we determine different allelic forms of HLA which can form polymorphisms

use primers

18

Is HLA part of the adaptive or complement immune system

adaptive

19

What is direct recognition

happens immediately after transplant.
not typical body process.
T cells get through due to damage of capillary wall from surgery and stress and bind to graft.

20

What is indirect recognition

normal process.
APC moves into tissue and is presented with graft peptides which it then processes and presents
migrates to lymph nodes where it can present it to T cells, which migrate to the graft

21

What is semidirection recognition.

• Recipient APc move in to tissue
• Binds with donor APC
• Migration of this new APC to lymph nodes where it will present to T cells.

22

define sensitization

Any event which elicits an HLA directed immune response
• Pregnancy- foetus is allograft
• Blood transfusion- contain WBC which have HLA.
• Transplantation- HLA or the donor

23

what methods are used to prevent sensitisation

• Serum screening- determines patients and donors HLA profile to see if they match
• Cross matching- checks recipients’ serum against donors.

24

How does cross matching take place

• Donor T lymphocyte with HLA
• Recipient serum added which many contain antibodies against the HLA.
• Florescence second antibody is used to see whether the antibody- HLA complex has formed
• This is read through a detector.

25

when does a hyper acute rejection occur

severely mismatched HLA

26

What happens in hyper acute rejection

• Antibodies in the recipient bind to endothelial cells of the transplant as they class it as foreign
• This activates the coagulation cascade
– Activate clotting cascade
– Activate complement
– Transplant becomes leaky and necrotic