Transplant

Question 1

What induces the strongest stimuli for transplant rejection?

Answer 1

MHC recognition

Question 2

name 2 MIA

What happens with the female-male antigen

Answer 2

HA-2 //H-Y

females may recognise male H-Y antigen as its sex specific

Question 3

1st rejection of transplant is within how long?

why?

Answer 3

within 2 weeks

T cells discover MHC

Question 4

2nd rejection of transplant is within how long?

Why

Answer 4

Days

Primed immune system

Question 5

As well as the cells MHC, what can also induce a rejection?

Answer 5

Passenger Leukocytes (APC donors recognition)

Question 6

The difference between the 1st and 2nd rejection with revascularization and infiltration?

Answer 6

2nd rejection doesnt have revascularization

Question 7

What % of rejection takes place for cornea transplant?

Why is it so low?

Answer 7

10%

Lacks lymphatic drainage and has the privileged status of the anterior chamber

Question 8

TH1 Recognise what on graft? What is then released to activate macrophages?

Answer 8

HLA (DP/DQ/DR)

Releases IL-2

Question 9

TH2 recognise what on grafts? What is then released to induce class switching?

Answer 9

MHC2

IL-4 released

Question 10

Both TH1 / 2 release what interleukin to activate CD8?

What can this then do?

Answer 10

Il-2

Activates CD8 –> MHC1 –> CTL

Question 11

Opportunistic infections can occur for transplants why>

Name a virus which infects graft patients and what can be given?

Answer 11

Immunosuppresants = low cytokine/CD4 response

Herpes Simplex Virus = Prophylactic IV Ig

Question 12

Hyperacute rejection occurs within how long? what is it mediated by and thus cause

Answer 12

<24 hours

Existing IgG/M = Complement activation

No vascularization takes place

Question 13

Early Acute Rejection involves what type of recognition?

Where does this occur and what cells are involved?

Answer 13

Direct Recognition of donor MHC via allospecific T

Peripheral Lymph nodes

Question 14

Acute late rejection involves what cells? what recognition is this?

Because of this process, how does it differ to early acute rejection in terms of time

Answer 14

Host dendrites –> foreign MHC –> allospecific T

Indirect Recognition

takes longer (>10 days)

Question 15

Chronic Rejection is done how long?

What response is this in terms of mediation

and what happens to the vascular?(3)

Answer 15

months - years

Humoural Cell mediated Response

CI in smooth walls / vessel occlusion / Ischaemia

Question 16

acute GvHD affects what for how long?

Chronic GvHD affects what

Answer 16

skin / liver (<100 days)

Thymus

Question 17

What procedure can be done to remove chance of GvHD from occuring?

Benefit of GvHD?

Answer 17

Depletion removes T donor cells

Lymphocyte recognise Host leukaemia

Question 18

Flow cytometry (…………..) phenotypes what?

What 2 other procedures can be done for tissue typing

Answer 18

PCR-SSOP phenotypes HLA

Serological tissue typing // mixed lymphocyte reaction

Question 19

Name 3 things prednisone (immunosuppressant) can do

Answer 19

decrease MHC2 expression / IL-1 by macrophages (diapedesis)

Inhibit lysosomal release via stabalizing membranes

Inhibit T cell cytokine production

Question 20

Name an immunosuppresant that inhibits T cell production + inhibits precursor for purine synthesis

Answer 20

Azathioprine

Question 21

Name a MAB that binds to IFN-Y

Name a MAB that binds to CD4

Answer 21

Fontolizumab

Clenoliximab

Question 22

What do the 2 MAB used as immunosuppressants do?

Answer 22

Inhibit T cell signalling / activation

Question 23

Cyclosporin and ….. is an immunosuppresant which suppresses what?

What does this suppression allow?

Answer 23

Tacrolimus

Suppresses IL-2 / 4 / IFN-Y

Prevents T cell signalling