Transplant

Question 1

What is transplantation?

Answer 1

Replacement of tissues or organ that have undergone irreversible pathological damage which threatens the patients life or, to a significant degree, considerably hampers their quality of life

Question 2

What are the types of graft in transplant?

Answer 2

Autograft- self
Isograft- identical twin
Allograft- one person to another
Xenograft- different species

Question 3

What are the types of deceased donor?

Answer 3

Brain dead

Cadaveric dead

Question 4

What are the major compatibility makers?

Answer 4

HLA

ABO

Question 5

What is HLA1?

Answer 5

Found in all cells and allow recognition as self

Recognise by cytotoxic T cells

Question 6

What is HLA2

Answer 6

Only in antigen presenting cells
Most important in rejection
T helper cells recognise

Question 7

What type of reaction with an ABO mismatch cause?

Answer 7

Hyperacute

Question 8

What are privileged sites?

Answer 8

Tissues with little immunological tissue, so don’t require tissue matching or immune suppression

Question 9

What is an example of a privileged site?

Answer 9

Eyes

Question 10

What is rejection?

Answer 10

Transplanted tissue is rejected by recipients immune system, which destroys transplanted tissue

Question 11

What are the causes of rejection?

Answer 11

ABO or HLA incompatible
Pre-formed immunity
Faied immunosuppression
Infections/environmental triggers

Question 12

What are the types of rejection?

Answer 12

Immediate
Acute
Chronic

Question 13

What is immediate rejection?

Answer 13

Seconds to minutes

Innate immune response caused by ABO or HLA incompatibility

Question 14

What is the process of immediate rejection?

Answer 14

Complement activation damages blood vessels

Inflammation and thrombosis

Question 15

What ar the risk factors for immediate rejection?

Answer 15

Previous transplant
Previous pregnancies
Blood transfusions

Question 16

What is acute rejection?

Answer 16

Usually days, up to 6 months

Innate and adaptive immune system

Question 17

What is the process of acute rejection?

Answer 17

Sensitisation phase
cellular infiltration of graft by cytotoxic T cells, B cells, NK cells and macrophages
Endothelial inflammation and parenchymal damage

Question 18

What is the sensitisation phase of acute rejection?

Answer 18

Recognition of allontigens by CD4 and CD8
APC reaction as T cell receptors react with APCs via MHC
Costimulation

Question 19

What is chronic rejection?

Answer 19

Most common cause of rejection
>6 months
Antibody mediated with other innate components

Question 20

What is the process of chronic rejection?

Answer 20

Myointimal proliferation in arteries- cytokines and antibodies cause a chronic inflammatory process that proliferates cell walls to protect themselves, which blocks off blood flow and leads to ischaemia and fibrosis

Question 21

How is rejection prevented?

Answer 21

ABO matching
Tissue typing
Prophylactic immune suppression

Question 22

What immune suppression is given post transplant?

Answer 22

Corticosteroids
Calcineurin inhibitors
Anti-proliferatives

Question 23

What is the treatment of rejection?

Answer 23

Corticosteroids- IV then oral, high dose
Anti-thymocyte globulin
Plasma exchange- esp goof for antibody mediated

Question 24

What are the possible complications of transplant?

Answer 24

Rejection
Infection
Neoplasia
Drug side effects
Recurrence of original disease
Surgical complications
Ethical

Question 25

What is graft vs host disease?

Answer 25

Immune cells from donor tissue attack the recipients tissues

Question 26

What factors are involved in graft vs host disease?

Answer 26

Immunocompetent graft
Immunocompromised host
HLA mismatch