Transplantation

Question 1

what are human leukocytes antigen (HLA) molecules

Answer 1

proteins found on cell surfaces that help IS recognise self and non-self cells.

Question 2

why do HLA molecules play a crtiical role in organ transplantation

Answer 2

determine whether transplanted organ will be accepted or rejected by recipients IS

Question 3

what is acute rejection

Answer 3

process when recipients immune cells attack and damage transplanted organ as it is recognised as foreign

Question 4

what are transplant recipients treated with to reduce risk of acute rejection

Answer 4

immunosuppressive medications - reduce activity of T cells

Question 5

2 ways HLA matching can be improved

Answer 5

Haploidentical transplantation - transplanting stem cells from a donor who is a partial HLA match with the recipient

gene editing

induced pluripotent stem cells

Question 6

2 immunosuprressive drugs used after kidney transplantation

Answer 6

calcineurin inhibitors

corticosteroids

antimetabolites

Question 7

2 ways organ availitibitly for transplant is limited

Answer 7

number of donors

suitability of organs

ability to transport organs quickly and safely to recipient

organ demand exceeds supply - long waiting lists and high mortality risk

Question 8

why are kidneys most commonly transplanted organ

Answer 8

ease of procurement and transplantation - can be transplanted from deceased donor or living donor

Question 9

what is hematopoietic cell transplantation also known as

Answer 9

bone marrow transplantation

Question 10

4 types of disease HCT can treat

Answer 10

1. malignant - cancwers like leukaemias, MM, lymphoma
2. non-malignant - sickle cell, thalassemia
3. inherited immune disorders - SCID
4. inherited metabolic disorders - hurler and hunter syndrome
5. autoimmune diseases - multiple sclerosis, systemic lupus
6. infections - recurrent with EBV

Question 11

2 risks that HCT carriers

Answer 11

graft-versus-host disease
infection
organ damage

Question 12

what is GVHD

Answer 12

Life-threatening complication that can occur after HCT, when donors’ immune cells recognise recipients’ tissues as foreign and attack them = tissue damage and inflammation

Question 13

what cells in donor recognise recipients tissues as foreign and moutn immune response in GVHD

Answer 13

T cells

Question 14

2 things GVHD severity depends on

Answer 14

degree of HLA mismatch

no. of donor immune cells infused

age and health of recipient

Question 15

2 ways of preventing GVHD

Answer 15

match donor and recipient HLA types as close as possible

selectively deplete certain types of immune cells from donor graft like T cells (T CELL DEPLETION)

Question 16

what is the beneficial efffect of some GVHDs known as

Answer 16

graft-versus-tumor effect

Question 17

when does GVT effect occur (leukaemia/lymphoma)

Answer 17

when donors immune cells recognise and attack recipients tumour cells which can reduce size/remove tumour

Question 18

what can be used to enhance GVT while minimising risk of nGVHD

Answer 18

Donor lymphocyte infusions to boost donor immune response against recipients tumour cells which minimising number of donor immune cells which attack the recipients normal tissues

Question 19

autograft

Answer 19

using tissue from patients own body

Question 20

isograft

Answer 20

tissue from identical twin - rejection risk is low

Question 21

allograft

Answer 21

tissue from genetically different individual of same species

Question 22

xenograft

Answer 22

tissue from different species

Question 23

chronic rejection

Answer 23

long-term complication of transplant - months or years after due to gradual organ damage due to IR