Introduction to SOT

Question 1

Is being an organ donor now opt in or out?

Answer 1

You now have to opt out of being an organ donor, this changed in May 2020.
Therefore you can receive organs from either a living or a dead donor

Question 1

What are some of the types of organ transplants you can undergo?

Answer 1

Heart
Liver
Lung
Pancreas
Bowel
Kidney
SPK - simultaneous pancreas and kidney
Multi-viscreal

Question 2

What are the two types of donors?

Answer 2

You can either receive an organ from somebody you know (directed) or from anyone (altruistic) via the organ transplant list

Question 3

What are some of the exclusions for being an organ donor?

Answer 3

CJD (Creutzfeldt–Jakob disease)
Ebola
Active cancer
HIV - but you can between two HIV patients

Question 4

What is the first process of organ transplant?

Answer 4

Assessment and identification of patients that are in the inclusion criteria for receiving a transplant.
Transplant is usually the last choice for example in patient with dialysis failure

Question 5

How do patients become entered on the transplant list?

Answer 5

The patients have to undergo an assessment with the MDT including consultants, surgeons but also including the Pharmacist
The patient’s inclusion criteria is assessed in addition to identifying any exclusion criteria to determine whether they are put on the transplant list.

Question 6

What are some of the exclusion criteria for receiving an organ donation?

Answer 6

For example a life expectancy less than 2 years and conditions that would qualify the patient as being ‘too sick for transplant’

Question 7

What is a transplant match dependent upon?

Answer 7

Recipient blood group matching
HLA compatibility

Question 8

What is the aim for transplant?

Answer 8

To increase the life expectancy and quality of life for the patient

Question 9

What is the main barrier to successful transplant with the organ efficiency optimised?

Answer 9

The patient’s own immune system due to it perceiving the transplanted organ as a foreign substance with risk of acute and chronic rejection.
A degree of immunosuppression must be received which can slowly be reduced over time as tolerance builds.

Question 10

What are the different types of grafts?

Answer 10

Xenografts
Autografts
Isografts
Allografts

Question 11

Define xenografts.

Answer 11

A graft between different species which has the greatest immune response.

Question 12

Define autografts.

Answer 12

One part of the body being transplanted to another, no rejection occurs. This includes a skin graft.

Question 13

Define isografts.

Answer 13

When a graft is between genetically identical individuals (identical twins)

Question 14

Define allografts.

Answer 14

Between members of the same species, varied response due to the type of organ transplanted and the type of organ.

Question 15

What aspect of the immune system is responsible for rejection?

Answer 15

Human leukocyte antigens (HLA) which are genes in major histocompatibility complexes (MHC) that help code for proteins that differentiate between self and non-self and therefore are the cause of rejection.

Question 16

Where are the two major histocompatibility complexes expressed?

Answer 16

MHC-I is expressed on the cell surface of all nucleated cells
MHC-II on antigen presenting cells such as macrophages and B cells

Question 17

How many signals are required for T-cell activation?

Answer 17

3 signals are required for T-cell activation. When they are activation they undergo clonal expansion and differentiate to express further effector functionals.
This results injury and cell death to the transplanted organ.

Question 18

What is the first signalling pathway?

Answer 18

Interaction between the TCR binding to the antigen presenting on the MHC complex.

Question 19

What is the second signalling pathway?

Answer 19

Co-stimulatory receptor/ligand interaction between the T-cell and the antigen presenting cell.
This is usually CD28 and CD80 and 86 and/or CD40 and the ligand

Question 20

Which pathways are activated by the co-stimulatory pathway?

Answer 20

Calcium-calcineurin pathway
MAPK
Protein kinase C - nuclear factor kappa B activation

This is responsible for transcription factor activation, bringing about these T-cell functions

Question 21

What is the third signalling pathway?

Answer 21

These involves growth factors present for cell cycle progression
This involves activation of PI-3K pathway and mTOR

Question 22

How is the host response to the transplant controlled?

Answer 22

HLA compatibility - poor compatibility, risk of the rejection is higher. Close match is required to ensure graft is accepted for longer.
Immunosuppression

Question 23

What genes are MHC I encoded by?

Answer 23

HLA-A, HLA-B, HLA-C

Question 24

What genes are MHC II encoded by?

Answer 24

HLA-DP, DQ or DR

Question 25

What are the strongest determinants for HLA compatibility?

Answer 25

HLA-DR more so than A or B region
Would want this match to be as close as possible

Question 26

What are the benefits of HLA-compatibility?

Answer 26

Better graft function
Fewer episodes of rejection
Longer graft survival due to less damage to the transplanted organ
Reduced immunosuppression and potency
Decreased risk of sensitisation

Mismatch can be overcome by immunosuppression