Immunology of Transplantation

Question 1

what is the major histocompatibility complex called in humans

Answer 1

histocompatilibilty locus antigen (HLA)

Question 2

function of HLA

Answer 2

molecules which imprint individuality on cells (mark them as your own cells)

Question 3

what class of HLA molecules are expressed by most somatic cells

Answer 3

class 1

Question 4

function of HLA class I molecules

Answer 4

present peptides from internally processed proteins

Question 5

which cells express HLA class II molecules

Answer 5

antigen presenting cells that are constantly sampling their microenvironment

Question 6

function of HLA class II molecules

Answer 6

present antigenic peptides derived from digested material (including pathogen, abnormal or foreign cells)

Question 7

what happens if a HLA class I molecule is associated with a virus derived protein

Answer 7

it is recognised as infected and killed by cytotoxic t cells

Question 8

what happens if a HLA class II molecule displays a peptide derived from a foreign cell/pathogen

Answer 8

t cell immune response stimulated

Question 9

if someone rejects a tranplant and gets a second similar one how would the body respond

Answer 9

rejected more quickly due to memory cells

Question 10

what is HLA profiling used for

Answer 10

allocating kidneys that best match individuals

Question 11

why is HLA not as important in liver transplant compared to kidney

Answer 11

liver is less immunogenic

Question 12

how is HLA mismatch reported

Answer 12

0-0-0 mismatch if all of HLA-A, -B and DR loci are the same
2-2-2 mismatch if all different - less good match

Question 13

immunosuppression drugs

Answer 13

corticosteroids
calcineurin inhibitors
anti-proliferative agents
various antibodies

Question 14

MoA of corticosteroids for immunosuppression

Answer 14

kills lymphocytes
interferes with T cell activation and gene transcription
anti-inflammatory agents

Question 15

immunosuppression drugs

Answer 15

corticosteroids
calcineurin inhibitors (CNIs)
anti-proliferative agents
various antibodies

Question 16

MoA of CNIs for immunosuppression

Answer 16

inhibit T cell activation by interfering with intraelluus signalling pathwy

Question 17

MoA of anti-proliferative agenst for immunosuppression

Answer 17

inhibit clonal expansion of T cells

Question 18

what investigations need to be done befroe transplantation

Answer 18

exercise ECG
myocardial perfusion studies
angiography - need decent vessels for anasatomosis

urodynamic dstudis
tumour markers

Question 19

DCD vs DBD cardaveric Tx meaning

Answer 19

donated after cardiac/brain death

Question 20

do live or dead donor kidneys have better long term outcomes

Answer 20

living

Question 21

where may a patient acquire cytotoxic Abs to many HLA antigens

Answer 21

previous transfusions
pregancies
previous transplantation

Question 22

what investigation can be used to detect HLA antibodies

Answer 22

luminex HLA antibody detection

Question 23

what type of transplant rejection shouldn’t happen now

Answer 23

hyperacute rejection

Question 24

when does hyperacute rejection occur

Answer 24

when the transplant carries antigens to which the recipient is already sensitised

Question 25

signs/presentation of acute transplant rejection

Answer 25

rise in creatinine reduce urine output tender transplant fever

Question 26

differential diagnosis of acute transplatn rejection

Answer 26

dehydration renal obstruction vascular catastrophe drug toxicity AKI

Question 27

treatment of acute rejection

Answer 27

high dose steroids to kill lymphocytes and reduce inflammation more potent immunosuppression or increased dose anti-t cell antibody plasma exchange for severe Ab mediated rejection

Question 28

progressive renal dysfunction interstitial fibrosis and vascular disease on renal biopsy are signs of

Answer 28

chronic rejection

Question 29

what type fo trasnplant is ideal for diabetcis

Answer 29

pancreas adn kidney

Question 30

risk factors for chronic rejection

Answer 30

increased HLA mismatch previous acute rejection poor drug compliance prolonged cold iscahmeia time of kidney prior to surgery

Question 31

causes of graft failure

Answer 31

delayed graft function infection afge o donor poor blood pressure control porteinuria

Question 32

msanagemnt of chronic rejection

Answer 32

eventaully dialysis or anothr transplant optimise immunosupprssion treat BP, lipids, proteinuria

Question 33

what are you at increawsed risk of when on immunosuppresion

Answer 33

infection cancer diabetes hypertension osteoporosis