Transplant Flashcards
What are the criteria for brainstem death (6)?
-Fixed unresponsive pupils
-Absent corneal reflex
-Absent ouculovestibular/caloric reflexes
-No response to supraorbital pressure
-No cough/gag reflex
-No respiratory efforts to hypercapnia (PaCO2 >6kPa or 6.5kPa if retainer)
Must also be normothermic, not sedated, all reversible circulatory, metabolic and endocrine disturbances excluded and reversible causes of apnoea exclude - in a patient who is comatosed with a known aetiology of irreversible brain damage
What is the most common complication after renal transplant?
Lymphocele - up to 50%
RAS 10% (thrombosis <1%)
Renal vein thrmobosis similar
Urine leak 10% (distinguish by measuring collection creatinine:serum creatinine)
Haemorrhage 1%
What is the most common side effect of cyclosporin?
Nephrotoxicity
Calcineurin inhibitor inhibits IL-2 and IFN-G – inhibits T cell activation
Also; hirsutism, gingival hyperplasia, tremor and hyperplasia
What mediates hyper acute rejection?
Preformed antibiodies within host
-Complement system activated by antigens
- neutrophils, endothelial and platelet activation
- inflammation scarring and ischaemia
Type 3 hypersensitivity reaction
Acute - type 2 hypersensitivity mediated by B cells
Chronic - Type 4 hypersensitivity mediated by humoral and cellular mechanisms
What is the most common side effect of azathioprine?
Pancytopenia (esp leukopenia)
Others include alopecia, <1% pancreatitis/hepatotoxicity
Prodrug of 6-mercaptopurine - inhibits purine synthesis
MMF is similar - but has less bone marrow suppression and lower rejection rates
What are the indications for pancreas organ transplantation?
Usually IDDM, 6% NIDDM
- ESRF
- Hypoglycaemic unawareness
- IDDM with uncontrolled ketoacidosis
Others
What are absolute contraindications to renal transplant (7)?
- Predicted survival < 5 years
- Incurable malignancy
- HIV (?not true)
- Severe CVS disease
- Predicted graft loss >50% at 1 year
- Anti-GBM antibody disease with circulating antibody
- Inability to comply with immunosuppressants
What proportion of patients are insulin independent at 1 year post pancreatic transplant?
82%
cf 14% after islet transplantation (injected into portal vein percutaneously)
How much liver can be removed from a healthy donor?
55-70% (regenerates to almost 100% function within 4-6 weeks)
Complications 10%, mortality 0-1%
What are the Milan Criteria for liver transplant?
For HCC
-Single tumour <5cm
-Up to 3 tumours all ≤3cm
-Single tumour 5-7cm stable over 6months
without major vessel or extra hepatic involvement
Which type of pancreas transplant has the best 1 year survival?
SPK 86%
PAK 80%
PTA 78%
Although complications and mortality higher with SPK
How is delayed graft function related to cold ischaemic time?
For every 6 hours, increases by 23%
Synergistic effect with Acute rejection - if both than 35% 5 year survival rate
Acute rejection more likely with DGF (37% vs 20%)
What are expanded criteria donors?
Donors with age >60 or
50-59 with vascular cormorbidities (hypertension, creatinine >133, death by ICH)
What is sirolimus?
Non-calcineurin (i.e. ciclosporin, tacrolimus) inhibitor immunosuppressant.
mammalian target of rapamycin (mTOR) inhibitor
also everolimus
lower nephrotoxicity/hypertension
What is Alemtuzumab?
anti-CD52 (all immune cells)
Often used with lyphmocyte depleting antibiodies in acute phase
What is the usual anti rejection protocol for renal transplants?
A Calcineurin inhibitor (Ciclosporin, Tacrolimus) or Sirolimus if intolerant
An anti proliferative drug (MMF, AZT)
Steroids
Probably should also have IL-2RA - Basiliximab, recently licensed and maybe anti-thymocyte globulin)
Which T-cell receptor binds to MHC-Class 1?
CD8- MHC Class 1 (A, B,C)
CD4 - MHC Class 2 (DP,DQ,DR)
Most important HLAs are DR > B >A, C
What are orthotopic and heterotopic transplants?
Orthotopic - normal anatomical site
Heterotopic - different
What are isograft, allograft and autografts?
Isograft - genetically identical (also syngeneic)
Allograft - same species, different genetically
Autograft - same individual
Which solid organ transplant is most commonly affected by vascular thrombosis?
Pancreas alone - 5-8%
In patients with blood group AB, what are the most important criteria for transplant?
Can receive any ABO,
therefore:
Living>DBD>DCD
then HLA
Rhesus is irrelevant
How frequently does acute rejection occur after a liver transplant?
Up to 40%, normally 7-10 days
Non specific features, obstructive jaundice, Banff schema
When might haematuria occur after a pancreatic transplant?
If there is a pancreaticoduodenocystostomy and Venus thrombosis occurs
What is the most common infection after a renal transplant?
UTI (30% in 3 months) - standard pathogens