Renal Transplant Flashcards
compare the renal function with dialysis and transplant
- dialysis will give a GFR of around 7
- transplant will give one of 50
age restrictions for transplant?
there are none, however co-morbidities accumulate with age that discourage transplantation
altruistic donation
- live donation
- directed (family/friend/spouse)/undirected
- paired pool donation
- financially procured
what is the difference in out comes between DCD and BSD donors
there is none
when does the benefit of a transplant begin
after around 3 months, before this there are greater risks
outline the patient assessment process
- reasonable life expectance - around 5 years
- safe to undergo operation
- Immunology – tissue typing and antibody screening
- Virology to exclude active infection. Problems can be encountered e.g. if the kidney has been exposed to CMV and the patient hasn’t
- Assess cardiorespiratory risk:
- ECG, ECHO ± ETT, coronary angiography
- CXR ± PFT, CPEX (cardio-pulmonary exercise testing – measure VC, ECG and HR)
- Assess peripheral vessels
- Asses bladder function – important
- Assess mental state
- Assess any co-morbidities/PMH
- Independent assessment out-with transplant team
must the patient recieve independent assessment outwith the transplant team
yes
patient contraindications to transplant
- malignancy
- active infection
- Hep C
- HIV
- untreated TB
- severe CV disease
- hostile bladder
what effect could IS have on malignancy
allow it to grow faster
what is the criteria for malignancy contraindicating transplantation
- known untreated
- 2-5 years clear of treated cancer
- watch out for eg breast cancer, which has late recurrence
is IS required when transplanting between monozygotic twins
epigenetics means they are slightly genetically different, so yes
what determines ones blood group
sugar on red cell surface
what sugars does blood group O have
- none, can donate to anyone
- can only take from O though
outline which blood groups can donate to which
which chromosome is HLA found on
chromosome 6
HLA action
code for MHC molecules which recognise anything non-self and activate immune system to destroy it
whicih 2 immunological things are importnat to match
blood group and HLA
what is the benefit of HLA matching
- critical
- gives better graft survival even with IS - 10% improvement at 3 years
what are the consequences of a bad HLA match
- person will be more sensitive to subsequent transplants if required
what is a sensitising event
periods in a person’s life where they become exposed to foreign antigens which they become immunologically primed to and develop pre-formed antibodies to the non-self antigen e.g.
- blood cell transfusion
- pregnancy or miscarriage
- previous transplant
what is the most common type of sensitising event
previous transplant
can a pregnancy and miscarriage both be classed as a sensitising event
yes, exposure of maternal blood to foetaa blood via placenta
in what circumstances does a sensitising event often cause problems in donations (maternal blood)
eg husband donating to wife if they have a child together
describe the systemi of kidney allocation
where do paediatric recipients fit into kidney allocation
get first choice irrespective of match
what is required with a eg 100 mismatch
additional IS as there is a greater chance of mismatch
what is a good way to overcome Ab.blood group incompatibitlity between donor and recepient
paired donation - can be done with multiple matches
Desensitisation
- the active removal of blood group or donsor specific antibody
- can be done by plasma exchange or B cell antibody (eg rituximab) to kill Ab producing cells
- Ab levels are monitored until they are low enough to proceed and then the transplant can proceed
outline the transplant procedure
- Transplant is placed extraperitoneally - inserted into iliac fossa and attached to the external iliac artery and vein
renal transplant: wound size, operation length, hospital time, recovery time
- Wound 15-20 cm long
- Average 2-3 hour operation
- 7-10 days in hospital
- Seen regularly after, follow up for life
- 3 months to get back to full activities
what are some surgical complications of a transplant
- Bleed – terminal
- Arterial stenosis, thrombosis
- Venous stenosis/kinking
- Ureteric stricture, hydronephrosis
- Wound infection
- Lymphocele - collection of lymphatic fluid in the body not bordered by an epithelial lining
how is the immediate graft function monitored
urine ouput, urea and creatinine
delayed graft function
- the graft takes 10-30 days to work
- often need HD in the iterim
- would biopsy regularly to make sure nothing else is going on
primary non function
this is where the graft never works
hyperacute rejection
- occurs within minutes of transplantation
- this is due to preformed Ab against HLA type 1 antigens
- unsalvageable
how is a hyperacute rejection managed
- unsalvageable so a transplant nephrectomy is required (removal)
how common is hyperacute rejection
rarely seen these days due to HLA matching
acute rejection
- cellular mediated - cytotoxic T cell mediated with primary activation of T cells
time frame of acute rejection
under 6 months
what virus can cause acute rejection
CMV
mangement of acute rejection
immunosuppression eg steroids
how may acute rejection present
- May present with fever, tachycardia, pain and tenderness over kidney, which may be enlarged
- Hypertension, raised creatinine and urea etc.
why does acue rejection usually occur
mismatched HLA
chronic rejection
- chronic allograft nephropathy
- this is a slow progressive decline in renal function which is Ab mediated
how does chronic rejection usually manifest
gradual reduction in renal function associated with proteinuria and exacerbated hypertension
induction IS treatment
- Basiliximab/Dacluzimab
what type of IS is given during surgery
high dose IV steroids eg prednisolone
maintenance IS treatment
- Prednisolone, tacrolimus, MMF
- Prednisolone, ciclosporin, azathioprine
how do Basiliximab/Dacluzimab work
- induction treatment - preventative
- prevent T cells being activated by blocking IL-2 receptors on CD4+ T cells
what is the mainstay of IS treatment
- steroids eg prednisolone
- suppres cytokines and inhibit lymphocyte proliferation, survival and action
name 2 calcineurin inhibitors
- Tacrolimus and ciclosporin
name 2 anti-metabolite drugs used in IS
- Azathioprine and MMF
what is teh most common side effect of IS
infection - often UTI, LRT
what organism are IC individuals particularly at risk of (causes pneumonia)
- Pneumocystic jirovecii
what clinical signs would make you susepct Pneumocystic jirovecii infection
- Fever, dry cough, SOB, weight loss and night sweats
- absence of chest signs
management of increased Pneumocystic jirovecii risk
prophylaxis: co-trimixazole
which virus is associated with acute rejection and early graft loss
CMV - upregulates immune system
importance of CMV post transplant
- most common and important
- cause of morbidity in first 3 months
- causes higher rates of acute rejection
how does CMV infection arise
- reactivation of previous infection due to IS
- donor kidney exposed to CMV but recipient not
clinical features of CMV
- Fever > pneumonitis > colitis > hepatitis > retinitis
- clinically very similar to glandular fever, lymphadenopathy, arthralgia, fatigue, hepatomegaly, jaundiced sclera
- atypical pneumonia
- chorioretinitis – can lead to irreversible blindness
- congenital infection and foetal damage
how is CMV risk managed
- Treat prophylactically with antivirals:
- PO valganciclovir in high risk patients
- IV gangciclovir if there is evidence of infection
BK nephropathy
-
Source of infection:
- Transmission occurs through donor kidney
- Reactivation in the recipient renal epithelium after transplantation – over IS
- can mimic rejection, manifests as renal dysfunction
how does BK virus present
- can mimic rejection
- resp infection - eg cold cough that wont go away
management of BK infection
there is no effective anti-viral therapy, so treatment is reducing immunotherapy
cancer in the IS
- there is a higher risk - accumulative risk and IS
- have a high index of suspicion
what is the most common type of malignancy post transplant
- dermatological -50% have cutaneous lesions by ten years
- significantly increased risk of SCC (also melanoma)
PTLD
- can occur in all forms of transplant
- there is B cell proliferation due to therapeutic IS after transplant
- increased risk with increased IS
- usually occurs 6 months post transplant
what are the majority of PTLD cases caused by
EBV
treatment of PTLD
- decrease IS
- chemotherapy with B cell antibody
- good outcomes
name 4 complications following transplant
- Atheromatous vascular disease
- Raised blood pressure
- Thrombosis
- Infections due to suppressed T cell immunity
graft vs host disease
- caused by engraftment of donor lymphocytes in several IS recipients
- Can occur with blood transfusions, when it is usually mild unless there is severe immunocompromise, but in its severe form is usually associated with bone marrow transplantation
how can graft vs host disease present
skin rash and diarrhoea
graft survival: cadaveric vs living donor transplant
60%:70%
