Transplantation Flashcards
What blood type can only receive their type of blood?
blood group O- have anti-A nad anti-B antibodies
What is HLA?
cell surface proteins expressed on cells
What are the 3 types of HLA important in transplantation?
HLA-A and HLA-B- type 1 and HLA-DR
How many types of each HLA does each patient have?
2- 1 from each parent
What is a haplotype?
each set of HLA (A, B and DR) are inherited as a set
What are the common ways of developing HLA antibodies?
pregnancy; transfusion and transplantation
What type of graft has the best chance of survival?
live related donor transplant
What happens when the T helper cell is presented with an HLA antigen?
stimulated B cells; NK cells; cytotoxic cells and complement and cytokines which lead to rejection
What happens if a patient is given too much immunosuppressive drugs?
BK virus; CMV; recurrent UTI; PCP; non-melanoma skin cancer; lymphoma
What is rejection?
non-self tissue is identified and attacked by host immune system causing damage to transplanted organ
What is a hyperacute rejection?
due to positive crossmatch (preformed antibodies to the transplant) and the graft is unsalvageable- will go black within minutes
What is acute rejection?
T or B cell mediated response
How can acute rejection be treated?
increased immunosuppression
What causes chronic rejection?
immunological and vascular deterioration of transplant
What drugs are given during the induction phase?
steroids; MMF; CyA; tacrolimus; antibodies
What drugs are given during the consolidation phase ?
steroids; MMF; CyA and tacrolimus
What drugs are given during the maintenance phase?
steroids, MMF, CyA and tacrolimus
What are examples of calcineurin inhibitors?
cyclosporin and tacrolimus
What is the function of calcineurin inhibitors?
inhibit activation of T helped cells- reduce NK and CD8 cell activation; decrease cytokine release to prevent B cell proliferation and antibody production
What are the side effects of calcineurin inhibitors?
renal dysfuction; HT; DM; tremors
How are calcineurin inhibitors metabolised?
cytochrome p450
What are examples of antimetabolites?
azathioprine and mycophenolate
What is the function of antimetabolites?
block purine synthesis by suppressing proliferation of lymphocytes and B cells
What are the SE of antimetabolites?
leucopaenia, anaemia, GI
What drug should azathioprine not be combined with?
allopurinol
What is the function of steroids?
non-selectively suppress the activity of T cells and proliferation of B cells
What are the SE of steroids?
OP; weight gain; infeection and DM
What are hte 2 types of cadaveric kidneys?
deceased brain dead and deceased cardiac death
How is suitability for transplantation decided?
> 5 years life expectancy; patients don’t get a kidney >6 months prior to starting HD; predominantly based on tissue typing not time on the list
How are patients assessed for transplant?
CVS risk; virology; CXR; bladder assessment; any comorbidity
What are the absolute CI to transplantation?
malignancy- untreated of within 2/5 years (depending on tumour); untreated TB; severe IHD not amenable to surgery; severe airway disease; active vasculitis; severe PVD (unusable vessels )
How are live donors assessed?
ECG; CXR; virology; GFR; quantification of proteinuria; 24hr BP; renal angiogram; Xmatch
Where is the transplanted kidney inserted?
pelvis
Why is there an increased risk of wound infection with transplantation?
patients are on immunosuppressives
What are the surgical complications of transplant?
bleeding; arterial/venous stenosis and thrombosis; ureteric stricture and hydronephrosis
What indicates good immediate graft function?
urine output and falling creat and urea
What is delayed graft function?
post transplant acute tubular necrosis; will work after 10-30 days
What is primary non-function?
transplant never works
What is the long term follow up of transplant patients?
late acute rejection; HT and CVS risk; chronic allograft nephropathy; UTI; recurrent primary renal disease; skin cancer surveillance
How can the graft be loss?
chronic rejection; cyclosporine/tacrolimus toxicity and ischaemia
