Renal Transplant Flashcards
(44 cards)
In end-stage renal failure, renal replacement therapies in the form of dialysis or renal transplant exist.
What is a transplant?
A tissue/organ taken from a person who has died or from a living donor and placed inside another person
What are the advantages of renal transplantation over dialysis? (6)
- Transplants mimic true renal function better than dialysis, as the transplanted kidney is operating 24/7 as a normal kidney should
- GFR is restored to ~50, compared to ~7 while on dialysis treatment
- Transplant offers the patient more freedom and so improves quality of life
- Survival is improved
- Financial benefit to patients as they can return to work
- Financial benefit to the NHS as dialysis is more expensive in the long run
What are the age restrictions for receiving a transplant?
There are none
However, co-morbidities often prevent transplant in elderly patients
What are the 3 types of donor that can give a transplant? Which is most common?
Decreased heart beating donors (most common)
Non-heart beating donors
Live donation
Describe each of the 3 types of transplant donor:
Decreased heart beating donors
Non-heart beating donors
Live donation
Decreased heart beating donors:
Patients on life support who have been confirmed as brain stem dead by two doctors, the organs are retrieved while the person’s heart is still beating
Non-heart beating donors:
An organ is retrieved from a person who is officially dead - as in their heart has stopped beating
Live donation:
A person who is still alive offers to have one of their organs removed and given to another
What is the difference between directed and undirected live donation?
Directed - the person wants to donate their organ to someone specifically e.g., a family member with ESRD
Undirected - the person wants to donate their organ but does not name or have an intended recipient to receive it
Number of kidney transplants being carried out has increased/decreased/stayed the same
Number of live donors offering kidneys has increased/decreased/stayed the same
Number of kidney transplants being carried out has increased
Number of live donors offering kidneys has stayed the same
What criteria must a patient/recipient meet to be considered for transplant?
- Life expectancy must be >5 years
- Must be fit enough to survive the operation and post-op period e.g., general anaesthetic, immunosuppression, post-op IV fluids etc.
- Must undergo an extensive assessment process
There is no survival benefit from transplantation until ? months after the transplant
3
What 8 investigations/assessments are carried out for the recipient before they can be considered for transplant?
- Immunology: tissue typing and antibody screening
- Virology (to check for previous or active infection)
- Assessment of cardiorespiratory risk e.g., ECG, Echo, Coronary angio, CXR, PFT
- Assess peripheral vessels (as blood will be shunted to the new kidney so ensure vessels are strong enough to still take blood to the legs)
- Assess bladder function
- Assess mental state (as transplant can exacerbate these)
- Assess any co-morbidity or PMHx which may affect the transplant or be exacerbated by immunosuppression
- Independent assessment by someone outwith the transplant team to ensure all the work-up has been performed adequately
List 8 contraindications to transplant
- Malignancy (current untreated or solid tumour in the past 2-5 years depending on grade)
- Active HCV/HIV infection
- Untreated TB
- Severe ischaemic heart disease, not amenable to surgery
- Severe airways disease
- Active vasculitis (should be suitable for transplant after a few months of treatment)
- Severe PVD (unusable vessels)
- Hostile bladder e.g., bladder outflow obstruction that will put back pressure on the new kidney
What criteria must a live donor meet to be considered as a donor? (7)
- Must be physically fit enough to cope with surgery and post-op period
- Must have adequate renal function to remain independent following nephrectomy
- Kidneys must be anatomically normal
- Should not have co-morbidities that will get worse with one kidney e.g., hypertension, proteinuria
- Should be immunologically compatible with the recipient
- Must be psychologically fit to donate e.g., able to cope with the recovery process
- Reasons for donating must be explored e.g., cannot be because they want to have a hold on/manipulate the recipient, cannot be because they have been coerced by someone else
Tissue typing must be carried out on the donor and recipient before transplant to reduce chance of organ rejection. What are the 2 types of tissue typing?
Blood group compatibility
HLA matching
What blood groups can a recipient have to be compatible with a donor with a blood group of... - O - A - B - AB ...?
- O: Any!
- A: A, AB
- B: B, AB
- AB: AB
What is HLA matching?
When recipients are matched with donors who have the same type of HLA (aka MHC) protein group found on antigen-presenting cells
What are the 3 main types of HLA group?
HLA-A, HLA-B, HLA-DR
Why is HLA matching important?
- There is a better chance of graft survival with immunosuppression
- Without immunosuppression, HLA matching is key to prevent rejection
Matching of which class of HLA (A, B or DR) is most important in renal transplantation?
HLA-DR as it is responsible for the most cases of acute graft loss
What is the top criteria for which recipient receives an available transplant?
A) Blood group compatibility
B) HLA matching
C) Time on the transplant list
Why?
B) HLA matching
This is because the organ is more likely to be rejected if there is a HLA mismatch. Once that organ has been rejected, subsequent transplants are more likely to be unsuccessful because the recipient now has antibodies formed against those particular foreign subtypes of HLA
List 3 sensitising events that can have lead to pre-formed antibodies which will attack non-self antigens in the transplant
Blood transfusion
Pregnancy or miscarriage
Previous transplant
With an undirected donated kidney, how is it decided who receives the organ?
- Any paediatric recipient is prioritised
- Then adult HLA match (i.e., 0, 0, 0 mismatch - HLA A, B, DR)
- Then 1, 0, 0 or 0, 1, 0 or 1, 1, 0 mismatch
- Then total HLA mismatch (this is when time on the waiting list comes into consideration)
In a directed kidney transplant, what are the two options if the paired donor and recipient are immunologically imcompatible?
- They can be involved in paired donation/ enter a paired donation pool
- The recipient can be desensitised
What is paired donation?
When an incompatible donor and recipient pair up with another incompatible donor and recipient where the donors will be able to swap recipients so that each receives a compatible organ
What is a paired donation pool?
- When multiple pairs of incompatible donors and recipients exchange donors until everyone finds a compatible match
- A non-directed donor is added to this pool to create a domino-effect
- The last kidney is given to a recipient on the transplant list
