Renal Transplant Flashcards
What is a renal transplant?
A surgical procedure involving a healthy kidney from a living or decreased donor being placed into a patient whose kidney is no longer functioning properly due to end stage kidney disease
Describe the renal transplant procedure
Renal transplantation involves the surgeon making an incision in the lower aspect of the abdomen
The donated kidney is then placed in the iliac fossa where it is anastomosed with the patient’s pelvic vessels, usually the external iliac vessels
The ureter of the donor kidney is then anatomised with the patient’s bladder
What vessels are anastomosed with the donated kidney?
External iliac vessels
In which three situations are the native kidneys removed during renal transplantation?
Polycystic Kidneys
Chronic Pyelonephritis
Renal Calculi
Why are polysystic kidneys removed in renal transplants?
This is due to the fact that the kidneys are abnormally large and therefore space is required for the donated kidney
Why are chronic pyelonephritis kidneys removed in renal transplants?
The infection could spread to the donated kidney
What is donor matching based on?
Human leukocyte antigen (HLA) type A, B and C on chromosome six
What do we do if the donors don’t fully match?
Recipients can receive treatment to desensitise them to the donor HLA
What are the two types of donors?
Deceased donors
Living donors
What is a deceased donor?
A deceased donor is someone who has just died
This person or their family members decided to donate healthy organs at the time of death in order to benefit people who need transplants
What are the two types of deceased donors?
Donation after Brain Death (DBD)
Donation after Cardiac Death (DCD)
What is donation after brain death (DBD)?
This means that the patient’s heart is still beating and therefore the kidney will continue to be perfused until the time of organ retrieval.
What is donation after cardiac death (DCD)?
This means that the patient’s heart is no longer beating and therefore the kidney would be deprived of blood before the time of organ retrieval
What is the standard criteria of deceased donors?
These are donors who are under the age of 50 and suffered brain death from any number of causes
What is the expanded criteria of deceased donors?
Expanded criteria donors are those over the age of 60, or those between the age of 50-59 and fulfil two of the following criteria…
Hypertension History
Death from Cerebrovascular Event
Terminal Creatinine > 133µmol/L
Which criteria of deceased donors indicates a greater risk of transplantation failure?
Expanded criteria
What is living donation?
It occurs when a living person donates an organ, or part of an organ, for transplantation to another person
These donations have a smaller chance of rejection in comparison to deceased donations
What are the two categories of living donors?
Living Related Donor
Living Unrelated Donor
What are living related donors?
These donors are biologically related to the patient
This therefore includes family members, such as a parents, children, brothers or sisters
What is the advantage of family members offering to donate to the recipient?
They are the most likely to be compatible living kidney donors
What are living unrelated donors?
These donors are those not biologically related to the patient
What are the three subclassifications of living unrelated donors?
Spousal Donors
Altruistic Donors
Paired Donors
What are altruistic donors?
These are donors that wish to donate with no intended recipient; they simply want to donate to someone who can benefit from a transplant
What are paired donors?
In paired donation, living donors and their recipients aren’t compatible for a transplant. However, the donor of each pair is compatible with the recipient of the other pair
What are donation chains?
This is when more than two pairs of donors and recipients may be linked with a nondirected living kidney donor
What four criteria exclude donors from donation?
The donor has been diagnosed with an active invasive cancer in the last three years
The donor has a haematological malignancy
The donor has an untreated systemic infection
The donor has HIV disease (however not HIV infection)
What are the three complications for recipients after renal transplantation?
Transplant rejection
Infection
Malignany
How does transplant rejection occur?
When the body’s immune system recognise the donated kidney as foreign
This specifically occurs when an antigen-presenting cell presents the donated kidney’s antigens to T-cells, which then recognise it as foreign via three signalling pathways
What are the three types of transplant rejection?
Hyperacute Transplant Rejection
Acute Transplant Rejection
Chronic Transplant Rejection
What is hyperacute transplant rejection?
It is characterised by ischaemia and necrosis of the graft that occurs from the time of transplant to 48 hours after transplant
What is acute transplant rejection?
It occurs from the first week to three months after transplantation
What is chronic transplant rejection?
It occurs over several years after transplantation
How do we prevent transplant rejection?
We prescribe drugs which inhibit these three signalling pathways
These drugs are known as immunosuppressants
What four immunosuppressants are used to prevent transplant rejection?
Basiliximab
Tacrolimus
Mycophenolate
Prednisolone
How does basixilimab work? When do we prescribe it?
It inhibits the interleukin-2 (CD25) protein in the third signalling pathway
This is the immunosuppressant prescribed initially in the induction phase
How does tacrolimus work? When do we prescribe it?
It inhibits the calcineurin protein in the first signalling pathway
This is prescribed long-term, and patients tend to take this for the rest of their life.
How does mycophenolate work? When do we prescribe it?
It is anti-proliferative agent and therefore prevents proliferation of the T-cells once a foreign antigen has been detected
This is prescribed long-term, and patients tend to take this for the rest of their life
How does prednisolone work? When do we prescribe it?
It inhibits cytokine gene transcription and therefore prevents recruitment and activation of T-cells
This is prescribed long-term, and patients tend to take this for the rest of their life.
What do we prescribe if patients are intolerant to tacrolimus?
Betacept
What are the four complications of immunosuppressants?
Hypertension
Type Two Diabetes
Osteoporosis
Ischaemic Heart Disease
When do infections tend to occur after renal transplantation?
Within the first six months
What two infections occur in renal transplant patients?
Cytomegalovirus (CMV)
BK Virus
What is CMV?
It is a viral infection of the herpes virus
When does the general population tend to be infected with CMV?
It tends to affect the general population at a young age and therefore most adult patients are resistant
What are the usual clinical features of CMV?
It is a harmless virus that causes cold sores and chicken pox
How is CMV a complication of renal transplantation?
In cases where the donor is CMV positive, however the recipient is CMV negative
Why is CMV infection more serious in renal transplant patients?
This is due to the fact that immunosuppression will be minimised and therefore the risk of rejection increases
How do we prevent CMV infection in renal transplant patients?
We prescribe a six-month prophylaxis against CMV infection with valaciclovir after renal transplantation
What is BK virus?
It is usually a harmless, asymptomatic viral infection that tends to affect the general population at a young age
What are the three complications of BK virus in renal transplant patients?
Ureteral stenosis
Interstitial nephritis
End stage kidney disease.
How do we treat BK virus in renal transplant patients?
We reduce immunosuppression
We prescribe antiviral therapy, such as cidofovir and leflunomide
What two malignancies tend to arise in renal transplant patients?
Skin
Lymphoma
What are the three complications of renal transplants for donors?
End Stage Kidney Disease
Albuminuria
Hypertension
Why is end stage kidney disease a complication for donors? How do we prevent this?
This is due to hypertrophy of their contralateral kidney
We assess the donor’s risk of end stage kidney disease before they are considered to be suitable for donation.
What is albuminuria?
The presence of albumin protein in the urine
