Principal of organ transplant Flashcards
Which of the following transplants is most susceptible to donor- recipient HLA mismatches?
Autologous skin graft Renal allograft Liver allograft Corneal allograft Cardiac valve allograft
Renal allograft
Autologous transplant- same individual (genetically identical)
Allograft - Genetically different
The kidney is highly susceptible to HLA mismatches and hyperacute rejection may occur in patients with IgG anti HLA Class I antibodies. The liver is at far lower risk of rejection of this nature. Although the heart is sensitive to HLA mismatches this is less than the kidney. Cardiac valves and the cornea incite little immunological response.
A 45 year old lady undergoes a renal transplant from a living related donor. She is well for several months, but on review in the outpatient department is noted to have persistent hypertension and a slight deterioration in renal function. What is the most likely explanation for this?
Renal vein thrombosis Acute rejection Renal artery thrombosis Lymphocele Renal artery stenosis
Renal artery stenosis
Renal artery stenosis typically occurs over several months and will usually result in the development of hypertension. Most cases can be assessed using duplex scanning and managed with angioplasty.
Which of the following is not true of hyper acute solid organ transplant rejection?
It may occur during the surgical procedure itself.
May occur as a result of blood group A, B or O incompatibility.
May be due to pre existing anti HLA antibodies.
On biopsy will typically show neo intimal hyperplasia of donor arterioles.
Complement system activation is one of the key mediators.
On biopsy will typically show neo intimal hyperplasia of donor arterioles.
These changes are more often seen in the chronic setting. Thrombosis is more commonly seen in the hyperacute phase.
A 39 year old lady undergoes a live related renal transplant. She progresses well. Two weeks following the transplant she is noted to have swelling overlying the transplant site and swelling of the ipsilateral limb. Urine output is acceptable and creatinine unchanged. What is the most likely cause?
Lymphocele Renal vein thrombosis Renal artery stenosis Acute rejection Renal artery thrombosis
Lymphocele
Swelling over the graft site is often due to a lymphocele and this is further suggested by the normal renal function. They cause symptoms through mass effect and limb swelling may occur. Treatment is often surgical.
A 52 year old male attends renal transplant clinic for a post operative assessment. You note that he is on ciclosporin and that a recent blood test shows that the ciclosporin level is elevated. Of the adverse effects noted below, which is the greatest concern?
Hyperthyroidism Diabetes Alopecia Hypothermia Nephrotoxicity
Nephrotoxicity
Ciclosporin- nephrotoxicity
This patient is at risk of nephrotoxicity and should be referred to the renal team as soon as possible. Alopecia is associated with azathioprine and diabetes is associated with long term use.
A 48 year old woman with end stage renal failure is undergoing a live donor renal transplant. The surgeon decides to implant the kidney in the left iliac fossa via a Rutherford Morison incision. To which of the following vessels should the transplanted kidney be anastomosed?
Aorta and inferior vena cava Internal iliac artery and vein Common iliac artery and vein External iliac artery and vein Inferior epigastric artery and vein
External iliac artery and vein
First time renal tranplants are typically implanted in the left or right iliac fossae. The vessels are usually joined to the external iliac artery and vein as these are the most easily accessible. The Rutherford Morison incision provides access to the external iliac vessels.
A 43 year old man undergoes a cadaveric renal transplant. The operation is uncomplicated. On removal of the vascular clamps the transplanted kidney immediately turns dusky and over the ensuing hours appears non viable. Which of the following best explains this event?
Chronic rejection Hyper acute rejection Acute rejection Sub chronic rejection Infection of the graft
Hyper acute rejection
Immediate rejection is due to the presence of pre-existing antibodies e.g. ABO mismatch. The transplanted organ should be removed.
In matching donated kidneys to the most appropriate recipient, apart from ABO matching, which of the following is most important?
HLA DR Rhesus HLA A HLA B Duffy antigen
HLA DR
The rhesus group is not important in matching donor and recipient kidneys.
You review a 42-year-old woman six weeks following a renal transplant for focal segmental glomerulosclerosis. Following the procedure she was discharged on a combination of tacrolimus, mycophenolate, and prednisolone. She has now presented with a five day history of feeling generally unwell with anorexia, fatigue and arthralgia. On examination, she has a temperature of 37.9 and has widespread lymphadenopathy. What is the most likely diagnosis?
Hepatitis C Coxsackie virus HIV Hepatitis B Cytomegalovirus
Cytomegalovirus
Cytomegalovirus is the most common and important viral infection in solid organ transplant recipients
Primary infection with CMV typically occurs 6 weeks post transplantation in a seronegative individual who receives an organ from a seropositive donor. Symptoms may occur as early as 20 days but can occur up to 6 months post transplant . Symptoms are often vague, retinitis can be pathognomonic, but is rarely seen in the transplant population. CMV disease is seen in 8% of renal transplant patients. Intravenous ganciclovir is the treatment of choice in such patients. Unfortunately, relapses are not uncommon.
A 52 year old female underwent a cadaveric renal transplant and recovers well post operatively. Her immunosupression regime consists of tacrolimus. Which of the substances listed below should be avoided?
Paracetamol Apple juice Penicillin Prune juice Grapefruit juice
Grapefruit juice
Tacrolimus is metabolised by the P450 enzyme system. This is inhibited by a number of naturally occurring substances, these include grapefruit, watercress and St.Johns Wort. These should all be avoided in immunosupressed patients taking tacrolimus.
You review a 42-year-old woman 8 months following a renal transplant for focal segmental glomerulosclerosis. She is on a combination of tacrolimus, mycophenolate, and prednisolone. She has now presented with a five day history of feeling generally unwell with jaundice, fatigue and arthralgia. On examination she has jaundice, widespread lymphadenopathy and hepatomegaly. What is the most likely diagnosis?
Hepatitis C Epstein-Barr virus HIV Hepatitis B Cytomegalovirus
Epstein-Barr virus
Post transplant complications
CMV: 4 weeks to 6 months post transplant
EBV: post transplant lymphoproliferative disease. > 6 months post transplant
Post transplant lymphoproliferative disorder is most commonly associated with Epstein-Barr virus. It typically occurs 6 months post transplant and is associated with high dose immunosupressant therapy. Remember cytomegalovirus presents within the first 4 weeks to 6 months post transplant.
A 38 year old lady donates her kidney to her niece. What type of transplant is this?
Xenograft Allograft Autograft Isograft None of the above
Allograft
Though related this donor will not be genetically identical and thus this will be an allograft.
A 43 year old lady undergoes a live related renal transplant. At the conclusion of the operation she has a good urine output and the graft appeared well perfused. On the ward she suddenly becomes anuric. What is the most likely cause?
Renal artery stenosis Renal vein thrombosis Renal artery thrombosis Hyperacute rejection Acute rejection
Renal artery thrombosis
Sudden loss of urine output is most commonly due to a blocked catheter. However, if this is excluded (and is not included in the options) the most worrisome cause is arterial thrombosis. This will often be a delayed diagnosis and the rate of graft loss is high.
A 28-year-old female undergoes a renal transplant for focal segmental glomerulosclerosis. Within hours of the operation the patient becomes unwell with features consistent with severe systemic inflammatory response syndrome. The patient is immediately taken back to theatre and the transplanted kidney is removed. What type of immunoglobulins are responsible for the graft rejection?
IgE IgM IgG IgD IgA
IgG
Hyperacute graft rejection is due to pre-existent antibodies to HLA antigens and is therefore IgG mediated
A 43 year old lady is recovering following a live donor related renal transplant. She has significant abdominal pain. Which of the following analgesic drugs should be avoided?
Paracetamol Morphine Nefopam Diclofenac Co-codamol
Diclofenac
Non steroidal anti inflammatory drugs may be nephrotoxic and therefore are usually avoided in patients who have undergone renal transplants. Paracetamol and morphine are metabolised predominantly in the liver. There is some renal contribution to morphine metabolism and excretion and the drug should be administered in reduced doses or avoided if the transplanted kidney stops functioning.
A 44 year old man with end stage renal failure undergoes a live donor renal transplant. During the immediate post operative period a good urine output is recorded. However, on return to the ward the nursing staff notice that the urinary catheter is no longer draining. Which of the interventions listed below is most likely to be required?
Bladder wash out Revision of the ureteric anastomosis Revision of the venous anastomosis Revision of the arterial anastomosis Graft nephrectomy
Bladder wash out
The most likely explanation for this event is a blocked catheter. This may be the result of blood clot from the ureteric anastomosis. Bladder irrigation will usually resolve the problem.
A 38 year old man is recovering following a live donor related renal transplant. The surgeon prescribes corticosteroids to reduce the risk of graft rejection. Which of the following will not occur as a result of their administration?
Suppression of macrophage activation
Reduction of expression of major histocompatibility complex antigens on the graft
Reduction in the proliferation of lymphocytes
Necrosis of activated lymphocytes
Reduction of expression of endothelial cell adhesion molecules
Necrosis of activated lymphocytes
Corticosteroids at higher doses are able to induce apoptosis of activated lymphocytes. Necrosis is a different process and not induced by steroids.
A 43 year old lady undergoes a live donor related renal transplant. Over the next few years it is noted that her renal function progressively deteriorates. What is the most likely underlying explanation?
Type I hypersensitivity reaction Type III hypersensitivity reaction Type II hypersensitivity reaction Type IV hypersensitivity reaction None of the above
Type IV hypersensitivity reaction
Chronic rejection of renal transplants is mediated via T lymphocytes and is therefore a type IV hypersensitivity reaction. This process can be mitigated by immunosupression.
What type of transplant best describes a 27 year old lady donating her right kidney to her identical twin sister?
Autograft Isograft Allograft Xenograft None of the above
Isograft
Identical twin to twin donations are usually genetically identical and are therefore isografts.
A 54-year-old man who has end stage diabetic nephropathy is being assessed for a renal transplant. When assessing the HLA matching between donor and recipient what is the most important HLA antigen to match?
DP B DR C A
DR
Renal transplant HLA matching - DR is the most important
A 63 year old woman with severe angina undergoes a coronary artery bypass procedure and her long saphenous vein is used as a bypass conduit. Which of the types of transplant listed below best describes this?
Allograft Isograft Xenograft Autograft None of the above
Autograft
The long saphenous vein is one of the commonest autografts in surgery.
A 48 year old lady with end stage renal failure receives a cadaveric renal transplant. The organ is ABO group matched only. On completion of the vascular anastomoses the surgeons remove the clamps. Over the course of the next twelve minutes the donated kidney becomes dusky and swollen and appears non viable. Which of the following is the most likely process that has caused this event?
IgG anti HLA Class I antibodies in the recipient
IgM anti HLA Class I antibodies in the recipient
IgG anti HLA Class I antibodies from the donor
IgM anti HLA Class I antibodies from the donor
IgM anti HLA Class II antibodies from the recipient
IgG anti HLA Class I antibodies in the recipient
Episodes of hyperacute rejection are typically due to preformed antibodies. ABO mismatch is the best example. However, IgG anti HLA Class I antibodies are another potential cause. These events are now seen less commonly because the cross matching process generally takes this possibility into account.
A 43 year old man undergoes a live donor renal transplant. The donor’s right kidney is anastomosed to the recipient. On removal of the arterial clamps there is good urinary flow noted and the wounds are closed. On return to the ward the nurses notice that the patient suddenly becomes anuric and irrigation of the bladder does not improve the situation. What is the most likely cause?
Renal artery thrombosis Acute rejection Blocked catheter Renal vein thrombosis Chronic rejection
Renal artery thrombosis
Right sided live donor transplants are extremely rare. This is because the vena cava precludes mobilisation of the right renal artery. The short right renal artery that is produced therefore presents a major challenge. The sudden cessation of urine output in this context is highly suggestive of an acute thrombosis. Delay in thrombectomy beyond 1 hour almost inevitably results in graft loss.
A 45 year old man with end stage renal failure undergoes a cadaveric renal transplant. The transplanted organ has a cold ischaemic time of 26 hours and a warm ischaemic time of 54 minutes. Post operatively the patient receives immunosuppressive therapy. Ten days later the patient has gained weight, becomes oliguric and feels systemically unwell. He also complains of swelling over the transplant site that is painful. What is the most likely cause?
Acute tubular necrosis Hyperacute rejection Ureteric occlusion Acute on chronic rejection Acute rejection
Acute rejection
The features described are those of worsening graft function and acute rejection. The fact that there is a 10 day delay goes against hyperacute rejection. Cold ischaemic times are a major factor for delayed graft function. However, even 26 hours is not incompatible with graft survival.
