ORGAN TRANSPLANT Flashcards
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
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.
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
When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A
The rhesus group is not important in matching donor and recipient kidneys.
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
Identical twin to twin donations are usually genetically identical and are therefore isografts.
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
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.
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
Immediate rejection is due to the presence of pre-existing antibodies e.g. ABO mismatch. The transplanted organ should be removed.
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
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 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
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 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. However, the urostomy is continuing to drain urine. 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
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 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
Renal transplant HLA matching - DR is the most important
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
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.
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
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 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
The long saphenous vein is one of the commonest autografts in surgery.
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.
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 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 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
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.
