MET3 Revision: Renal III Flashcards
Renal biopsy, or trauma, is a risk factor for subsequent development of a []
Name two presentations that the above answer may present with [2]
Renal biopsy may cause renal arteriovenous malformations (AVMs)
most common presentation is with hypertension and haematuria
Describe the two immunological compatibility issues when it comes to transplantation [2]
Blood groups
HLA
Which type of GN is associated with renal transplants? [1]
Focal sclerosis glomerulosclerosis
What are two mechanisms that acute rejection occurs? [2]
(probably don’t learn that much)
Acute rejection can be either via:
Acute Cellular Rejection (ACR)
- Cytotoxic T lymphocyte response
- Macrophage response
OR
Acute Antibody Mediated Response (AMR)
- B lymphocyte response making antibodies (agaisnt MHC Class 1 /2 antigens or ABO blood group antigens)
Describe the features of acute graft failure:
- Why does it usually occur? [2]
- How does it present? [3]
- Prognosis? [2]
- usually due to mismatched HLA; also caused by CMV infection
- usually asymptomatic and is picked up a rising creatinine, pyuria and proteinuria
- potentially reversbile with steroid and immunosuppressant
What are the sites of action used for immunosuppressive drugs? [3] and what drugs used? [5]
Calcineurin inhibitors:
* Calcineurin is an enzyme that activates T-cells of the immune system.
* E.g. Cyclosporin and tacrolimus
Anti-proliferative drugs:
* (target nucleus at end stage of T cell activation)
* e.g. Azathioprine and Mycophenolic acid
Prevent cytokine (IL-2) gene activation
* Use cortiosteroids
* e.g. Prednisolone
Rapamycin: stops clonal expansion of T cells
Explain how can you prevent acute rejection of transplants? [2]
HLA matching (make sure that not positive for match)
Minimising ischaemia-reperfusion injury:
* Ischaemia causes upregulation of adhesion molecules, which increases adhesion of leukocytes when blood is reperfused.
* More leukocytes increases chance of rejection, SO try and limit ischaemia time.
* Cold ischaemia time: 12 hrs
* Warm ishaemia time: 1 hour
Describe the features of hyperacute rejection [3]
- Happens within minutes to hours of transplant
- Occurs due to pre-exisiting antibodies agaisnt ABO or HLA antigens (that have already been pre-activated)
- Leads to neutrophil inifiltration, intravascular coagulation and cortical necrosis
What is delayed graft function (DGF)? [1]
What does the risk of DGF increaese with? [1]
Delayed graft function (DGF) is defined by the need for dialysis in the first week after transplantation.
Risk increases with prolonged WITs and CITs (therefore is relatively rare with living donor grafts). Whilst most DGF kidneys eventually function, there is a recognised association with increased rejection rates and decreased graft survival rates.
Describe the AEs of the following drugs used in kidney transplantation:
- Immunosuppressants [2]
- Tacrolimus [1]
- Cyclosporine [1]
- Steroids [1]
- Immunosuppressants cause seborrhoeic warts and skin cancers (look for scars from skin cancer removal)
- Tacrolimus causes a tremor
- Cyclosporine causes gum hypertrophy
- Steroids cause features of Cushing’s syndrome
Two doses of which drug are given after a transplant to prevent acute rejection [1]
Basiliximab is a monoclonal antibody targeting the interleukin-2 receptor on T-cells.
What increases the chance of having better kidney transplant outcomes?
Patient and donor kidneys are matched based on the human leukocyte antigen (HLA) type A, B and C.
They do not have to match fully, but the closer the match, the less likely there is organ rejection and the better the outcomes.
Recipients can receive treatment to desensitise them to the donor HLA in preparation for a transplant from a living donor.
Which infections can occur secondary to immunosuppressant medication? [3]
Pneumocystis jiroveci pneumonia (PCP/PJP)
Cytomegalovirus (CMV)
Tuberculosis (TB)
State complications related to immunosuppressants w/ kidney transplants [5]
Ischaemic heart disease
Type 2 diabetes (steroids)
Infections are more likely, more severe and may involve unusual pathogens:
- Viral, e.g. cmv and warts (CMV affects 8-10% of all transplant recipients
- Bacterial infection especially of the urine (40-50% of female transplant recipients)
- Fungal infections such as pneumocystis
Non-Hodgkin lymphoma
Skin cancer (particularly squamous cell carcinoma)
When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows []
When HLA matching for a renal transplant the relative importance of the HLA antigens are as follows DR > B > A
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