Systemic Disease Affecting the Kidneys Flashcards
What defines renovascular disease?
Stenosis of the renal artery or one of its branches
What is the most common cause of renovascular disease?
Atherosclerosis
What is the second most common cause of renovascular disease after atherosclerosis?
Fibromuscular dysplasia
What demographic is fibromuscular dysplasia most likely to affect?
Females aged < 50
What percentage of cases of fibromuscular dysplasia are familial? What is significant about these cases?
10% - they are often bilateral
In those with bilateral renal artery stenosis, what happens after treatment is given with an ACE inhibitor or ARB?
Decline in renal function, possible AKI
How does renovascular disease most commonly present?
Hypertension which is resistant to treatment
Patients with renovascular disease can experience ‘flash’ pulmonary oedema - what is meant by this?
Sudden onset pulmonary oedema, with no LV impairment on ECHO
What sign of renovascular disease may be detectable on abdominal examination?
Abdominal bruit
What is the first line imaging investigation for renovascular disease?
Renal ultrasound + Doppler
What happens to the size of a kidney affected by renovascular disease?
It is small
What is the gold standard imaging investigation for renovascular disease?
CT/MR angiogram
What is the treatment of choice for hypertension management in those with unilateral renal artery stenosis?
ACE inhibitor or ARB
When are ACE inhibitors and ARBs contraindicated in renovascular disease?
If the condition is bilateral
What are some interventional options for the management of renovascular disease?
Transluminal angioplasty / revascularisation surgery
Kimmelstiel-Wilson nodules seen on histology suggests what underlying pathology?
Diabetic nephropathy
What are the 4 main stages of diabetic nephropathy?
Elevated GFR / glomerular hyperfiltration / microalbuminuria / nephropathy
What defines microalbuminuria?
30-300mg of albumin passed in 24h
Patients with diabetes should be screened annually for what, to detect early evidence of renal damage?
Microalbuminuria
In diabetics, microalbuminuria gives early warning of impending renal problems, but is also a strong independent risk factor for what?
Cardiovascular disease
How can microalbuminuria be detected?
By using specialised dipsticks or an albumin: creatinine ratio
In diabetic patients who are positive for microalbuminuria, what treatment is required?
ACE inhibitor or ARB
An albumin: creatinine ratio of what suggests microalbuminuria?
> 2.5mg/mmol
What is the target blood pressure for all diabetic patients?
< 130/80
What is the target blood pressure for diabetic patients with microalbuminuria?
< 125/75
Once an ACE inhibitor or ARB has been started, what blood test should be monitored periodically?
U&Es
If a diabetic patient is started on an ACE inhibitor or ARB, the medication should be stopped if there is a rise in creatinine of more than what?
20%
Other than blood pressure control, what are some other areas of management for microalbuminuria in diabetics?
Good glycaemic control and management of CV risk factors
What is an option for RRT in type 1 diabetic patients which is not available to type 2 diabetic patients?
Simultaneous kidney-pancreas transplant
What is the most common class of lupus nephritis?
Class IV
What is meant by class IV lupus nephritis?
Diffuse proliferative glomerulonephritis
Glomeruli showing a ‘wire loop’ appearance on histology is suggestive of which pathology?
Lupus nephritis
How is lupus nephritis managed?
Immunosuppression and tight control of hypertension
cANCA and anti-PR3 antibodies are suggestive of which small vessel vasculitis?
GPA
pANCA and anti-MPO antibodies are suggestive of which small vessel vasculitis?
MPA and EGPA
How is small vessel vasculitis managed?
Immunosuppression +/- plasma exchange
What is the ‘classic’ presentation of myeloma?
Back pain and renal failure
What are the two main signs which can be detected on blood testing that are suggestive of myeloma?
Anaemia and hypercalcaemia
What blood testing is done specifically to detect myeloma?
Protein electrophoresis and serum free light chains
What urine testing is done specifically to detect myeloma?
Bence-Jones proteins
How should hypercalcaemia caused by myeloma be managed?
Saline +/- bisphosphonates
What are the definitive management options for myeloma?
Chemotherapy or stem cell transplant
Regardless of the underlying cause, what are the two main features of haemolytic uraemic syndrome?
Thrombocytopenia and AKI
90% of cases of haemolytic uraemic syndrome are due to what?
Infection with E. coli O157
If haemolytic uraemic syndrome is caused by infection, what other clinical features will be present?
Abdominal pain and bloody diarrhoea
What will be seen on a blood film of someone with haemolytic uraemic syndrome?
Fragmented RBCs (schistocytes)
What will be seen on urinalysis of someone with haemolytic uraemic syndrome?
Proteinuria and haematuria
What are the two major abnormalities that will be seen on an FBC of someone with haemolytic uraemic syndrome?
Low Hb and platelets
The mortality of thrombotic thrombocytopenic purpura is reduced from > 90% to 20% with what treatment?
Plasma exchange
The unexplained occurrence of thrombocytopenia and anaemia should prompt immediate consideration of what diagnosis?
Thrombotic thrombocytopenic purpura
What additional symptoms may Henoch-Schonlein purpura have over IgA nephropathy?
Purpuric rash (on extensor surfaces), polyarthritis and abdominal pain
Immunofluorescence will be positive for what in a skin or renal biopsy of someone with Henoch-Schonlein purpura?
IgA and C3
Anti-GBM disease is caused by autoantibodies to what?
Type IV collagen
Other than the kidneys, what other body systemic is affected by anti-GBM disease and what symptom does it usually cause?
Respiratory - causes haemoptysis
Patients with anti-GBM disease usually present with what?
Haematuria, or nephritic syndrome
How is anti-GBM disease treated?
Plasma exchange, steroids +/- cytotoxic immunosuppressants
How does amyloidosis affecting the kidneys present?
Proteinuria, or nephrotic syndrome
What happens to the size of the kidneys affected by amyloidosis?
Large
A renal biopsy which shows positive Congo-red staining with red-green birifringence under polarised light microscopy suggests what diagnosis?
Amyloidosis
