Theme 10: Kidney and Urinary Tract Pathology Flashcards
What parameters define nephrotic syndrome?
Proteinuria >3.5g/24hrs
or
Urine protein/creatinine ratio >300-350mg/mmol
If a patient passes 100-400 ml of urine in 24 hours, this is described as:
a) Dysuria
b) Anuria
c) Oliguria
d) Polyuria
c) Oliguria
If a patient passes <100 ml of urine in 24 hours, this is described as:
a) Dysuria
b) Anuria
c) Oliguria
d) Polyuria
b) Anuria
If a patient passes >3000 ml of urine in 24 hours, this is described as:
a) Dysuria
b) Anuria
c) Oliguria
d) Polyuria
d) Polyuria
Which renal function test uses a formula that takes into account age, sex and ethnicity?
eGFR
Uses the abbreviated MDRD equation
Fluids and solutes that are reabsorbed by the renal tubules are returned to the circulation by the __?__
Peritubular capillary network
What is the primary cause of nephrotic syndrome in adults?
Membranous nephropathy
- Usually M aged <60y
- Related to autoantibodies against PLA2R
True or false: Nephrotic Syndrome results from damage to the glomerulus
True
Glomerular damage increases the permeability to albumin and other plasma proteins.
True or false: Nephritic syndrome involves the loss a lot of blood?
True
Nephritic syndrome is characterised by haematuria. This is due to podocytes developing large pores which allow blood and protein to escape in the urine.
Nephrotic syndrome is characterised by proteinuria.
What is the clinical picture associated with nephrotic syndrome?
Frothy urine caused by massive proteinuria (>3.5g in 24hrs).
This causes hypoalbuminaemia, leading to oedema (due to loss of intravascular colloid pressure) and hyperlipidemia (liver compensates for albumin loss but also creates lots of lipids at the same time).
NephrOtic and prOtein both have an ‘O’!
What are the primary causes of nephrotic syndrome?
Adults:
- Membranous glomerulonephritis
Children:
- Minimal change glomerulonephritis
Both:
- Focal segmental glomerulosclerosis
What are the primary causes of nephritic syndrome?
Post-infectious glomerulonephritis
- Streptococcal
- Appears weeks after URTI
IgA Nephropathy
- Appears a day or two after URTI
What clinical picture is seen with acute renal failure?
Anuria/oliguria (<400 ml/24hrs)
- Malaise
- Nausea
- Vomiting
- Electrolyte imbalance
What is the most common cause of renal artery stenosis?
Atheroma
What complications arise from renal artery stenosis?
Ischaemic injury to affected kidney –> reduced function
Activation of RAAS –> hypertension
__?__ results in a permanently reduced eGFR due to a reduction in the number of functional nephrons.
Chronic renal failure
How can renal disease cause anaemia?
Reduced renal function = reduced EPO production
What is isolated haematuria?
Haematuria (+/- proteinuria) with normal renal function
Causes:
- IgA nephropathy
- Thin basement membrane disease
- Alport’s disease (type IV collagen abnormality)
- Urological malignancy (e.g. renal cell carcinoma)
What are the risk factors for acute pyelonephritis?
Female (ascending infection)
Diabetes
Instrumentation
Urinary tract structural abnormalities
What are the major complications associated with acute and chronic pyelonephritis?
Acute pyelonephritis:
- Abscess formation
Chronic pyelonephritis:
- Scarring
- Chronic renal failure