Glomerular Pathology Flashcards
What characterises nephrotic syndrome?
- Proteinuria
- Hypoalbumiaemia
- Peripheral oedema
(also hyperlipidaemia)
How does urine appear in a patient with nephrotic syndrome?
Frothy
Why does hypoalbuminaemia occur in a patient with nephrotic syndrome?
Albumin is lost in urine -> proteinuria
This is because gaps in podocytes allow proteins to leak
Why does a patient with nephrotic syndrome present with peripheral oedema?
Decreased intravascular oncotic pressure
Why does a patient with nephrotic syndrome present with hyperlipidaemia?
Liver tries to compensate for hypoalbuminaemia and increases production - the side effect is an increase in the production of lipids
What are the primary causes of nephrotic syndrome?
- Minimal change glomerulonephritis
- Focal segmental glomerulosclerosis
- Membranous glomerulonephritis
What are some secondary causes of nephrotic syndrome?
- SLE
- Hep B and C
- HIV
- Diabetes
- Malignancy
What kind of syndrome does minimal change glomerulonephritis lead to?
Nephrotic syndrome
How does minimal change glomerulonephritis appear under a microscope?
Under light microscope - normal
Under electron microscope - loss of foot processes on podocytes - widening of filtration slits
What do most patients with minimal change glomerulonephritis respond well to?
Steroids
What is the pathogenesis of minimal change glomerulonephritis?
Unknown circulating factor causing damage to podocytes
What is focal segmental glomerulosclerosis and what does it lead to?
Nephrotic syndrome
Like the adult version of minimal change
What is the commonest cause of primary nephrotic syndrome in adults?
Membranous glomerulonephritis
What is one difference between membranous glomerulonephritis and focal segmental glomerulosclerosis?
FSGM - no immune complexes deposited
MGN - immune complexes are deposited
What characterises nephritic syndrome?
- Haematuria
- Oligouria
- Red cell casts (distinguishing feature)
What is the most common cause of primary nephritic syndrome?
Berger’s disease (IgA nephropathy)
What are some causes of nephritic syndrome?
- Post streptococcal glomerulonephritis
- IgA nephropathy
- Goodpasture’s syndrome
- SLE
- Hepatitis
- Systemic vasculitis
What is goodpasture’s syndrome?
An autoimmune disease in which antibodies attack the basement membrane in lungs and kidneys, leading to bleeding from the lungs and kidney failure
In what syndrome are red cell casts present?
Nephritic
What is Alport syndrome?
A genetic disease characterised by progressive chronic kidney disease with symptoms of haematuria, sensorineural deafness and ocular abnormalities
How is Alport syndrome inherited?
X linked recessive
What is the cause of Alport syndrome?
Mutation in the gene that codes for a5 chain of type IV collagen
What class of drugs are known to slow the progression of renal disease?
ACE inhibitors
What are the 3 layers of the glomerulus?
Endothelium, basement membrane (type IV collagen) and epithelial podocytes
What is the name of the spaces between the foot processes of podocytes?
Filtration slits
What is the commonest cause of end stage renal disease?
Diabetic nephropathy
Why isn’t diabetic nephropathy seen in children?
It does not develop until a patient has had diabetes
(either type 1 or type 2) for around 8-15 years.
What is the earliest change seen in diabetic nephropathy?
Hyperfiltration and an increase in GFR
What histological changes are seen in diabetic nephropathy?
Glomerular BM thickening, mesangial expansion and glomerular sclerosis
What is diabetic nephropathy characterised by?
- Proteinuria
- A gradual decline in GFR
- Hypertension
Why does a thickened GBM allow more bigger molecules to get through?
Thickened GBM increases pore size, also high intraglomerular pressure increases chance of more bigger molecules getting through
What are the nodules seen in diabetic nephropathy called?
Kimmelstiel-wilson nodules
What is the first clinical sign of diabetic nephropathy?
Microalbuminuria
Why does GFR fall in the later stages of diabetic nephropathy?
Mesangial expansion/sclerosis -> reduced surface area for filtration
Overt proteinuria
How long do most patients with diabetic nephropathy take to reach end stage kidney disease?
3-7 years
What are the risk factors for diabetic nephropathy?
- Genetics
- Race (causasians have a lower risk)
- Hypertension
- Hyperglycaemia
- High level of hyperfiltration
- Older age
- Smoking
How can you prevent diabetic nephropathy?
Tight glycaemic and BP control
What effect does angII have on glomerularly permeability to proteins?
Increases permeability
What histological changes are seen in hypertensive nephrosclerosis?
- Vascular changes tor renal arteries and arterioles
- Fibroelastic intimal thickening - narrowing of lumen
- Hyalinosis of afferent arteriolar walls
