Urinary: Glomerular Pathology

Question 1

What is nephrotic syndrome?

Answer 1

The glomerular filter can leak causing significant loss of protein and blood.
This results in decreased oncotic pressure therefore oedema
The most likely site of injury is the podocyte layer (most of selective permeability)

Question 2

What is nephritic syndrome?

Answer 2

The glomerular filter can become blocked therefore starts to break down which leads to haematuria
There is acute kidney injury and reduced eGFR leading to hypertension

Question 3

Wha are some common causes of nephrotic syndrome?

Answer 3

Primary causes: minimal change glomerulonephritis, focal segment glomerulosclerosis, membranous glomerulonephritis
Secondary causes: diabetes mellitus

Question 4

What is minimal change glomerulonephritis?

Answer 4

Usually presents in childhood with heavy proteinuria (nephrotic)
Responds to steroids
Usually no progression to renal failure
It is due to loss of the podocyte layer

Question 5

What is focal segment glomerulosclerosis?

Answer 5

Usually presents in adults (nephrotic) 
Sclerosis so the glomerulus has scarring
Doesnt respond well to steroids
There is a circulating factor damaging the podocytes 
It progresses to renal failure

Question 6

What is membranous glomerulonephritis?

Answer 6

Commonest cause of nephrotic syndrome in adults
Rule of thirds: 1/3 get better, 1/3 stay same, 1/3 progress to renal failure
It is thought to be autoimmune due to IgG deposits

Question 7

How does diabetes mellitus cause nephrotic syndrome?

Answer 7

There is progressive proteinuria, and progressive renal failure
The basement membrane becomes thickened

Question 8

What are the causes of nephritic syndrome?

Answer 8

Most common cause is IgA nephropathy

Thin glomerular basement membrane disease

Question 9

What is IgA nephropathy?

Answer 9

Commonest cause of nephritic syndrome - IgA is deposited
Can present at any age, classically with haematuria +/- proteinuria
A significant proportion progress to renal failure - there is no effective treatment so just have to try and support renal function

Question 10

What is thin glomerular basement membrane disease?

Answer 10

A hereditary nephropathy causing nephritic syndrome

It is rare - the basement membrane never forms properly so is very thin

Question 11

What is goodpasture syndrome?

Answer 11

Rare but very clinically important
There is rapid onset of severe nephritic syndrome - an antibody to collage 4 suddenly starts attacking own basement membrane
Associated with pulmonary haemorrhage in smokers
There is an on call service - treatable with immunosuppression and plasmophoresis (replace plasma with donor) if caught early