Nephrotic Syndrome

Question 1

How does blood enter the glomerulus?

Answer 1

It enters the glomerulus via an afferent arteriole

The blood is under high pressure

Question 2

How is filtrate formed in the Bowman’s capsule?

Answer 2

Fluid passes across the walls of the capillary and the nephron and into the capsule

Question 3

Why is it significant that the pressure is high in the afferent arteriole?

Answer 3

Fluid needs to be forced out of the glomerulus and into the Bowman’s capsule to form the ultrafiltrate

Question 4

What is the capillary hydrostatic pressure and the Bowman’s capsule hydrostatic pressure?

Answer 4

Capillary - 45 mmHg

Bowman’s capsule - 10 mmHg

Question 5

What is the plasma protein oncotic pressure in the tubule?

What is significant about this?

Answer 5

25 mmHg

Once the fluid is in the tubule, it keeps it there and prevents it from leaving

It draws fluid towards the tubule

Question 6

What are the layers of the glomerular filtration barrier?

Answer 6

From the interior of the Bowman’s capsule:

1. epithelial foot process
2. slit membrane
3. basement membrane
4. endothelial cells of the capillary (fenestra between them)

Capillary lumen

Question 7

What are the 3 layers of the basement membrane?

Answer 7

1. lamina rara
2. lamina densa
3. lamina rara

Question 8

What is the main function of the glomerular filtration barrier?

Answer 8

It prevents proteins from leaking into the urine

Question 9

How is the urine modulated in nephrotic syndrome?

Answer 9

There is loss of protein in the urine

This is proteinuria

Question 10

What is hypoalbuminaemia in nephrotic syndrome?

Answer 10

This involves the level of albumin in the blood being abnormally low

Question 11

What is the consequence of losing protein in the urine?

Answer 11

Oedema

This results due to a loss of oncotic pressure

Question 12

What is the consequence of having low plasma albumin?

Answer 12

The liver increases its production of cholesterol

This leads to hypercholesterolaemia

Question 13

What causes the loss of protein in urine in nephrotic syndrome?

Answer 13

Injury to the epithelial foot processes of the nephron

Question 14

What is the most common cause of nephrotic syndrome in children?

Answer 14

Minimal change disease

Question 15

What are the most common causes of nephrotic syndrome in adults?

Answer 15

1. membranous nephropathy
2. focal segmental glomerulosclerosis
3. amyloid

Question 16

What happens to the foot processes in nephrotic syndrome?

Answer 16

They become flattened and collapsed

There is loss of the filtration slits

Question 17

What is the main treatment of nephrotic syndrome?

Answer 17

Potent Immunosuppressants

e.g. steroids, cyclophoshamide, rituximab, plasma exchange, azathioprine

Question 18

What is the risk of giving potent immunosuppressants to patients?

Answer 18

They are more prone to infection

Question 19

What causes CRP to increase?

Answer 19

Bacterial infection and inflammation

e.g. cancer promotes an inflammatory response

Question 20

How can amyloid be identified through staining?

Answer 20

It shows apple green birefringence in polarised light

With Congo Red stain

Question 21

What is amyloid usually secondary to?

Answer 21

Myeloma