Nephrotic Syndrome

Question 1

How is nephrotic syndrome characterised?

Answer 1

Oedema
Proteinuria >3.5g/day
Hypoalbuminaemia

Question 2

How does nephrotic syndrome result in oedema?

Answer 2

Loss of abumin results in reduced plasma oncotic pressure

Sodium retention in interstium

Question 3

What are the complications of nephrotic syndrome?

Answer 3

Higher risk of infection
Venous thromboembolism 
Progression of CKD
Hypertension
Hyperlipidaemia

Question 4

How does nephrotic syndrome cause venous thromboembolism?

Answer 4

Anticlotting factors are lost in the urine (AT3, protein C, protein S)
Liver makes clotting factors (e.g.fibrinogen) to replace proteins lost in the urine

Question 5

How does nephrotic syndrome cause hyperlipidaemia?

Answer 5

The liver becomes overactive to replace proteins lost in the urine

Question 6

What is the most common type of nephrotic disease in children?
What is the pathophysiology?

Answer 6

Minimal change disease

Related to an autoimmune process, the immune system attacks epithelium and defaces the podocytes.

Question 7

How is minimal change disease diagnosed?

Answer 7

Kidney biopsy- electron microscopy shows changes

Light microscopy and immuno staining appears normal

Question 8

How are all nephrotic syndromes treated?

Answer 8

Diuretics
Fluid restriction
Reduce salt intake
(IV albumin can be used in extreme situations with renal failure and hypotension)

Question 9

How is minimal change treated?

Answer 9

(Same as all nephrotic syndromes)
Plus
Steroids (high dose for 4 weeks, then tapered down, 90% will go into remission)

Question 10

What is the most common nephrotic syndrome in adults?

Answer 10

Membranous nephropathy

Question 11

How is primary and secondary membranous nephropathy differentiated?

Answer 11

Blood test for Anti PLA2RAb

+ve is primary

Question 12

What is an important association of membranous nephropathy?

Answer 12

30% of MN cases are associated with malignancy e.g. breast, lung, colon
Can also be associated with other autoimmune conditions e.g. SLE

Question 13

How is MN treated?

Is primary always treated?

Answer 13

Treat the cause
Immunosppressants
Primary MN will spontaneously resolve within 6 months in 30% of cases- after this time, treat with ACEi and statins

Question 14

What is the pathophysiology of focal segmental glomerulonephritis?

Answer 14

Podocyte damage

Proteins build up (hyalinosis), leading to sclerosis

Question 15

What is the cause of primary and secondary FSGS?

Answer 15

Primary-idiopathic (immunological process)

Secondary- hyperfiltration (obesity, hypertension, reflux nephropathy as a child, one kidney), sickle cell disease, HIV

Question 16

What is the problem with the treatment of FSGS?

Answer 16

Primary can be steroid resistant

Question 17

What features of diabetes will likely already be present if diabetic nephropathy develops?

Answer 17

Retinopathy

Peripheral neuropathy

Question 18

What is the classic feature of diabetic nephropathy on biopsy?

Answer 18

Kimmelsteil wilson nodules

Question 19

What is the pathophysiology of MN?

Answer 19

Subepithelial deposition of immune complexes

Question 20

What is the pathophysiology of diabetic nephropathy?

Answer 20

Excess glucose binds to proteins, esp at the efferent arteriole.
This is called hyaline atherosclerosis, which obstructs blood flow and increases pressure in the nephron
Mesangial cells will react by secreting more structural matrix, leading to the BM thickening

Question 21

How is diabetic nephropathy treated?

Answer 21

Aggressive control of diabetes and blood pressure

Steroids will worsen condition

Question 22

Describe a complication of relapsing minimal change disease?

Answer 22

Recurrent infections

This is due to loss of immunoglobulins in the urine