Nephrotic Syndrome

Question 1

What is the management of minimal change disease?

Answer 1

• Prednisolone 1mg/kg for 4-16 wks
• Cyclophosphamide next step for steroid resistant cases

Question 2

What are possible complications of nephrotic syndrome?

Answer 2

• Thromboembolism → hypercoagulable due to inc clotting factors, reduced anti-thrombin III and platelet abnormalities; increased risk of VTE including DVT/PE, treat with heparin and warfarin
• Infection → urine losses of immunoglobulins leads to increased risk of urinary, respiratory and CNS infection; ensure pneumococcal vaccination given
• Hyperlipidaemia → inc cholesterol, LDL and triglycerides; thought due to hepatic synthesis in respons to decreased oncotic pressure and defective lipid breakdown

Question 3

What is minimal change disease?

Answer 3

• 75% cases in children and 25% in adults
• Idiopathic (most) or in associated w drugs (NSAIDs, lithium) or paraneoplastic (Hodgkin’s lymphoma)
• Does NOT cause renal failure

Question 4

What is membranous nephropathy?

Answer 4

• Primary or secondary to malignancy, infection or immunological disease
• Indolent disease w/ spontaneous remission in 25%

Question 5

How is minimal change disease diagnosed?

Answer 5

Light microscopy is normal (hence the name)

Question 6

What is nephrotic syndrome a triad of?

Answer 6

• Proteinuria >3g/24hr
• Hypoalbuminaemia < 30g/L
• Oedema

Question 7

What are the 4 principles for management of nephrotic syndrome?

Answer 7

• Reduce oedema
• Treat underlying cause
• Reduce proteinuria
• Complications

Question 8

What are primary causes of nephrotic syndrome?

Answer 8

• Minimal change disease
• Membranous nephropathy
• Focal segmental glomerulosclerosis (FSGS)
• Membranoproliferative GN

Question 9

What is the pathophysiology of nephrotic syndrome?

Answer 9

• Filtration barrier of kidney is formed by podocytes, glomerular basement membrane (GBM) and endothelial cells
• Proteinuria results from podocyte pathology
• Abnormal fxn in minimal change disease
• Immune-mediated damage in membranous nephropathy
• Podocyte injury/death in FSGS

Question 10

What is the presentation of nephrotic syndrome?

Answer 10

• Generalised
• Pitting oedema
• Fatigue
• Foamy or bubbly urine

Question 11

How do you reduce oedema in nephrotic syndrome?

Answer 11

• Fluid (1L/day) and salt restriction
• Diuresis with loop diuretics
• If gut oedema affects oral absorption of diuretics, give IV
• Aim 0.5-1kg weight loss per day to avoid intravascular volume depletion

Question 12

What are secondary causes of nephrotic syndrome?

Answer 12

• Diabetes mellitus
• Lupus nephritis
• Myeloma
• Amyloid
• Pre-eclampsia

Question 13

How do you reduce proteinuria?

Answer 13

• ACE-i / ARB reduces proteinuria
• May not be needed in minimal change disease

Question 14

How is FSGS diagnosed?

Answer 14

Renal biopsy

• Shows focal + segmental sclerosis and hyalinosis on light microscopy
• Effacement of foot processes on electron microscopy

Question 15

What is the treatment for FSGS?

Answer 15

• ACE-i / ARB for BP control
• Corticosteroids in primary disease

Question 16

How is membranous nephropathy diagnosed and managed?

Answer 16

• Dx → anti-phospholipase A2 receptor antibody in 70-80% idiopathic disease
• ACE-i / ARB and BP control in all

Question 17

What is focal segmental glomerulosclerosis (FSGS)?

Answer 17

• Commonest glomerulonephritis seen on renal biopsy
• Primary (idiopathic) or secondary (HIV, heroin, lithium, lymphoma)
• All at risk of progressive CKD and kidney failure

Question 18

What is the spectrum of glomerular diseases?

Answer 18

Question 19

How do you treat the underlying cause?

Answer 19

• Adults need a renal biopsy (diuresis may be needed first if gut oedema)
• In children, minimal change disease is commonest; biopsy is not needed unless steroid resistant or clinical features of a different cause