Nephrotic Syndrome

Question 1

Definition

Answer 1

Nephrotic syndrome is characterised by a triad of:

o Proteinuria (> 3 g/24 hr)
o Hypoalbuminaemia (< 30 g/L)
o Oedema

o Hypercholesterolaemia is also a common feature

Question 2

Aetiology

Answer 2

• Most commonly caused by: minimal change glomerulonephritis in children
• However, ALL forms of glomerulonephritis can cause nephrotic syndrome

• Other causes:
o Diabetes mellitus
o Sickle cell disease
o Amyloidosis
o Malignancies (lung and GI adenocarcinomas)
o Drugs (e.g. NSAIDs)
o Alport's syndrome
o HIV

Question 3

Epidemiology

Answer 3

• 90% of nephrotic syndrome in CHILDREN is due to minimal change glomerulonephritis

• Most common cause of nephrotic syndrome in ADULTS:
o Diabetes mellitus
o Membranous glomerulonephritis

Question 4

Presenting symptoms

Answer 4

• Family history of atopy (in those with minimal change glomerulonephritis)
• Family history of renal disease

• Swelling of face, abdomen, limbs, genitalia (due to hypoalbuminaemia)

• Symptoms of the underlying cause (e.g. SLE)
• Symptoms of complications

Question 5

Signs on physical examination

Answer 5

• Oedema: periorbital, peripheral, genital

* Ascites: fluid thrill, shifting dullness

Question 6

Investigations (bloods)

Answer 6

o FBC
o U&E
o LFTs (low albumin)
o ESR/CRP
o Glucose
o Lipid profile (check for secondary hyperlipidaemia)
o Immunoglobulins
o Complement

Question 7

Investigations (to identify cause)

Answer 7

Tests to identify the cause

o SLE - ANA, anti-dsDNA antibodies

o Infections:
• Group A -haemolytic streptococcal infection (ASO titre)
• HBV infection (serology)
• Plasmodium malariae (blood film)

o Goodpasture’s Syndrome - anti-glomerular basement antibodies

o Vasculitides - polyangiitis with granulomatosis, microscopic polyarteritis (check ANCA)

Question 8

Investigations (other)

Answer 8

• Urine
o Urinalysis (check protein and blood)
o MC&S
o 24 hr collection (calculate creatinine clearance and 24 hr protein excretion)

• Renal Ultrasound
o Exclude other causes (e.g. reflux nephropathy)

• Renal Biopsy
• Other imaging: Doppler ultrasound, renal angiogram, CT or MRI (if renal vein thrombosis suspected)