Nephrotic Syndrome

Question 1

Define

Answer 1

The nephrotic syndrome is a triad of:

(1) Proteinuria (>3 g/24 hrs)
(2) Hypalbuminaemia (<25 g/L)
(3) Oedema

Severe hyperlipidaemia is often present (total cholesterol >10 mmol)

Question 2

Causes

Answer 2

• Not a diagnosis - always seek out underlying cause
• Most commonly caused by: minimal change glomerulonephritis in children
• However, ALL forms of glomerulonephritis can cause nephrotic syndrome
• Other causes:
  
  • Diabetes mellitus
  • Sickle cell disease
  • Amyloidosis
  • Malignancies (lung and GI adenocarcinomas)
  • Drugs (e.g. NSAIDs)
  • Alport’s syndrome
  • HIV

Question 3

Risk factors

Answer 3

FHx of atopy or renal disease

Question 4

Epidemiology

Answer 4

Minimal change glomerulonephritis most common cause in children (90%), usually boys age <5 years
Most common cause in adults is: DM or membranous glomerulonephritis

Question 5

Symptoms

Answer 5

• 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 (e.g. renal vein thrombosis: loin pain, haematuria)

Question 6

Signs

Answer 6

Oedema – periorbital, peripheral , genital Pitting oedema in areas of low tissue resistance

Ascites – fluid thrill, shifting dullness

Question 7

Investigations

Answer 7

Bloods

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

Tests to identify the cause

• SLE - ANA, anti-dsDNA antibodies
• Infections: Group A b-haemolytic streptococcal infection (ASO titre)
• HBV infection (serology)
• Plasmodium malariae (blood film)
• Goodpasture’s Syndrome - anti-glomerular basement antibodies
• Vasculitides - polyangiitis with granulomatosis, microscopic polyarteritis (check ANCA)

Urine

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

Renal Ultrasound

Exclude other causes (e.g. reflux nephropathy)

Renal Biopsy

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