nephrotic syndrome

Question 1

definition

Answer 1

characterised by: proteinuria, hypomicroalbuminuria, and oedema (and hypercholesterolaemia)

Question 2

aetiology

Answer 2

Commonest cause is minimal change glomerulonephritis in children, but all forms of glomerulonephritis can cause nephrotic syndrome.
Other causes: Diabetes mellitus, sickle cell disease, amyloidosis, malignancies (lung and GI adenocarcinomas), drugs (NSAIDs), Alport’s syndrome, HIV infection.

Question 3

epidemiology

Answer 3

Most common cause of nephrotic syndrome in children (90%): minimal change glomerulonephritis (usually seen in boys <5 years, rare in black populations).
Most common causes of nephrotic syndrome in adults: diabetes mellitus, membranous glomerulonephritis.

Question 4

risk factors

Answer 4

Family history of atopy in those with minimal change glomerulonephritis, family history of renal disease.

Question 5

symptoms

Answer 5

Swelling of face, abdomen, limbs, genitalia.
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.
Ascites: Fluid thrill, shifting dullness.

Question 7

investigations

Answer 7

Blood: FBC, U&E, LFT (reduced albumin), ESR/CRP, glucose, lipid profile (secondary hyperlipidaemia), immunoglobulins, complement (C3, C4)

Tests to identify the underlying cause of glomerulonephritis:

SLE: ANA, anti-dsDNA.
Infections: Group A b-haemolytic streptococcal infection (ASO titre), HBV infection (serol-
ogy), plasmodium malariae (blood films).
Goodpasture’s syndrome: Anti-glomerular basement membrane antibodies.
Vasculitides: e.g. Wegener’s and microscopic polyarteritis (ANCA).
Urine: Urinalysis (protein, blood), microscopy, culture, sensitivity, 24-h collection (to calculate
creatinine clearance and 24-h protein excretion).
Renal ultrasound: Excludes other renal diseases that may cause proteinuria, e.g. reflux
nephropathy.
Renal biopsy: In all adults and in children who have unusual features or do not respond to
steroids.
Other imaging: Doppler ultrasound, renal angiogram, CT or MRI are options if renal vein
thrombosis is suspected.

Question 8

things to monitor

Answer 8

Monitor:
. BP, U&E, weight, fluid balance.
. Thromboprophylaxis: Heparin.