Q: Mrs Jones makes an urgent appointment for her son Jack, who is 10 years old and presents complaining of a headache, swelling of his hands and feet, and dark urine.
On examination, you find him to be hypertensive and have macroscopic haematuria. What is your provisional diagnosis and what further tests would you now request?
A: Jack most likely has glomerulonephritis (GN) with nephrotic features (peripheral oedema) and nephritic features (hypertensive headache, macroscopic haematuria).
A urine dipstick is a simple way to determine the degree of urinary blood and protein loss. A protein dipstick result of 3+ is usually indicative of significant proteinuria (>3 g protein/24 hours).
A urine microscopy can be helpful in confirming active nephritis (Table 1). Further tests indicated in a child presenting with acute nephritis or mixed nephrotic-nephritic picture are outlined in Table 2.
A renal biopsy is not indicated in children with presentations consistent with minimal change nephrotic syndrome or post-streptococcal GN with appropriate clinical resolution.
Where the diagnosis is unclear a renal biopsy can be helpful in delineating the type of GN, which provides a guide to therapy and prognosis. Cases in which the aetiology of nephritis is not clear need to be followed closely to avoid missing rapidly progressive glomerulonephritis.
Dr Sam Mehr, Trainee of the Royal College of Pathologists of Australasia
Dr Melanie Wong, Fellow of the Royal College of Pathologists of Australasia
Dr Stephen Alexander, Paediatric Nephrologist at The Children’s Hospital, Westmead, NSW
|Table 1 – Interpretation of urinary red and white cell findings|
|Dysmorphic red cells
Eumorphic red cells
|Red cell casts||Glomerular damage|
|White cell casts||Pyelonephritis, nephrosis, nephritis|
Table 2 – Tests indicated in nephritis or mixed nephrosis-nephritis
|Test||Reason for ordering test|
|Full blood count||Dilutional anaemia (acute renal failure)
Anaemia, lymphopaenia, thrombocytopaenia (SLE)
|Electrolytes, urea and creatinine||Acute renal impairment|
|C3, C4*||Low complement may be associated with some types of nephritis – remember the rule of “S”
• Post-streptococcal GN
• Mesangiocapillary GN
• Systemic lupus erythematosus
• Subacute bacterial endocarditis
|ASOT, anti-DNaseB (convalescent testing may be necessary)||Post-streptococcal GN|
|Renal ultrasound||Confirm two kidneys are present and are structurally normal|
|* Some healthy individuals may normally have a low C4 (C4 null allele)|
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