Oedema, Hypotension and Proteinuria

🗒️ Question

A 4 year old boy presents to the paediatric clinic with a 3 week history of progressive generalised oedema, particularly noticeable in the periorbital area, abdomen and lower extremities. His mother also reports that his urine has become frothy and that he has been more lethargic than usual. There is no history of recent infections and he has not experienced any episodes of haematuria. 

On examination, the boy appears pale and puffy with pitting oedema. His observations are stable with a blood pressure of 90/60 mmHg. 

Laboratory tests reveal the following:

• Urinalysis: 4+ proteinuria, no haematuria

• Serum albumin: 18 g/L (normal: 35-50 g/L)

• Serum cholesterol: 8.5 mmol/L (normal: <5.2 mmol/L)

• Serum creatinine: 40 µmol/L (normal: 20-60 µmol/L)

• Serum complement levels (C3 and C4): within normal range

What is the most likely diagnosis?

(A) Acute post-streptococcal glomerulonephritis
(B) Minimal change disease
(C) Focal segmental glomerulosclerosis
(D) Membranous nephropathy
(E) IgA nephropathy