Nephrotic Syndrome

Nephrotic syndrome results from leaky glomeruli (the kidney’s filtering units) that allow important proteins, such as albumin, to spill into the urine. This results in low blood albumin (hypoalbuminemia), leading to fluid retention and swelling (oedema) mainly in ankles, feet and periorbital areas. Foamy urine suggests proteinuria; hyperlipidaemia is due to overcompensation of the liver.

Common symptoms are fatigue, loss of appetite and weight gain due to fluid retention. The primary causes are minimal change disease (children) or membranous nephropathy (adults); the secondary causes are diabetes, lupus, infections (HIV, hepatitis), amyloidosis, and medications.

Diagnosis: urine >3.5g protein/24 h, bloodwork (albumin <3 g/dL, elevated cholesterol), and biopsy for aetiology. Treatment is aimed at addressing the underlying cause; ACE inhibitors (ACEi) and angiotensin receptor blockers (ARBs) help decrease proteinuria and control blood pressure. Diuretics and salt restriction relieve oedema. KDIGO recommendations state that immunosuppressants (steroids, cyclophosphamide, rituximab) cause remission in primary instances.

Complications: thrombosis, infections, acute kidney injury, progression to end-stage renal disease Monitoring lipids, diet, and immunisation is crucial. Prognosis is variable but good in paediatric minimal change disease (90% remit). In adults, there is a larger probability of relapse/chronicity.