Nephrotic syndrome in infants and children: pathophysiology and management

Abstract

Nephrotic syndrome is defined by nephrotic-range proteinuria (≥40 mg/m²/hour or urine protein/creatinine ratio ≥200 mg/mL or 3+ protein on urine dipstick), hypoalbuminaemia (<25 g/L) and oedema. This review focuses on the classification, epidemiology, pathophysiology, management strategies and prognosis of idiopathic nephrotic syndrome of childhood, and includes a brief overview of the congenital forms.

Keywords:

• Nephrotic syndrome
• oedema
• minimal change disease
• focal segmental glomerulosclerosis
• steroid-responsive nephrotic syndrome
• steroid-resistant nephrotic syndrome
• idiopathic nephrotic syndrome

Abbreviations:

• NS: nephrotic syndrome
• MCD: minimal change disease
• FSGS: focal segmental glomerulosclerosis
• SSNS: steroid-sensitive nephrotic syndrome
• SRNS: steroid-resistant nephrotic syndrome
• FRNS: frequently relapsing nephrotic syndrome
• KDIGO: Kidney Disease Improving Global Outcomes
• ESRD: end-stage renal disease
• VPF: vascular permeability factor
• CLC-1: cardiotrophin-like cytokine 1
• suPAR: soluble urokinase-type plasminogen activator receptor
• AKI: acute kidney injury
• DVT: deep vein thrombosis
• LCAT: lecithin-cholesteryl acyltransferase
• RAAS: renin-angiotensin-aldosterone system
• ENaC: epithelial sodium channel
• ANA: antinuclear antigen
• anti-dsDNA: anti-double stranded DNA
• ANCAs: anti-neutrophil cytoplasmic antibodies
• ASOT: anti-streptolysin titres
• CNIs: calcineurin inhibitors
• MMF: mycophenolate mofetil
• CNS: congenital nephrotic syndrome
• CMV: cytomegalovirus
• uPCR: urine protein:creatinine ratio