Rapidly Progressive Glomerulonephritis

Key points

• Rapidly progressive glomerulonephritis (RPGN) is a clinical syndrome of rapidly declining kidney function with nephritic urinary abnormalities; crescentic GN is the classic biopsy correlate.
• Major causes include anti-GBM disease, ANCA-associated vasculitis and immune-complex GN such as lupus nephritis or IgA nephropathy; the old list should not be restricted to 'SLE and microscopic polyarteritis'.
• Typical nephritic features include haematuria, dysmorphic red cells/red-cell casts, proteinuria, hypertension, oliguria and rapidly rising creatinine.
• MRCP emergency: RPGN requires urgent serology/renal assessment and often biopsy; delay in treating anti-GBM disease or severe ANCA vasculitis can cause irreversible kidney/lung injury.
• Pattern recognition: pulmonary haemorrhage + RPGN → anti-GBM disease or ANCA-associated vasculitis until proven otherwise.