[Acute kidney failure in glomerulonephritis and in angiitis]

Area of Science:

• Nephrology
• Pathology

Context:

• Postinfectious glomerulonephritis (PIGN) can present with acute kidney injury (AKI), including oligoanuria.
• Distinguishing between different PIGN subtypes is crucial for prognosis and management.

Purpose:

• To highlight the diagnostic importance of renal biopsy in oligoanuric PIGN.
• To differentiate PIGN subtypes based on biopsy findings and their clinical implications.

Summary:

• Renal biopsy is essential for classifying oligoanuric PIGN into endocapillary/exsudative or endo-/extracapillary proliferative forms.
• The endocapillary form, often post-streptococcal, is typically regressive. The proliferative form, linked to various bacterial infections, has a poorer prognosis.
• Other causes of crescentic glomerulonephritis include anti-glomerular basement membrane (GBM) disease and vasculitis (e.g., polyarteritis nodosa, Wegener granulomatosis), presenting with AKI.
• Anti-GBM disease shows linear IgG deposits on immunofluorescence; early treatment with plasma exchange, corticosteroids, and alkylating agents can prevent end-stage renal disease.
• IgA nephropathy can also present with haematuria and AKI.

Impact:

• Accurate diagnosis through renal biopsy guides appropriate treatment strategies for glomerulonephritis.
• Early intervention in anti-GBM disease and other forms of glomerulonephritis can significantly improve renal survival and patient outcomes.
• Understanding the diverse causes and presentations of AKI in glomerulonephritis is vital for effective clinical management.