Etiology

Tip

• The most common cause of nephritic syndrome is immune complex deposition, which leads to serum hypocomplementemia.
• IgA nephropathy is an exception, which is characterized by normal serum complement levels

• ANCA-associated glomerulonephritis (pauci-immune glomerulonephritis)
  • Granulomatosis with polyangiitis
  • Microscopic polyangiitis
  • Eosinophilic granulomatosis with polyangiitis
• Anti-glomerular basement membrane (GBM) associated glomerulonephritis
  • Anti-GBM disease (Goodpasture disease)
  • Anti-GBM glomerulonephritis (no lung involvement)
• Immune complex-mediated glomerulonephritis
  • Low C3 levels
    • Lupus nephritis
    • Infection-related glomerulonephritis
      • Poststreptococcal glomerulonephritis
  • Normal C3 levels
    • IgA nephropathy
    • IgA vasculitis

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Classifications

• Poststreptococcal glomerulonephritis
• Diffuse proliferative glomerulonephritis
• Rapidly progressive glomerulonephritis

Pathophysiology

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Clinical features

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Diagnostics

• Urinalysis: nephritic sediment
  • Hematuria (either microhematuria or intermittent macrohematuria)
  • Acanthocytes
  • Red blood cell casts: RBC casts form through the congregation of proteins and RBCs inside the tubules.
  • Mild to moderate proteinuria of > 150 mg/24 h but < 3.5 g/24 h (nonselective glomerular proteinuria)
  • Sterile pyuria and sometimes WBC casts
• Blood tests
  • ↑ Creatinine, ↓ GFR
  • Azotemia with ↑ BUN
  • Complement, ANA, ANCA, and anti-GBM antibodies

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Treatment

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