Description

• Glomerulonephritis presents with the nephritic syndrome: hematuria with RBC casts, hypertension, variable azotemia, and edema. Proteinuria and oliguria may also be present.
• Acute glomerulonephritis is associated with inflammation and cell proliferation in the glomerular tuft. It may be rapidly progressive.
• Chronic glomerulonephritis indicates permanent damage has occurred.

Epidemiology

• Postinfectious glomerulonephritis can occur after any infection; ~80% of cases are secondary to a streptococcal infection.
• Acute poststreptococcal glomerulonephritis (APSGN) can occur in anyone >2 years but is most frequently found in boys 5 to 15 years old. It can be sporadic or epidemic.
• Incidence of APSGN has declined over the last 2 decades.
• Chronic glomerulonephritis occurs more often at the end of the 1st decade of life and in adults.

Risk Factors

Exposure to nephritogenic streptococci

Etiology

Can be categorized based on serum complement levels and presence of renal-limited versus systemic disease

• Low serum complement level: systemic diseases
  • Vasculitis and autoimmune disease (e.g., systemic lupus erythematosus [SLE])
  • Subacute bacterial endocarditis (SBE)
  • Shunt nephritis
  • Cryoglobulinemia
• Low serum complement level: renal diseases
  • APSGN
  • Membranoproliferative glomerulonephritis, C3 glomerulopathy
• Normal serum complement level: systemic diseases
  • Microscopic polyangiitis (MPA)
  • Granulomatosis with polyangiitis (GPA)
  • Henoch-Schönlein purpura (HSP)
  • Hypersensitivity vasculitis
  • Anti-GBM disease (Goodpasture syndrome)
• Normal serum complement level: renal diseases
  • IgA nephropathy
  • Idiopathic rapidly progressive glomerulonephritis
  • Pauci-immune glomerulonephritis (renal-limited ANCA vasculitis)
  • Immune-complex disease