Wegener's granulomatosis

From Ganfyd

Originally thought of as a complication of sepsis, it was described by the German pathologist Friedrich Wegener in a 1937 publication (translation in [1]) with a subsequent landmark article by Jacob Churg and Godman in 1954.[2] Of the many eponymously named diseases, Wegener's granulomatosis is often singled out as a disease which should be dissociated from the person first describing it on the basis of Wegener's close links with Nazism.[3]

Wegener's granulomatosis is characterised by necrotising granulomatous inflammation and pauci-immune (i.e. a lack of deposits of immune complex) small vessel vasculitis. For those who eschew eponyms, granulomatosis with polyangiitis is the alternative term. An association with Staphylococcus aureus has been described and several possible mechanisms have been described.^[4]

Presentation

• Upper airways involvement
  • Nasal discharge
  • Sinusitis
  • Epistaxis
• Saddle nose deformity
• Lower airways involvement with inflammation/granuloma formation
  • Trachea
  • Bronchi
  • Lung e.g. abnormal CXR
• Systemic
  • Pyrexia
  • Arthritis
  • Cutaneous vasculitis
  • Mononeuritis or polyneuritis
• Renal (70%)
  • Necrotising glomerulonephritis (usually type III crescentic glomerulonephritis)

Investigations

• Urinalysis/Microscopy - as screen for renal disease with common presentations
• c-ANCA - good specificity but poor sensitivity. A small number of cases are associated with positive p-ANCA.
• Biopsy

Differential Diagnosis

Almost always involves a large number of infective and systemic diseases as often presents with non-specific upper or lower airways problems or unexpected renal impairment. c-ANCA does not distinguish between say microscopic polyangiitis or Churg-Strauss syndrome

Treatment

• Steroids usually at high dose
• Cyclophosphamide for vasculitic complications
• Methotrexate for granulomatous complications

References