Wegener Granulomatosis

Diagnosis

Indications for Testing

• Persistent upper airway symptoms with other systemic manifestations

Laboratory Testing

• Nonspecific testing
  • CBC – may demonstrate anemia, thrombocytopenia
  • Urinalysis – hematuria, proteinuria common
  • ESR – usually elevated
• ANCA – target testing toward two main neutrophil granule components, serine PR3 and myeloperoxidase
  • Anti-PR3 predominate – suggests WG (found in 70-80% of cases)
  • Anti-myeloperoxidase – nonspecific

Histology

• Tissue biopsy of involved organ to confirm presence of small artery vasculitis with granulomatous infiltration – gold standard

Imaging Studies

• X-ray  – chest or sinus
• CT/MRI – more sensitive in identifying small inflammatory lesions

Prognosis

• Relapses are common, especially if maintenance treatments are fully withdrawn
• Flare-ups might follow reductions of corticosteroid doses

Differential Diagnosis 

• Other vasculitides
  • Polyarteritis nodosa
  • Churg-Strauss syndrome
  • Henoch Schönlein purpura
• Connective tissue disease
  • Systemic lupus erythematosus
  • Mixed connective tissue disease
  • Sjögren syndrome
• Granulomatous disease
  • Sarcoidosis
  • Lymphomatoid granulomatosis

Clinical Background

Wegener granulomatosis (WG) is a multi-system disorder characterized by small artery vasculitis and necrotizing granulomas. WG classically involves a triad of organ systems, including the upper respiratory tract, lungs, and kidneys. However, WG confined to the head and neck is not uncommon.

Epidemiology

• Incidence – 3/100,000 in the U.S.
• Age – 55 years (mean age of diagnosis)
• Sex – M:F, equal

Organism

• Secondary infection, usually with S. aureus, is common in nasal WG

Pathophysiology

• Circulating neutrophils and monocytes express antineutrophil cytoplasm antibody (ANCA) antigens and proteinase 3 (PR3) on the cell surface
• ANCA releases reactive oxygen species and lysosomal enzymes, contributing to inflammation of vessel walls
• ANCA and PR3 attack the vessels, causing endothelial cell injury and necrotizing inflammation

Clinical Presentation

• Constitutional – weight loss, fever, myalgias
• Otorhinolaryngological
  • Otologic – serous otitis media, sensorineural hearing loss
  • Rhinologic – nasal congestion, rhinorrhea, anosmia, sinusitis, nasal septal perforation
  • Ophthalmologic – episcleritis, keratitis
  • Laryngeal/tracheal – subglottic stenosis, tracheal stenosis
• Renal – glomerulonephritis, proteinuria, hematuria
• Cardiovascular – pericarditis, cardiac ischemia, arrhythmias
• Neurological – mononeuropathy multiplex, sensorimotor polyneuropathy
• Dermatological – palpable purpura, ulcers, Raynaud phenomena
• Neurological – neuropathies, seizures, CNS palsies
• Pulmonary – cough, dyspnea

Treatment

• Glucocorticoids and immunosuppressants

Indications for Laboratory Testing

• Tests generally appear in the order most useful for common clinical situations
• Click on number for test-specific information in the ARUP Laboratory Test Directory