Wegener Granulomatosis

Indications for Testing

Persistent upper airway symptoms with other systemic manifestations

Laboratory Testing

Nonspecific testing
- CBC – may show anemia, thrombocytopenia
- Urinalysis – hematuria, proteinuria are common
- ESR – usually elevated
ANCA – targeted testing toward two main neutrophil granule components, including serine PR3 and myeloperoxidase
- Anti-PR3 predominate – pathogenic for WG; (found in 70-80% of cases)
- Anti-myeloperoxidase – nonspecific

Histology

Tissue biopsy of involved organ site – confirm presence of small artery vasculitis with granulomatous infiltration

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 withdraw
Flare-ups might follow reductions of corticosteroid doses

Differential Diagnosis

Other vasculitides
- Polyarteritis nodosa
- Churg-Strauss syndrome
- Behçet syndrome
- Henoch Schönlein purpura
Connective tissue disease
Granulomatous disease
- Sarcoidosis
- Lymphomatoid granulomatosis

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, the lungs and the 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 by 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