Granulomatosis With Polyangiitis

Overview

Formerly known as Wegener’s granulomatosis, granulomatosis with polyangiitis (GPA) is a rare ANCA-associated autoimmune vasculitis typically affecting the upper and lower respiratory tracts and the kidneys.

Epidemiology

• Males are slightly more affected than females
• Peak age of presentation is 35-55 years, although any age can be affected

Risk Factors & Associations

• Family history
• Staphylococcus aureus nasal carriage
• Previous parvovirus infection

Presentation

• Upper respiratory tract features
  • Epistaxis, sinusitis, nasal crusting
  • Destruction of nasal cartilage, saddle-shaped nose
• Lower respiratory tract features
  • Dyspnoea, chest pain, cough, haemoptysis
• Renal features:
  • Rapidly-progressing glomerulonephritis
• General features:
  • Fatigue, malaise, weakness, fever, night sweats, anorexia, weight loss

Other features

• Chronic ear infections
• Hearing loss
• Abdominal pain
• Conjunctivitis, episcleritis, or scleritis
• Mononeuritis multiplex

Differential Diagnoses

Eosinophilic granulomatosis with polyangiitis (EPGA)

• Asthma present
• Eosinophilia present
• pANCA present

Anti-glomerular basement membrane disease

• Also presents with haemoptysis and glomerulonephritis and is clinically indistinguishable from GPA
• Anti-GBM antibodies positive
• Epistaxis not usually seen

Other vasculitides

• Polyarteritis nodosa spares the respiratory tract and kidneys
• Other vasculitides have an absence of respiratory tract features

Systemic lupus erythematosus (SLE)

• Photosensitive rashes and other features of SLE

Sarcoidosis

• Features of sarcoidosis present, such as erythema nodosum, lymphadenopathy, splenomegaly, and uveitis

Cocaine abuse

• History of illicit drug use
• Cocaine abuse affects the hard palate as well as the nasal septum

Non-Hodgkin’s lymphoma

• Features of NHL present, such as palpable lymphadenopathy

Investigations

• Urinalysis and microscopy:
  • Haematuria
  • Proteinuria
• CT chest:
  • Lung nodules which may cavitate may be seen
  • Infiltrates may be seen
• Anti-neutrophil cytoplasmic antibodies (ANCA) – pANCA and cANCA:
  • c-ANCA is associated with granulomatosis with polyangiitis
• Urea and electrolytes (U&Es):
  • May show renal dysfunction
• C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)L
  • May be elevated
• Renal biopsy:
  • Confirms glomerulonephritis

Management

Management generally involves inducing remission with the use of corticosteroids with or without cyclophosphamide, and methotrexate in some scenarios.

Complications

• Acute kidney injury
• Chronic kidney disease
• Chronic conjunctivitis
• Respiratory failure
• Nasal septum perforation and saddle-shaped nose deformity
• Venous thromboembolism
• Deafness
• Blindness

Prognosis

• Infection, vasculitis, acute kidney injuries, malignancy, heart failure, and myocardial infarction are the leading causes of death
• A poorer prognosis is thought to be due to deteriorating renal function