Granulomatosis with polyangiitis (formerly termed Wegener's granulomatosis)

Granulomatosis with polyangiitis (GPA) is a rare form of vasculitis which was formerly termed Wegener's granulomatosis.

The term Wegener's granulomatosis has largely been superseded by GPA (1,2):

• " in part because of concerns about the suitability of Friedrich Wegener as the source of an eponym. The most distinctive pathological feature of Wegener's granulomatosis is multi-focal necrotizing inflammation that has long been called granulomatosis. The systemic variant of Wegener's granulomatosis also is characterized by inflammation in many different vessels or different types, i.e. polyangiitis. Thus, granulomatosis with polyangiitis is a very appropriate alternative term for Wegener's granulomatosis. This term also is in accord with the name for a closely related vasculitis, i.e. microscopic polyangiitis" (1)

Granulomatosis with polyangiitis (GPA) is an idiopathic vasculitis of medium and small arteries, characterized by necrotizing granulomatous inflammation.

It is a rare form of necrotising vasculitis characterised by (1,2,3,4):

• pulmonary disease
• upper and lower respiratory tract lesions - affecting nose, sinuses, and lung
• focal or diffuse glomerulonephritis

This disease is generally characterized by antineutrophil cytoplasm antibodies (ANCA) - however there are rare cases with negative ANCA.

• GPA affects people at any age, with predominance of the sixth and seventh decade of life.

Other summary features include:

• disease may run a course that might vary from indolence to one of rapid progression leading to life-threatening multiorgan failure
• disease generally develops over a period of time with the mean period from onset of symptoms to diagnosis ranging from 4.7 to 15 months
• without treatment it is invariably fatal
• diagnosis of GPA is based on Criteria of the American College of Rheumatology
• standard treatment procedure is divided into two essential phases, induction and maintenance
  • induction phase is based on combination of systemic corticosteroid and immunosuppressant therapy
  • maintenance phase comprises corticosteroids and azathioprine/methotrexate supplementation
  • surgical treatment ought to be considered for patients who are not responding to pharmacotherapy (5)

Notes:

• necrotising granulomatous inflammation usually involving the upper and lower respiratory tract, and necrotising vasculitis predominantly affecting small to medium vessels (e.g. capillaries, venules, arterioles, arteries and veins) (4)
• necrotising glomerulonephritis is common (4)
• in 80%–95% of the patients the first symptoms of GPA are otorhinolaryngological manifestations of head and neck including nose/sinuses, ears, eyes, larynx/trachea, oral cavity, and salivary glands (5)

References:

1. Jennette JC.Nomenclature and classification of vasculitis: lessons learned from granulomatosis with polyangiitis (Wegener's granulomatosis).Clin Exp Immunol. 2011 May;164 Suppl 1:7-10
2. Jennette JC.Overview of the 2012 revised International Chapel Hill Consensus Conference nomenclature of vasculitides.Clin Exp Nephrol. 2013 Oct;17(5):603-606
3. Ponniah I et al. Wegener's granulomatosis: The current understanding. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005 Sep;100(3):265-70.
4. ARC Autumn 2012. Topical Reviews - ANCA-associated vasculitis; 1:1-12.
5. Wojciechowska J et al.Granulomatosis With Polyangiitis in Otolaryngologist Practice: A Review of Current Knowledge. Clin Exp Otorhinolaryngol. 2016 Mar;9(1):8-13.