ACR, EULAR Classification Criteria for Granulomatosis With Polyangiitis (Part 3)
Before we continue with this week’s column, it is best to discuss first the terminologies that are important to this topic.
The antineutrophil cytoplasmic antibody (ANCA)–associated vasculitides (AAV) are multisystem disorders involving inflammation of the small blood vessels and include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA).
GPA is characterized by necrotizing granulomatous inflammation involving the ears, nose, and upper and lower respiratory tracts, and necrotizing vasculitis affecting predominantly small-tomedium-sized vessels, often including necrotizing glomerulonephritis.
Now let’s start the discussions.
There are several key reasons for the development of revised classification criteria for the vasculitides, including a decline in the relevance of the American College of Rheumatology (ACR) classification cluster regarding AAV.
There was a consensus that any such criteria must now incorporate testing for ANCA.
There is also consideration for cross-sectional diagnostic imaging tools, including magnetic resonance imaging and computed tomography; and the introduction and adoption of the classification of patients with MPA.
It is important to realize that there have been methodologic advances in the derivation of classification criteria. The creation of classification criteria improves the treatment modalities of these diseases.
We will be discussing in the next few weeks the development of the criteria and validation of the revised ACR/European Alliance of Associations for Rheumatology (EULAR)–endorsed classification criteria for GPA.