ACR, EULAR Classification Criteria for Granulomatosis With Polyangiitis (Part 4)

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).

The American College of Rheumatolgy created a detailed and complete description of the methods involved in the development of the classification criteria for GPA.

There was an international Steering Committee composed of investigators with expertise in vasculitis, statisticians, and data managers was established to oversee the diagnostic and classification criteria in Vasculitis (DCVAS).

The Steering Committee established a 5-stage plan using data-driven and consensus methodology to develop the criteria for each of 6 forms of vasculitis.

The first stage is the generation of candidate classification items for the systemic vasculitides. The items were generated by expert opinion and reviewed by a group of experts across a range of specialties using a nominal group technique.

The second stage is the consideration of the DCVAS prospective observational study. There was a prospective, observational study conducted for this purpose.

The third stage involves items specifically for AAV.

The next stage involves expert review to derive a gold standard–defined set of cases of AAV and validated by experts.

The last stage involved the derivation and validation of the final classification criteria.

We will be discussing the different criteria in our next column.