Classification Criteria for ANCA Associated Vasculitis - Ready for Prime Time?

Area of Science:

• Rheumatology
• Immunology
• Clinical Trials

Background:

• Classification of ANCA-associated vasculitis (AAV) has faced historical challenges due to overlapping criteria and lack of ANCA integration.
• Previous classification systems hindered direct comparison of AAV cohorts and epidemiological studies.

Purpose of the Study:

• To review the evolution of AAV classification criteria.
• To evaluate the performance and implications of the 2022 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for AAV.

Main Methods:

• Review of historical and recent classification criteria for AAV.
• Analysis of studies evaluating the 2022 ACR/EULAR criteria in diverse patient cohorts.

Main Results:

• The 2022 ACR/EULAR criteria represent a significant advancement by incorporating ANCA status and modern imaging techniques.
• These new criteria demonstrate good performance but introduce complexities related to ANCA serotypes and potential discrepancies with established histopathological features.
• Previous criteria were criticized for omitting ANCA or surrogate markers and for overlap issues.

Conclusions:

• The 2022 ACR/EULAR criteria offer improved classification for AAV but require careful application due to new considerations.
• Further research is needed to address the impact of ANCA serotypes and reconcile new criteria with histopathological findings in AAV.