Classification and epidemiology of vasculitis: Emerging concepts

Area of Science:

• Rheumatology
• Immunology
• Epidemiology

Background:

• The American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology (EULAR) have published new classification criteria for large vessel vasculitis (LVV) and anti-neutrophil cytoplasmic antibody-associated vasculitides (AAVs).
• These criteria incorporate contemporary diagnostic methods, aiming to modernize the classification of these rare autoimmune conditions.
• Existing data indicate Takayasu arteritis is rare, while giant cell arteritis is common in older adults. AAV incidence is stable, but prevalence is rising due to improved survival.

Purpose of the Study:

• To introduce and discuss the implications of the new ACR/EULAR classification criteria for LVV and AAVs.
• To highlight the need for further validation of these criteria in independent and diverse patient cohorts.
• To explore potential impacts of the new criteria on reported epidemiological data (incidence and prevalence) of vasculitides.

Main Methods:

• Review and analysis of the recently published ACR/EULAR classification criteria for LVV and AAVs.
• Discussion of existing epidemiological studies on LVV and AAVs, including incidence and prevalence trends.
• Consideration of the potential influence of the new criteria on future epidemiological research and reporting.

Main Results:

• The new ACR/EULAR criteria provide a modern framework for classifying LVV and AAVs, integrating current diagnostic techniques.
• Validation in diverse populations, particularly those underrepresented in the development cohort, is crucial.
• The criteria may alter established figures for vasculitis incidence and prevalence, necessitating confirmatory studies.

Conclusions:

• The new ACR/EULAR classification criteria represent a significant advancement in the diagnosis of large vessel vasculitis and ANCA-associated vasculitides.
• Independent validation across varied populations is essential to ensure generalizability and accuracy.
• Ongoing research is required to understand the full impact of these criteria on the epidemiological landscape of vasculitis.