[Classification of systemic vasculatides]

Area of Science:

• Rheumatology
• Immunology
• Pathology

Background:

• Vasculitides are inflammatory conditions affecting blood vessel walls, causing stenosis or occlusion.
• Current classifications include the 1990 American College of Rheumatology criteria and the 1994 Chapel Hill nomenclature.
• The Chapel Hill nomenclature differentiated polyarteritis nodosa from microscopic polyangiitis and emphasized the role of antineutrophil cytoplasm autoantibodies (ANCA).

Purpose of the Study:

• To review the classification of vasculitides.
• To highlight the diagnostic significance of ANCA in primary systemic vasculitides.
• To correlate ANCA specificities with specific small-vessel vasculitides.

Main Methods:

• Review of existing literature and classification systems for vasculitis.
• Analysis of clinical presentations, histological features, and affected vessel size in vasculitis.
• Examination of the association between ANCA and specific vasculitic entities.

Main Results:

• Primary systemic vasculitides are clinically classified based on presentation, histology, and vessel size.
• ANCA are associated with several small-vessel vasculitides.
• Wegener's granulomatosis (90%), microscopic polyangiitis (80%), and Churg-Strauss syndrome (over 33%) show ANCA positivity, with specificities like anti-proteinase 3 and anti-myeloperoxidase.

Conclusions:

• Classification of vasculitis relies on a combination of clinical, histological, and serological markers.
• ANCA are crucial diagnostic markers for specific types of small-vessel vasculitis.
• Understanding ANCA patterns aids in differentiating and diagnosing conditions like Wegener's granulomatosis and microscopic polyangiitis.