Re-evaluation of 129 patients with systemic necrotizing vasculitides by using classification algorithm according to...

Area of Science:

• Rheumatology
• Immunology
• Internal Medicine

Background:

• Systemic necrotizing vasculitides require accurate classification for diagnosis and research.
• Existing criteria, including the American College of Rheumatology (ACR) and Chapel Hill Consensus Criteria (CHCC), have limitations.
• A novel classification algorithm (CA) was proposed by Watts et al. to improve classification.

Purpose of the Study:

• To validate the newly proposed classification algorithm (CA) for systemic necrotizing vasculitides in a clinical cohort.
• To assess the agreement between the CA and existing diagnostic criteria.
• To evaluate the practicality and utility of the CA in patient reclassification.

Main Methods:

• Retrospective analysis of 129 patients with vasculitis.
• Reclassification of patients using the proposed CA, incorporating ACR, CHCC, and Sorensen (So) surrogate markers.
• Statistical analysis using Kappa statistic to assess agreement between criteria.

Main Results:

• The majority of patients (12 CSS, 91% WG, 78% MPA, 93% c-PAN) retained their prior diagnoses after applying the CA.
• Significant agreement was observed between ACR and So criteria in Wegener's granulomatosis (WG) (κ=0.62).
• The CA successfully reclassified some previously unclassified patients and facilitated categorization within WG and microscopic polyangiitis (MPA).

Conclusions:

• The CA is a helpful and practical tool for classifying systemic necrotizing vasculitides, particularly in epidemiological studies.
• The algorithm demonstrated good concordance with previous diagnoses for most patients.
• Discrepancies in classification may arise from the diverse features (clinical, histopathological, serological) captured by different criteria.