Jan Sznajd

Are the 1990 American College of Rheumatology vasculitis classification criteria still valid

Objectives Advances in diagnostic techniques have led to better distinction between types of vasculitis, potentially affecting the utility of the 1990 ACR classification criteria for vasculitis. This study tested the performance of these criteria in a contemporary vasculitis cohort. Methods The Diagnosis and Classification in Vasculitis Study provided detailed clinical, serological, pathological and radiological data from patients with primary systemic vasculitis and clinical context-specific comparator conditions. Fulfilment of six ACR criteria sets and their diagnostic performance was evaluated in patients with a given type of vasculitis and its comparator conditions. Results Data from 1095 patients with primary systemic vasculitis and 415 with comparator conditions were available. For classification, sensitivities and specificities for ACR classification criteria were, respectively, 81.1% and 94.9% for GCA; 73.6% and 98.3% for Takayasus arteritis; 65.6% and 88.7% for granulomatosis with polyangiitis; 57.0% and 99.8% for eosinophilic granulomatosis with polyangiitis; 40.6% and 87.8% for polyarteritis nodosa; 28.9% and 88.5% for microscopic polyangiitis; and 72.7% and 96.3% for IgA-vasculitis. Overall sensitivity was 67.1%. Of cases identified by their respective criteria, 16.9% also met criteria for other vasculitides. Diagnostic specificity ranged from 64.2 to 98.9%; overall, 113/415 comparators (27.2%) fulfilled at least one of the ACR classification criteria sets. Conclusion Since publication of the ACR criteria for vasculitis, the sensitivity for each type of vasculitis, except GCA, has diminished, although the specificities have remained high, highlighting the need for updated classification criteria.

OP0055 Using The Birmingham Vasculitis Activity Score as A Screening Tool in Patients with Suspected Vasculitis

Background The Birmingham Vasculitis Activity Score (BVAS) is validated to assess disease activity in systemic vasculitis, but has not been widely tested in conditions mimicking vasculitis. Objectives To explore the utility of BVAS in screening patients with suspected vasculitis. Methods We analysed data from the ACR/EULAR Diagnostic and Classification Criteria in Vasculitis Study (DCVAS), using the submitting physicians diagnosis (certainty >75%) as the gold-standard, with predetermined criteria to identify appropriate comparators for each vasculitis. BVAS score and frequency of individual items were evaluated in: giant cell arteritis (GCA); Takayasu arteritis (TAK); polyarteritis nodosa (PAN); and the anti-neutrophil cytoplasm antibody (ANCA) associated vasculitides (AAV) comprising granulomatosis with polyangiitis (GPA), eosinophilic GPA (EGPA) and microscopic polyangiitis (MPA); and their comparator conditions. Results 1122 patients with vasculitis and 487 comparators were analysed. The BVAS score (median (IQR)) was significantly higher (p<0.0001) in patients with each type of AAV vs comparators: GPA 19 (12–25) vs 11 (6–17); EGPA 18 (12–26) vs 11 (6–17); MPA 19 (14–24) vs 11 (5–17). Between 5–12 individual BVAS items were found significantly more frequently in each of these vasculitides than their comparators: bloody nasal discharge/nasal crusts, sinus involvement, pulmonary infiltrate, nodules/cavities in lung, proteinuria, haematuria for GPA; pulmonary infiltrate, wheeze, sensory peripheral neuropathy, mononeuritis multiplex, heart involvement (pericarditis, ischaemic pain, cardiomyopathy or congestive failure) for EGPA; fever, bloody nasal discharge/nasal crusts, pulmonary infiltrate, proteinuria, haematuria and any renal function abnormalities for MPA. These items were used to develop classification trees whose performance is shown in the table. We analysed whether including an ANCA result in the trees altered their performance (table). This led to an increase in sensitivity for MPA (from 71% to 98%), whereas only slight changes were recorded for GPA and MPA. For PAN, GCA and TAK there was no significant difference in BVAS score compared to comparators, and few or no BVAS items were discriminative.Table 1. Classification tree performance Sensitivity Specificity Not including ANCA result Including ANCA result* Not including ANCA result Including ANCA result* GPA 82% 88% 81% 81% EGPA 82% 89% 94% 92% MPA 71% 98% 83% 80% *For GPA: c-ANCA and/or PR3-ANCA were included; for EGPA and MPA: p-ANCA and/or MPO-ANCA. Conclusions BVAS consists of several items highly specific for GPA, EGPA and MPA, from which we have developed classification trees which can facilitate accurate and systematic screening of patients with suspected AAV based on clinical parameters alone. Whilst the ANCA result contributed to the classification of MPA, it had little additional value in distinguishing GPA or EGPA from their comparator conditions, limiting the value of ANCA testing for the purpose of screening for AAV. By contrast, BVAS is not effective in distinguishing PAN, GCA or TAK from comparator conditions. Acknowledgement Italian and British societies of rheumatology for supporting first author. Disclosure of Interest A. Floris Grant/research support from: Bursary by Italian Society of Rheumatology, N. Goodfellow: None declared, J. Sznajd: None declared, K. Wawrzycka-Adamczyk: None declared, H. Querin: None declared, A. Craven: None declared, J. Rosa: None declared, P. Merkel: None declared, R. Watts: None declared, R. Luqmani Grant/research support from: GSK, Nordic, Medimmune, Chemocentryx, Roche, UCB, Consultant for: GSK, Nordic, Medimmune, Chemocentryx