FRI0218 Validation of the consensus methodology algorithm for the classification of systemic necrotizing vasculitis

• Published in: Annals of the rheumatic diseases Vol. 71; no. Suppl 3; pp. 387 - 388
• Main Authors: Sharma, A., Mittal, T., Rathi, M., Minz, R., Singh, S.
• Format: Journal Article
• Language: English
• Published: Kidlington BMJ Publishing Group Ltd and European League Against Rheumatism 01.06.2013; Elsevier Limited
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/annrheumdis-2012-eular.2675

Background The current classification of systemic necrotizing vasculitis (SNV) is confusing as many patients satisfy criteria for different diseases in different classification systems. Recently, a new classification algorithm was proposed by Watts et al1 by using the American College of Rheumatology (ACR), Chapel Hill Consensus Criteria (CHCC) and Sorensen surrogate markers (So) for a more uniform classification of patients suffering from these rare disorders. Objectives The algorithm uses a stepwise approach for individual patient diagnosis and prioritizes individual criteria as per previous validation. In the present study, we have attempted to re-analyze patients of SNV seen at our center using the consensus methodology algorithm. Methods All patients of primary systemic necrotizing vasculitis who presented to the rheumatology clinic at our center between Jan 2007 and Jun 2011 were included in the study. Results Seventy nine patients of SNV were studied (see Table 1). One patient diagnosed as MPA had to be excluded from analysis as she had previously been diagnosed to have Behcet’s disease. All patients of CSS, WG and MPA were reclassified to the same diagnostic subcategory after application of the algorithm. Four (22%) of 18 PAN patients were unclassifiable after application of the consensus algorithm while 1 was reclassified as MPA. All previously unclassifiable patients could be classified either as MPA or WG after application of the new algorithm. Table 1 Number of patientsNumber of patients reclassifiedDetails (% of all patients)in the same diagnostic subcategory CSS4 (5.0%)4 (100%)1 patient reclassified using Lanham criteria WG45 (57.0%)45 (100%)42 patients – 2a; 2 patients – 2c; 1 patient 2d MPA5 (6.3%)4 (80%)1 patient excluded from analyses PAN18 (22.8%)13 (72.2%)1 patient reclassified to MPA; 4 patients reclassified to unclassifiable Unclassifiable7 (8.9%)0 (0%)1 patient reclassified to WG; 6 patients reclassified to MPA Conclusions We conclude that the new classification algorithm is a reliable method for classification of SNV for epidemiological purposes References Watts R, Lane S, Hanslik T et al. Ann Rheum Dis 2007;66:222-227 Disclosure of Interest None Declared