Se Lane

Development and validation of a consensus methodology for the classification of the ANCA-associated vasculitides and polyarteritis nodosa for epidemiological studies

Background: The classification of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN) for epidemiology studies is confusing. The existing schemes such as American College of Rheumatology (ACR) criteria, Chapel Hill Consensus Conference (CHCC) definitions and Lanham criteria produce overlapping and conflicting classifications, making it difficult to compare incidence figures. Aim: To develop a consensus method of using these criteria and definitions for epidemiological studies to permit comparison without confounding by classification. Methods: A stepwise algorithm was developed by consensus between a group of doctors interested in the epidemiology of vasculitis. The aim was to categorise patients with Wegener’s granulomatosis, microscopic polyangiitis (MPA), Churg–Strauss syndrome (CSS) and PAN into single clinically relevant categories. The ACR and Lanham criteria for CSS, and ACR criteria for Wegener’s granulomatosis were applied first, as these were considered to be the most specific. Surrogate markers for Wegener’s granulomatosis were included to distinguish Wegener’s granulomatosis from MPA. MPA was classified using the CHCC definition and surrogate markers for renal vasculitis. Finally, PAN was classified using the CHCC definition. The algorithm was validated by application to 20 cases from each centre and 99 from a single centre, followed by a paper case exercise. Results: A four-step algorithm was devised. It successfully categorises patients into a single classification. There was good correlation between observers in the paper case exercise (91.5%; unweighted κ = 0.886). Conclusion: The algorithm achieves its aim of reliably classifying patients into a single category. The use of the algorithm in epidemiology studies should permit comparison between geographical areas.

Epidemiology of systemic vasculitis: a ten-year study in the United Kingdom.

OBJECTIVE To describe the epidemiology of the primary systemic vasculitides (PSV; Wegeners granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, polyarteritis nodosa) in a well-defined population over a 10-year period. METHODS An inception cohort of patients from the Norwich Health Authority (NHA) who were >15 years of age and had PSV first diagnosed between January 1, 1988 and December 31, 1997 was collected. Incidence rates were adjusted for age and sex to the 1992 population. The prevalence of PSV in this cohort was estimated on December 31, 1997. Patients were classified according to the American College of Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions. RESULTS Eighty-two NHA residents fulfilled the inclusion criteria. There were 47 men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall annual incidence of PSV among NHA residents was 19.8/million (95% confidence interval [95% CI] 15.8-24.6). The point prevalence on December 31, 1997 was 144.5/million (95% CI 110.4-185.3). PSV was more common in males (23.5/million; 95% CI 17.3-31.3) than females (16.4/million; 95% CI 11.4-22.8). The age- and sex-specific incidence showed a clear increase with age, with an overall peak in the 65-74 year age group (60.1/million). CONCLUSION In our study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly.

Geoepidemiology of systemic vasculitis: comparison of the incidence in two regions of Europe

OBJECTIVE The aetiopathogenesis of the primary systemic vasculitides (PSV) is unknown but includes both environmental and genetic factors. The development of classification criteria/definitions for PSV allows comparison of the epidemiology between different regions. METHODS The same methods and the American College of Rheumatology (1990) criteria or Chapel Hill definitions were used to compare the epidemiology of Wegeners granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and polyarteritis nodosa in Norwich (east England population 413 500) and Lugo (northwest Spain population 204 100). Patients with PSV were identified between 1 January 1988 and 31 December 1998. RESULTS Overall, the incidence of PSV in adults was almost equal in Norwich (18.9/million) and Spain (18.3/million). The incidence of Wegeners granulomatosis in Norwich (10.6/million) was greater than in Spain (4.9/million). There was a marked age-specific increase in incidence in Norwich with a peak age 65–74 years (52.9/million), but a virtually equal age distribution between ages 45 and 74 in Lugo (34.1/million). There was no significant increase with time in either population, or evidence of cyclical changes in incidence. CONCLUSION These data support the suggestion that environmental factors may be important in the pathogenesis of PSV.

Epidemiology of vasculitis in Europe

We recently compared the annual incidence of primary systemic vasculitis (PSV) in two different regions of Europe (Norwich, UK (latitude 52°N) and Lugo, Spain (latitude 43°N)).1Wegeners granulomatosis (WG) was more common in Norwich (10.6/million) than in Spain (4.9/million), though the overall incidence of PSV was similar. This supports the idea that environmental factors may be important in the aetiopathogenesis of PSV. To extend our observations we have now studied the incidence of PSV in northern Europe (Tromso, Norway (latitude 70°N)). …

Classification of vasculitis: EMA classification using CHCC 2012 definitions

The classification of the antineutrophil cytoplasmic antibody (ANCA) associated vasculitides (granulomatosis with polyangiitis (Wegeners) (GPA), eosinophilic granulomatosis with polyangiitis (Churg Strauss) (EGPA), and microscopic polyangiitis (MPA)) and polyarteritis nodosa (PAN) remains contentious.1 The American College of Rheumatology (ACR) 1990 classification criteria do not include MPA or use ANCA, while the Chapel Hill Consensus Conference (CHCC) definitions (1994) did not include ANCA and although not intended to be used in classification, are widely used for that purpose.2 In order to harmonise the use of the two systems for epidemiological studies, a consensus algorithm for the classification of ANCA vasculitis and PAN was …

Intra-articular corticosteroids in septic arthritis: beneficial or barmy?

We read with interest the paper by Wysenbeek et al about the treatment of staphylococcal septic arthritis in rabbits by intra-articular corticosteroids in addition to antibiotics1 and would like to share our recent clinical experience that we feel pertinent to this scientific research. Traditional teaching dictates that intra-articular corticosteroids are contraindicated in the management of septic arthritis, the appropriate treatment being antibiotics and …

Nocardia farcinica complicating Cogan's syndrome

Nocardiosis is an uncommon bacterial gram-positive infection caused by aerobic actinomycetes in the genus Nocardia. Nocardiosis is typically regarded as an opportunistic infection with approximately two-thirds of infected patients being immunocompromised. In this case report we describe a 45-year-old female who presented with a right thigh abscess. She had been taking high-dose prednisolone and ciclosporin for Cogans syndrome. She presented with erythema and severe pain over her right thigh. Ultrasound showed a collection and Nocardia farcinica was isolated. This case report stresses the importance of considering atypical infections in immunocompromised patients, even with minor symptoms, to avoid delay in diagnosis and treatment.