Therapeutic advances in the treatment of vasculitis.

Considerable therapeutic advances for the treatment of vasculitis of the young have been made in the past 10 years, including the development of outcome measures that facilitate clinical trial design. Notably, these include: a recognition that some patients with Kawasaki Disease require corticosteroids as primary treatment combined with IVIG; implementation of rare disease trial design for polyarteritis nodosa to deliver the first randomised controlled trial for children; first clinical trials involving children for anti-neutrophil cytoplasmic antibody (ANCA) vasculitis; and identification of monogenic forms of vasculitis that provide an understanding of pathogenesis, thus facilitating more targeted treatment. Robust randomised controlled trials for Henoch Schönlein Purpura nephritis and Takayasu arteritis are needed; there is also an over-arching need for trials examining new agents that facilitate corticosteroid sparing, of particular importance in the paediatric population since glucocorticoid toxicity is a major concern.

Performance of Birmingham Vasculitis Activity Score and disease extent index in childhood vasculitides.

OBJECTIVES: To evaluate the performance of the Birmingham Vasculitis Activity Score (BVAS) v3 and the Disease Extent Index (DEI) for the assessment of disease activity in 4 primary childhood (c-) systemic vasculitides. METHODS: Patients fulfilling the EULAR/PRINTO/PRES (Ankara) c-vasculitis classification criteria for Henoch-Schönlein purpura (HSP), childhood (c) polyarteritis nodosa (c-PAN), c-Wegener's granulomatosis (c-WG) and c-Takayasu arteritis (c-TA) with disease duration at the time of diagnosis ≤3 months were extracted from the PRINTO database. The performance of the BVAS and DEI were examined by assessing convergent validity, the pattern of disease involvement, and responsiveness. We also evaluated alternative unweighted scoring methods for both tools. RESULTS: The analysis set included 796 patients with 669 HSP, 80 c-PAN, 25 c-WG and 22 c-TA. The median age at diagnosis was 6.9 years (6.6-12) and median delay in making the diagnosis from the onset of signs/symptoms was 0.01 (0.003-0.027) years. A strong correlation was found between the BVAS and DEI (rs=0.78) while correlation with the physician global assessment was moderate (rs=0.48) with BVAS and poor with DEI (rs=0.25). Both the BVAS and DEI sub-scores and total scores were able to descrive the disease involvement in the 4 childhood vasculitides. Responsiveness was large (>1.5) for both tools. The performance characteristics of the BVAS and DEI with the unweighted methods were comparable. CONCLUSIONS: This study demonstrates that both the BVAS and DEI are valid tools for the assessment of the level of disease activity in a large cohort of childhood acute and chronic vasculitides.

Recent developments in the classification and assessment of vasculitis.

The systemic vasculitides are a group of multisystem diseases characterized by inflammation of blood vessels. The aetiopathogenesis is unknown, and therefore nomenclature and classification are often descriptive and based on pathological features. Generally agreed classification schemes are vital to enable large multicentre or multinational clinical trials to be undertaken. An algorithm has recently been developed to harmonize use of the American College of Rheumatology (ACR) 1990 criteria and the Chapel Hill Consensus Conference definitions. Despite this, a revision of the classification criteria is still needed, and diagnostic criteria need to be developed ab initio. The very complexity of the diseases makes accurate objective assessment critical, especially for the conduct of clinical trials. Several standardized assessment tools for both disease activity and damage have been developed over the past two decades and are now widely used in both clinical trials and routine practice. A second generation of tools is now under development.

The future of damage assessment in vasculitis.

Damage denotes the aspects of chronic disease that do not reverse with therapy. This concept is particularly important for the primary systemic vasculitides, since the careful differentiation between activity and damage may help avoid unnecessary exposure to cytotoxic medications. Damage significantly influences both longterm prognosis and quality of life. Because the primary systemic vasculitides have diverse manifestations, the use of a damage assessment instrument is crucial to ensure reproducibility. The Vasculitis Damage Index (VDI) is the only validated measure for damage assessment in vasculitis. Use of the VDI in recent clinical trials has shown that it may not adequately determine the full spectrum of damage experienced by patients with vasculitis of small- and medium-size vessels. We propose reexamining the way in which damage is assessed, focusing on vasculitides of small- and medium-size vessels, and outline an initiative to create a substantially revised and improved damage assessment instrument using data-driven approaches. This initiative is part of a larger international effort to create a unified approach to disease assessment for the primary systemic vasculitides.

Diagnosis and assessment of systemic vasculitis.

The diagnosis of systemic vasculitis requires clinical evidence with appropriate symptoms and physical signs, supported by histological or radiological confirmation. Earlier recognition of these diseases has been facilitated by a greater awareness of their incidence, and also by the more widespread introduction of the anti-neutrophil cytoplasmic antibody (ANCA) test. Early diagnosis provides a greater potential for effective intervention in the course of disease and this may limit subsequent damage. However, an early diagnosis poses the more difficult challenge in the classification of the vasculitides, since traditional classification systems have depended on the presence of well-established manifestations of the disease. The accurate assessment of disease activity and damage in vasculitis has become necessary as a result of significant improvements in survival with the use of chemotherapy. The disease course however is frequently characterised by relapse as well as the scars of irreversible organ damage from disease and drug toxicity. Clinical methods of assessment are simple to apply, reliable and often more effective than any current laboratory test in evaluating the effects of therapy and determining changes in therapy. The increasing use of surrogate clinical measures of disease should provide a greater opportunity to establish the effectiveness of existing and novel therapies in the management of these complex diseases.

The socioeconomic impact of vasculitis.

Information detailing the socioeconomic impact of the vasculitides on society has been difficult to obtain. Recent published studies provide preliminary information suggesting that the impact of systemic vasculitis may be significant and far greater than previously anticipated. A rough estimate of expenditures for vasculitis-related hospitalizations for polyarteritis nodosa, hypersensitivity vasculitis, Wegener's granulomatosis, giant cell arteritis and Takayasu's arteritis in the US amounted to $150 million per year. Costs associated with outpatient care, disability, and death were not calculated. A more comprehensive investigation into the economic and social burden of these conditions is necessary. Aspects to consider include quantifying the incidence and prevalence of disease, estimating the direct, indirect, and intangible costs of care, assessing long-term clinical outcomes, and measuring quality of life from the patient perspective.