Table 5

Points to consider in the development of classification criteria and definitions in the systemic vasculitides

StatementLevel of evidence
Biopsy:
1. Although histology is fundamental to the diagnosis of vasculitis and exclusion of its' mimics, biopsy of affected organs is not always possible and yields vary significantly according to conditions and target organsIII
2. TAB is an important tool in the diagnosis of GCAIa
3. Cases of HSP usually have IgA deposits present on biopsyIIb
Laboratory testing:
4. ANCA testing plays an important diagnostic role in suspected small vessel vasculitisIa
5. In suspected PAN, the absence of ANCA has diagnostic valueIIa
6. The role of clinical features and additional surrogate biomarkers for vasculitis is likely to have an important role in the development of future diagnostic criteriaIV
Diagnostic radiology:
7. CT and MRA techniques can replace standard angiography in the diagnosis of TAKIIa
8. Ultrasound and high resolution MRI may have a role in the diagnosis of GCAUS Ia/MRI IIa
9. The role of abdominal angiography in the diagnosis of adult PAN is unclearIII
10. CT and MRI may be useful in diagnosing ENT involvement associated with WG/CSSIII
11. The role of radiology in the diagnosis of CNS vasculitis is unclearIII
Nosology:
12. The nomenclature in use for distinguishing between ‘disease definitions’, ‘classification’ and ‘diagnostic’ criteria is confusing and should be clarified wherever possibleIV
13. Nosology of different forms of vasculitis should be a reflection of their aetiopathogenesis wherever this has been determined. In the absence of this, definition must rely on a clear accurate description of the salient features of the conditionIV
14. The use of eponyms should be reviewed if a more rational approach to nomenclature can be developed, based on aetiopathogenesis, but their retention is necessary at present to avoid confusionIV
Definitions:
15. Age is worthy of inclusion in the definitions of some forms of vasculitis, but its role should not be overstatedIII
Research agenda:
16. Future criteria initiatives should include all forms of vasculitis, providing definitions of less common syndromes not covered by CHCCIV
17. The development of a classification tree will provide the foundations to future criteriaIV
  • ANCA, anti-neutrophil cytoplasm antibody; CHCC, Chapel Hill Consensus Conference; CNS, central nervous system; ENT, ear, nose and throat; GCA, giant cell arteritis; HSP, Henoch–Schönlein purpura; MRA, magnetic resonance angiography; PAN, polyarteritis nodosa; TAB, temporal artery biopsy; TAK, Takayasu disease; US, ultrasound; WG/CSS, Wegener's granulomatosis/Churg–Strauss syndrome.