The extent and pattern of organ damage in small vessel vasculitis measured by the Vasculitis Damage Index (VDI)

To assess the extent and pattern of irreversible organ damage in patients with Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), polyarteritis nodosa (PAN), and Churg-Strauss syndrome (CSS) by a cross-sectional point prevalence study within a defined geographical area.

The Vasculitis Damage Index (VDI) was recorded for 86 prevalent cases, classified as 46 patients with WG, 27 with MPA, nine with PAN, and four with CSS from a defined population in southern Sweden, with a median age of 64.8 years and a median disease duration of 9 years. The VDI was determined for all patients at the day of point prevalence (pp), 1 January 2003.

The median VDI score was 3 [interquartile range (IQR) 2-5] for all patients: 3 (2-4) for WG, 3 (1.5-4.5) for MPA, 5 (2-6) for PAN, and 1.5 (0.75-2.75) for CSS. Only 9% of patients had not been assigned a single item of damage. The most common damage was cardiovascular, followed by renal, neuropsychiatric, ear nose and throat (ENT), and musculoskeletal. Major vascular and treatment-related damage was associated with advanced age whereas ENT damage was more prevalent in younger patients. There was an almost complete separation between ENT damage and cardiac and renal damage with only two out of the 22 patients assigned ENT damage having experienced renal damage; none had been assigned cardiac damage. Patients with cardiac damage had significantly higher damage rates.

Damage remains an important problem for patients with systemic vasculitis despite effective remission-inducing drugs. Only a small fraction of patients are unmarked by their disease.