New features of disease after diagnosis in 6 forms of systemic vasculitis.

OBJECTIVE: To quantify the occurrence of features of vasculitis that initially present after diagnosis in 6 types of primary vasculitis.
METHODS: Standardized collection of data on 95 disease manifestations in 6 vasculitides, including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (Churg-Strauss; EGPA), polyarteritis nodosa (PAN), giant cell arteritis (GCA), and Takayasu arteritis (TAK), was obtained within a set of multicenter longitudinal, observational cohorts. For each form of vasculitis, the frequency of disease-specific manifestations at diagnosis was compared to the cumulative frequency of each manifestation. The percentage of patients who initially developed severe manifestations after diagnosis, defined as organ- or life-threatening in the small and medium vessel vasculitides (GPA, MPA, EGPA, PAN) and as ischemic/vascular in the large vessel vasculitides (GCA, TAK), was reported.
RESULTS: Out of 838 patients with vasculitis, 490 (59%) experienced ≥ 1 new disease manifestation after diagnosis. On average, patients with vasculitis experienced 1.3 new manifestations after diagnosis (GPA = 1.9, MPA = 1.2, EGPA = 1.5, PAN = 1.2, GCA = 0.7, and TAK = 1.0). New severe manifestations occurred after diagnosis in 224 (27%) out of 838 patients (GPA = 26%, MPA = 19%, EGPA = 21%, PAN = 23%, GCA = 24%, and TAK = 44%). Timing of onset of new manifestations was not significantly associated with disease duration.
CONCLUSION: A majority of patients with vasculitis develop new disease features after diagnosis, including a substantial number of new, severe manifestations. Ongoing assessment of patients with established vasculitis should remain broad in scope.