Presentation: Elevated Serum Levels of Soluble CX3CL1 in Patients with Systemic Vasculitis: Potential Involvement in Microscopic Polyangiitis (2007)

2005 Elevated Serum Levels of Soluble CX3CL1 in Patients with Systemic Vasculitis: Potential Involvement in Microscopic Polyangiitis

BACKGROUND and PURPOSE: CX3CL1 is a chemokine expressed in endothelial cells and may play a key role in the pathogenesis of inflammatory vascular diseases. Consistent with that idea, we recently observed higher serum CX3CL1 levels and greater expression of its specific receptor, CX3CR1, in cases of rheumatoid vasculitis than in rheumatoid arthritis. Our aim in the present study was to test the hypothesis that CX3CL1 contributes to the pathogenesis of systemic vasculitis.
Methods: Twenty eight patients with systemic vasculitis were divided into three groups based on the size of the affected vessels, according to the definitions adopted by the Chapel Hill Consensus Conference: Wegener's granulomatosis (WG, n=2), Churg-Strauss syndrome (CSS, n=3), microscopic polyangiitis (MPA, n=13) and Henoch-Schonlein purpura (HSP, n=1) were considered small vessel vasculitis (SVV, n=19); polyarteritis nodosa (PAN, n=3) was considered medium-sized vessel vasculitis (MVV, n=3); and giant cell arteritis (GCA, n=3) and Takayasu arteritis (TA, n=3) were considered large vessel vasculitis (LVV, n=6). Sera from patients with systemic vasculitis and healthy individuals (controls) were collected, and soluble (s)CX3CL1 levels were measured using an enzyme-linked immunosorbent assay. Disease activity of vasculitis was assessed using the Birmingham vasculitis activity scores (BVAS).
Results: Serum sCX3CL1 levels were significantly higher in all vasculitis patients (2030.1±342.3 pg/ml) than in the healthy controls (113.5±113.5 pg/ml). Among the vasculitis patients, sCX3CL1 levels were significantly higher in patients in the SVV group (2577.1±436.7 pg/ml) than in the other two groups (MVV; 827.0±359.5 pg/ml and LVV; 899.5±402.7 pg/ml). Among the SVV group, sCX3CL1 levels were significantly higher in patients with MPA (3324.5±515.9 pg/ml) than in those with other types of SVV (CSS; 970.3±251.3 pg/ml, WG; 723.7±154.4 pg/ml). A positive correlation was observed between serum sCX3CL1 levels in MPA patients and CRP and ESR levels and BVAS. Notably, serum sCX3CL1 levels were diminished following successful treatment of the vasculitis and clinical improvement. Conclusions: Our findings suggest that CX3CL1 is involved in the pathogenesis of systemic vasculitis, especially small vessel vasculopathy, and may serve as a useful serologic inflammatory marker of disease activity in MPA.

 M. Matsunawa, None; K. Wakabayashi, None; T. Odai, None; T. Isozaki, None; N. Yajima, None; Y. Miwa, None; M. Negishi, None; H. Ide, None; T. Kasama, None.