Increased Serum MCP-1 Levels in Systemic Vasculitis Patients with Renal Involvement.

Monocyte chemotactic protein 1 (MCP-1) plays a significant role in inflammation pathways by affecting monocyte/macrophage migration, the number of monocytes and T lymphocytes, and osmosis. Inflammation is closely linked to various types of systematic vasculitis. Here we characterized serum MCP-1 levels in systemic vasculitis patients. This cross-sectional study included serum samples collected from 43 patients with systemic vasculitis and 43 healthy controls (HCs). Serum MCP-1 levels in the samples were measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Serum MCP-1 levels were significantly higher in patients with systemic vasculitis relative to HCs (parentheses indicate quartile values) [134.65 (73.74, 262.75) pg/mL versus 59.1 (37.41, 90.18) pg/mL, P < 0.001]. Furthermore, systemic vasculitis patients having renal involvement had significantly higher MCP-1 levels relative to patients without renal involvement [196.16 (104.41, 310.35) pg/mL versus 73.74 (41.24, 145.95) pg/mL, P = 0.001] and HCs [196.16 (104.41, 310.35) pg/mL versus 59.10 (37.41, 90.18) pg/mL, P < 0.001]. Serum MCP-1 levels in systemic vasculitis patients were positively correlated with serum creatinine levels (r = 0.387, P < 0.010) and with 24-h proteinuria (r = 0.404, P < 0.014). Receiver operating characteristic (ROC) analysis showed that the cutoff value for MCP-1 to distinguish systemic vasculitis from HCs was 72.73 pg/mg, and the area under the ROC curve was 0.772. The sensitivity and specificity were 76.7% and 72.1%, respectively. Serum MCP-1 levels were significantly higher in patients with systemic vasculitis than in HCs, especially in patients with renal involvement. Thus, serum MCP-1 has the potential to be a biomarker for systemic vasculitis with renal involvement.