Association of serum high mobility group box 1 levels with disease activity and renal involvement in patients with systemic vasculitis.

High mobility group box 1 (HMGB1) is a kind of proinflammatory mediator that acts as an alarmin when released by dying, injured or activated cells. Previous studies have reported that HMGB1 are closely linked to antineutrophil cytoplasmic antibody-associated vasculitis (AAV). The present study aimed to evaluate whether serum HMGB1 levels were associated with systemic vasculitis (VAs).The study population consisted of 51 patients with VAs, 46 patients with essential hypertension (EH) and 46 healthy controls (HC). Thirty-five patients with VAs had in active stage and 16 patients with VAs in an inactive stage. Furthermore, 31 patients with VAs had renal involvement, the other 20 patients were selected for without renal involvement. Serum HMGB1 levels were measured by enzyme-linked immunosorbent assay. Associations between serum HMGB1 levels with clinical and laboratory parameters were analyzed.Serum HMGB1 levels in patients with VAs were significantly higher than in EH and HC (all P < .05), and no difference regarding serum HMGB1 levels could be found between EH and HC (P = .208). Serum HMGB1 levels in VAs patients with active stage were significantly higher than those in HC and VAs patients with inactive stage (all P < .05). Patients with renal involvement and non-renal involvement had increased HMGB1 levels compared with HC (all P < .05). In addition, serum HMGB1 levels were significantly higher in patients with renal involvement compared with non-renal involvement patients (P = .001). Correlation analysis showed that serum HMGB1 levels were positive significant correlated with the Birmingham Vasculitis Activity Score, hypersensitive C reactive protein (Hs-CRP), serum creatinine (Scr) and 24-hour proteinuria (all P < .05). Among the subsets of VAs, serum HMGB1 levels were significantly higher in AAV, polyarteritis nodosa (PAN) and takayasu arteritis (TA) than in HC (all P < .05). More interestingly, serum HMGB1 were significantly higher in patients with PAN compared with AAV and TA patients (all P < .05). Furthermore, there was positive correlation between serum HMGB1 levels and Hs-CRP, Scr, and 24-hour proteinuria in patients with PAN (all P < .05).Serum HMGB1 levels are increased in patients with VAs compared with HC and EH and can reflect the disease activity and renal involvement.