Objective: High mobility group box 1 (HMGB-1), a kind of proinflammatory mediator, is associated with inflammatory conditions and tissue damage. Previous studies have reported that circulating HMGB-1 levels in patients with active antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) were associated with renal manifestations and burdens of granulomatous inflammation. The current study aimed to investigate whether circulating HMGB-1 levels were associated with disease activity in AAV.
Methods: Plasma samples from 74 patients with AAV in active stage and 65 patients with AAV in remission were collected. The plasma levels of HMGB-1 were determined by enzyme-linked immunosorbent assay. Associations between plasma levels of HMGB-1 with clinical and pathologic parameters were analyzed.
Results: Plasma levels of HMGB-1 in active AAV patients were significantly higher than those in normal controls and AAV patients in remission (median 6.11 [interquartile range (IQR) 3.25-12.79] ng/ml versus median 1.12 [IQR 0.53-1.39] ng/ml, P< 0.001; median 6.11 [IQR 3.25-12.79] ng/ml versus median 3.04 [IQR 1.97-4.63] ng/ml, P < 0.001, respectively). Correlation analysis showed that plasma levels of HMGB-1 correlated with initial serum creatinine (r = 0.275, P = 0.018), estimated glomerular filtration rate (r = -0.277, P = 0.017), the Birmingham Vasculitis Activity Score (r = 0.308, P = 0.008), and C-reactive protein level (r = 0.309, P = 0.008). Among the patients with myeloperoxidase (MPO)-ANCA, those within the first quartile of plasma HMGB-1 levels had a significantly lower level of MPO-ANCA than those within the other 3 quartiles.
Conclusion: Circulating HMGB-1 levels might reflect the disease activity and renal involvement of AAV vasculitis.
Copyright © 2013 by the American College of Rheumatology.