Preliminary study of high mobility group box chromosomal protein 1(HMGB1) in ankylosing spondylitis patients.

Abstract To compare the serum levels of high mobility group box chromosomal protein 1 (HMGB1) between patients with AS and healthy controls, and evaluate its association with disease activities and functional abilities; to investigate the cell surface receptors related to HMGB1 in AS patients. The HMGB1 serum levels from71 previously untreated AS patients and 40 healthy controls were detected by ELISA method. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Functional Index (BASFI), erythrocytesedimentationrate (ESR), and C-reactive protein (CRP) levels were assessed on these participants. The mRNA expression of HMGB1 and its relevant cell surface receptors RAGE, TLR2, TLR4, and IL-1Racp complex were analysed by RT-PCR. The HMGB1 serum levels from AS patients were significantly higher than those from healthy controls and remarkably positive correlated with BASDAI, ASDAS, BASFI, CRP, and ESR. ASDAS showed more correlated to HMGB1 serum levels than BASDAI. Besides, the expression of TLR2, TLR4, and IL-1Racp from PBMCs revealed significant correlations with the expression of HMGB1. HMGB1 might be a good laboratory index for the evaluation of disease activities and disease severity in AS patients. Further, extracellular HMGB1 play its inflammatory role mainly via the expression of cell surface receptors TLR2, TLR4 and IL-1RAcP complex.