Association analysis of high-mobility group box-1 protein 1 (HMGB1)/toll-like receptor (TLR) 4 with nasal interleukins in allergic rhinitis patients

Background: High mobility group box 1 (HMGB1) acts as an inflammatory mediator initiator, and has shown to increase in nasal secretions of allergic rhinitis (AR) patients. The purpose of the present study was to investigate the association of HMGB1 and its receptor, toll-like receptor (TLR) 4 with proinflammatory interleukins in AR patients. Methods: The interleukin (IL) -4, -5, -13, -17A, -10 in nasal lavage fluid and the serum IgE were examined with enzyme-linked immunosorbent assay (ELISA) in 125 AR patients or 87 healthy subjects (as control). The mRNA levels of HMGB1, receptor for advanced glycation end products (RAGE) and TLR 2, 3 and 4 were examined in these participants with real-time quantitative PCR (RT-qPCR) method. Spearman rank correlation was adopted to analyze the relationship between any two factors of clinical characteristics and laboratory-examined biomarkers. Results: IL-4, -5, -13 and -17A were significantly higher, whereas IL-10 was markedly lower in the nasal lavage fluid samples from AR patients, compared with the control subjects. High expression of HMGB1, TLR2 and TLR4 were observed in the nasal brushing samples from these AR patients, whereas there was no significant difference for the mRNA levels of TLR3 and RAGE. Besides, HMGB1/TLR4 mRNA levels correlated positively with IL-4, -5, -13 and -17A, whereas negatively with IL-10. A linear regression of HMGB1/TLR4 was also found positively with IL-4, -5 (only for TLR4), -13 or -17A, whereas negatively with IL-10. Conclusion: High mRNA levels of HMGB1 and TLR4 were found in the nasal brushing samples in AR patients, correlating positively with IL-4, -5, -13 or -17A, wheareas negatively with IL-10. HMGB1/TLR4 signaling pathway might be well responsive targets as immunotherapy for allergic rhinitis.