High-Mobility Group Protein Box 1 is Upregulated in Children with Henoch-Schonlein Purpura

Henoch-Schonlein purpura (HSP) is a common systemic vasculitis in children. High-mobility group protein box 1 (HMGB1) is an inflammatory cytokine involved in many autoimmune diseases. This study aimed to examine the expression of HMGB1 in HSP. Fifty-six children with HSP (HSP group) and 32 healthy children (Control group) were enrolled, and their clinic data were collected. Real-time polymerase chain reaction was used to detect mRNA levels of HMGB1, Toll-like receptor 2 (TLR2), TLR4, receptor of advanced glycation end products (RAGE), and nuclear factor-B (NF-B) in peripheral blood mononuclear cells (PBMCs). Enzyme-linked immunosorbent assay was used to detect serum levels of HMGB1, interleukin-6 (IL-6), IL-8, and tumor necrosis factor- (TNF-). The mRNA levels of HMGB1, TLR2, TLR4, and NF-B in PBMCs were upregulated in HSP group with kidney injury compared with control group without kidney injury (P<0.05). The serum levels of HMGB1, IL-6, IL-8, and TNF- in HSP group with kidney injury were significantly higher than in control group without kidney injury (P<0.05). There was correlation between serum HMGB1 and TLR2, TLR4, NF-B, IL-6, IL-8, and TNF- in HSP group (P<0.05), and there was correlation between NF-B and TLR2 and between NF-B and TLR4 (P<0.05). HMGB1 is upregulated in children with HSP and correlated with high serum levels of proinflammatory cytokines.