Pattern of release and relationship between HMGB-1 and IL-6 following blunt trauma

High mobility group box-1 (HMGB-1), a recently identified inflammatory cytokine, is implicated in the pathogenesis of several inflammatory, infective and neoplastic processes. Patterns of expression following blunt trauma have not been adequately reported in the literature. This study aimed to quantify the serum concentrations of HMGB-1 following blunt trauma, and assess its relationship with the more established interleukin 6 (IL-6).

20 patients with median injury severity score 17 (range 9-36) sustaining closed diaphyseal fractures of the femur treated by intramedullary nailing were included in the study. Serum concentrations of HMGB-1 and IL-6 were measured at several time points during their treatment.

A strong correlation was observed between admission and day 1 post-op concentrations of IL-6 and both the injury severity score (ISS) and the requirement for intensive care unit treatment. Serum concentrations of HMGB-1 did not demonstrate such a correlation. Around day 3 when IL-6 concentrations begin to fall, serum HMGB-1 concentrations were observed to increase.

IL-6 concentration measured early after admission is again shown to be strongly associated with overall injury severity and requirement for intensive care unit treatment. In contrast, HMGB-1 appears to be a late inflammatory mediator with levels becoming elevated once serum concentrations of IL-6 begin to fall. However, we were unable to demonstrate any relationship with injury severity or requirement for ICU care at any stage. These preliminary findings may form the basis for future research in this area.