Introduction: Fire smoke inhalation a recognized etiologic factor of airway injuries. The objective of this study was evaluation of serum high-mobility group box 1 (HMGB1) protein concentration in subjects exposed to fire smoke (SEFS).

Material and methods: The study group consisted of 40 consecutive patients admitted to the Toxicology Unit, Lodz, Poland after exposure to fire smoke. Serum HMGB1 concentrations were measured upon admission to hospital and rechecked on the 2nd and on the day of discharge. Patients also underwent routine toxicological diagnostic procedures applied in case of those exposures, such as carboxyhaemoglobin (COHb) levels and urinary thiocyanate concentrations. The same diagnostic tests were performed in 10 healthy volunteers not exposed to smoke of the control group.

Results: The average serum SEFS concentration of HMGB1 protein was not significantly higher on admission in comparison with the respective values recorded on the 2nd day and on the day of discharge. The mean serum level of HMGB1 protein of exposed group was higher than that one in the control group, however the difference was not statistically significant. The highest concentration of HMGB1 protein was noted in serum of 28 subjects exposed to fire smoke reporting at least one symptom and the difference was statistically significant in a comparison with the control group.

Conclusion: As indicated, an acute exposure to smoke may lead to transient increase of HMGB1 in serum in exposed subjects. Further studies are necessary in order to confirm the importance of this protein in pathogenesis of acute airway injury due to exposure to fire smoke.