OBJECTIVETo investigate the changes in serum level of high mobility group protein B1 (HMGB1) in patients with delayed encephalopathy after acute carbon monoxide poisoning and the clinical significance of these changes.

METHODSThirty-four patients with delayed encephalopathy after acute carbon monoxide poisoning (delayed encephalopathy group), 30 normal controls (control group), and 32 cases of acute carbon monoxide poisoning without delayed encephalopathy (carbon monoxide poisoning group) were recruited in this study. The serum HMGB1 level was determined by enzyme-linked immunosorbent assay. The correlation between serum HMGB1 level and scores of the activity of daily living scale (ADL), Information-Memory-Concentration Test (IMCT), and Hasegawa dementia scale (HDS) was determined.

RESULTSIn the acute stage of carbon monoxide poisoning, the serum HMGB1 level of delayed encephalopathy group was significantly higher than those of the carbon monoxide poisoning group and the control group (P < 0.01). In the delayed encephalopathy group, serum HMGB1 level in the convalescent stage was significantly lower than that in the acute stage (P < 0.05); ADL score was higher and HDS and IMCT scores were lower in the acute stage than in the convalescent stage (P < 0.01). In the delayed encephalopathy group, serum HMGB1 level was positively correlated with HDS and ADL scores in both acute stage and convalescent stage (correlation coefficients: 0.612, 0.607, 0.609, and 0.612, P < 0.01).

CONCLUSIONHMGB1, as an important late mediator of inflammation, is involved in the inflammatory reaction in delayed encephalopathy, and is positively correlated with HDS and ADL scores, indicating that it can be used as one of the major indicators in monitoring carbon monoxide poisoning.