Effect of treatment with anti-HMGB1 antibody or sham IgG on serum HMGB1 concentrations in acetaminophen (APAP)-induced acute liver injury (ALI). ALI was induced in C57 BL/6 male mice with a single dose of APAP (350 mg/kg dissolved in 1 mL saline) by intraperitoneal (i.p.) injection. 2 hrs after the APAP injection, 400 μg of anti-HMGB1 antibody in 0.5 mL saline was i.p. injected into mice in the anti-HMGB1 group, the same amount of sham IgG or saline alone was given to the sham IgG group and the control animals at the equivalent time points. The same amount of anti-HMGB1 or the sham IgG was repeated 24 hours after the first administration. Serum HMGB1 concentrations were measured 24 hours after APAP injection from the anti-HMGB1 group, the sham IgG group and the control group (n = 6 for each group). 3 separate groups of mice were used to measure serum HMGB1 concentrations at 48 h time point from the anti-HMGB1 group (n = 10), the sham IgG group (n = 9) and the control group (n = 6). Results are means ± SEM. *indicates p < 0.05 (analysis of variance followed by Fisher’s LSD test).