Change of HMGB1 synovial protein expression before and during infliximab therapy. Immunohistochemical scoring of HMGB1 protein expression was unchanged during the nine weeks of infliximab therapy. Values represent mean scores of highly concordant scoring recorded by the two independent investigators (ES and CG). The correlation was statistically confirmed by Spearman rank sum tests with a correlation coefficient (rs)of 0.74 (significant at p < 0.002). Scoring for each section was evaluated using a 0 to 4 scale with increments of 0.5. Index 0 corresponds to no HMGB1 expression and 4 to highest degree of HMGB1 protein expression. Separate analyses were performed for lining layer, vessels and cellular infiltrates in each of the sections. (a) Change of overall HMGB1 protein expression for each patient. (b) Change of HMGB1 expression in cellular infiltrates. (c) Change of HMGB1 expression in lining layer. (d) Change of HMGB1 expression in endothelium.