Relationship between effect of polymyxin B-immobilized fiber and high-mobility group box-1 protein in septic shock patients

Direct hemoperfusion (DHP) using a polymyxin B (PMX)-immobilized fiber column has been used for treatment of endotoxemia-induced septic shock in Japan since 1994 and is now an accepted therapy for reducing serum endotoxin levels. Although a reduction in inflammatory cytokines has been reported, the detailed mechanism of DHP-PMX is not known. We investigated the high-mobility group box-1 (HMGB-1) level in septic shock patients treated with DHP-PMX. Subjects (n = 20) were separated into two group: those whose systolic blood pressure increased to more than 30 mm Hg immediately after DHP-PMX (effective [E] group: nine cases) and those whose systolic blood pressure did not increase to more than 30 mm Hg (noneffective [N-E] group: 11 cases). The interleukin-6, plasminogen activator inhibitor-1, and HMGB-1 levels were measured in each group. The Pao2/Fio2 ratio and the Sepsis-Related Organ Failure Assessment (SOFA) score were also evaluated. Pretreatment interleukin-6, plasminogen activator inhibitor-1, and HMGB-1 levels were similar in the E and N-E groups, but mortality rate was significantly higher in the N-E group. Furthermore, posttreatment SOFA score was significantly lower in the E group. In the E group, only the HMGB-1 levels improved significantly after DHP-PMX. Present data suggest that the circulation dynamics of septic shock patients can be improved by reducing HMGB-1 levels by using DHP-PMX.