HEMOPERFUSION WITH POLYMYXIN BIMMOBILIZED FIBERS (PMX-F) IMPROVES THE IMMUNOSUPPRESSION IN PATIENTS WITH SEPTIC SHOCK

Objective: Peripheral blood mononuclear cells (PBMCs) from septic patients have a reduced capacity to respond to lipopolysaccharide (LPS). This study was to evaluate whether this reduced activity is associated with differential monocyte surface antigen expression, and whether PMX-F treatment improves this impaired monocyte functions in patients with septic shock. Materials and Methods: PBMCs were isolated from 15 septic patients and 13 healthy controls. Cells were either unstimulated or stimulated ex vivo with LPS (1 ug/ml) for the measurement of TNFα and IL-1β production, and were stained for CD14, CD16, TLR-4, HLA-DR surface expression. PMX-F treatment was performed in 7 patients who met the criteria for septic shock, and the above-mentioned parameters were evaluated before and after the PMX-F treatment. Results: TNF α and IL-1β?production from PBMCs stimulated with LPS in septic patients was decreased as compared to healthy controls. TLR-4 and CD16 expression on monocytes were significantly increased in septic patients than in controls, and their proportion of CD16+CD14+ monocytes was greatly elevated. HLA-DR expression on CD14+CD16+ monocytes was significantly reduced in septic patients. PMX-F treatment for septic shock patients reduced the number of CD16+CD14+ monocytes. Furthermore, reduced LPS-stimulated TNF α production and HLA-DR expression on monocytes were significantly increased after the PMX-F treatment. Conclusions: PBMCs from septic patients have a reduced capacity to respond to LPS, and this impairment is associated with the increased proportion of CD16+CD14+ monocytes and the decreased HLA-DR expression on monocytes. PMX-F treatment improves this impaired immune response in patients with septic shock.