Efficacy of Cytokine Removal by Plasmadiafiltration Using a Selective Plasma Separator: In Vitro Sepsis Model

More effective removal of pro- and anti-inflammatory cytokines may play an important role in the treatment of sepsis. Plasmadiafiltration (PDF) with a larger selective plasma separator was performed to study the cytokine and plasma protein permeability profiles of the membrane in an in vitro sepsis model. The in vitro sepsis model was constructed by exposure of human whole blood to bacterial lipopolysaccharide. EVACURE 2A, a selective plasma separator, was placed in the blood circuit of PDF. Sieving coefficients of cytokines and plasma protein were tested in post-dilution PDF mode at the following operating parameters: blood flow rate 150 mL/min; dialysate flow rate 33.33 mL/min; replacing fluid flow rate 6.67 mL/min; ultrafiltration rate 5 mL/min. An enzyme linked immunoadsorbent assay was used to measure the concentrations of tumor necrosis factor-α (TNF-α), high-mobility group box 1 protein (HMGB1), interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1ra), interleukin-2 (IL-2), interleukin-2 receptor (IL-2r), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10) in plasma and ultrafiltrate. Sieving coefficients of different solutes ranged from 0.1 to 1.0 at first, decreased 10%–60% after 1 h of PDF, and then remained stable. Total clearance rates of cytokines ranged from 15 to 80 mL/min. The concentrations of cytokines decreased 20–80% after 1 hour of PDF. The sieving coefficient of albumin was 0.1 at first and then decreased to 0.05 after 1 hour of therapy. Plasmadiafiltration with Evacure 2A plasma separator can effectively remove almost all of the inflammatory mediators with low albumin loss.