Comparison of Interleukin-6 Removal Properties among Hemofilters Consisting of Varying Membrane Materials and Surface Areas: An in vitro Study

<i>Background/Aims:</i> We sought to identify the most relevant hemofilter for cytokine removal based on the mechanisms of filtration and adsorption. <i>Methods:</i> Ascites were filtered using four types of hemofilters composed of different membrane materials (polymethyl methacrylate, PMMA, cellulose triacetate, CTA, or polysulfone, PS) and different surface areas (1.0 or 2.1 m²) to investigate the rate of interleukin-6 (IL-6) filtration. Next, ascites were perfused through each hemofilter without obtaining a filtrate to study each filter’s adsorptive capability. <i>Results:</i> The PMMA hemofilters resulted in a marginal observed IL-6 filtration rates, whereas the CTA and PS hemofilters resulted in highly effective IL-6 filtration. Regarding the IL-6 adsorptive capabilities of the filters, the PMMA hemofilter with a large surface area showed the highest level of IL-6 clearance. <i>Conclusion:</i> The present findings suggest that when cytokine removal based on filtration is desired, CTA or PS hemofilters should be selected. When IL-6 removal based on adsorption is desired, a PMMA hemofilter with a large surface area should be selected.