Evaluation of B-2-microglobulin (B2M) removal by new cuprammonium rayon (cupra) membrane dialyzers with different membrane structures

Abstract

Two types of cupra membrane; one with large pore size (UP) and the other with much larger pore size developed newly (SP), were evaluated for removal capacity of B2M. The mechanism of B2M removal was also studied on these membrane dialyzers. Sieving coefficient on in vitro experiment using minimodule of SP and UP membrane was 0.83 and 0.61 respectively. Solute permeability was 7.5 and 3.0x10^-5cm/sec. Clinical study used 2 types of dialyzers with different surface area in each membrane; 1.0 and 1.5m² as SP module and 1.5 and 2.1m² as UP. Clearance and removal amount showed larger removal capacity with larger pore size and larger surface area membrane. SP dialyzer(1.5m²) had a largest clearance and removal amont; 26.5ml/min and 280mg respectively. The contribution of diffusion was much larger than that of convection on the B2M removal with these dialyzer. In conclusion, cupra membrane dialyzer with larger pore size succeeded to remove a sufficient amount of B2M by diffusive mechanism rather than convective one.