Abstract
Four types of dialyzers with high-performance membranes have been examined to evaluate their sieving coefficients (SC) and removal rates for low molecular weight proteins (MW; 11, 800-66, 000) such as β2-microglobulin (β2-MG), prolactin (PRL), α1-microglobulin (α1-MG), α1-acid glycoprotein (α1-AGP) and albumin (Alb) in four maintenance hemodialysis patients by cross-over methods. Studies involved CL-SS15W (SS), BK-1.6P (BK), FB-150U (FB) and AM-FP-15 (FP).
In SS, the SC of all solutes showed relatively higher values, although removal rates were lower than with the other types of dialyzers. This suggests that unequal amounts of dialysate flowed among fiber bundles in the dialyzer. In BK, the SC of β2-MG, PRL and α1-MG were low despite high removal rates, suggesting that the membrane absorbed these low molecular weight proteins, In FB, β2-MG and PRL were removed efficiently, but other low molecular weight proteins showed lower removal rates and SC, suggesting that some low molecular weight proteins over 20, 000 to 30, 000 MW were not removed efficiently. In FP, SC was the highest but the removal rate was lower than the estimated removal rate based on SC. This suggests that this dialyzer did not maximize the characteristics of the high performance membrane in the same way as the SS.
In conclusion, these high-performance membrane dialyzers have good characteristic functions in removing low molecular weight proteins. A new method should be established to evaluate removal characteristics of low molecular weight proteins.
