Abstract
In an attempt to niminize an amount of replacement fluid, double filtration plasmapheresis in which larger molecules are discarded after selective concentration has been devised and clinically applied. Selectivity in concentration performance is analyzed. Sieving coefficient of the plasma separator is very much dependent upon a size of molecules, namely, the larger the molecualar size is, the smaller is sieving coefficient present. On the other hand, larger molecules show larger concentration coefficient by the plasma filter. Consequently, pathogenic factors of larger molecules are selectively and effectively removed.
