Selective removal of high level cryoglobulins (CG) and immune complexes (IC) by a large pore membrane.

The investigated membranes having a pore size of 3 micron or less can retain over 95% of cryoprecipitable proteins and immune complexes with nearly complete passage of other plasma proteins at 4 degrees C. Based on this result, the G-3 module consisting of V-3000 membrane was chosen for further study. The G-3 module (0.148 m2 of surface area) processed a 10 times higher plasma volume per unit surface area with higher selectivity than the Asahi Plasmaflo AP 06M. Separation efficiency of cryoprecipitable proteins and immune complexes in cryoglobulinemic plasmas by cryofiltration at 4 degrees C is related to the composition of the cryoprecipitable protein; three of four plasmas contained cryoprecipitable proteins that were removable by cryofiltration. Cryoprecipitation was too slow in one of four plasmas. For this plasma SDS PAGE showed its light chain to be of higher molecular weight than other plasmas. Two of four plasmas had elevated amounts of IC that were removed by cryofiltration.