Management of immune-mediated and paraproteinemic diseases by membrane plasma separation and cascade filtration.

Membrane plasma separation was utilized in the management of 19 patients with autoimmune, immune complex or paraproteinemic diseases. In these patients 34 procedures were carried out employing a new filter composed of polyvinyl alcohol hollow fibers with a nominal pore size of 0.4 micrometer. Cascade filtration was performed in 23 procedures using a second filter built up with ethylenevinylalcohol copolymer hollow fibers with a nominal pore size of 0.1-0.2 micrometer. Both filters employed showed a very good biocompatibility, and no untoward effect was observed. Using the differential sieving effect of cascade filtration it was possible to eliminate circulating immune complexes and immunoglobulin M without the loss of necessary plasma components.