Ten of 13 (76.9%) rheumatoid arthritis (RA) patients having intensive cryofiltration treatment showed improvement and 5 of 7 (71.4%) of RA patients treated on maintenance cryofiltration therapy showed improvement. Encouraged by these results, 2 centers were established for controlled trial studies of RA patients. Four of 4 (100%) rheumatoid vasculitis patients treated by cryofiltration and 4 of 7 (57.1%) patients treated with plasma exchange showed clinical improvement. An SLE patient with thrombocytopenia showed a dramatic rise in platelet count during intensive (3 day/wk) plasma exchange treatments despite little prior response to drugs, platelet infusions and splenectomy. Plasmapheresis was effective in improving clinical symptoms and lipid abnormalities in a primary sclerosing cholangitis patient without causing hypoproteinemia during the long-term therapy (4 yrs).