Aluminum-binding protein in dialysis dementia. II. Characterization in plasma by ultrafiltration

Ultrafiltration experiments, using Amicon membranes with molecular weight exclusions of 1,000, 10,000 and 30,000 daltons, have revealed that Desferal, both in vitro and in vivo, markedly increases aluminum ultrafilterability in plasma from patients with dialysis dementia. Ultrafilterability was greater with the 10,000-dalton membrane (60%) as compared with the 1,000-dalton membrane (40%); the difference could be related to the presence of an 8,000-dalton aluminum-binding protein in the 10,000-dalton filtrate. These observations are pertinent to in vivo dialysis studies which have demonstrated enhanced aluminum clearance with high-permeability polyacrylonitrile dialysis membranes.