Serum β ₂-Microglobulin Levels in Patients Chronically Dialyzed with CA-210 versus CT-190 Dialysis Membranes

Abstract

β₂-Microglobulin (B₂M) amyloidosis (dialysis-related amyloidosis), manifested primarily by carpal tunnel syndrome and destructive osteoarthropathy, is a major sequel of long-term dialysis. Previous investigators have shown that high-flux biocompatible synthetic membranes (e.g., polyacrylonitrile) lower β₂M levels when compared to cellulosic membranes (e.g., cuprophane). To date, however, no study has compared β₂M levels of patients dialyzed with the two more biocompatible cellulosic membranes CA-210 (cellulose acetate) and CT-190 (cellulose triacetate; high flux, more biocompatible). We retrospectively compared the serum β₂M levels in two chronic hemodialysis populations: 22 patients on CT-190 and 21 patients on CA-210. There was no difference between the two groups with regard to age, sex, or duration of dialysis. The patients on the CA-210 membrane had significantly higher serum β₂M levels (mean ± SE; 53.6 ± 4.7 vs. 36.8 ± 2.6 mg/l, CA-210 vs. CT-190, respectively, p = 0.003). Subsequently we switched 13 patients dialyzed with a CA-210 membrane to a CT-190 membrane and followed serum β₂M levels for 14 months. We found a significant decrease in serum β₂M levels within 1 month which was maintained over 14 months of follow-up (47.4 ± 4.4 vs. 62.8 ± 6.7 mg/l, CT-190 at 14 months vs. CA-210 at baseline, respectively, p < 0.01).