Transmembranous Transport and Adsorption of Beta-2-microglobulin during Hemodialysis using Polysulfone, polyacrylonitrile, polymethylmethacrylate and Cuprammonium Rayon Membranes

Abstract

Beta-2-microglobulin (b2M) was identified as a causative agent of amyloidosis associated with long-term hemodialysis (HD). Therefore, we examined handling of b2M during a 4-hour hemodialysis session. We compared b2M adsoprtion and diffusive/convective elimination between high-flux membranes such as polysulfone (PS; F 60®, Fresenius), polyacrylonitrile (AN 69; FiltralR, Hospal) and polyacrylonitrile (PAN, PAN 12CX2R, Asahi) and less permeable membranes such as cuprammonium rayon (CR; AM 160 HR, Asahi) and polymethylmethacrylate (PMMA; BK-1.6 UR, Toray). To calculate total elimination, arterio-venous differences of b2M were measured at 0, 5, 20, 60 and 240 minutes; dialysate concentration was analyzed to evaluate diffusive/convective transport. Differences between recovery in dialysate and total removal were regarded as amount removed by adsorption. Total elimination per 4-hour hemodialysis session and per m2 membrane surface was 154.7 ± 12.3 mg for the PS, 137.8 ± 28.4 mg for the AN 69, 179.8 ± 47.5 mg for the PAN, 130.8 ± 11.8 mg for the PMMA and 14.4 ± 16.0 mg for the CR membrane. Diffusive/convective transport was 128.0 ± 18.1 mg for PS, 54.7 ± 8.1 mg for AN 69 and 106.5 ± 20.8 mg for PAN and insignificant for PMMA and CR. Adsorption was 26.7 ± 4.3 mg for PS, 83.1 ± 29.0 mg for AN 69 and 59.8 ± 17.2 mg for PAN. Besides transmembranous transport sorption is an important mode of elimination. Weekly endogenous generation rate is about twice as high as b2M elimination

Clinical cross-over comparison of mid-dilution hemodiafiltration using a novel dialyzer concept and post-dilution hemodiafiltration

“…While b 2 m clearance was 21.7% higher, b 2 m mass transfer into dialysate was 53% higher in mid-dilution HDF. Certainly, this finding has to be regarded with some caution because b 2 m adsorption, which can be considerably high with synthetic dialysis membranes [19], was not taken into account. To assess adsorption, spent dialysate samples (taken at the instantaneous clearance measurement time point) were analyzed for b 2 m for computing mass balance error.…”

Influence of Blood Flow on Adsorption of β2‐Microglobulin onto AN69 Membrane

“…Several studies have demonstrated the adsorption of P2M onto synthetic dialyzer membranes . The polyacrylonitrile (PAN-AN69) (AN69) membrane is one of those with a marked adsorption capacity for P2M (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). Unfortunately, none of these adsorption studies has provided data about the influence of blood flow on the amount of P2M being adsorbed onto membranes.…”

Low‐Molecular Weight Protein Removal by High‐Flux Dialyzers: Basic Mechanisms and Effect of Reprocessing

“…Based on numerous studies (11,(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), several general conclusions relating to the dialytic removal of ␤2M can be provided. First, negligible ␤2M removal by lowflux unsubstituted cellulosic membranes generally occurs, although certain exceptions do exist (31).…”