Long-term effect of medium cut-off dialyzer on middle uremic toxins and cell-free hemoglobin.

Nam-Jun Cho,Md Imtiazul Islam,Samel Park,Hyo-Wook Gil,Ho-Yeon Song,Eun Young Lee,Giuseppe Remuzzi

doi:10.1371/journal.pone.0220448

Abstract

The medium cut-off (MCO) dialyzer has shown good clearance of large middle molecules, but its long-term effects are unclear. We investigated whether MCO hemodialysis (HD) over one year could reduce middle molecule levels and cell-free hemoglobin (CFH), without albumin loss. A prospective cohort study in 57 hemodialysis patients was conducted. The patients were assigned to the MCO dialyzer group or the high-flux dialyzer group, according to the HD machine they used. The reduction ratio (RR) and one-year changes in small and middle molecules and CFH were analyzed. Over a 12-month follow-up, MCO HD did not reduce the serum levels of middle molecules (lambda free light chain [FLC], from 135.7 ± 39.9 to 132.0 ± 39.1 mg/L; kappa FLC, from 168.2 ± 58.5 to 167.7 ± 65.8 mg/L; β2-microglobulin, from 25.6 ± 9.6 to 28.4 ± 4.8 mg/L) or albumin (from 3.96 ± 0.31 to 3.94 ± 0.37 g/dL). MCO HD provided excellent RR of lambda FLC (49.3 ± 10.3%), kappa FLC (69.6 ± 10.4%) and β2-microglobulin (80.9 ± 7.3%), compared to high-flux HD. CFH was also removed well during an MCO HD session (RR of CPH, 85.5 [78.7–97.3] %), but long-term change was not significant (from 57.8 [46.2–79.1] to 62.0 [54.6–116.7] mg/L). The MCO dialyzer can be used effectively and safely in conventional HD settings, but long-term effects on large middle molecules and CFH were not significant. Further studies are needed to verify clinical benefits of the MCO dialyzer.

Highlights

When end-stage renal disease (ESRD) develops, various organ functions deteriorate due to accumulation of uremic toxins, leading to high mortality rates [1, 2]
We showed that reduction ratios of middle and large middle molecules in the medium cut-off (MCO) group were higher than those of the high-flux group
Recent studies reported that MCO HD removed large middle molecules, including lambda free light chains (FLC) and α1-glycoprotein more sufficiently than high-flux HD and on-line hemodiafiltration (ol-HDF) [10,11,12, 25]

Summary

Introduction

When end-stage renal disease (ESRD) develops, various organ functions deteriorate due to accumulation of uremic toxins, leading to high mortality rates [1, 2]. Uremic toxins exhibit a broad array of physicochemical characteristics, mechanisms of generation, and pathobiological actions at the cellular and molecular levels [3]. According to the size and protein-binding properties of toxins, uremic toxins can be classified as small molecules (500 Da–60 kDa), and protein-bound molecules [4]. Traditional hemodialysis (HD) membranes have focused on removal of small molecule toxins, such as urea and creatinine, but gradually middle molecule toxins have attracted attention because of their impact on disease progression and mortality [5, 6]. After introduction of highflux membranes and on-line hemodiafiltration (ol-HDF), clearance of β2-microglobulin.

Methods

Results

Conclusion