Removal of Middle Molecules and Dialytic Albumin Loss: A Cross-over Study of Medium Cutoff and High-Flux Membranes with Hemodialysis and Hemodiafiltration

Armando Armenta-Alvarez; Salvador Lopez-Gil; Iván Osuna; Nadja Grobe; Xia Tao; Gabriela Ferreira Dias; Xiaoling Wang; Joshua Chao; Jochen G Raimann; Stephan Thijssen; Hector Perez-Grovas; Bernard Canaud; Peter Kotanko; Magdalena Madero

doi:10.34067/KID.0000000000000185

Removal of Middle Molecules and Dialytic Albumin Loss: A Cross-over Study of Medium Cutoff and High-Flux Membranes with Hemodialysis and Hemodiafiltration

Kidney360. 2023 Aug 1;4(8):1095-1102. doi: 10.34067/KID.0000000000000185. Epub 2023 Jun 12.

Authors

Affiliations

¹ Division of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
² Center for Research in Infectious Diseases, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
³ Research Division, Renal Research Institute, New York, New York.
⁴ Fresenius Medical Care, Fresnes, France.
⁵ Icahn School of Medicine at Mount Sinai, New York, New York.

Abstract

Key Points:

HDF and MCO have shown greater clearance of middle-size uremic solutes in comparison with HF dialyzers; MCO has never been studied in HDF.
MCO in HDF does not increase the clearance of B2M and results in a higher loss of albumin.

Background: Middle molecule removal and albumin loss have been studied in medium cutoff (MCO) membranes on hemodialysis (HD). It is unknown whether hemodiafiltration (HDF) with MCO membranes provides additional benefit. We aimed to compare the removal of small solutes and β2-microglobulin (B2M), albumin, and total proteins between MCO and high-flux (HFX) membranes with both HD and HDF, respectively.

Methods: The cross-over study comprised 4 weeks, one each with postdilutional HDF using HFX (HFX-HDF), MCO (MCO-HDF), HD with HFX (HFX-HD), and MCO (MCO-HD). MCO and HFX differ with respect to several characteristics, including membrane composition, pore size distribution, and surface area (HFX, 2.5 m²; MCO, 1.7 m²). There were two study treatments per week, one after the long interdialytic interval and another midweek. Reduction ratios of vitamin B12, B2M, phosphate, uric acid, and urea corrected for hemoconcentration were computed. Dialysis albumin and total protein loss during the treatment were quantified from dialysate samples.

Results: Twelve anuric patients were studied (six female patients; 44±19 years; dialysis vintage 35.2±28 months). The blood flow was 369±23 ml/min, dialysate flow was 495±61 ml/min, and ultrafiltration volume was 2.8±0.74 L. No significant differences were found regarding the removal of B2M, vitamin B12, and water-soluble solutes between dialytic modalities and dialyzers. Albumin and total protein loss were significantly higher in MCO groups than HFX groups when compared with the same modality. HDF groups had significantly higher albumin and total protein loss than HD groups when compared with the same dialyzer. MCO-HDF showed the highest protein loss among all groups.

Conclusions: MCO-HD is not superior to HFX-HD and HFX-HDF for both middle molecule and water-soluble solute removal. Protein loss was more pronounced with MCO when compared with HFX on both HD and HDF modalities. MCO-HDF has no additional benefits regarding better removal of B2M but resulted in greater protein loss than MCO-HD.

Trial registration: ClinicalTrials.gov NCT03938285.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Albumins
Cross-Over Studies
Hemodiafiltration*
Humans
Renal Dialysis*

Substances

Albumins

Associated data

ClinicalTrials.gov/NCT03938285