[HFR vs HDF-ON line: plasmatic amino acids loss evaluation]

Area of Science:

• Nephrology and Dialysis Technology
• Biochemistry and Molecular Nutrition

Background:

• High-convection dialysis techniques like hemodiafiltration (HDF) can lead to the loss of vital molecules, including amino acids.
• Low plasmatic levels of branched-chain amino acids (BCAA) are associated with malnutrition in hemodialysis patients.
• Hemodiafiltration reinfusion (HFR) is an on-line HDF process designed to remove uremic toxins while returning a repaired ultra-filtrate.

Purpose of the Study:

• To compare plasmatic amino acid levels, particularly BCAAs, before and after dialysis in patients undergoing HFR versus on-line HDF.
• To investigate the impact of HFR and HDF on the loss of essential, non-essential, and branched-chain amino acids.

Main Methods:

• Eleven male patients on bicarbonate dialysis were randomized to either HFR or on-line HDF for one week.
• Blood samples were collected pre- and post-dialysis during weekly sessions.
• Gas chromatography was used to determine total, essential, non-essential, and BCAA levels.

Main Results:

• No significant differences in pre-dialytic amino acid levels were observed between the HFR and HDF groups.
• Post-dialysis, HDF treatment resulted in a significantly higher loss rate of total essential, non-essential, and BCAA compared to HFR.
• Post-dialysis total amino acid levels were 2395 ± 492.8 µmol/L in HFR versus 1852 ± 302.6 µmol/L in HDF (p=0.018).

Conclusions:

• HFR demonstrates a significant advantage in preserving amino acids, including BCAAs, during dialysis compared to standard HDF.
• The reduced loss of amino acids with HFR may help mitigate malnutrition and anorexia in dialysis patients.
• HFR offers a high-convection treatment that effectively removes medium molecules without compromising essential physiologic molecules.