Molecular Size and Origin Do Not Influence the Harmful Side Effects of Hydroxyethyl Starch on Human Proximal Tubule Cells (HK-2) In Vitro

Raphael R. Bruno, Winfried Neuhaus, Norbert Roewer, Christian Wunder, Martin A. Schick

    Publications: Contribution to journalArticlePeer Reviewed

    Abstract

    BACKGROUND:: Recently, clinical trials revealed renal impairment induced by hydroxyethyl starch (HES) in septic patients. In prior studies, we managed to demonstrate that HES accumulated in renal proximal tubule cells (PTCs). The related pathomechanism has not yet been discovered. To validate our hypothesis that the HES molecule itself is harmful, regardless of its molecule size or origin, we conducted a comprehensive study to elucidate the influences of different HES preparations on PTC viability in vitro. METHODS:: Cell viability of human PTC was measured with a cytotoxicity assay, quantifying the reduction of tetrazolium salt to colored formazan. Experiments were performed by assessing the influence of different carrier solutions of HES (balanced, nonbalanced, culture medium), different average molecular weights (70, 130, 200 kDa), different origins (potato or corn derived), and various durations of incubation (2-21 hours). Furthermore, HES 130/0.4 was fractionated by ultrafiltration, and the impact on cell viability of average single-size fractions with <3, 3 to 10, 10 to 30, 30 to 50, 50 to 100, and >100 kDa was investigated. We also tested the possible synergistic effects of inflammation induced by tumor necrosis factor-α. RESULTS:: All tested HES solutions, regardless of origin or carrier matrix, decreased cell viability in an equivalent, dose-dependent manner. Coincubation with tumor necrosis factor-α did not reduce HES-induced reduction of cell viability. Minor differences were detected comparing 70, 130, and 200 kDa preparations. Analysis of fractionated HES revealed that each fraction decreased cell viability. Even small HES molecules (10-30 kDa) were significantly deleterious. CONCLUSIONS:: For the first time, we were able to show that only the total mass of HES molecules applied is responsible for the harmful impact on renal PTC in vitro. Neither molecular size nor their origin showed any relevance.

    Original languageEnglish
    Pages (from-to)570-577
    Number of pages8
    JournalAnesthesia and Analgesia
    Volume119
    Issue number3
    DOIs
    Publication statusPublished - Sep 2014

    Austrian Fields of Science 2012

    • 301207 Pharmaceutical chemistry

    Keywords

    • CRITICALLY-ILL PATIENTS
    • SEVERE SEPSIS
    • INTENSIVE-CARE
    • SURGERY
    • RESUSCITATION
    • 6-PERCENT
    • SAFETY
    • INFUSION
    • EFFICACY

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