Dextran 500 Improves Recovery of Inflammatory Markers: An In Vitro Microdialysis Study

Abstract

Cerebral microdialysis (CMD) is used in severe traumatic brain injury (TBI) in order to recover metabolites in brain extracellular fluid (ECF). To recover larger proteins and avoid fluid loss, albumin supplemented perfusion fluid (PF) has been utilized, but because of regulatory changes in the European Union, this is no longer practicable. The aim with this study was to see whether fluid, absolute (AR), and relative (RR) recovery for the novel carrier, Dextran 500, was better than conventional PF for a range of cytokines and chemokines. An in vitro setup mimicking conditions observed in the neurocritical care of TBI patients was used, utilizing 100-kDa molecular-weight cut-off CMD catheters inserted through a triple-lumen bolt cranial access device into an external solution with diluted cytokine standards in known concentrations for 48 h (divided into 6-h epochs). Samples were run on a 39-plex Luminex (Luminex Corporation, Austin, TX) assay to assess cytokine concentrations. We found that fluid recovery was inadequate in 50% of epochs with conventional PF, whereas Dextran PF overcame this limitation. The AR was higher in the Dextran PF samples for a majority of cytokines, and RR was significantly increased for macrophage colony-stimulating factor and transforming growth factor-alpha. In summary, Dextran PF improved fluid and cytokine recovery as compared to conventional PF and is a suitable alternative to albumin supplemented PF for protein microdialysis.

Axonal marker neurofilament light predicts long-term outcomes and progressive neurodegeneration after traumatic brain injury

“…www.science.org/doi/10.1126/scitranslmed.abg9922 Materials and Methods Sensitivity Analysis Figs. S1 to S6 Tables S1 to S16 Contributor list: The BIO-AX-TBI Group References (61)(62)(63)(64)(65)(66)(67)(68)(69) View/request a protocol for this paper from Bio-protocol.…”

Time-Dependent Changes in the Biofluid Levels of Neural Injury Markers in Severe Traumatic Brain Injury Patients–Cerebrospinal Fluid and Cerebral Microdialysates: A Longitudinal Prospective Pilot Study

“…Technical issues include the use of standard CSF perfusion fluid that was used to perfuse the catheters, which may be suboptimal for protein recovery. 72 Because of various issues, including patient safety, we were unable to collect sufficient quantities of bECF samples at all time points that would have enabled higher (e.g., daily or even higher) temporal resolution.…”

A pilot study of inflammatory mediators in brain extracellular fluid in paediatric TBM

“…The low analyte concentrations in our data could, therefore reflect a) that the molecule was not present in the ECF, although this is less likely given that those analytes were present in the VCSF, b) it was not detected due to insufficient sensitivity of the analysis kit for low concentrations or c) the relative recovery of the molecule through the microdialysis testing modality was insufficient to detect low concentrations. The use of dextran or albumin as a perfusion fluid may have increased the yield [ 24 , 25 ]. It is promising, however, to be able to generate pilot data on ECF cytokine concentrations in TBM.…”

“…relative recovery of the molecule through the microdialysis testing modality was insufficient to detect low concentrations. The use of dextran or albumin as a perfusion fluid may have increased the yield [24,25]. It is promising, however, to be able to generate pilot data on ECF cytokine concentrations in TBM.…”