Extracorporeal Elimination of Pro- and Anti-inflammatory Modulators by the Cytokine Adsorber CytoSorb in Patients with Hyperinflammation: A Prospective Study

Introduction: The release of pro-inflammatory cytokines in critically ill patients with sepsis leads to endothelial dysfunction resulting in cardiocirculatory insufficiency. Their extracorporeal elimination using the cytokine adsorber CytoSorb (CS) (adsorption of especially hydrophobic molecules < 60 kDa) might be promising, but data about the adsorption capacity as well as a potential harmful adsorption of anti-inflammatory cytokines are missing so far.

Methods: The prospective Cyto-SOLVE-study included 15 patients with sepsis or other hyperinflammatory conditions (interleukin 6 > 500 pg/ml), continuous kidney replacement therapy, and the application of CS. Various cytokines and chemokines were measured pre- and post-CS as well as in patients' blood at predefined timepoints. Significant changes in the concentrations were detected with the Wilcoxon test with associated samples. Clearance of the adsorber (ml/min) was calculated with: RESULTS: Most of the inflammatory mediators showed a high initial extracorporeal clearance of 70-100 ml/min after CS installation, which dropped quickly to 10-30 ml/min after 6 h of treatment. No difference in clearance was observed between pro- and anti-inflammatory cytokines. Despite extracorporeal adsorption, a significant (p < 0.05) decrease in the blood concentration after 6 h was only observed for the pro-inflammatory cytokines tumor necrosis factorα (TNF-α) (median 284 vs. 230 pg/ml), vascular endothelial growth factor (VEGF) (median 294 vs. 252 pg/ml), macrophage inflammatory protein 1a (MIP-1a) (median 11.1 vs. 9.0 pg/ml), and regulated upon activation, normal T cell expressed and secreted (RANTES) (median 811 vs. 487 pg/ml) as well as the anti-inflammatory cytokines interleukin 4 (median 9.3 vs. 6.4 pg/ml), interleukin 10 (median 88 vs. 56 pg/ml), and platelet-derived growth factor (PDGF) (median 177 vs. 104 pg/ml). A significant (p < 0.05) decrease in patients' blood after 12 h was only detected for interleukin 10.

Conclusions: CS can adsorb pro- as well as anti-inflammatory mediators with no relevant difference regarding the adsorption rate. A fast saturation of the adsorber resulted in a rapid decrease of the clearance. The potential clinical benefit or harm of this unspecific cytokine adsorption needs to be evaluated in the future.

Trial Registration: ClinicalTrials.gov NCT04913298, registration date June 4, 2021.