Supplementary Material for: Interleukin-6 removal and clinical effects of Oxiris: a systematic review and meta-analysis.

Introduction
Sepsis is a life-threatening condition associated with high mortality due to an unregulated host immune response. Extracorporeal blood purification (EBP) therapies have been proposed as adjunctive treatments to immunomodulate patients; however, none have been consistently shown to be effective in reducing mortality. In several observational studies, Oxiris has been associated with cytokine reduction and a potential benefit in influencing inflammatory diseases. This meta-analysis explores the association between cytokine removal and clinical efficacy of the Oxiris membrane using interleukin-6 (IL-6) as a biomarker.
Methods
This review includes articles on EBP with Oxiris membranes in adult patients with sepsis/septic shock or COVID-19. No time or language restrictions were applied to the systematic literature search. Data extraction and statistical analysis were limited to the cytokines and clinical data reported in the included articles. The most representative cytokine was IL-6 and the selected outcomes included VIS (Vasoactive-Inotropic Score), SOFA score, procalcitonin (PCT) and c-reactive protein (CRP). The review used meta-analysis and unpaired t-test to estimate differences between groups of patients treated with or without Oxiris.
Results
The study found no significant differences in demographics between the intervention and control groups at baseline. Intervention group showed a significant reduction in vasoactive inotropic score, norepinephrine dose, SOFA score, procalcitonin and C-reactive protein.
Conclusion
We reviewed 8 studies in which IL-6 was significantly reduced in the Oxiris group compared to the control. This meta-analysis found that the use of the Oxiris membrane resulted in significant clinical improvement during treatment.