Cytokine Adsorption Therapy during Extracorporeal Membrane Oxygenation in Adult Patients with COVID-19

Hemoadsorption as Adjuvant Therapy in Acute Respiratory Distress Syndrome (ARDS): A Systematic Review and Meta-Analysis

BACKGROUND

Acute respiratory distress syndrome (ARDS) is often a consequence of a dysregulated immune response; therefore, immunomodulation by extracorporeal cytokine removal has been increasingly used as an adjuvant therapy, but convincing data are still missing. The aim of this study was to investigate the effects of adjunctive hemoadsorption (HA) on clinical and laboratory outcomes in patients with ARDS.

METHODS

We performed a systematic literature search in PubMed, Embase, CENTRAL, Scopus, and Web of Science (PROSPERO: CRD42022292176). The population was patients receiving HA therapy for ARDS. The primary outcome was the change in PaO2/FiO2 before and after HA therapy. Secondary outcomes included the before and after values for C-reactive protein (CRP), lactate, interleukin-6 (IL-6), and norepinephrine (NE) doses.

RESULTS

We included 26 publications, with 243 patients (198 undergoing HA therapy and 45 controls). There was a significant improvement in PaO2/FiO2 ratio following HA therapy (MD = 68.93 [95%-CI: 28.79 to 109.06] mmHg, p = 0.005) and a reduction in CRP levels (MD = -45.02 [95%-CI: -82.64; -7.39] mg/dL, p = 0.026) and NE dose (MD = -0.24 [95%-CI: -0.44 to -0.04] μg/kg/min, p = 0.028).

CONCLUSIONS

Based on our findings, HA resulted in a significant improvement in oxygenation and a reduction in NE dose and CRP levels in patients treated with ARDS. Properly designed RCTs are still needed.

EFFICACY OF SUPPLEMENTAL HEMOADSORPTION THERAPY ON SEVERE AND CRITICAL PATIENTS WITH COVID-19: AN EVIDENCE-BASED ANALYSIS

ABSTRACT

Background: The COVID-19 pandemic has posed a disproportionately high threat to the global health system and social stability. COVID-19 damage can lead to hyperinflammation and tissue damage due to a "cytokine storm," which in turn contributes to an increase in the mortality rate. Extracorporeal hemoadsorption therapy (HAT) in patients with severe COVID-19 may improve organ function and stabilize hemodynamic status; however, the effects of supplemental HAT remain controversial. Methods: The Cochrane Library, Embase, and PubMed databases were comprehensively searched from inception to August 20, 2022, for potential studies. Results: A total of 648 patients with severe COVID-19 in three randomized controlled trials and 11 observational studies met the inclusion criteria. A meta-analysis indicated that supplemental HAT significantly improved the mortality rate of patients with severe COVID-19 compared with conventional therapy (relative risk [RR] = 0.74, 95% confidence interval [CI] = 0.56 to 0.96, P = 0.026). In subgroup analyses, supplemental HAT significantly decreased mortality rates in patients without extracorporeal membrane oxygenation (ECMO) support (RR = 0.59, 95% CI = 0.44-0.79, P < 0.0001), while a significant difference was not observed in patients requiring ECMO support (RR = 1.61, 95% CI = 0.63-4.09, P = 0.316). Standardized mean difference (SMD) meta-analysis showed that IL-6 removal was more significant in HAT group than conventional therapy group (SMD = 0.46, 95% CI = 0.01 to 0.91, P = 0.043), followed by C-reactive protein (SMD = 0.70, 95% CI = -0.04 to 1.44, P = 0.065) and IL-8 (SMD = 0.36, 95% CI = -0.34 to 1.07, P = 0.311). No evidence of substantial publication bias concerning mortality was observed. Conclusion: Given the better mortality outcomes, HAT confers clinical benefits to patients with severe COVID-19, which correlated with cytokine removal by HAT. Cytokine adsorption may not provide clinical benefits for patients with severe COVID-19 requiring ECMO and should be used with caution. However, because of the very low quality of evidence, multicenter randomized trials with large sample sizes are required to verify these findings.

CytoSorb in patients with coronavirus disease 2019: A rapid evidence review and meta-analysis

Background

After its approval by the European Union in 2011, CytoSorb therapy has been applied to control cytokine storm and lower the increased levels of cytokines and other inflammatory mediators in blood. However, the efficiency of this CytoSorb treatment in patients with coronavirus disease (COVID-19) still remains unclear. To elucidate the Cytosorb efficiency, we conducted a systematic review and single-arm proportion meta-analysis to combine all evidence available in the published literature to date, so that this comprehensive knowledge can guide clinical decision-making and future research.

Methods

The literature published within the period 1 December 2019 to 31 December 2021 and stored in the Cochrane Library, Embase, PubMed, and International Clinical Trials Registry Platform (ICTRP) was searched for all relevant studies including the cases where COVID-19 patients were treated with CytoSorb. We performed random-effects meta-analyses by R software (3.6.1) and used the Joanna Briggs Institute checklist to assess the risk of bias. Both categorical and continuous variables were presented with 95% confidence intervals (CIs) as pooled proportions for categorical variables and pooled means for continuous outcomes.

Results

We included 14 studies with 241 COVID-19 patients treated with CytoSorb hemadsorption. Our findings reveal that for COVID-19 patients receiving CytoSorb treatment, the combined in-hospital mortality was 42.1% (95% CI 29.5-54.6%, I² = 74%). The pooled incidence of adjunctive extracorporeal membrane oxygenation (ECMO) support was 73.2%. Both the C-reactive protein (CRP) and interleukin-6 (IL-6) levels decreased after CytoSorb treatment. The pooled mean of the CRP level decreased from 147.55 (95% CI 91.14-203.96) to 92.36 mg/L (95% CI 46.74-137.98), while that of IL-6 decreased from 339.49 (95% CI 164.35-514.63) to 168.83 pg/mL (95% CI 82.22-255.45).

Conclusions

The majority of the COVID-19 patients treated with CytoSorb received ECMO support. In-hospital mortality was 42.1% for the COVID-19 patients who had CytoSorb treatment. Both CRP and IL-6 levels decreased after Cytosorb treatment.

Effect of extracorporeal hemoadsorption in critically ill patients with COVID-19: A narrative review

COVID-19 has been affecting the world unprecedentedly and will remain widely prevalent due to its elusive pathophysiological mechanism and the continuous emergence of new variants. Critically ill patients with COVID-19 are commonly associated with cytokine storm, multiple organ dysfunction, and high mortality. To date, growing evidence has shown that extracorporeal hemoadsorption can exert its adjuvant effect to standard of care by regulating immune homeostasis, reducing viremia, and decreasing endotoxin activity in critically ill COVID-19 cases. However, the selection of various hemofilters, timing of initiation and termination of hemoadsorption therapy, anticoagulation management of extracorporeal circuits, identification of target subgroups, and ultimate survival benefit remain controversial. The purpose of this narrative review is to comprehensively summarize the rationale for the use of hemoadsorption in critically ill patients with COVID-19 and to gather the latest clinical evidence in this field.

Use of CytoSorb© Hemoadsorption in Patients on Veno-Venous ECMO Support for Severe Acute Respiratory Distress Syndrome: A Systematic Review

Acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality. Adjunct hemoadsorption is increasingly utilized to target underlying hyperinflammation derived from ARDS. This article aims to review available data on the use of CytoSorb© therapy in combination with V-V ECMO in severe ARDS, and to assess the effects on inflammatory, laboratory and clinical parameters, as well as on patient outcomes. A systematic literature review was conducted and reported in compliance with principles derived from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. When applicable, a before-and-after analysis for relevant biomarkers and clinical parameters was carried out. CytoSorb© use was associated with significant reductions in circulating levels of C-reactive protein and interleukin-6 (p = 0.039 and p = 0.049, respectively). Increases in PaO2/FiO2 reached significance as well (p = 0.028), while norepinephrine dosage reductions showed a non-significant trend (p = 0.067). Mortality rates in CytoSorb© patients tended to be lower than those of control groups of most included studies, which, however, were characterized by high heterogeneity and low power. In an exploratory analysis on 90-day mortality in COVID-19 patients supported with V-V ECMO, the therapy was associated with a significantly reduced risk of death. Based on the reviewed data, CytoSorb© therapy is able to reduce inflammation and potentially improves survival in ARDS patients treated with V-V ECMO. Early initiation of CytoSorb© in conjunction with ECMO might offer a new approach to enhance lung rest and promote recovery in patients with severe ARDS.

Hemoperfusion: technical aspects and state of the art

Background

Blood purification through the removal of plasma solutes by adsorption to beads of charcoal or resins contained in a cartridge (hemoperfusion) has a long and imperfect history. Developments in production and coating technology, however, have recently increased the biocompatibility of sorbents and have spurred renewed interest in hemoperfusion.

Methods

We performed a narrative assessment of the literature with focus on the technology, characteristics, and principles of hemoperfusion. We assessed publications in ex vivo, animal, and human studies. We synthesized such literature in a technical and state-of-the-art summary.

Results

Early hemoperfusion studies were hampered by bioincompatibility. Recent technology, however, has improved its safety. Hemoperfusion has been used with positive effects in chronic dialysis and chronic liver disease. It has also demonstrated extraction of a variety of toxins and drugs during episodes of overdose. Trials with endotoxin binding polymyxin B have shown mixed results in septic shock and are under active investigation. The role of non-selective hemoperfusion in sepsis or inflammation remains. Although new technologies have made sorbents more biocompatible, the research agenda in the field remains vast.

Conclusion

New sorbents markedly differ from those used in the past because of greater biocompatibility and safety. Initial studies of novel sorbent-based hemoperfusion show some promise in specific chronic conditions and some acute states. Systematic studies of novel sorbent-based hemoperfusion are now both necessary and justified.