A Multicenter Evaluation of the Seraph 100 Microbind Affinity Blood Filter for the Treatment of Severe COVID-19

Extracorporeal pediatric renal replacement therapy: diversifying application beyond kidney failure

The utilization of extracorporeal renal replacement therapy (RRT), including continuous renal replacement therapy (CRRT) and hemodialysis (HD), beyond the treatment of volume overload and acute kidney injury (AKI) has witnessed a significant shift, demonstrating the potential to improve patient outcomes for a range of diseases. This comprehensive review explores the non-kidney applications for RRT platforms in critically ill children, focusing on diverse clinical scenarios such as sepsis, inborn errors of metabolism, liver failure, drug overdose, tumor lysis syndrome, and rhabdomyolysis. In the context of sepsis and septic shock, RRT not only facilitates fluid, electrolyte, and acid/base homeostasis, but may offer benefits in cytokine regulation, endotoxin clearance, and immunomodulation which may improve multi-organ dysfunction as well as hemodynamic challenges posed by this life-threatening condition. RRT modalities also have an important role in caring for children with inborn errors of metabolism, liver failure, and tumor lysis syndrome as they can control metabolic derangements with the efficient clearance of endogenous toxins in affected children. In cases of drug overdose, RRT is a crucial tool for rapid extracorporeal clearance of exogenous toxins, mitigating potential organ damage. The intricate interplay between liver failure and kidney function is examined, elucidating the role of RRT and plasma exchange in maintaining fluid and electrolyte balance when hepatic dysfunction complicates the clinical picture. Furthermore, RRT and HD are explored in the context of rhabdomyolysis, highlighting their utility in addressing AKI secondary to traumatic events and crush syndrome.

Effect of a biomimetic pathogen adsorbing device on inflammatory biomarkers in COVID-19 patients

INTRODUCTION

The Seraph 100 Microbind Affinity blood filter eliminate bacteria, viruses, fungi and toxins from blood stream.

METHODS

This is a prospective multicenter observational biomarker trial in PCR-positive SARS-CoV-2 patients with acute respiratory failure. Biomarkers were sequentially tested at three time points.

RESULTS

Forty-two patients with SARS-CoV-2 detected by PCR with acute respiratory failure were included. When receiving hemoperfusion treatment, 27 (64%) patients were on mechanical ventilation, 41 (98%) patients were treated in the ICU. The 3-month survival was 52%. After one hemoperfusion treatment cycle, D-dimer (p = 0.014), hemoglobin (p = 0.003) and LDH (p = 0.001) concentrations were significantly reduced 4 days after treatment. From the multiplex assay IL-1b, CXCL8/ IL-8, IL-10, IL-13, IL-15, CCL11/Eotaxin, G-CSF, and CXCL10/IP-10 were significantly reduced 1 h after treatment, however not 4 days later.

CONCLUSION

Hemoperfusion with Seraph 100 Microbind Affinity Filter in patients with severe COVID-19 can transiently reduce several inflammatory biomarkers in the blood.

The Seraph 100® Microbind Affinity Blood Filter Does Not Alter Levels of Circulating or Mucosal Antibodies in Critical COVID-19 Patients

PURIFY-OBS-1 is an observational study evaluating the safety and efficacy of Seraph 100® Microbind Affinity Blood Filter (Seraph 100) use for COVID-19 patients with respiratory failure admitted to the intensive care unit (ICU). The Seraph 100 is a hemoperfusion device containing heparin-coated beads that can bind to, and reduce levels of, some circulating pathogens and inflammatory molecules. This study evaluated whether treatment with the Seraph 100 affected circulating and mucosal antibody levels in critically ill COVID-19 subjects. SARS-CoV-2 anti-spike and anti-nucleocapsid IgG and IgA levels in serum were evaluated at enrollment and on days 1, 4, 7, and 28 after Seraph 100 application, while anti-spike and nucleocapsid IgG, IgA, and secretory IgA levels in tracheal aspirates were evaluated at enrollment and on days 1, 2, 3, 7, and 28. Serum samples were also collected from the pre- and post-filter lines at 1 and 4 h following Seraph 100 application to evaluate the direct impact of the filter on circulating antibody levels. Treatment with the Seraph 100 did not alter the levels of circulating or mucosal antibodies in critically ill COVID-19 subjects admitted to the ICU.

[Extracorporeal removal of pathogens using a biomimetic adsorber-A new treatment strategy for the intensive care unit : Seraph® 100 Microbind® Affinity Blood Filter and its fields of application]

BACKGROUND

In 2019 the World Health Organization (WHO) listed antimicrobial resistance among the top 10 threats to global health. The Seraph® 100 Microbind® Affinity blood filter (Seraph® 100) has been in use since 2019 to eliminate pathogens from the bloodstream in addition to anti-infective pharmacotherapy. It is the first device used to rapidly and efficiently reduce the number of circulating bacteria and viruses.

OBJECTIVE

After a background on the concept of extracorporeal pathogen removal in general, this review summarizes the preclinical and clinical data on the Seraph® 100 Affinity Blood Filter. The clinical effect of this treatment and potential therapeutic options are described.

METHODS

Structured PubMed review including references published up to February 2024.

RESULTS

Case reports, uncontrolled observational studies and data from registries show widespread clinical use of the Seraph® 100 ranging from difficult to treat bacterial (super) infections to viral infections. The treatment can be done as stand-alone hemoperfusion or in combination with all forms of kidney replacement therapy as well as in extracorporeal membrane oxygenation.

CONCLUSION

The use of the Seraph® 100 varies in terms of duration, concomitant therapy and clinical settings. Due to the absence of prospective controlled trials the clinical effect cannot be properly evaluated.

Sorbent functionalization with vancomycin enhances bacteria killing in extracorporeal hemoadsorption

BACKGROUND

The level of bacteremia in patients with sepsis and septic shock is a predictor of complications and mortality, regardless of the type of bacteria. Devices for bacteria, endotoxin and cytokines removal by adsorption have been recently developed. Thus, extracorporeal blood purification therapies have been proposed as adjunctive therapy in sepsis in combination with drugs. Some potentially useful drugs, however, are precluded due to their organ or metabolic toxicity. The present study represents a preliminary report on the in vitro effect of a sorbent device (minimodule with HA380 beads, Jafron medical, Zhuhai, China) in which the particles have been functionalized with vancomycin on the surface. The impact of the surface-modified beads on circulating bacteria (Staphylococcus aureus) has been tested in a simulated in vitro circulation.

METHODS

In vitro experiments were carried out with 800 mL of blood enriched with S. aureus species. Blood was circulated in the vancomycin-functionalized and non-functionalized mini-module cartridges in hemoadsorption setup (300 mL each) and the bactericidal effect was assessed. Also, 200 mL of blood was used as a control.

RESULTS

A significant increase in the time to positivity of blood cultures was observed after 60 min and also after 120 min of therapy with the mini-module functionalized with vancomycin as opposed to the non-functionalized cartridge.

CONCLUSIONS

These results suggest a possible way of treating sepsis by using drug- or antibiotic-functionalized cartridges without worrying about pharmacological toxicity. The prolongation of the time to bacterial culture positivity to S. aureus after a passage through a column packed with beads functionalized with vancomycin represents a proof of concept.

Using the Seraph® 100 Microbind® Affinity blood filter under slow flow conditions through 18 G and 16 G central lines

INTRODUCTION

The Seraph® 100 Microbind® Affinity blood filter (Seraph® 100) has been in use since 2019 for the treatment of fulminant or difficult to treat blood stream infections as an adjunct to pharmacotherapy. In 2020 the device received emergency use authorization by the US Food and Drug Administration for the treatment of critically ill COVID-19 patients with confirmed or imminent respiratory failure. Results of an international registry showed that the Seraph® 100 was operated under blood flow rates of 100-350 mL/min. As those conditions require a large bore central line, a dialysis catheter is currently considered indispensable to operate the Seraph® 100. The use of smaller catheter lumina has neither been evaluated in vitro nor in vivo.

METHODS

In vitro pressure data before and after the Seraph® 100 at various blood pump rates (prepump line 16 G, postpump line 18 G) with saline and human plasma were obtained. Further, anecdotal flow and pressure data of two patients treated with the Seraph® 100 for a COVID-19 infection are reported.

RESULTS

At a pump speed of 50 mL/min pre-Seraph® pressure using saline was -70 [-70 to -60] mm Hg. In comparison, using plasma pre-Seraph® pressure was lower at -120 [-120 to -105] mm Hg; p < 0.001 (t-test). The post-Seraph® pressure at 50 mL/min using saline of 120 [110-130] mm Hg was not different from plasma at 130 [120-140] mm Hg, p = 0.152 (t-test). Blood flow rates of 50 mL/min did not lead to preAP levels below -250 mm Hg in the two clinical cases.

CONCLUSION

Seraph® 100 blood flow rate of 50 mL/min may be achieved using low flow vascular access, allowing to treat a blood volume 72 L in 24 h.

Use of Therapeutic Apheresis methods in ICU

Apheresis is a modern medical approach in which plasma or cellular components are separated from the whole blood. Apheresis can be either diagnostic or therapeutic. Diagnostic apheresis is typically applied in hematology and cancer research. Therapeutic Apheresis (TA) includes a broad spectrum of extracorporeal treatments applied in various medical specialties, including Intensive Care Unit (ICU). Considering the complexity of the pathophysiologic characteristics of various clinical entities and in particular sepsis, apheresis methods are becoming increasingly applicable. Therapeutic Plasma Exchange (TPE) is the most common used method in ICU. It is considered as first line therapy for Thrombotic Thrombocytopenic Purpura (TTP) and Guillain Barre Syndrome, while the current data for sepsis are scarce. Over the last decades, technologic evolution has led to increasing application of new and more selective methods based on adsorptive techniques. In this review we will describe the current data of characteristics of different techniques, safety and clinical impact of apheresis methods used in ICUs.

Seraph 100 Microbind Affinity Blood Filter Does Not Clear Antibiotics: An Analysis of Antibiotic Concentration Data from PURIFY-OBS

INTRODUCTION

Novel hemoperfusion systems are emerging for the treatment of sepsis. These devices can directly remove pathogens, pathogen-associated molecular patterns, cytokines, and other inflammatory markers from circulation. However, significant safety concerns such as potential antibiotic clearance need to be addressed prior to these devices being used in large clinical studies.

METHODS

Prospective, observational study of 34 participants undergoing treatment with the Seraph 100® Microbind Affinity Blood Filter (Seraph 100) device at 6 participating sites in the USA. Patients were included for analysis if they had a record of receiving an antibiotic concurrent with Seraph 100 treatment. Patients were excluded if there was missing information for blood flow rate. Blood samples were drawn pre- and post-filter at 1 h and 4 h after treatment initiation. These average pre- and post-filter time-concentration observations were then used to estimate antibiotic clearance in L/h (CLSeraph) due to the Seraph 100 device.

RESULTS

Of the 34 participants in the study, 17 met inclusion and exclusion criteria for the antibiotic analysis. Data were obtained for 7 antibiotics (azithromycin, cefazolin, cefepime, ceftriaxone, linezolid, piperacillin, and vancomycin) and one beta-lactamase inhibitor. Mean CLSeraph for the antibiotics investigated ranged from -0.57 to 0.47 L/h. No antibiotic had a CLSeraph statistically significant from 0.

DISCUSSION/CONCLUSION

The Seraph 100 did not significantly clear any measured antibiotic in clinical samples. These data give further evidence to suggest that these therapies may be safely administered to critically ill patients and will not impact concentrations of administered antibiotics.

Use of the Seraph® 100 Microbind® Affinity Blood Filter in an adolescent patient with disseminated adenoviral disease

BACKGROUND

The Seraph® 100 Microbind® Affinity Blood Filter (Seraph® 100) is an adjunctive pathogen adsorption device with emergency use authorization for use with extracorporeal therapies to treat COVID-19 infection.

CASE

Here, we describe the use of Seraph® 100 in a 17-year-old chronically immunosuppressed patient status post deceased donor kidney transplant who presented initially for hematuria, dysuria, and fevers, and was found to have disseminated adenovirus (ADV) infection complicated by nephritis, viral pneumonia, elevated transaminases, and bone marrow suppression. Despite halting immunosuppression for 2 weeks, she remained febrile to 40.2 °C, with serum ADV counts > 10 million copies/mL (> log 7). Due to concerns about nephrotoxicity from cidofovir treatment, she underwent 2 intermittent treatments with Seraph® 100 to reduce viral load. Fever curve, blood counts, and transaminases stabilized in the days following treatment, and the patient was able to resume her prior immunosuppression regimen without a rebound in viral counts.

CONCLUSIONS

This adolescent kidney transplant patient with disseminated ADV infection tolerated in-line treatment with Seraph® 100 without major clinical adverse events related to the adsorber, and had resolution of her ADV infection and good clinical recovery.

[Hemoperfusion in anesthesia and intensive care medicine: benefits, risks, and evidence for different systems]

BACKGROUND

Hemoperfusion is a technique for the extracorporeal elimination of endogenous and exogenous toxins and harmful mediators by adsorption. It can be used as a stand-alone device, as part of a heart-lung machine or extracorporeal membrane oxygenation (ECMO) or, as is currently the case, integrated into a kidney replacement procedure. In the meantime, various suppliers offer devices with different technologies.

OBJECTIVE

The aim of this work was to evaluate the benefits, risks and evidence of the different systems, how they work and for which indications they are approved in Germany.

METHOD

To achieve this goal, a narrative assessment of the existing literature and guidelines for different indications was performed. The focus was on in vivo studies.

RESULTS

In principle, a distinction must be made in adsorption techniques between pure adsorption and the combination as adsorption and kidney replacement therapy. The adsorbers available in Germany include Cytosorb®, HA-330, Seraph®-100 and Toraymyxin. Combined procedures (adsorption and kidney replacement) are offered with coupled plasma filtration and adsorption (CPFA) and oXiris®. Most adsorbers have been developed for cytokine and endotoxin removal in patients with sepsis; however, to date, no randomized controlled trial (RCT) has demonstrated a survival benefit when using hemoperfusion. Therefore, the S3 guidelines for treatment of sepsis and the surviving sepsis campaign guidelines advise against its routine use. When the corona pandemic began, hemoperfusion was considered as a promising therapeutic approach. Cytosorb®, Seraph®-100, and oXiris® received emergency approval by the FDA to be used in critically ill patients with COVID-19, so questions arose about the appropriateness and importance of its use; however, the data generated did not show positive results, so its use cannot be recommended routinely either. In addition, they are not mentioned as a treatment option in the current guidelines. The use of adsorption procedures in patients with liver failure and rhabdomyolysis has only been rudimentarily studied, so any evidence is currently lacking. The only adsorber that has CE approval in Germany for both applications is Cytosorb®. In the next few years, studies will have to follow that investigate the efficacy and thus either justify or refute the use in clinical routine. Hemoperfusion procedures are used in the heart-lung machine as part of cardiac surgery for either cytokine or anticoagulant adsorption. No congruent data are available to support the use for the elimination of cytokines. If emergency cardiac surgery is required in a patient with pre-existing anticoagulation, hemoperfusion procedures can be used to prevent bleeding complications. Cytosorb® has CE approval for this indication. All available techniques are nonselective adsorption processes, so that adsorption of known and unknown substances can occur. Unintentional adsorption of drugs, such as various anti-infective agents is a relevant risk, especially when used in patients with sepsis.

DISCUSSION

Various adsorption systems can eliminate different known and unknown substances. Currently, there is a lack of evidence for all indications and systems to justify their routine use except in clinical trials. Future clinical trials should evaluate the potential benefits but also dangers, so that in the meantime the routine use can be justified or a recommendation against the use can be given.

AKI in Adults with COVID-19 Infection: Mechanisms of Development and Role of Blood Filtration Devices in Treatment

During the coronavirus disease 2019 (COVID-19) pandemic, acute kidney injury (AKI) was a common sequela of COVID-19 infection and predicted disease severity and mortality. Extracorporeal blood purification techniques involving blood filtration devices are an emerging treatment for AKI in the setting of severe COVID-19 infections. In this review, we discuss potential mechanisms for the development of AKI in COVID-19 patients as well as the various available blood filtration devices and the role they may play in managing the AKI in COVID-19 patients. A total of seven blood filters currently available were compared based on their potential in treating AKI in COVID-19 patients. Blood filtration devices show potential as an emerging treatment modality for COVID-19-induced AKI, but further clinical trials are necessary before their widespread adoption and usage.

Proceedings of the 2022 UAB CRRT Academy: Non-Invasive Hemodynamic Monitoring to Guide Fluid Removal with CRRT and Proliferation of Extracorporeal Blood Purification Devices

In 2022, we celebrated the 15th anniversary of the University of Alabama at Birmingham (UAB) Continuous Renal Replacement Therapy (CRRT) Academy, a 2-day conference attended yearly by an international audience of over 100 nephrology, critical care, and multidisciplinary trainees and practitioners. This year, we introduce the proceedings of the UAB CRRT Academy, a yearly review of select emerging topics in the field of critical care nephrology that feature prominently in the conference. First, we review the rapidly evolving field of non-invasive hemodynamic monitoring and its potential to guide fluid removal by renal replacement therapy (RRT). We begin by summarizing the accumulating data associating fluid overload with harm in critical illness and the potential for harm from end-organ hypoperfusion caused by excessive fluid removal with RRT, underscoring the importance of accurate, dynamic assessment of volume status. We describe four applications of point-of-care ultrasound used to identify patients in need of urgent fluid removal or likely to tolerate fluid removal: lung ultrasound, inferior vena cava ultrasound, venous excess ultrasonography, and Doppler of the left ventricular outflow track to estimate stroke volume. We briefly introduce other minimally invasive hemodynamic monitoring technologies before concluding that additional prospective data are urgently needed to adapt these technologies to the specific task of fluid removal by RRT and to learn how best to integrate them into practical fluid-management strategies. Second, we focus on the growth of novel extracorporeal blood purification devices, starting with brief reviews of the inflammatory underpinnings of multiorgan dysfunction and the specific applications of pathogen, endotoxin, and/or cytokine removal and immunomodulation. Finally, we review a series of specific adsorptive technologies, several of which have seen substantial clinical use during the COVID-19 pandemic, describing their mechanisms of target removal, the limited existing data supporting their efficacy, ongoing and future studies, and the need for additional prospective trials.

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.

Single-Center Experience With the Seraph-100® Microbind® Affinity Blood Filter in Patients With SARS-CoV-2 Infection and Septic Shock at a Military Treatment Facility

INTRODUCTION

Coronavirus disease 2019 (COVID-19) infection is characterized by a dysregulated inflammatory response, which may result in severe hemodynamic instability and septic shock. The Seraph-100® Microbind® Affinity Blood Filter is a commercially available extracorporeal pathogen absorbent device with the ability to bind pathogens and cytokines present within the blood. Our study aimed to evaluate the efficacy of the Seraph-100® for patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and septic shock.

MATERIALS AND METHODS

A retrospective review was performed to evaluate the use of the Seraph-100® blood filter at a Single Center tertiary-care facility at Brooke Army Medical Center from 2020 to 2021. Nine patients (11 treatments) were completed with the Seraph-100® blood filter in patients with SARS-CoV-2 infection and septic shock. The Seraph-100® blood filter was used in combination with continuous renal replacement therapy and slow low-efficiency dialysis or directly in parallel with the extracorporeal membrane oxygenation circuit.

RESULTS

Within this cohort, there was a statistically significant improvement in the following clinical parameters comparing values to before and after treatment with the Seraph-100® blood filter: Mean arterial pressure (mmHg) (64.2 ± 2.36 vs. 76.2 ± 2.68; P < .001), heart rate (beats per minute) (128 ± 6.6 vs. 100.3 ± 6.07; P < .001), administered fraction of oxygen (%) (74.4 ± 10.58 vs. 60.3 ± 10.35; P < .001), serum lactate (mmol/L) (6.14 ± 1.25 vs. 2.8 ± 1.14; P = .0095), and pH (7.29 ± 0.03 vs. 7.39 ± 0.04; P = .0203). There were statistically significant improvements in vasopressor requirements: norepinephrine (mcg/min) (36.3 ± 4.74 vs. 8.3 ± 3.92; P < .001), vasopressin (units/min) (0.04 ± 0.004 vs. 0.02 ± 0.003; P < .001), dobutamine (mcg/kg/min) (2.3 ± 1.00 vs. 0.2 ± 0.75; P = .006) and angiotensin II (ng/kg/min) (34.5 ± 6.4 vs. 3.3 ± 5.26; P < .001).

CONCLUSIONS

The use of the Seraph-100® blood filter was associated with statistically and clinically significant improvements in hemodynamic parameters and decreased vasopressor requirements in patients with septic shock and SARS-CoV-2 infection.

[Hemoperfusion and plasmapheresis in the intensive care unit]

In addition to kidney replacement procedures, several other extracorporeal procedures are employed in the intensive care unit. Hemoperfusion with activated charcoal was the predominant treatment used for removal of toxins from the 1970s until the millennium. Nowadays, this treatment does no longer play a clinically meaningful role as even strongly protein-bound toxins can be removed by effective dialysis procedures in case poisoning. The concept of a cytokine adsorber was introduced 10 years ago, which is directed towards withstanding the cytokine storm. Despite negative data from prospective randomized controlled studies, its use is steadily increasing in Germany. A totally different treatment concept is the biomimetic pathogen adsorber, which removes bacteria, viruses and fungi from the bloodstream by binding to immobilized heparin. Whether this rapid reduction of the pathogen load translates into an improvement of clinically relevant endpoints is unclear, as prospective randomized controlled studies are lacking. For the early hours of septic shock a very old procedure, plasmapheresis, has recently regained interest. The results of two large randomized controlled studies in this setting from Europe and Canada will become available in 2025/2026. The rationale to use plasma exchange in early sepsis is that this procedure not only removes cytokines but also replenishes reduced levels of protective factors, such as angiopoietin‑1, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13) and protein C, if fresh plasma is used as exchange fluid. All afore mentioned procedures do not only have a different mode of action but are also used at seperate time points of bloodstream infections and/or sepsis.

Rationale for sequential extracorporeal therapy (SET) in sepsis

Sepsis and septic shock remain drivers for morbidity and mortality in critical illness. The clinical picture of patients presenting with these syndromes evolves rapidly and may be characterised by: (a) microbial host invasion, (b) establishment of an infection focus, (c) opsonisation of bacterial products (e.g. lipopolysaccharide), (d) recognition of pathogens resulting in an immune response, (e) cellular and humoral effects of circulating pathogen and pathogen products, (f) immunodysregulation and endocrine effects of cytokines, (g) endothelial and organ damage, and (h) organ crosstalk and multiple organ dysfunction. Each step may be a potential target for a specific therapeutic approach. At various stages, extracorporeal therapies may target circulating molecules for removal. In sequence, we could consider: (a) pathogen removal from the circulation with affinity binders and cartridges (specific), (b) circulating endotoxin removal by haemoperfusion with polymyxin B adsorbers (specific), (c) cytokine removal by haemoperfusion with sorbent cartridges or adsorbing membranes (non-specific), (d) extracorporeal organ support with different techniques for respiratory and cardiac support (CO₂ removal or extracorporeal membrane oxygenation), and renal support (haemofiltration, haemodialysis, or ultrafiltration). The sequence of events and the use of different techniques at different points for specific targets will likely require trials with endpoints other than mortality. Instead, the primary objectives should be to achieve the desired action by using extracorporeal therapy at a specific point.

First-Time Use of the Seraph® 100 Microbind® Affinity Blood Filter in an Adolescent Patient with Severe COVID-19 Disease: A Case Report

The Seraph® 100 Microbind® Affinity Blood Filter (Seraph® 100) is a hemoperfusion device designed to adsorb bacteria, viruses, and toxins when added to extracorporeal circuits. The FDA granted emergency use authorization in adults, but this device had never been utilized in children. A 17-year-old patient with asthma presented with respiratory distress due to COVID-19. His course was complicated by respiratory failure, rhabdomyolysis, and stage 3 AKI requiring initiation of continuous kidney replacement therapy (CKRT) on ICU day 3. The Seraph® 100 filter was added on ICU day 4. He was treated with 3 filters from ICU day 4 to 8. On ICU day 8, he was extubated and CKRT discontinued. He required no further kidney replacement therapy but did not have laboratory work post-discharge. In conclusion, this adolescent patient with COVID-19 and AKI requiring CKRT tolerated treatment with the Seraph® 100 Microbind® Affinity Blood Filter without significant adverse events.

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.

Hämoperfusion und Plasmapherese auf der Intensivstation

Neben Nierenersatzverfahren werden auf der Intensivstation mehrere andere extrakorporale Verfahren eingesetzt. In den 1970er- bis 2000er-Jahren stand die Hämoperfusion mit Aktivkohlekapseln zur Entfernung von Toxinen im Vordergrund. Dies ist mittlerweile aufgrund der effektiven Dialyseverfahren, die im Vergiftungsfall auch stark proteingebundene Toxine entfernen, fast bedeutungslos geworden. Vor 10 Jahren erlebte ein Zytokinadsorber die Markteinführung, der darauf gerichtet ist, den „Zytokinsturm“ zu überstehen. Dieser erfreut sich trotz ernüchternder Daten aus prospektiven, randomisierten, kontrollierten Studien wachsender Beliebtheit. Ein gänzlich anderes Therapiekonzept ist der biomimetische Pathogenadsorber, der Bakterien, Viren und Pilze durch Bindung an immobilisiertes Heparin aus dem Blutstrom entfernt. Ob sich diese schnelle Reduktion der Pathogenlast in eine Verbesserung klinisch relevanter Endpunkte übersetzt, ist unklar, da hier prospektive, randomisierte und kontrollierte Studien gänzlich fehlen. Für ein sehr altes Verfahren, nämlich die Plasmapherese, werden wir für die Frühphase der Sepsis bis zum Jahr 2025/2026 Ergebnisse aus 2 großen randomisierten, kontrollierten Studien aus Europa und Kanada erhalten. Neben der Entfernung von Zytokinen erhofft man sich durch die Verwendung von Frischplasma als Austauschflüssigkeit auch das Wiederauffüllen reduzierter protektiver Faktoren wie Angiopoietin 1, ADAMTS13 („a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13“) und Protein C. Alle genannten Verfahren funktionieren nicht nur unterschiedlich, sondern werden auch zu unterschiedlichen Zeitpunkten der Blutstrominfektion/Sepsis eingesetzt.

Activated Platelets and Platelet-Derived Extracellular Vesicles Mediate COVID-19-Associated Immunothrombosis

Activated platelets and platelet-derived extracellular vesicles (EVs) have emerged as central players in thromboembolic complications associated with severe coronavirus disease 2019 (COVID-19). Platelets bridge hemostatic, inflammatory, and immune responses by their ability to sense pathogens via various pattern recognition receptors, and they respond to infection through a diverse repertoire of mechanisms. Dysregulated platelet activation, however, can lead to immunothrombosis, a simultaneous overactivation of blood coagulation and the innate immune response. Mediators released by activated platelets in response to infection, such as antimicrobial peptides, high mobility group box 1 protein, platelet factor 4 (PF4), and PF4⁺ extracellular vesicles promote neutrophil activation, resulting in the release of neutrophil extracellular traps and histones. Many of the factors released during platelet and neutrophil activation are positively charged and interact with endogenous heparan sulfate or exogenously administered heparin via electrostatic interactions or via specific binding sites. Here, we review the current state of knowledge regarding the involvement of platelets and platelet-derived EVs in the pathogenesis of immunothrombosis, and we discuss the potential of extracorporeal therapies using adsorbents functionalized with heparin to deplete platelet-derived and neutrophil-derived mediators of immunothrombosis.