Supplementary Material for: Combined Extracorporeal Therapy with Pathogen Hemoadsorption and Cell-Directed Immunomodulation Strategies: A Two-Case Series

BACKGROUND: Sepsis remains a critical global health issue, causing multiple organ failure and high mortality rates, despite advances in antimicrobial therapies and supportive care. Extracorporeal blood purification (EBP) techniques have emerged as promising adjunctive strategies for the management of severe infections. The Seraph® 100 Microbind® Affinity Blood Filter (Seraph 100, ExThera Medical, Martinez, CA) targets pathogens, while the Selective Cytopheretic Device (SCD, SeaStar Medical, Denver, CO) neutralizes activated leukocytes. Although individually validated, evidence of the combined use of Seraph 100 and SCD remains scarce. CASE SUMMARY: We present two cases that illustrate the combined use of Seraph 100 and SCD. The first case involves a 43-year-old woman with bacterial pneumonia, septic shock, and acute kidney injury (AKI). She underwent Seraph 100 hemoperfusion followed by SCD therapy, which improved her hemodynamics, oxygenation, and renal function, ultimately leading to full recovery. The second case involved a 31-year-old man with Influenza, severe hypoxemia, and multiorgan failure. Despite advanced therapies, including veno-arterial venous ECMO (VAV-ECMO), Seraph 100, and SCD, his condition deteriorated, resulting in multiorgan failure and eventual death. CONCLUSION: These cases highlight the potential benefits and challenges of combining EBP, such as Seraph 100 and SCD. While successful in one case, the fatal outcome in the second underscores the importance of optimal patient selection, timing, and therapeutic strategies. Further research is needed to evaluate the efficacy of combined EBP and to identify approaches for improving outcomes in critically ill patients.