Seraph 100 Hemoperfusion for Management of Severe COVID-19: Assessment of Serum and Plasma Analytes Pre- and Post-Filtration

Introduction: We report an Intervention/outcome study of 33 severe COVID-19 subjects who received Seraph 100 Microbind Affinity Blood Filter (Seraph 100) hemoperfusion therapy (15 survivors, 18 non-survivors) under emergency authorization from the FDA. Our objective was to determine if Seraph 100 hemoperfusion reduces SARS-CoV-2 RNA titers and/or markers of inflammation and/or epi/ endothelial damage. Methods: Viral RNA and 78 protein analytes related to endothelial/epithelial damage and/or inflammation were quantified in systemic blood samples from 33 severe COVID-19 subjects collected upon intensive care unit (ICU) admission and then immediately before and after blood passed through the heparin-based Seraph 100 filter at two time points on the first day of hemoperfusion. Viral RNA titers were quantified using droplet digital PCR. Protein analytes were quantified using multiplex/multianalyte panels on MesoScale Discovery and ProteinSimple Ella platforms. Results: A total of 15/33 subjects had detectable viral RNA in baseline samples (shortly after ICU admission). These initial viremia levels were low, and they did not change uniformly post-perfusion. Five of 55 protein analytes that were upregulated 1.4–120X at ICU admission relative to healthy controls showed significant decreases across the filter during the indicated time points on the first day of hemoperfusion: IP-10/CXCL10, fms-like tyrosine kinase 1, MIG/CXCL9, hepatocyte growth factor (HGF), and receptor for advanced glycosylation end products (RAGE). Paired t tests identified 25 additional analytes that showed significant decreases (p < 0.05) only without Bonferroni correction. Conclusion: Initial freely circulating SARS-CoV-2 RNA levels of ICU-admitted subjects were low or undetectable. The Seraph 100 filter did not significantly reduce viral RNA titers in their plasma. However, multiple circulating proteins with roles in inflammation, endothelial/ epithelial damage, and/or angiogenesis decreased significantly across the filter. Larger prospective trials will be required to determine if such transient reductions translate into improved patient outcomes. However, this study did not demonstrate a direct reduction of free SARS-CoV-2 viral RNA by the Seraph 100.