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/multi-analyte 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.