Plasma Biomarkers Associated to Outcome in Patients with Sars-Cov-2 Infection

Abstract

Background: A serious consequence of respiratory infections with SARS-CoV-2 is Acute Kidney Injury (AKI). The aim of this study was to evaluate some novel biomarkers measured in plasma for their associations with the outcome of this infection as to AKI and mortality. Methods: Four different HNL (Human Neutrophil Lipocalin) assays were constructed using different antibody configurations, reflecting both neutrophil and epithelial cell activities. TK-1 (Thymidine kinase-1) was measured as a sign of cell destruction and proliferation. For comparison the plasma concentrations of NGAL (Neutrophil Gelatinase Associated Lipocalin), the cytokines IL-6, IL-8 and IFN-γ and of cystatin C, and procalcitonin were also measured. One hundred and three patients with severe respiratory failure admitted to the ICU were sampled for blood at admittance and at day three (n=67) after admittance. Results: Sixty-five percent of the patients developed AKI. The performance of the HNL assay 763/8F was most closely associated to outcome as to AKI and mortality with Area Under the Receiver Operating Characteristics Curve (AUC) of 0.87 and a sensitivity of 80% and a specificity of 88% in COVID-19 patients with and without severe AKI (p<0.0001). TK-1 was significantly related to the development of AKI (p=0.01) and the three cytokines were related to mortality (p=0.004-p<0.001). Conclusion: The HNL variant 763/8F and TK-1 are novel biomarkers that might become useful and novel tools in the management of COVID-19 patients, but likely also in other patients affected by AKI.