Increased serum levels of soluble TNF-α receptor is associated with mortality of ICU COVID-19 patients

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has spread to almost 100 countries, infected over 10M patients and resulted in 505K deaths worldwide as of 30 th June 2020. The major clinical feature of severe COVID-19 requiring ventilation is acute Respiratory Distress Syndrome (ARDS) with multi-functional failure as a result of a cytokine storm with increased serum levels of cytokines such as TNF-α and IL-6 being reported. TNF-α levels are increased during the cytokine storm in very ill patients and soluble receptors for IL-6 and IL-2 are present in the blood of COVID-19 patients, Objectives To elucidate the involvement of serum levels of soluble TNF-Receptor of severe and mild COVID-19 patients to determine for severity of disease. Method We recruited16 severe COVID-19 patients in the ICU on ventilator support and 26 milder COVID-19 patients who were hospitalised but not within the intensive care unit (ICU) between March-May 2020 at the Masih Daneshvari Hospital Tehran, Iran. After harvesting of whole blood the serum was isolated and soluble TNF-Receptor levels measured by ELISA. Results Serum levels of the usually inhibitory soluble TNF-α receptor 1 (sTNFαR1) were significantly elevated in severe COVID-19 patients at admission to ICU. High serum levels of sTNFαR1 were associated with mortality of severe COVID-19 patients treated within ICU. Conclusions This pilot study demonstrates for role of STNF-αR1 receptor in severity of disease. Future studies should examine whether lower levels of systemic sTNFαR1 at admission may indicate a better disease outcome.