Myeloid-derived suppressor cells in the blood of Iranian COVID-19 patients

BackgroundA cytokine storm and lymphopenia are reported in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection associated with coronavirus disease 2019 (COVID-19). Myeloid-derived suppressive cells (MDSCs) exist in two different forms, granulocyte (G-MDSCs) and monocytic (M-MDSCs) that both suppress T-cell function. Serum IL-6 and IL-8 levels seem to correlate with the number of blood MDSCs. ObjectiveTo determine the frequency of MDSCs in severe COVID-19 patients from Iran and their correlations with serum IL-8 levels. Methods37 severe (8 on ventilation, 29 without ventilation) and 13 moderate COVID-19 patients together with 8 healthy subjects were enrolled at the Masih Daneshvari Hospital, Tehran-Iran between 10th April 2020-9th March 2021. Clinical and biochemical features, serum and whole blood were obtained. CD14, CD15, CD11b and HLA-DR expression on MDSCs was measured by flow cytometry. ResultsM-MDSCs (P[≤]0.0001) and G-MDSCs (P[≤]0.0001) frequency were higher in Iranian COVID-19 patients compared to healthy subjects. M-MDSC frequency was higher in non-ventilated compared to moderate COVID-19 subjects (P=0.004). Serum IL-8 levels were higher in patients with COVID-19 than in normal healthy subjects (P=0.03). IL8 level was significant difference in ventilated, non-ventilated and moderate patients (P=0.005). The frequency of G-MDSCs correlated negatively with INR (r=-0.39, P=0.02). ConclusionSerum IL-8 levels did not correlate with the number of systemic MDSCs in COVID-19 patients. The highest levels of M-MDSCs were seen in the blood of severe non-ventilated patients. MDSC frequency in blood in the current study did not predict the survival and severity of COVID-19 patients.

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

BackgroundSevere 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 30th 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- and IL-6 being reported. TNF- 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, ObjectivesTo elucidate the involvement of serum levels of soluble TNF-Receptor of severe and mild COVID-19 patients to determine for severity of disease. MethodWe 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. ResultsSerum levels of the usually inhibitory soluble TNF- receptor 1 (sTNFR1) were significantly elevated in severe COVID-19 patients at admission to ICU. High serum levels of sTNFR1 were associated with mortality of severe COVID-19 patients treated within ICU. ConclusionsThis pilot study demonstrates for role of STNF-R1 receptor in severity of disease. Future studies should examine whether lower levels of systemic sTNFR1 at admission may indicate a better disease outcome.