Background Although the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load in respiratory specimens has been widely used to diagnose coronavirus disease 2019 (COVID-19), it is undeniable that serum SARS-CoV-2 nucleic acid (RNAemia) could be detected in a fraction of COVID-19 patients. However, it is not clear whether testing for RNAemia is correlated with the occurrence of cytokine storms or with the specific class of patients. Methods This study enrolled 48 patients with COVID-19 admitted to the General Hospital of Central Theater Command, People’s Liberation Army, a designated hospital in Wuhan, China. The patients were divided into 3 groups according to the Diagnosis and Treatment of New Coronavirus Pneumonia (sixth edition) guidelines issued by the National Health Commission of China. Clinical and laboratory data were collected, and the serum viral load and interleukin 6 (IL-6) level were determined. Results Analysis of clinical characteristics of 48 cases of COVID-19 showed that RNAemia was diagnosed only in the critically ill group and seemed to reflect the severity of the disease. Furthermore, the level of the inflammatory cytokine IL-6 in critically ill patients increased significantly, almost 10 times that in other patients. More importantly, the extremely high IL-6 level was closely correlated with the detection of RNAemia (R = 0.902). Conclusions Detectable serum SARS-CoV-2 RNA (RNAemia) in patients with COVID-19 was associated with elevated IL-6 concentration and poor prognosis. Because elevated IL-6 may be part of a larger cytokine storm that could worsen outcome, IL-6 could be a potential therapeutic target for critically ill patients with an excessive inflammatory response.

Background:Although the SARS-CoV-2 viral load detection of respiratory specimen has been widely used for novel coronavirus disease diagnosis, it is undeniable that serum SARS-CoV-2 nucleic acid (RNAaemia) could be detected in a fraction of the COVID-19 patients. However, it is not clear that if the incidence of RNAaemia could be correlated with the occurrence of cytokine storm or with the specific class of patients. Methods:This study enrolled 48 patients with COVID-19 admitted to the General Hospital of Central Theater Command, PLA, a designated hospital in Wuhan, China. The patients were divided into three groups according to the Dia gnosis and Treatment of New Coronavirus Pneumonia (version 6) published by the National Health Commission of China. The clinical and laboratory data were collected. The serum viral load detection and serum IL-6 levels were determined. Except for routine statistical analysis, Generalized Linear Models (GLMs) analysis was used to establish a patient status prediction model based on real-time RT-PCR Ct value. Findings:The Result showed that cases with RNAaemia were exclusively confirmed in critically ill patients group and appeared to reflect the illness severity. Further more, the inflammatory cytokine IL-6 levels were significantly elevated in critically ill patients, which is almost 10-folds higher than those in other patients. More importantly, the extremely high IL-6 level was closely correlated with the incidence of RNAaemia (R=0.902) and the vital signs of COVID-19 patients (R= -0.682). Interpretation:Serum SARS-CoV-2 viral load (RNAaemia) is strongly associated with cytokine storm and can be used to predict the poor prognosis of COVID-19 patients.Moreover, our results strongly suggest that cytokine IL-6 should be considered as a therapeutic target in critically ill patients with excessive inflammatory response. All rights reserved. No reuse allowed without permission. the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

We still know very little about how the human immune system responds to SARS-CoV-2. Here we construct a SARS-CoV-2 proteome microarray containing 18 out of the 28 predicted proteins and apply it to the characterization of the IgG and IgM antibodies responses in the sera from 29 convalescent patients. We find that all these patients had IgG and IgM antibodies that specifically bind SARS-CoV-2 proteins, particularly the N protein and S1 protein. Besides these proteins, significant antibody responses to ORF9b and NSP5 are also identified. We show that the S1 specific IgG signal positively correlates with age and the level of lactate dehydrogenase (LDH) and negatively correlates with lymphocyte percentage. Overall, this study presents a systemic view of the SARS-CoV-2 specific IgG and IgM responses and provides insights to aid the development of effective diagnostic, therapeutic and vaccination strategies.