A virus-derived microRNA-like small RNA serves as a serum biomarker to prioritize the COVID-19 patients at high risk of developing severe disease
Zheng Fu, Jian Wang, Zheng Wang, Ying Sun, Jian Wu, Yongchen Zhang, Xingxiang Liu, Zhen Zhou, Likun Zhou, Chen‐Yu Zhang, Yongxiang Yi, Xinyi Xia, Lin Wang, Xi Chen
Abstract
The COVID-19 outbreak has caused a health crisis and economic hardship across the world, and the sudden deterioration of COVID-19 patients into a severe type of illness is a major cause of the high mortality in current pandemic. Since medical facilities do not have reliable biomarkers to predict likelihood of disease progression and identify high-risk patients that require immediate medical attention, patients can only be treated after the appearance of severe symptoms, thereby missing the best treatment window. Furthermore, because patients cannot be stratified at admission, they have to be quarantined and treated without screening, which often leads to high pressure on healthcare services and overwhelming of medical resources. Therefore, it is urgent to develop a biomarker that can accurately predict the severity and prognosis of COVID-19 patients in their pre-severe stage, thereby improving treatment outcome, reducing mortality rate, and assuring proper use of the limited medical resources. Recent studies by us and others have demonstrated that microRNAs (miRNAs), a group of small, single-stranded, noncoding RNAs produced by eukaryotic cells and viruses, circulate in human blood in a highly stable, cell-free form 1 , 2 . Our further studies have demonstrated that RNA viruses (Ebola 3 and H5N1 4 ) can encode miRNA-like small RNAs (milRNAs) and that circulating viral milRNAs can be exploited for early diagnosis of viral infection and prediction of prognosis 3 . Here, we identified SARS-CoV-2-encoded milRNAs in patients’ sera and evaluated their potential in predicting high-risk individuals before manifestation of severe symptoms.