biostudies-literatureUnknownZhang YNational Major Science and Technology Projects of ChinaZhejiang Province Natural Science FoundationUnderstanding the immunological characteristics of monocytes-including the characteristics associated with fibrosis-in severe coronavirus disease 2019 (COVID-19) is crucial for understanding the pathogenic mechanism of the disease and preventing disease severity. In this study, we performed single-cell transcriptomic sequencing of peripheral blood samples collected from six healthy controls and 14 COVID-19 samples including severe, moderate, and convalescent samples from three severely/critically ill and four moderately ill patients. We found that the monocytes were strongly remodeled in the severely/critically ill patients with COVID-19, with an increased proportion of monocytes and seriously reduced diversity. In addition, we discovered two novel severe-disease-specific monocyte subsets:Engineering (Beijing, China)https://www.ebi.ac.uk/biostudies/studies/S-EPMC8196473biostudies-literatureIdentification of Monocytes Associated with Severe COVID-19 in the PBMCs of Severely Infected patients Through Single-Cell Transcriptome Sequencing.PMC8196473Xia HXu KHuang CSheng JGuo JZhang YWang SHe KChen YGao HLuo RLi LfalseIdentification of Monocytes Associated with Severe COVID-19 in the PBMCs of Severely Infected patients Through Single-Cell Transcriptome Sequencing.Understanding the immunological characteristics of monocytes-including the characteristics associated with fibrosis-in severe coronavirus disease 2019 (COVID-19) is crucial for understanding the pathogenic mechanism of the disease and preventing disease severity. In this study, we performed single-cell transcriptomic sequencing of peripheral blood samples collected from six healthy controls and 14 COVID-19 samples including severe, moderate, and convalescent samples from three severely/critically ill and four moderately ill patients. We found that the monocytes were strongly remodeled in the severely/critically ill patients with COVID-19, with an increased proportion of monocytes and seriously reduced diversity. In addition, we discovered two novel severe-disease-specific monocyte subsets:2021-01-01T00:00:00Z2021 Jun2025-04-26T05:09:24.261Z2022-02-10T17:45:29.87ZS-EPMC81964733415035210.1016/j.eng.2021.05.009