Elevated Calprotectin and Abnormal Myeloid Cell Subsets Discriminate Severe from Mild COVID-19

摘要

Blood myeloid cells are known to be dysregulated in coronavirus disease 2019(COVID-19),caused by SARS-CoV-2.It is unknown whether the innate myeloid response differs with disease severity and whether markers of innate immunity discriminate high-risk patients.Thus,we performed high-dimensional flow cytometry and single-cell RNA sequencing of COVID-19 patient peripheral blood cells and detected disappearance of non-classical CD14LowCD16High monocytes,accumulation of HLA-DRLow classical monocytes(Human Leukocyte Antigen-DR isotype),and release of massive amounts of calprotectin(S100A8/S100A9)in severe cases.Immature CD10LowCD101-CXCR4+/-neutrophils with an immunosuppressive profile accumulated in the blood and lungs,suggesting emergency myelopoiesis.