Long pentraxin 3 (PTX3) is an essential component of humoral innate immunity, involved in resistance to selected pathogens and in the regulation of inflammation^1,2,3. The present study was designed to assess the presence and significance of PTX3 in Coronavirus Disease 2019 (COVID-19)^4,5,6,7. RNA-sequencing analysis of peripheral blood mononuclear cells, single-cell bioinformatics analysis and immunohistochemistry of lung autopsy samples revealed that myelomonocytic cells and endothelial cells express high levels of PTX3 in patients with COVID-19. Increased plasma concentrations of PTX3 were detected in 96 patients with COVID-19. PTX3 emerged as a strong independent predictor of 28-d mortality in multivariable analysis, better than conventional markers of inflammation, in hospitalized patients with COVID-19. The prognostic significance of PTX3 abundance for mortality was confirmed in a second independent cohort (54 patients). Thus, circulating and lung myelomonocytic cells and endothelial cells are a major source of PTX3, and PTX3 plasma concentration can serve as an independent strong prognostic indicator of short-term mortality in COVID-19.

Long pentraxin 3 (PTX3) 是体液先天免疫的重要组成部分，参与对选定病原体的抵抗和炎症^1,2,3的调节。本研究旨在评估 PTX3 在 2019 年冠状病毒病 (COVID-19) 中的存在和意义^4,5,6,7. 外周血单个核细胞的 RNA 测序分析、单细胞生物信息学分析和肺尸检样本的免疫组织化学显示，骨髓单核细胞和内皮细胞在 COVID-19 患者中表达高水平的 PTX3。在 96 名 COVID-19 患者中检测到 PTX3 血浆浓度升高。在多变量分析中，PTX3 成为 COVID-19 住院患者 28 天死亡率的强独立预测因子，优于传统的炎症标志物。在第二个独立队列（54 名患者）中证实了 PTX3 丰度对死亡率的预后意义。因此，循环和肺骨髓单核细胞和内皮细胞是 PTX3 的主要来源，