Departments of Pathology, Molecular and Cell-Based Medicine, The Icahn School of Medicine at Mount Sinai Hospital, New York, NY, 10029, USA.
Departments of Pathology, Molecular and Cell-Based Medicine, The Icahn School of Medicine at Mount Sinai Hospital, New York, NY, 10029, USA.
Hum Pathol. 2021 Aug;114:110-119. doi: 10.1016/j.humpath.2021.04.012. Epub 2021 May 4.
Coronavirus disease 2019 (COVID-19) is an ongoing pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although viral infection is known to trigger inflammatory processes contributing to tissue injury and organ failure, it is unclear whether direct viral damage is needed to sustain cellular injury. An understanding of pathogenic mechanisms has been handicapped by the absence of optimized methods to visualize the presence and distribution of SARS-CoV-2 in damaged tissues. We first developed a positive control cell line (Vero E6) to validate SARS-CoV-2 detection assays. We then evaluated multiple organs (lungs, kidneys, heart, liver, brain, intestines, lymph nodes, and spleen) from fourteen COVID-19 autopsy cases using immunohistochemistry (IHC) for the spike and the nucleoprotein proteins, and RNA in situ hybridization (RNA ISH) for the spike protein mRNA. Tissue detection assays were compared with quantitative polymerase chain reaction (qPCR)-based detection. SARS-CoV-2 was histologically detected in the Vero E6 positive cell line control, 1 of 14 (7%) lungs, and none (0%) of the other 59 organs. There was perfect concordance between the IHC and RNA ISH results. qPCR confirmed high viral load in the SARS-CoV-2 ISH-positive lung tissue, and absent or low viral load in all ISH-negative tissues. In patients who die of COVID-19-related organ failure, SARS-CoV-2 is largely not detectable using tissue-based assays. Even in lungs showing widespread injury, SARS-CoV-2 viral RNA or proteins were detected in only a small minority of cases. This observation supports the concept that viral infection is primarily a trigger for multiple-organ pathogenic proinflammatory responses. Direct viral tissue damage is a transient phenomenon that is generally not sustained throughout disease progression.
新型冠状病毒病(COVID-19)是由严重急性呼吸系统综合征冠状病毒 2 型(SARS-CoV-2)引起的持续大流行疾病。虽然已知病毒感染会引发炎症过程,导致组织损伤和器官衰竭,但尚不清楚是否需要直接的病毒损伤来维持细胞损伤。由于缺乏优化的方法来可视化受损组织中 SARS-CoV-2 的存在和分布,因此对发病机制的理解受到了阻碍。我们首先开发了一个阳性对照细胞系(Vero E6)来验证 SARS-CoV-2 检测方法。然后,我们使用免疫组织化学(IHC)检测刺突蛋白和核蛋白,以及 RNA 原位杂交(RNA ISH)检测刺突蛋白 mRNA,对来自 14 例 COVID-19 尸检病例的多个器官(肺、肾、心、肝、脑、肠、淋巴结和脾)进行了评估。将组织检测方法与基于定量聚合酶链反应(qPCR)的检测方法进行了比较。在 Vero E6 阳性细胞系对照中,在 14 例肺组织中有 1 例(7%),在其他 59 个器官中均未检测到 SARS-CoV-2(0%)。IHC 和 RNA ISH 结果完全一致。qPCR 证实 SARS-CoV-2 ISH 阳性肺组织中病毒载量很高,而在所有 ISH 阴性组织中均未检测到或病毒载量很低。在死于 COVID-19 相关器官衰竭的患者中,使用组织检测方法通常无法检测到 SARS-CoV-2。即使在显示广泛损伤的肺组织中,也只有少数病例检测到 SARS-CoV-2 病毒 RNA 或蛋白。这一观察结果支持这样一种观点,即病毒感染主要是引发多器官致病炎症反应的触发因素。直接的病毒组织损伤是一种短暂的现象,通常不会在整个疾病过程中持续存在。