Human immunity to SARS-CoV-2 has been characterised extensively; however, our understanding of the immune responses in the lung, the site of infection, is limited. A previous study assessing bronchoalveolar lavage (BAL) samples showed a higher proportion of inflammatory monocytes and macrophages in patients with severe COVID-19 disease. In contrast, the moderate patients showed an accumulation of clonally expanded CD8 T cells.1 The data suggested an enhanced inflammation in the lungs, but paired analysis of peripheral blood and BAL is even more limited.2 In this issue, Saris et al present a study in which the authors characterised the cellular immune composition of paired blood and BAL samples from 17 patients with severe COVID-19 infection, of which 4 patients were deceased.3 They observed a significant increase in monocyte populations in BAL of all patients, consistent with the idea that activated blood monocytes migrate to the …

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肺部对 SARS-CoV-2 的免疫反应

人类对 SARS-CoV-2 的免疫力已被广泛表征；然而，我们对肺部（感染部位）免疫反应的了解是有限的。先前评估支气管肺泡灌洗 (BAL) 样本的研究表明，严重 COVID-19 疾病患者的炎症单核细胞和巨噬细胞比例较高。相比之下，中度患者表现出克隆扩增的 CD8 T 细胞的积累。1 数据表明肺部炎症增强，但外周血和 BAL 的配对分析更加有限。2 在这个问题上，Saris 等人提出了一个在这项研究中，作者对来自 17 名严重 COVID-19 感染患者的配对血液和 BAL 样本的细胞免疫成分进行了表征，其中 4 名患者已死亡。