PDF(Pubmed)
Abstract：
In the present study, we show that SARS-CoV-2 can infect palatine tonsils, adenoids, and secretions in children without symptoms of COVID-19, with no history of recent upper airway infection. We studied 48 children undergoing tonsillectomy due to snoring/OSA or recurrent tonsillitis between October 2020 and September 2021. Nasal cytobrushes, nasal washes, and tonsillar tissue fragments obtained at surgery were tested by RT-qPCR, immunohistochemistry (IHC), flow cytometry, and neutralization assay. We detected the presence of SARS-CoV-2 in at least one specimen tested in 27% of patients. IHC revealed the presence of the viral nucleoprotein in epithelial surface and in lymphoid cells in both extrafollicular and follicular regions, in adenoids and palatine tonsils. Also, IHC for the SARS-CoV-2 non-structural protein NSP-16 indicated the presence of viral replication in 53.8% of the SARS-CoV-2-infected tissues. Flow cytometry showed that CD20+ B lymphocytes were the most infected phenotypes, followed by CD4+ lymphocytes and CD123 dendritic cells, CD8+ T lymphocytes, and CD14+ macrophages. Additionally, IF indicated that infected tonsillar tissues had increased expression of ACE2 and TMPRSS2. NGS sequencing demonstrated the presence of different SARS-CoV-2 variants in tonsils from different tissues. SARS-CoV-2 antigen detection was not restricted to tonsils but was also detected in nasal cells from the olfactory region. Palatine tonsils and adenoids are sites of prolonged RNA presence by SARS-CoV-2 in children, even without COVID-19 symptoms. IMPORTANCE This study shows that SRS-CoV-2 of different lineages can infect tonsils and adenoids in one quarter of children undergoing tonsillectomy. These findings bring advancement to the area of SARS-CoV-2 pathogenesis, by showing that tonsils may be sites of prolonged infection, even without evidence of recent COVID-19 symptoms. SARS-CoV-2 infection of B and T lymphocytes, macrophages, and dendritic cells may interfere with the mounting of immune responses in these secondary lymphoid organs. Moreover, the shedding of SARS-CoV-2 RNA in respiratory secretions from silently infected children raises concern about possible diagnostic confusion in the presence of symptoms of acute respiratory infections caused by other etiologies.
摘要：
在本研究中,我们证明SARS-CoV-2可以感染腭扁桃体，腺样体，无COVID-19症状，近期无上呼吸道感染史的儿童分泌物。我们研究了在2020年10月至2021年9月期间因打鼾/OSA或复发性扁桃体炎而接受扁桃体切除术的48名儿童。鼻细胞刷，洗鼻剂,通过RT-qPCR检测手术获得的扁桃体组织碎片，免疫组织化学（IHC），流式细胞术,和中和测定。我们检测到SARS-CoV-2存在于27%的患者中的至少一个测试样本中。IHC显示上皮表面和滤泡外和滤泡区域的淋巴样细胞中存在病毒核蛋白，腺样体和腭扁桃体。此外，SARS-CoV-2非结构蛋白NSP-16的IHC表明在53.8％的SARS-CoV-2感染的组织中存在病毒复制。流式细胞术显示CD20+B淋巴细胞是最多的感染表型，其次是CD4+淋巴细胞和CD123树突状细胞，CD8+T淋巴细胞，和CD14+巨噬细胞。此外,图IF表明感染的扁桃体组织具有增加的ACE2和TMPRSS2的表达。NGS测序证明来自不同组织的扁桃体中存在不同的SARS-CoV-2变体。SARS-CoV-2抗原检测不仅限于扁桃体，还可以在嗅觉区域的鼻细胞中检测到。腭扁桃体和腺样体是SARS-CoV-2在儿童中延长RNA存在的部位，即使没有COVID-19症状。重要性这项研究表明，不同谱系的SRS-CoV-2可感染1/4扁桃体切除术儿童的扁桃体和腺样体。这些发现为SARS-CoV-2发病机制领域带来了进步，通过显示扁桃体可能是长期感染的部位，即使没有近期COVID-19症状的证据。SARS-CoV-2感染B和T淋巴细胞,巨噬细胞，树突状细胞可能会干扰这些次级淋巴器官中免疫反应的产生。此外，在默默地感染儿童的呼吸道分泌物中,SARS-CoV-2RNA的脱落引发了人们的担忧,即在出现由其他病因引起的急性呼吸道感染症状时,可能存在诊断混乱.
