Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA.
Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
Pediatr Res. 2021 Nov;90(5):1023-1030. doi: 10.1038/s41390-021-01364-2. Epub 2021 Jan 27.
In infants admitted to an ICU with respiratory failure, there is an association between the ratio of CD8 to CD4 T cells within the upper respiratory tract and disease severity. Whether this ratio is associated with respiratory disease severity within children presenting to a pediatric emergency department is not known.
We studied a convenience sample of 63 children presenting to a pediatric emergency department with respiratory symptoms. T cell subsets in the nasal mucosa were analyzed by flow cytometry. We compared CD4 and CD8 T cells subsets in these samples and analyzed the proportion of these subsets that expressed markers associated with tissue residency.
We were able to identify major subsets of CD8 and CD4 T cells within the nasal mucosa using flocked swabs. We found no difference in the ratio CD8 to CD4 T cells in children with upper or lower respiratory illness. A positive association between tissue-resident memory T cell frequency and patient age was identified.
In our patient populations, the CD8:CD4 ratio was not associated with disease severity. The majority of T cells collected on nasal swabs are antigen experienced, and there is an association between the frequency of tissue-resident T cells and age.
Immune cell populations from the nasal mucosa can be captured using flocked nasal swabs and analyzed by flow cytometry. Nasal CD8:CD4 ratio does not predict respiratory illness severity in children presenting to the emergency department. The frequency of CD8 and CD4 resident memory T cells within the nasal mucosa increases with age.
在因呼吸衰竭而住进 ICU 的婴儿中，上呼吸道内 CD8 与 CD4 T 细胞的比值与疾病严重程度相关。而在因呼吸问题而到儿科急诊就诊的儿童中，这一比值是否与呼吸疾病的严重程度相关，目前尚不清楚。
我们对 63 名因呼吸症状而到儿科急诊就诊的儿童进行了一项便利抽样研究。通过流式细胞术分析鼻黏膜中的 T 细胞亚群。我们比较了这些样本中 CD4 和 CD8 T 细胞亚群，并分析了表达组织驻留相关标志物的这些亚群的比例。
我们使用植绒拭子成功地在鼻黏膜中鉴定出了 CD8 和 CD4 T 细胞的主要亚群。我们未发现上呼吸道或下呼吸道疾病患儿的 CD8/CD4 T 细胞比值存在差异。组织驻留记忆 T 细胞频率与患者年龄呈正相关。
在我们的患者群体中，CD8:CD4 比值与疾病严重程度无关。鼻拭子采集的 T 细胞多数具有抗原经验，组织驻留 T 细胞的频率与年龄相关。
使用植绒鼻拭子可以采集鼻黏膜中的免疫细胞群体，并通过流式细胞术进行分析。鼻 CD8:CD4 比值不能预测儿科急诊就诊患儿的呼吸疾病严重程度。鼻黏膜内 CD8 和 CD4 组织驻留记忆 T 细胞的频率随年龄增长而增加。
