Asthma is a complex disease with variable course. Efforts to identify biomarkers to predict asthma severity, the course of disease and response to treatment have not been very successful so far. We have previous suggested that PAR-2 and CRTh2 expression on specific peripheral blood cell subtypes may be biomarkers of asthma severity. We reasoned that parameters that remain stable when asthma symptoms are controlled would be the most appropriate to evaluate for their utility to predict loss of asthma control and/or severity of the disease. Nineteen stable asthmatics were recruited from the University of Alberta Asthma clinic and followed in clinic every 3 months for a total of 4 visits. Patients had spirometry and completed the ACQ questionnaire in every visit. Blood was drawn in every visit and analyzed for a number of immune parameters by flow cytometry. These parameters included PAR-2 and CRTh2 expression on monocyte subgroups and T lymphocytes respectively, as well as numbers of eosinophils, innate lymphoid type-2 cells (ILC2) and dendritic cells. Within person stability of immune and physiological parameters was calculated using the intraclass correlation (ICC) using R version 3.4.0. FEV1 (% predicted), FEV1/FVC ratio, ACQ5 and ACQ7 did not differ significantly over the 4 visits, as would be expected for patients with stable asthma. Peripheral blood eosinophil numbers by Kimura stain and by flow cytometry showed ICC scores of 0.44 and 0.52 respectively, indicating moderate stability. The % of ILC2 cells in peripheral blood also showed moderate stability [ICC score of 0.45 (0.14–0.67)]. The stability for all other immune parameters was poor. Among the peripheral blood immune parameters we studied, only numbers of eosinophils and ILC2 in peripheral blood were moderately stable over a year in stable asthmatics. Further studies are required to understand the reasons for the variability of the other cell types.

中文翻译：

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哮喘患者外周血免疫标志物的稳定性

哮喘是一种病程多变的复杂疾病。迄今为止，识别生物标志物以预测哮喘严重程度、病程和对治疗的反应的努力还不是很成功。我们之前曾提出，特定外周血细胞亚型上的 PAR-2 和 CRTh2 表达可能是哮喘严重程度的生物标志物。我们推断，当哮喘症状得到控制时保持稳定的参数将最适合评估其预测哮喘控制丧失和/或疾病严重程度的效用。从阿尔伯塔大学哮喘诊所招募了 19 名稳定的哮喘患者，每 3 个月在诊所进行一次随访，共 4 次就诊。患者进行肺活量测定并在每次访问中完成 ACQ 问卷。每次就诊时抽取血液，并通过流式细胞术分析许多免疫参数。这些参数分别包括单核细胞亚群和 T 淋巴细胞上的 PAR-2 和 CRTh2 表达，以及嗜酸性粒细胞、先天淋巴细胞 2 型细胞 (ILC2) 和树突状细胞的数量。使用 R 版本 3.4.0 使用组内相关性 (ICC) 计算免疫和生理参数的人体内稳定性。FEV1（预测百分比）、FEV1/FVC 比率、ACQ5 和 ACQ7 在 4 次就诊中没有显着差异，正如对稳定哮喘患者所预期的那样。木村染色和流式细胞仪测得的外周血嗜酸性粒细胞数分别显示 ICC 评分为 0.44 和 0.52，表明稳定性中等。外周血中 ILC2 细胞的百分比也显示出中等稳定性 [ICC 评分为 0.45 (0.14–0.67)]。所有其他免疫参数的稳定性都很差。在我们研究的外周血免疫参数中，只有外周血中嗜酸性粒细胞和 ILC2 的数量在一年内在稳定的哮喘患者中适度稳定。需要进一步的研究来了解其他细胞类型变异的原因。