Objectives

To analyse the diagnostic performance of eosinopenia, alone or combined with polymorphonuclear neutrophils (PMN) and/or lymphocytes, as a marker of active COVID-19 in patients hospitalized for suspicion of SARS-CoV-2 infection.

Methods

A prospective observational study including patients hospitalized for suspicion of COVID-19 in a COVID unit was performed from 20th March to 5th April 2020, in Perpignan, France. Patients for which there was a doubt upon diagnosis, who were recently under oral corticosteroids, had myeloid malignancy or human immunodeficient virus infection were excluded. SARS-CoV-2 detection was performed using an RT-PCR assay, from nasopharyngeal swab specimens. Complete blood count were performed for all patients.

Results

One-hundred and twenty-one patient were included: 57 patients were diagnosed with COVID-19, 64 patients were not. Eosinophil count was lower in the COVID-19 group (median: 0/μL versus 70/μL, p < 0.0001). To diagnose COVID-19, eosinopenia had a sensitivity of 89.5% and a specificity of 78.1% while lymphopenia's were 73.7% and 62.5% respectively. Using area under curve (AUC) of receiving operating characteristics (ROC) curves, eosinophil's optimal cut-off level was 10/μL, sensitivity and specificity were 86%, and 79.7% respectively. Regarding the eosinophil/PMN ratio, the optimal cut-off level was 3.344, sensitivity and specificity were 87.7% and 73.4% respectively. The AUC of lymphocyte/PMN ratio was significantly lower than eosinophil/PMN ratio's (0.621 versus 0.846, p = 0.0003).

Conclusion

Eosinopenia – <10/μL – and eosinophil/PMN ratio are useful, low-cost, reproducible tools to help diagnose COVID-19, during an epidemic period, in a population of hospitalized patients admitted for suspicion of COVID-19.

中文翻译：

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嗜酸性粒细胞减少<100 /μL作为活性COVID-19的标志物：一项观察性前瞻性研究

目标

为了分析因怀疑SARS-CoV-2住院的患者，嗜酸性粒细胞减少症（单独或与多形核中性粒细胞（PMN）和/或淋巴细胞联合）作为活性COVID-19的标志物的诊断性能。

方法

一项前瞻性观察性研究于2020年3月20日至4月5日在法国佩皮尼昂进行了研究，其中包括因怀疑COVID-19而住院的患者。排除了对诊断有疑问的患者，这些患者最近接受口服皮质类固醇激素治疗，患有髓样恶性肿瘤或人类免疫缺陷病毒感染。使用RT-PCR分析从鼻咽拭子样本中进行SARS-CoV-2检测。对所有患者进行全血细胞计数。

结果

包括一百二十一例患者：57例被诊断为COVID-19的患者，64例未被诊断为COVID-19的患者。COVID-19组的嗜酸性粒细胞计数较低（中位数：0 /μL与70 /μL，p <0.0001）。为了诊断COVID-19，曙红减少症的敏感性为89.5％，特异性为78.1％，而淋巴细胞减少症的敏感性分别为73.7％和62.5％。使用接收工作特征（ROC）曲线的曲线下面积（AUC），嗜酸性粒细胞的最佳截断水平为10 /μL，敏感性和特异性分别为86％和79.7％。关于嗜酸性粒细胞/ PMN比率，最佳临界水平为3.344，敏感性和特异性分别为87.7％和73.4％。淋巴细胞/ PMN比值的AUC显着低于嗜酸性粒细胞/ PMN比值（0.621对0.846，p = 0.0003）。

结论

嗜酸细胞减少症（<10 /μL）和嗜酸性粒细胞/ PMN比率是有用的，低成本的，可重现的工具，可在流行期间对因怀疑是COVID-19而住院的患者人群进行诊断，以帮助诊断COVID-19。