key: cord-283909-xwy3rm3f
authors: Lippi, Giuseppe; Henry, Brandon M
title: Eosinophil count in severe coronavirus disease 2019 (COVID-19)
date: 2020-04-21
journal: QJM
DOI: 10.1093/qjmed/hcaa137
sha: 
doc_id: 283909
cord_uid: xwy3rm3f

nan

We read with interest the article of Qian et al, 1 who showed a trend, though nonsignificant, towards eosinopenia in patients with coronavirus disease 2019 (COVID-19).

Therefore, we carried out a systematic literature search to identify additional studies which addressed this clinically and biologically important aspect.

We conducted an electronic search in Medline, Scopus and Web of Science, with the keywords "Leukocytes" OR "White Blood Cells" OR "Eosinophils" AND "coronavirus disease 2019" OR "COVID-19" without date (i.e., up to March 18, 2020) and language limits. All articles were accurately screened by the two authors, and those reporting data on the eosinophil count in patients with or without severe form of COVID-19 were included in a pooled analysis. The reference list of each document that could be identified with our search criteria was also hand-searched for detecting other eligible studies. A pooled analysis was then carried out, with calculation of the weighted mean difference (WMD) and 95% confidence interval (95% CI) of eosinophil count in patients with or without the severe form of COVID-19. Mean and standard deviation used for calculating the WMD were extrapolated from sample size, median and interquartile range (IQR), as suggested by Hozo et al. 2 The statistical analysis was performed with MetaXL software Version 5.3 (EpiGear International Pty Ltd., Sunrise Beach, Australia). This study was carried out in accordance with the declaration of Helsinki and with the term of local legislation.

Overall, 26 articles were originally identified using our search criteria.

Following elimination of duplicates, 24 were excluded after title, abstract or full text screening, since they were not pertinent to COVID-19 disease (n=18), were literature reviews (n=2), editorial material (n=1), or did not reported the eosinophil count in COVID-19 patients with or without severe disease (n=3). Two additional studies were found from the reference list of the previously identified documents, such that a final https://mc.manuscriptcentral.com/qjm total of 4 articles were included. 1,3-5 However, one of these studies was excluded as it failed to provide necessary values for calculating the WMD (i.e., the eosinophil count was below the limit of measurement in both cohort of patients with and without severe COVID-19). 5 Overall, the three remaining studies included 294 patients, 75 of whom (25.5%) with severe COVID-19. 1, 3, 4 All studies were based in China, severe disease was defined as onset of respiratory distress in two studies 1, 4 and need of mechanical ventilation in the remaining. 3 The results of the pooled analysis is shown in figure 1 , attesting that the eosinophil count was not found to be significantly different between patients with or without severe COVID-19 (WMD, -0.01×10 9 ; 95% CI, -0.07 to 0.04×10 9; I2, 0%; Weighted mean difference (WMD) and 95% confidence interval (95% CI) of eosinophil count in patients with or without severe coronavirus disease 2019 (COVID-19). 1, 3, 4 

Epidemiologic and Clinical Characteristics of 91 Hospitalized Patients with COVID-19 in Zhejiang, China: A retrospective, multi-centre case series

Estimating the mean and variance from the median, range, and the size of a sample

Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan, China

Clinical Features of 69 Cases with Coronavirus Disease

Dysregulation of immune response in patients with COVID-19 in Wuhan, China