Eosinophils and Chronic Respiratory Diseases in Hospitalized COVID-19 Patients

• Main Authors: Marcela Valverde-Monge, José A. Cañas, Blanca Barroso, Diana Betancor, Laura Ortega-Martin, Alicia Gómez-López, María Jesús Rodríguez-Nieto, Ignacio Mahíllo-Fernández, Joaquín Sastre, Victoria Del Pozo
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-06-01
• Series: Frontiers in Immunology
• Subjects: chronic respiratory diseases; COVID-19; eosinopenia; eosinophils; asthma; COPD (chronic obstructive pulmonary disease)
• Online Access: https://www.frontiersin.org/articles/10.3389/fimmu.2021.668074/full

BackgroundStudies on the role of eosinophils in coronavirus disease 2019 (COVID-19) are scarce, though available findings suggest a possible association with disease severity. Our study analyzes the relationship between eosinophils and COVID-19, with a focus on disease severity and patients with underlying chronic respiratory diseases.MethodsWe performed a retrospective analysis of 3018 subjects attended at two public hospitals in Madrid (Spain) with PCR-confirmed SARS-CoV-2 infection from January 31 to April 17, 2020. Patients with eosinophil counts less than 0.02×109/L were considered to have eosinopenia. Individuals with chronic respiratory diseases (n=384) were classified according to their particular underlying condition, i.e., asthma, chronic pulmonary obstructive disease, or obstructive sleep apnea.ResultsOf the 3018 patients enrolled, 479 were excluded because of lack of information at the time of admission. Of 2539 subjects assessed, 1396 patients presented an eosinophil count performed on admission, revealing eosinopenia in 376 cases (26.93%). Eosinopenia on admission was associated with a higher risk of intensive care unit (ICU) or respiratory intensive care unit (RICU) admission (OR:2.21; 95%CI:1.42-3.45; p<0.001) but no increased risk of mortality (p>0.05).ConclusionsEosinopenia on admission conferred a higher risk of severe disease (requiring ICU/RICU care), but was not associated with increased mortality. In patients with chronic respiratory diseases who develop COVID-19, age seems to be the main risk factor for progression to severe disease or death.