The Relationship Between Asthma, Eosinophilia, and Outcomes in COVID-19 Infection

Ho, Kam Sing; Howell, Daniel; Rogers, Linda; Narasimhan, Bharat; Verma, Hannah; Steiger, David

BACKGROUND: The impact of asthma diagnosis and asthma endotype on outcomes from COVID-19 infection remains unclear. OBJECTIVE: To describe the association between asthma diagnosis and endotype and clinical outcomes among patients diagnosed with COVID-19 infection. METHODS: Retrospective multicenter cohort study of outpatients and inpatients presenting to six hospitals in the Mount Sinai Health System New York metropolitan region between March 7 th to June 7 th , 2020, with COVID-19 infection, with and without a history of asthma. The primary outcome assessed was in-hospital mortality. Secondary outcomes included hospitalization, intensive care unit (ICU) admission, mechanical ventilation, and hospital length of stay. Outcomes were compared in patients with or without asthma using a multivariate Cox regression model. Outcomes stratified by blood eosinophilia count were also assessed. RESULTS: Of 10,523 patients diagnosed with COVID-19 infection, 4902 patients were hospitalized, and 468 had a diagnosis of asthma (4.4%). When adjusted for COVID-19 disease severity, comorbidities, and concurrent therapies, patients with asthma had a lower mortality [adjusted odds ratio (OR) 0.64 (0.53-0.77), p<0.001] and a lower rate of hospitalization and ICU admission [OR 0.43 (0.28-0.64) p<0.001 and OR 0.51 (0.41-0.64), p<0.001 respectively]. Those with blood eosinophils ≥200 cells/μL, both with and without asthma, had lower mortality. CONCLUSION: Patients with asthma may be at a reduced risk of poor outcomes from COVID-19 infection. Eosinophilia, both in those with and without asthma, may be associated with reduced mortality risk.