NEUTROPHILS and SECONDARY INFECTIONS in COVID-19 INDUCED acute respiratory distress syndrome

Holliday, Zachary M.; Alnijoumi, Mohammed M.; Reed, Mark A.; Earhart, Alexander P.; Schrum, Adam G.; Allen, Lee-Ann H.; Krvavac, Armin

Background SARS-CoV-2 virus is the cause of the current global pandemic and has affected more than 188 countries worldwide. Infection by the virus can have diverse clinical manifestations with one of the most severe clinical manifestation being respiratory failure and the development of acute respiratory distress syndrome. Clinical manifestations of acute respiratory distress syndrome secondary to SARS-CoV-2 are also diverse with a lack of diagnostic tools to distinguish between primary viral infection and secondary bacterial infections. Methods Single center, retrospective case-control study of bronchoalveolar lavage fluid cell counts, flow cytometry and culture results from mechanically ventilated patients with SARS-CoV-2 (COVID-19) pneumonia and acute respiratory distress syndrome. Results Neutrophils were the predominant cell type in bronchoalveolar fluid samples up to two weeks into mechanical ventilation. There also was a strong correlation between positive respiratory cultures and significant elevation in bronchoalveolar fluid neutrophil counts/percentages and serum c-reactive protein (CRP) levels. Absolute levels of T cell subtypes correlated with reduced lung compliance measurements. Conclusion Patients with SARS-CoV-2 and severe respiratory disease are at risk for secondary infections. In some COVID-19 patients, serum CRP and bronchoalveolar fluid neutrophils may be correlated with a secondary infection.