Neutrophils and secondary infections in COVID-19 induced acute respiratory distress syndrome

Abstract

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.

Multi-omic longitudinal study reveals immune correlates of clinical course among hospitalized COVID-19 patients

“…CyTOF analysis also shows a greater frequency of neutrophils in the more severe trajectory groups 4 and 5, a marker of severe COVID-19 outcome as noted previously 55 , 56 and possibly reflecting secondary bacterial infection. 57 Neutrophil influx into the lung may damage lung epithelial cells and contribute to lung pathology, which may be amplified by release of NETs and neutrophil granule contents. In addition, cytokine/chemokine assays (Olink) identified multiple modules associated with disease severity including cytokines produced by neutrophils, pro-inflammatory modules, and activators of macrophages.…”

Bacterial and Fungal Co-Infections and Superinfections in a Cohort of COVID-19 Patients: Real-Life Data from an Italian Third Level Hospital

“…To fight the inflammatory syndrome, many immunomodulant agents are used, such as corticosteroids, anti-interleukin-1 (IL-1), anti-interleukin-6 (IL-6), and inhibitors of the JAK-STAT pathway [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. The use of immune suppressive drugs, combined with the natural immune suppression caused by the virus, can lead to a surge of secondary bacterial and fungal infections [ 8 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”

Heparin-Binding Protein in Bronchoalveolar Lavage Fluid as a Biomarker for Discriminating Severe Bacterial and Viral Pneumonia in Critically Ill Children

“…Carreto-Binaghi et al [12] analyzed cytokines and collectins in BALF samples to investigate the pulmonary immunological response of pneumonia patients infected with Histoplasma capsulatum and Pneumocystis jirovecii. The presence of neutrophils in BALF is considered strongly predictive of a secondary bacterial infection in COVID-19-induced acute respiratory distress syndrome [13]. However, information about the role of HBP in BALF for the differential diagnosis of bacterial pneumonia in critically ill children is scarce.…”