Preliminary study of cd64 on monocytes and neutrophils in children with severe SARS-CoV-2 infection: Comparison with other viruses and bacteria

ABSTRACT

AIMS & OBJECTIVES: The immune response to SARSCoV-2 is not completely understood. The flow cytometry (FC) allows measuring leukocyte populations instantaneously. One of the better-studied molecules is the immunoglobulin-Fc fragment receptor I (FcγRI) or CD64. Its expression informs about the patient immune status. The aim of this study was to describe the CD64 expression in healthy children requiring pediatric intensive care unit (PICU) admission because of SARS-COV-2 infection. Later, we compare it to previous viral or bacterial infections that caused PICU admission in our centre. METHODS: Prospective observational study (March 2020 to May 2020). The percentage of CD64-positive cells and the CD64 mean fluorescence intensity (MFI) on monocytes (mCD64) and neutrophils (nCD64) were determined. The FC was done on a blood sample obtained at PICU admission. Healthy children with positive serology (IgM) or nasopharyngeal swab using real-time reverse transcriptasepolymerase chain reaction were included. The values are expressed as median and range, p < 0.05 was considered statistically significant. RESULTS: Children from the SARS-CoV-2 group were older (p= 0,000), there were no other baseline differences. CONCLUSIONS: The CD64 expression was higher compared to other causes of PICU admission. It could be linked to immune dysregulation. Prospective observational studies are needed.