Analysis of the Morphology of Monocytes and Lymphocytes from COVID-19 Patients Using Low-Voltage Scanning Electronic Microscopy.

Severe course of COVID-19 is largely determined by hyperactivation of the immune system, or cytokine storm, in which immune cells (lymphocytes, monocytes, etc.) play a major role. Using low-voltage scanning electron microscopy, we studied the morphology of lymphocytes and monocytes during cytokine storm. Monocytes and lymphocytes were isolated by fluorescence sorting from the blood of healthy volunteers (n=6) and patients with COVID-19 (n=5) during cytokine storm (IL-6>23 ng/ml, smear positive for SARS-CoV-2). For each patient, 11-32 individual cells were analyzed at magnification of 18-32,000 times. Measurements showed that monocyte size was increased during cytokine storm (p=0.0001).