Fig. 4From: Ultrastructural study confirms the formation of single and heterotypic syncytial cells in bronchoalveolar fluids of COVID-19 patientsMature syncytial cells under SEM imaging. Syncytial cells were generated by the fusion of multiple cells of (A) neutrophil origin (confirmed by surface projection), (B) monocytes (identified by smooth surface), and (C) macrophage origin (cytoplasmic projection). ARDS-like COVID-19 patients Mature syncytial cells were observed in severe ARDS-like patients but not in the mild or moderate stage of the disease. White arrow, SARS-CoV-2 virus; B, bacteria (orange arrow).Back to article page