ABSTRACT
Severe coronavirus disease 2019 (COVID-19) is characterized by acute respiratory distress syndrome and multiple organ dysfunction, in which the host immune response plays a pivotal role. Excessive neutrophil activation and subsequent superfluity of neutrophil extracellular traps (NETs) can lead to tissue damage, and several studies have shown the involvement of neutrophils in severe COVID-19. However, the detailed responses of each neutrophil subset to SARS-CoV-2 infection has not been fully described. To explore this issue, we incubated normal-density granulocytes (NDGs) and low-density granulocytes (LDGs) with different viral titers of SARS-CoV-2. NDGs form NETs with chromatin fibers in response to SARS-CoV-2, whereas LDGs incubated with SARS-CoV-2 display a distinct morphology with condensed nuclei and moderate transcriptional changes. Based on these transcriptional changes, we suggest that AGO2 possibly plays a role in LDG regulation in response to SARS-CoV-2.
ABSTRACT
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), presents with severe pneumonia and fatal systemic complications. Currently, SARS-CoV-2 vaccines are effective in reducing the risk of new onset and getting worse of the disease. However, autoimmune diseases such as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been reported to develop after COVID-19 vaccine administration. A 71-year-old woman presented with fever, malaise, urinary abnormalities, and renal dysfunction after receiving the COVID-19 vaccine (Pfizer-BioNTech). We clinically diagnosed AAV with her manifestations and serological test (myeloperoxidase-ANCA-positive). Her clinical findings were improved after immunosuppressive therapy. We examined her genetic susceptibility to AAV, and we found that her allele was HLA-DRB1*09:01, which is a risk allele of myeloperoxidase-AAV. Mechanistically, SARS-CoV-2 vaccines would activate immunity, including neutrophils, and trigger AAV onset in this patient with a genetic risk to develop AAV. The pathophysiology of this case would share with that of autoimmune/inflammatory syndrome induced by adjuvants in the absence of external adjuvants.