COVID-19 Severity Is Associated with Differential Antibody Fc-mediated Innate Immune Functions

Beyond neutralization, antibodies elicit several innate immune functions including complement deposition (ADCD), phagocytosis (ADCP), and cytotoxicity (ADCC). These functions can be both beneficial (by clearing pathogens) and/or detrimental (by inducing inflammation). We tested the possibility that qualitative differences in SARS-CoV-2 specific antibody-mediated innate immune functions contribute to Coronavirus disease 2019 (COVID-19) severity. We found that antibodies from hospitalized COVID-19 patients elicited higher ADCD but lower ADCP compared to antibodies from non-hospitalized COVID-19 patients. Consistently, higher ADCD was associated with higher systemic inflammation during COVID-19. Our study points to qualitative, differential features of anti-SARS-CoV-2 antibodies as potential contributors to COVID-19 severity.