AUTHOR=Hou Haifeng , Yang Huan , Liu Pengcheng , Huang Changwu , Wang Meng , Li Yuejin , Zhu Mingsong , Wang Jing , Xu Yuan , Wang Youxin , Ma Qingwei , Li Dong , Liao Pu , Wang Wei 

TITLE=Profile of Immunoglobulin G N-Glycome in COVID-19 Patients: A Case-Control Study

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.748566

DOI=10.3389/fimmu.2021.748566

ISSN=1664-3224

ABSTRACT=<p>Coronavirus disease 2019 (COVID-19) remains a major health challenge globally. Previous studies have suggested that changes in the glycosylation of IgG are closely associated with the severity of COVID-19. This study aimed to compare the profiles of IgG <italic>N</italic>-glycome between COVID-19 patients and healthy controls. A case-control study was conducted, in which 104 COVID-19 patients and 104 age- and sex-matched healthy individuals were recruited. Serum IgG <italic>N</italic>-glycome composition was analyzed by hydrophilic interaction liquid chromatography with the ultra-high-performance liquid chromatography (HILIC-UPLC) approach. COVID-19 patients have a decreased level of IgG fucosylation, which upregulates antibody-dependent cell cytotoxicity (ADCC) in acute immune responses. In severe cases, a low level of IgG sialylation contributes to the ADCC-regulated enhancement of inflammatory cytokines. The decreases in sialylation and galactosylation play a role in COVID-19 pathogenesis <italic>via</italic> the activation of the lectin-initiated alternative complement pathway. IgG <italic>N</italic>-glycosylation underlines the complex clinical phenotypes of SARS-CoV-2 infection.</p>