The Characterization of Disease Severity Associated IgG Subclasses Response in COVID-19 Patients

• DOI: 10.3389/fimmu.2021.632814
• Publication Date: 2021-03-04T05:09:16Z
• Authors: Huanle Luo; Tingting Jia; Jiamin Chen; Shike Zeng; Zengzhao Qiu; Shu Wu; Xu Li; Yuxuan Lei; Xin Wang; Weihua Wu; Renli Zhang; Xuan Zou; Tiejian Feng; Ruxia Ding; Yue Zhang; Yao-Qing Chen; Caijun Sun; Tian Wang; Shisong Fang; Yuelong Shu
• Keywords: Adult; Male; China; Adolescent; T-Lymphocytes; Immunology; Antibodies, Viral; Severity of Illness Index; Young Adult; 03 medical and health sciences; 0302 clinical medicine; Humans; Child; SARS-CoV-2; COVID-19; antibody response; RC581-607; Middle Aged; host immune response; Immunoglobulin A; 3. Good health; Immunoglobulin M; Immunoglobulin G; cytokine production; Cytokines; disease severity; Female; Immunologic diseases. Allergy

Increasing evidence suggests that dysregulated immune responses are associated with the clinical outcome of coronavirus disease 2019 (COVID-19). Nucleocapsid protein (NP)-, spike (S)-, receptor binding domain (RBD)- specific immunoglobulin (Ig) isotypes, IgG subclasses and neutralizing antibody (NAb) were analyzed in 123 serum from 63 hospitalized patients with severe, moderate, mild or asymptomatic COVID-19. Mild to modest correlations were found between disease severity and antigen specific IgG subclasses in serum, of which IgG1 and IgG3 were negatively associated with viral load in nasopharyngeal swab. Multiple cytokines were significantly related with antigen-specific Ig isotypes and IgG subclasses, and IL-1β was positively correlated with most antibodies. Furthermore, the old patients (≥ 60 years old) had higher levels of chemokines, increased NAb activities and SARS-CoV-2 specific IgG1, and IgG3 responses and compromised T cell responses compared to the young patients (≤ 18 years old), which are related with more severe cases. Higher IgG1 and IgG3 were found in COVID-19 patients with comorbidities while biological sex had no effect on IgG subclasses. Overall, we have identified diseases severity was related to higher antibodies, of which IgG subclasses had weakly negative correlation with viral load, and cytokines were significantly associated with antibody response. Further, advancing age and comorbidities had obvious effect on IgG1 and IgG3.