COVID-19 diagnosis and study of serum SARS-CoV-2 specific IgA, IgM and IgG by a quantitative and sensitive immunoassay

Huan Ma; Weihong Zeng; Hongliang He; Dan Zhao; Yunru Yang; Dehua Jiang; Peigen Zhou; Yingjie Qi; Weihuang He; Changcheng Zhao; Ruting Yi; Xiaofang Wang; Bo Wang; Yuanhong Xu; Yun Yang; Arnaud John Kombe Kombe; Chengchao Ding; Jiajia Xie; Yong Gao; Linzhao Cheng; Yajuan Li; Xiaoling Ma; Tengchuan Jin

We attempted to analyze the kinetics of all the three isotypes of antibodies when multiple serum were significantly older (median age of 62· 5) than those patients with moderate (median age of 46) and 287 mild symptoms (median age of 30). Remarkably, we found that IgA concentrations in severe cases were 288 significantly higher than mild or moderate cases (figure 3A). IgG levels in moderate and severe COVID-289 19 patients were also higher than mild cases (p < 0· 0001) ( figure 3C ). The observation that serum IgG 290 levels were higher in severe and moderate than mild COVID-19 patients have been previously reported 291 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.