Evaluations of serological test in the diagnosis of 2019 novel coronavirus (SARS-CoV-2) infections during the COVID-19 outbreak

Dachuan Lin; Lei Liu; Mingxia Zhang; Yunlong Hu; Qianting Yang; Jiubiao Guo; Youchao Dai; Yuzhong Xu; Yi Cai; Xinchun Chen; Kaisong Huang; Zheng Zhang

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10. 1101 /2020 2 in both IgM and IgG testing manners was seen in our chemiluminescence method, suggesting a 186 higher sensitivity of our approach compared to the tested ELISA kit (Table 3, that a single IgG testing is feasible in the clinical diagnosis for SARS-CoV-2, as a higher specificity and 199 sensitivity were observed in our chemiluminescence method. In the humoral immune response, the 200 antibody IgM was generally produced earlier than the IgG isotype as the IgM can be expressed 201 without the isotype switching. Unexpectedly, we only observed a slight detection rate difference (not 202 statistically significant) between these two antibody isotype testing manner in patients in the first 203 week or more than two weeks after onset of disease. However, compared to the IgG approach, our 204 IgM method showed a lower specificity (higher false-positive cases) in our testing. As the IgM and IgG 205 . CC-BY-NC 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.