Early antibody response to SARS-CoV-2

Dittadi, R.; Afshar, H.; Carraro, P.

Background. The role and significance of the immune response to SARS-CoV-2 infection is not yet well known. Methods. We therefore conducted a study on 46 symptomatic subjects with disease ascertained by laboratory tests to evaluate the presence of IgG and IgM antibodies in these subjects in relation to the time elapsed since the onset of symptoms. The analytical performance of the method used in the study (Maglumi 800, SNIBE, China) and the effect of two different serum and plasma matrices were also assessed. Results. IgG positivity was demonstrated in 100% of cases 15 days after the onset of the disease. IgM show lower concentrations and do not exceed 77% of cases after 15 days. The analytical performance of the method used was confirmed to be good in terms of imprecision, linearity, commutability in two blood sample matrices. Conclusion. The serological study through the search for specific IgG for SARS-CoV-2 results in our case series is sensitive and suitable for population research and can also play a role in diagnosis. The diagnostic performance of specific IgMs are lower.