Differential Reactivity of Anti-SARS-CoV-2 IgM/IgG in Response to Disease Onset in an Egyptian Cohort

Background:During an epidemic, it is neither economic nor time-saving to just rely on molecular diagnostics to identify the emerged pathogen and/or monitor response to treatment. Aim and Methodology: In this study we prove if we can distinguish between infection-confirmed (IC; V-qRT-PCR-positive) and infection-unconfirmed (IU; V-qRT-PCR-unchecked) Egyptian cohorts in response to disease onset using IgM/IgG AMP rapid test. Results: The IC individuals were 45 of them 22 were females and 23 were males whereas the IU individuals were 90 of them 47 were females and 43 were males. Of the 22 IC females, 31.8% were IgM positive (MP), 59% were IgG positive (GP) and 31.8% were positive for both antibody classes (MGP). Of the 23 the IC males, 91.3% were MGP and 14.2% were only GP. Of the 47 IU females, 21.2% were MP, 61.7% were GP, and 21.2% were MGP. Of the 43 IU males, 16.2% were MP, 51.1% were GP, and 16.2% were MGP. Studying the association between disease severity grade (DSG) and the IgM/IgG prevalence rates revealed 1) a nonsignificant positive correlation (NS-PC) in IC females, 2) a PC in IU females that was NS for IgM and S for IgG, 3) a nonsignificant negative correlation (NS-NC) in IC males, and 4) a NS-PC for both IgM/IgG in IU males. Conclusion: Detectability of virus-specific IgM/IgG varied among symptomatic/asymptomatic cases and in the individuals of different DSG.