Assessment of the levels of antispike SARS-CoV-2 IgG antibodies and their association with clinical characteristics in cohort of patients in Saudi Arabia

Background: Coronavirus disease 2019 (COVID-19) has caused a global public health crisis. The disease is known to be caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, but the detailed characteristics of the immune response to this novel virus have not been fully elucidated yet. In this study, we aimed to determine the level of immunoglobulin G (IgG) antibodies and their correlation with clinical features at three time points postinfection in a group of patients in Saudi Arabia. Method: In this prospective observational study, we collected the demographic and clinical data from 43 polymerase chain reaction (PCR)-confirmed patients and measured the COVID-19 antispike IgG levels at three different visits. Result: The seroconversion rate after COVID-19 infection was 88.4% in the study participants, with no significant changes in the IgG levels through the three visits. The duration of shortness of breath had a significant positive correlation with the IgG level of the patients. Using the logistic regression model, participants having coughs were found to be 12.48 times more likely to develop positive IgG. The IgG levels were less in smokers than nonsmokers [Odds ratio = 6.42 (95% CI 2.11-19.48); P = 0.001]. Conclusion: Positive IgG levels have been developed in most COVID-19 patients and did not significantly change over 3 months following the diagnosis. The level of IgG antibodies was found to be significantly associated with the presence of cough, duration of shortness of breath, and the smoking habit of the patients. These findings have clinical and public health significance and need to be validated in larger studies in different populations.