Abstract
Background: During the coronavirus disease 2019 (COVID-19) pandemic, antibody screening is a critical tool to assess anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity. We examined variation in antibody titers associated with age and sex among patients with confirmed COVID-19.
Methods: Blood IgG levels were tested in 1081 patients with positive SARS-CoV-2 quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests between 1 September and 31 December 2020. Patients who did not experience reinfection were identified. Serum IgG levels were measured by immunofluorescence assay. Antibody positivity and antibody titers were analyzed according to time since infection, sex, and age.
Results: The mean (standard deviation) age was 41.2 (14.2) years and 41.2% of patients were women. The lowest antibody positivity rate between the first and ninth month post-infection was detected in the sixth month. The lowest antibody titers among patients aged 20 to 80 years occurred in those aged 30 to 39 years. The IgG titer was positively correlated with age in years (r = 0.125) and decades (r = 0.126).
Conclusions: Six months after infection, anti-SARS-CoV-2 antibody titers increased. Anti-SARS-CoV-2 antibody titers also increased with age. Immunity and pathogenicity should be investigated in addition to antibody positivity rates and antibody titers.
Keywords: Antibody; coronavirus disease 2019; fluorescent antibody technique; immunity; serology; severe acute respiratory syndrome coronavirus-2.
【저자키워드】 Coronavirus disease 2019, Immunity, serology, antibody, severe acute respiratory syndrome coronavirus-2, fluorescent antibody technique, 【초록키워드】 COVID-19, coronavirus disease, SARS-CoV-2, IgG, Coronavirus disease 2019, coronavirus, pandemic, serology, antibody, Variation, Infection, Sex, severe acute respiratory syndrome coronavirus-2, severe acute respiratory syndrome Coronavirus, reverse transcription polymerase chain reaction, polymerase chain reaction, RT-qPCR, Reinfection, anti-SARS-CoV-2 antibody, immunofluorescence assay, Patient, Antibody titer, age, reverse transcription, women, antibody screening, respiratory, pathogenicity, Quantitative, Critical, Antibody titers, fluorescent antibody technique, Coronavirus-2, Chain Reaction, Post-infection, Standard deviation, acute respiratory syndrome, fluorescent antibody, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus-2, fluorescent, positive, polymerase chain, lowest, tested, analyzed, occurred, examined, addition, investigated, were measured, age and sex, IgG level, positively correlated, 【제목키워드】 immunofluorescence, measurement, patients with COVID-19,