Associations between COVID-19 symptom
In this study, researchers used stored samples and data from 216 participants who donated COVID-19 convalescent plasma (CCP) and whose accompanying symptom data from April 2020 to January 2021 was available. . All of these individuals were over the age of 18 and eligible to donate blood, and their average age was 49 at the time of collection.
Plasma samples were analyzed using three serological tests: Euroimmun Anti-SARS-CoV-2 ELISA, CoronaCHEK™ COVID-19 IgG/IgM Rapid Test Cassette which measured immunoglobulin G responses ( IgG) to SARS-CoV-2 peak (S1) and receptor binding domain (RBD), respectively, while the Bio-Rad Platelia SARS-CoV-2 total antibody ELISA measured the total antibody response to the nucleocapsid (N) protein of SARS-CoV-2.
The researchers used multi-array electrochemiluminescence detection technology to screen 35 plasma cytokine and chemokine analytes. They used binomial logistic regressions to calculate odds ratios [ORs] for associations between serology results and reported symptoms; similarly, they calculated adjusted odds ratios [aOR] for all COVID-19 symptoms.
More than 83% of the test samples showed a positive antibody response in all three serological tests. Between 40-60% of people with no symptoms and 73-75% with sore throats showed relative stability in all three tests.
Regardless of symptom presentation, antibodies produced by the CCP responded similarly to different parts of SARS-CoV-2, and test reactivity was consistent across all COVID-19 symptoms. Additionally, hospitalization, male gender, and persistent cough were associated with seropositive outcomes, suggesting that recovering individuals with these symptoms most likely generated a robust antibody response.
Signal/threshold (S/C) ratio results were generated for the Euroimmun and BioRad ELISAs. They were stratified by five symptoms of COVID-19: cough, sore throat, no symptoms, and other symptoms. For the Bio-Rad test, people reporting a cough or other symptoms had the highest mean S/C ratio, and those with a sore throat and no symptoms had the lowest mean S/C ratio. For the Euroimmune test, the highest S/C ratios were generated by samples from individuals reporting cough, other symptoms, sore throat, and no symptoms.