Known ethnodemographic risk factors associated with mortality from COVID-19 are linked to the magnitude of serological responses in mild-to-moderate COVID-19, according to the results of a recent study published in BMJ Open Respiratory Research.
Whole blood samples from healthcare workers who had self-isolated from COVID-19 in the United Kingdom were retrospectively tested for the presence of anti-SARS-CoV-2 spike glycoprotein antibodies. These results were interpreted in the context of the symptoms of their original illness and ethnodemographic variables.
Among the 956 healthcare workers included in the analysis, the overall seroprevalence within
the cohort was 46.2%. The seroprevalence of immunoglobulin isotypes was 36.3%, 18.7% and 8.1% for IgG, IgA and IgM, respectively. When associations were examined between seroprevalence and disease, it was determined that increasing age, non-White ethnicity, and obesity were independently associated with greater IgG antibody response against the spike glycoprotein. Furthermore, both self-reported fever and fatigue were associated with greater IgG and IgA responses.
The study authors wrote, “The variables we identify as affecting the antibody response are known population level risk factors for poor outcome, and it is plausible that an immunological mechanism is implicated in disease pathogenesis.” They added, “Further studies must continue to explore these associations, particularly in mild disease, to inform COVID-19 pathogenesis.”
Disclosure: A study author declared affiliations with industry. Please see the original reference for a full list of authors’ disclosures.
Shields AM, Faustini SE, Perez-Toledo M, et al. Serological responses to SARS-CoV-2 following non-hospitalised infection: clinical and ethnodemographic features associated with the magnitude of the antibody response. BMJ Open Resp Res. Published online September 24, 2021. doi:10.1136/bmjresp-2020-000872