Serological responses to SARS-CoV-2 following non-hospitalised infection: clinical and ethnodemographic features associated with the magnitude of the antibody response

Abstract

ObjectiveTo determine clinical and ethnodemographic correlates of serological responses against the SARS-CoV-2 spike glycoprotein following mild-to-moderate COVID-19.DesignA retrospective cohort study of healthcare workers who had self-isolated due to COVID-19.SettingUniversity Hospitals Birmingham NHS Foundation Trust, UK (UHBFT).Participants956 health care workers were recruited by open invitation via UHBFT trust email and social media.InterventionParticipants volunteered a venous blood sample that was tested for the presence of anti-SARS-CoV-2 spike glycoprotein antibodies. Results were interpreted in the context of the symptoms of their original illness and ethnodemographic variables.ResultsUsing an assay that simultaneously measures the combined IgG, IgA and IgM response against the spike glycoprotein (IgGAM), the overall seroprevalence within this cohort was 46.2% (n=442/956). The seroprevalence of immunoglobulin isotypes was 36.3%, 18.7% and 8.1% for IgG, IgA and IgM respectively. IgGAM identified serological responses in 40.6% (n=52/128) of symptomatic individuals who reported a negative SARS-CoV-2 PCR test. Increasing age, non-white ethnicity and obesity were independently associated with greater IgG antibody response against the spike glycoprotein. Self-reported fever and fatigue were associated with greater IgG and IgA responses against the spike glycoprotein. The combination of fever and/or cough and/or anosmia had a positive predictive value of 92.3% for seropositivity.Conclusions and relevanceAssays employing combined antibody detection demonstrate enhanced seroepidemiological sensitivity and can detect prior viral exposure even when PCR swabs have been negative. We demonstrate an association between known ethnodemographic risk factors associated with mortality from COVID-19 and the magnitude of serological responses in mild-to-moderate disease. The combination of cough, and/or fever and/or anosmia identifies the majority of individuals who should self-isolate for COVID-19.

Diabetes, obesity, metabolism, and SARS-CoV-2 infection: the end of the beginning

“…Analysis of anti-IgG responses directed against the S1 domain in 2,112 persons with confirmed symptomatic SARS-CoV-2 infection at ~63 days after symptom onset revealed that people with overweight or obesity were less likely to be antibody-negative ( Petersen et al., 2020 ). These findings were corroborated by analysis of non-hospitalized individuals with symptoms of COVID-19 and relatively greater IgG responses against the spike protein in people with obesity ( Shields et al., 2020 ).…”

Longitudinal analysis of SARS‐CoV‐2 antibodies in 8000 U.S. first‐time convalescent plasma donations

“…The resulting curvilinear model (Figure 4) confirmed that the highest index S/C values can be expected in plasma from advanced age donors and donations collected soon after COVID-19 recovery. Obesity has been associated with increased COVID-19 severity [28][29][30] and with greater IgG response, 31 and while the current study did not evaluate donor body mass index in relation to SARS-CoV-2 antibody levels in plasma donations, these might be additional factors to be considered in CP collection.…”

“…Obesity has been associated with increased COVID‐19 severity 28–30 and with greater IgG response, 31 and while the current study did not evaluate donor body mass index in relation to SARS‐CoV‐2 antibody levels in plasma donations, these might be additional factors to be considered in CP collection.…”

Antibody response to SARS-CoV-2 infection in humans: A systematic review

“…It is not possible to draw robust conclusions on the associations of antibody response with age, sex, ethnicity or comorbidities, and although disease severity positively correlated with higher IgG antibody titres in a number of studies, distinguishing causation from correlation is not possible. More recent evidence shows that while responses may be of lower magnitude in milder cases, they are still elicited and may be protective-although evidence on response patterns in milder illness remains in short supply [164,169].…”