Disparities of SARS-CoV-2 Nucleoprotein-Specific IgG in Healthcare Workers in East London, UK

Abstract

Introduction: SARS-CoV-2 antibody detection serves as an important diagnostic marker for past SARS-CoV-2 infection and is essential to determine the spread of COVID-19, monitor potential COVID-19 long-term effects, and to evaluate possible protection from reinfection. A study was conducted across three hospital sites in a large central London NHS Trust in the UK, to evaluate the prevalence and duration of SARS-CoV-2 IgG antibody positivity in healthcare workers.Methods: A matrix equivalence study consisting of 228 participants was undertaken to evaluate the Abbott Panbio™ COVID-19 IgG/IgM rapid test device. Subsequently, 2001 evaluable healthcare workers (HCW), representing a diverse population, were enrolled in a HCW study between June and August 2020. A plasma sample from each HCW was evaluated using the Abbott Panbio™ COVID-19 IgG/IgM rapid test device, with confirmation of IgG-positive results by the Abbott ArchitectTM SARS-CoV-2 IgG assay. 545 participants, of whom 399 were antibody positive at enrolment, were followed up at 3 months.Results: The Panbio™ COVID-19 IgG/IgM rapid test device demonstrated a high concordance with laboratory tests. SARS-CoV-2 antibodies were detected in 506 participants (25.3%) at enrolment, with a higher prevalence in COVID-19 frontline (28.3%) than non-frontline (19.9%) staff. At follow-up, 274/399 antibody positive participants (68.7%) retained antibodies; 4/146 participants negative at enrolment (2.7%) had seroconverted. Non-white ethnicity, older age, hypertension and COVID-19 symptoms were independent predictors of higher antibody levels (OR 1.881, 2.422–3.034, 2.128, and 1.869 respectively), based on Architect™ index quartiles; participants in the first three categories also showed a greater antibody persistence at 3 months.Conclusion: The SARS-CoV-2 anti-nucleocapsid IgG positivity rate among healthcare staff was high, declining by 31.3% during the 3-month follow-up interval. Interestingly, the IgG-positive participants with certain risk factors for severe COVID-19 illness (older age, Black or Asian Ethnicity hypertension) demonstrated greater persistence over time when compared to the IgG-positive participants without these risk factors.

Persistence of SARS-CoV-2-Specific Antibodies for 13 Months after Infection

“…To date, both sero-epidemiological and targeted cohort studies from different countries have reported detectable levels of virus-specific antibodies and duration of the protective immune response from 3 to 13 months after infection [6,7,10,12,13,17,19,21,24,25]. Previous cohort studies on the formation and persistence of SARS-CoV-2-specific humoral immune response mainly included healthcare workers as a target group having the highest risk of being exposed to SARS-CoV-2 [13,14,16,19,20,24,26,27]. However, a long-term monitoring of antibody levels in naturally infected healthcare workers seems to be difficult or even impossible after the start of a global vaccination, as the healthcare sector is considered a priority group for vaccination in many countries [28].…”

“…The cohort study conducted in the UK demonstrated that the levels of antibodies against the SARS-CoV-2 N protein declined by 31.3% over a period of 3 months [20]. In contrast, another cohort study of healthcare workers in the UK showed that the seropositivity against the SARS-CoV-2 S protein remained stable in 94% (95% credibility interval [CrI] 91-96%) of participants for 6 months [14].…”

The β-NGF/TrkA signalling pathway is associated with the production of anti- nucleoprotein IgG in convalescent COVID-19

“…Similarly, high variability in the presence, titre and duration of specific antibodies has been reported (2)(3)(4), often positively correlating with disease severity (3)(4)(5). Some factors determining differences in clinical manifestations and humoral response, such as age, ethnicity and co-or pre-existing medical conditions have already been described (2,6). Underlying genetic and molecular determinants of humoral responses are currently being investigated with some promising results, although these studies mainly focussed on subjects experiencing severe COVID-19 (7)(8)(9).…”

“…SARS-CoV-2 infected subjects can display symptoms within a wide range of severity, from asymptomatic or pauci-symptomatic forms (characterised by fever, cough, fatigue, sore throat, loss of smell) to respiratory failure and systemic manifestations (sepsis, septic shock, and multiple organ dysfunction syndromes (1). Similarly, high variability in the presence, titre and duration of specific antibodies has been reported (2)(3)(4), often positively correlating with disease severity (3)(4)(5). Some factors determining differences in clinical manifestations and humoral response, such as age, ethnicity and co-or pre-existing medical conditions have already been described (2,6).…”

“…The presence of anti-Nucleocapsid protein (NP) IgG and IgM in serum samples was determined using the Panbio TM COVID-19 IgG/IgM Rapid Test Device (Fingerstick Whole Blood/Venous Whole Blood/Serum/Plasma) (Panbio TM ; Abbott Rapid Diagnostics Jena GmbH, Jena, Germany) according to the manufacturer's instructions and as previously described (2). Anti-NPIgG leves in serum samples were quantified using the Abbott Architect i2000 chemiluminescent microparticle immunoassay (Architect) was for SARS-CoV-2 IgG (Abbott Diagnostics, IL, USA; Architect) according to the manufacturer's instructions and as previously described (2).…”