Predominance of Distinct Autoantibodies in Response to SARS-CoV-2 Infection (preprint)

BackgroundImproved knowledge regarding the prevalence and clinical significance of the broad spectrum of autoantibodies triggered by SARS-CoV2 infection can clarify the underlying pathobiology, enhance approaches to evaluating heterogeneity of COVID-19 clinical manifestations, and potentially guide options for targeting immunosuppressive therapy as the need for more effective interventions continues to evolve. In this study, we sought to determine the prevalence of autoimmune antibodies in diverse cohort of SARS-CoV-2 positive healthcare workers and measure the extent to which factors associated with triggered autoimmunity are activated even following mild and asymptomatic infection. MethodsAntigen microarrays were used to profile reactivity of IgG autoantibodies against 91 proteins and cytokines based on autoantibody profiling studies in autoimmune diseases. ResultsIn this discovery screening study, we found that 90% of the IgG positive individuals demonstrated reactivity to at least one autoantibody. When compared to results of the same assays conducted on samples from pre-COVID-19 controls, our primary cohort of individuals with SARS-CoV-2 IgG antibody positivity had significantly elevated IgG against twelve additional proteins including CHD3, CTLA4, HARS, IFNA4, INS, MIF, MX1, RNF41, S100A9, SRP19, TROVE2, and VEGFA. These findings confirmed that all severity levels of SARS-CoV-2 infection, even asymptomatic infections, trigger a robust and diverse autoimmune response; our results also highlight the utility of multiparametric autoantibody detection in this setting. InterpretationTaken together, our findings underscore the serological diversity underlying the clinical heterogeneity of COVID-19 infection and its sequelae, including the long-Covid phenotypes. FundingThis work was supported in part by Cedars-Sinai Medical Center (JEE; SC), the Erika J Glazer Family Foundation (JEE; JEVE; SC), CSMC Precision Health Grant (JFB), the F. Widjaja Family Foundation (JGB, GYM, DM), the Helmsley Charitable Trust (JGB, GYM, DM), and NIH grants K23-HL153888 (JEE) and DK062413 (DPBM). RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSCurrently, several studies have shown the possible involvement of autoimmunity in patients affected by coronavirus disease 2019 (COVID-19). In contrast to cytokine storms, which tend to cause systemic, short-duration problems, autoantibodies (AABs) are thought to result in targeted, longer-term damage and development of autoimmune diseases. Added value of this studyAccording to our knowledge, we evaluated the largest number of protein antigens to characterize the prevalence and heterogeneity of the AABs signature in SARS-CoV-2 convalescent individuals. We examined autoimmune reactivity to SARS-CoV-2 in the absence of extreme clinical disease to acknowledge the existence of AABs even among those who had mild-to-moderate or no symptoms during their illness, as a hallmark of ongoing long-COVID syndrome. Through our analysis we suggest that VEGFA, MIF, IFNA4, SPP1 and APOH could be used as hallmark for SARS-CoV-2 infection and activation of the autoimmune system. Implications of all the available evidenceOur study comprehensively characterized the heterogeneity of the AABs signature in SARS-CoV-2 convalescent individuals. The results established a list of diagnostic signatures and potential therapeutic targets for long-Covid-19 patients although follow-up long-term studies are required. We believe that our findings will serve as a valuable resource, to drive further exploration of long-COVID syndrome pathogenesis.

Paradoxical Sex-Specific Patterns of Autoantibodies Response to SARS-CoV-2 Infection (preprint)

BackgroundAmidst the millions of individuals affected directly by the pandemic, pronounced sex differences in the susceptibility and response to SARS-CoV-2 infection remain poorly understood. Emerging evidence has highlighted the potential importance of autoimmune activation in modulating not only the acute response but also recovery trajectories following SARS-CoV-2 exposure. Given that immune-inflammatory activity can be sex-biased in the setting of severe COVID-19 illness, we deliberately examined sex-specific autoimmune reactivity to SARS-CoV-2 in the absence of extreme clinical disease. MethodsWe used a bead-based array containing over 90 autoantigens previously linked to a range of classic autoimmune diseases to assess autoantibody (AAB) titers in 177 participants. All participants had confirmed evidence of prior SARS-CoV-2 infection based on presence of positive anti-nucleocapsid IgG serology results (Abbott Diagnostics, Abbott Park, Illinois). We used multivariate analysis to determine whether sex-bias was associated with increased rates of AABs reactivity and symptom burden after SARS-CoV2 infection. Results82.4% of AABs reactivity was associated with being male compared to 17.6% with female. We found a diversity of AABs responses that exhibited sex-specific patterns of frequency distribution as well as associations with symptomatology and symptom burden. ConclusionOur results reveal a remarkable sex-specific prevalence and selectivity of AAB responses to SARS-CoV-2. Further understanding of the nature of triggered and persistent AAB activation among men and women exposed to SARS-CoV-2 will be essential for developing effective interventions against immune-mediated sequelae of COVID-19.

SARS-CoV-2 Seroprevalence in Relation to Timing of Symptoms (preprint)

Of individuals with SARS-CoV-2 IgG antibody testing performed, those who contemporaneously experienced a cluster of Covid-19 relevant symptoms in the 1-2 months preceding the antibody assay were more likely to test positive whereas those who experienced the symptom clustering in the prior 3-6 months were more likely to test negative. These findings suggest that antibodies likely wane over a period of months, particularly in relation to the timing of symptoms.

SARS-CoV-2 Seroprevalence Across a Diverse Cohort of Healthcare Workers (preprint)

Importance: Antibody testing is important for understanding patterns of exposure and potential immunity to SARS-CoV-2. Prior data on seroprevalence have been subject to variations in selection of individuals and nature as well as timing of testing in relation to exposures. Objective: We sought to determine the extent of SARS-CoV-2 seroprevalance and the factors associated with seroprevelance across a diverse cohort of healthcare workers. Design: Observational cohort study of healthcare workers, including SARS-CoV-2 serology testing and participant questionaires. Participants: A diverse and unselected population of adults (n=6,062) employed in a multi-site healthcare delivery system located in Los Angeles County, including individuals with direct patient contact and others with non-patient-oriented work functions. Exposure: Exposure and infection with the SARS-CoV-2 virus, as determined by seropositivity. Main Outcomes: Using Bayesian and multi-variate analyses, we estimated seroprevalence and factors associated with seropositivity and antibody titers, including pre-existing demographic and clinical characteristics; potential Covid-19 illness related exposures; and, symptoms consistent with Covid-19 infection. Results: We observed a seroprevalence rate of 4.1%, with anosmia as the most prominently associated self-reported symptom in addition to fever, dry cough, anorexia, and myalgias. After adjusting for potential confounders, pre-existing medical conditions were not associated with antibody positivity. However, seroprevalence was associated with younger age, Hispanic ethnicity, and African-American race, as well as presence of either a personal or household member having a prior diagnosis of Covid-19. Importantly, African American race and Hispanic ethnicity were associated with antibody positivity even after adjusting for personal Covid-19 diagnosis status, suggesting the contribution of unmeasured structural or societally factors. Notably, number of people, or children, in the home was not associated with antibody positivity. Conclusion and Relevance: The demographic factors associated with SARS-CoV-2 seroprevalence among our healthcare workers underscore the importance of exposure sources beyond the workplace. The size and diversity of our study population, combined with robust survey and modeling techniques, provide a vibrant picture of the demographic factors, exposures, and symptoms that can identify individuals with susceptibility as well as potential to mount an immune response to Covid-19.

Pre-Existing Characteristics Associated with Covid-19 Illness Severity (preprint)

BackgroundCertain individuals, when infected by SARS-CoV-2, tend to develop the more severe forms of Covid-19 illness for reasons that remain unclear. MethodsWe studied N=442 patients who presented with laboratory confirmed Covid-19 illness to our U.S. metropolitan healthcare system. We curated data from the electronic health record, and used multivariable logistic regression to examine the association of pre-existing traits with a Covid-19 illness severity defined by level of required care: need for hospital admission, need for intensive care, and need for intubation. ResultsOf all patients studied, 48% required hospitalization, 17% required intensive care, and 12% required intubation. In multivariable-adjusted analyses, patients requiring a higher levels of care were more likely to be older (OR 1.5 per 10 years, P<0.001), male (OR 2.0, P=0.001), African American (OR 2.1, P=0.011), obese (OR 2.0, P=0.021), with diabetes mellitus (OR 1.8, P=0.037), and with a higher comorbidity index (OR 1.8 per SD, P<0.001). Several clinical associations were more pronounced in younger compared to older patients (Pinteraction<0.05). Of all hospitalized patients, males required higher levels of care (OR 2.5, P=0.003) irrespective of age, race, or morbidity profile. ConclusionsIn our healthcare system, greater Covid-19 illness severity is seen in patients who are older, male, African American, obese, with diabetes, and with greater overall comorbidity burden. Certain comorbidities paradoxically augment risk to a greater extent in younger patients. In hospitalized patients, male sex is the main determinant of needing more intensive care. Further investigation is needed to understand the mechanisms underlying these findings.