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2.
Non-conventional in English | [Unspecified Source], Grey literature | ID: grc-750507

ABSTRACT

During virus infection B cells are critical for the production of antibodies and protective immunity. Here we show that the human B cell compartment in patients with diagnostically confirmed SARS-CoV-2 and clinical COVID-19 is rapidly altered with the early recruitment of B cells expressing a limited subset of IGHV genes, progressing to a highly polyclonal response of B cells with broader IGHV gene usage and extensive class switching to IgG and IgA subclasses with limited somatic hypermutation in the initial weeks of infection. We identify extensive convergence of antibody sequences across SARS-CoV-2 patients, highlighting stereotyped naive responses to this virus. Notably, sequence-based detection in COVID-19 patients of convergent B cell clonotypes previously reported in SARS-CoV infection predicts the presence of SARS-CoV/SARS-CoV-2 cross-reactive antibody titers specific for the receptor-binding domain. These findings offer molecular insights into shared features of human B cell responses to SARS-CoV-2 and other zoonotic spillover coronaviruses.

3.
Ann Intern Med ; 174(8): 1073-1080, 2021 08.
Article in English | MEDLINE | ID: covidwho-1456490

ABSTRACT

BACKGROUND: Assessing the evolution of SARS-CoV-2 immune response among patients receiving dialysis can define its durability in a highly clinically relevant context because patients receiving dialysis share the characteristics of persons most susceptible to SARS-CoV-2 infection. OBJECTIVE: To evaluate the persistence of SARS-CoV-2 receptor-binding domain (RBD) IgG in seroprevalent patients receiving dialysis. DESIGN: Prospective. SETTING: Nationwide sample from dialysis facilities. PATIENTS: 2215 patients receiving dialysis who had evidence of SARS-CoV-2 infection as of July 2020. MEASUREMENTS: Remainder plasma from routine monthly laboratories was used to measure semiquantitative RBD IgG index value over 6 months. RESULTS: A total of 2063 (93%) seroprevalent patients reached an assay detectable response (IgG index value ≥1). Most (n = 1323, 60%) had responses in July with index values classified as high (IgG ≥10); 1003 (76%) remained within this stratum. Adjusted median index values declined slowly but continuously (July vs. December values were 21 vs. 13; P < 0.001). The trajectory of the response did not vary by age group, sex, race/ethnicity, or diabetes status. Patients without an assay detectable response (n = 137) were more likely to be White and in the younger (18 to 44 years) or older (≥80 years) age groups and less likely to have diabetes and hypoalbuminemia. LIMITATION: Lack of data on symptoms or reverse transcriptase polymerase chain reaction diagnosis, cohort of persons who survived infection, and use of a semiquantitative assay. CONCLUSION: Despite impaired immunity, most seropositive patients receiving dialysis maintained RBD antibody levels over 6 months. A slow and continual decline in median antibody levels over time was seen, but no indication that subgroups with impaired immunity had a shorter-lived humoral response was found. PRIMARY FUNDING SOURCE: Ascend Clinical Laboratories.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Immunoglobulin G/blood , Protein Domains/immunology , Renal Dialysis , Spike Glycoprotein, Coronavirus/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/immunology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , SARS-CoV-2 , Young Adult
4.
Clin Chem ; 2021 Oct 04.
Article in English | MEDLINE | ID: covidwho-1450383

ABSTRACT

BACKGROUND: Detection of SARS-CoV-2 nucleocapsid antigen in blood has been described, but the diagnostic and prognostic role of antigenemia is not well understood. This study aimed to determine the frequency, duration, and concentration of nucleocapsid antigen in plasma and its association with COVID-19 severity. METHODS: We utilized an ultrasensitive electrochemiluminescence immunoassay targeting SARS-CoV-2 nucleocapsid antigen to evaluate 777 plasma samples from 104 individuals with COVID-19. We compared plasma antigen to respiratory nucleic acid amplification testing (NAAT) in 74 individuals with COVID-19 from samples collected ± 1 day of diagnostic respiratory NAAT, and in 52 SARS-CoV-2-negative individuals. We used Kruskal-Wallis tests, multivariable logistic regression, and mixed-effects modeling to evaluate whether plasma antigen concentration was associated with disease severity. RESULTS: Plasma antigen had 91.9% (95% CI 83.2-97.0%) clinical sensitivity and 94.2% (84.1-98.8%) clinical specificity. Antigen-negative plasma samples belonged to patients with later respiratory cycle thresholds (Ct) when compared with antigen-positive plasma samples. Median plasma antigen concentration (log10 fg/mL) was 5.4 (IQR 3.9-6.0) in outpatients, 6.0 (5.4-6.5) in inpatients, and 6.6 (6.1-7.2) in intensive care unit (ICU) patients. In models adjusted for age, sex, diabetes, and hypertension, plasma antigen concentration at diagnosis was associated with ICU admission (OR 2.8 [95% CI 1.2-6.2], P=.01), but not with non-ICU hospitalization. Rate of antigen decrease was not associated with disease severity. CONCLUSIONS: SARS-CoV-2 plasma nucleocapsid antigen exhibited comparable diagnostic performance to upper respiratory NAAT, especially among those with late respiratory Ct. In addition to currently available tools, antigenemia may facilitate patient triage to optimize intensive care utilization.

5.
Front Immunol ; 12: 739037, 2021.
Article in English | MEDLINE | ID: covidwho-1448729

ABSTRACT

Background: Transfusion of COVID-19 convalescent plasma (CCP) containing high titers of anti-SARS-CoV-2 antibodies serves as therapy for COVID-19 patients. Transfusions early during disease course was found to be beneficial. Lessons from the SARS-CoV-2 pandemic could inform early responses to future pandemics and may continue to be relevant in lower resource settings. We sought to identify factors correlating to high antibody titers in convalescent plasma donors and understand the magnitude and pharmacokinetic time course of both transfused antibody titers and the endogenous antibody titers in transfused recipients. Methods: Plasma samples were collected up to 174 days after convalescence from 93 CCP donors with mild disease, and from 16 COVID-19 patients before and after transfusion. Using ELISA, anti-SARS-CoV-2 Spike RBD, S1, and N-protein antibodies, as well as capacity of antibodies to block ACE2 from binding to RBD was measured in an in vitro assay. As an estimate for viral load, viral RNA and N-protein plasma levels were assessed in COVID-19 patients. Results: Anti-SARS-CoV-2 antibody levels and RBD-ACE2 blocking capacity were highest within the first 60 days after symptom resolution and markedly decreased after 120 days. Highest antibody titers were found in CCP donors that experienced fever. Effect of transfused CCP was detectable in COVID-19 patients who received high-titer CCP and had not seroconverted at the time of transfusion. Decrease in viral RNA was seen in two of these patients. Conclusion: Our results suggest that high titer CCP should be collected within 60 days after recovery from donors with past fever. The much lower titers conferred by transfused antibodies compared to endogenous production in the patient underscore the importance of providing CCP prior to endogenous seroconversion.


Subject(s)
COVID-19/therapy , Convalescence , SARS-CoV-2/immunology , Seroconversion , Adult , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antigens, Viral/blood , Blood Donors , COVID-19/blood , COVID-19/immunology , Female , Humans , Immunization, Passive , Kinetics , Male , Middle Aged , Outpatients , RNA, Viral/blood
6.
Arthritis Rheumatol ; 2021 Sep 12.
Article in English | MEDLINE | ID: covidwho-1404543

ABSTRACT

Managing patients with rheumatic disease during the COVID-19 pandemic has posed a unique challenge. Immunosuppressed patients are at an increased risk for developing severe COVID-19 and may not derive full protection from the vaccine (1-5). Thus, it is paramount we develop strategies whereby rheumatic disease patients can be protected from the pandemic virus and its variants.

7.
EBioMedicine ; 67: 103355, 2021 May.
Article in English | MEDLINE | ID: covidwho-1385438

ABSTRACT

BACKGROUND: There is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses. METHODS: We describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape. FINDINGS: We found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape. INTERPRETATION: Our results highlight the potential need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered.


Subject(s)
COVID-19/immunology , Immune Evasion , Mutation , Precursor Cell Lymphoblastic Leukemia-Lymphoma/virology , SARS-CoV-2/genetics , COVID-19/virology , Child, Preschool , Evolution, Molecular , Female , Genome, Viral , High-Throughput Nucleotide Sequencing , Humans , Immunity, Humoral , Male , Precursor Cell Lymphoblastic Leukemia-Lymphoma/immunology , SARS-CoV-2/classification , SARS-CoV-2/immunology , Sequence Analysis, RNA , Whole Genome Sequencing , Young Adult
9.
Nature ; 596(7872): 410-416, 2021 08.
Article in English | MEDLINE | ID: covidwho-1305364

ABSTRACT

The emergency use authorization of two mRNA vaccines in less than a year from the emergence of SARS-CoV-2 represents a landmark in vaccinology1,2. Yet, how mRNA vaccines stimulate the immune system to elicit protective immune responses is unknown. Here we used a systems vaccinology approach to comprehensively profile the innate and adaptive immune responses of 56 healthy volunteers who were vaccinated with the Pfizer-BioNTech mRNA vaccine (BNT162b2). Vaccination resulted in the robust production of neutralizing antibodies against the wild-type SARS-CoV-2 (derived from 2019-nCOV/USA_WA1/2020) and, to a lesser extent, the B.1.351 strain, as well as significant increases in antigen-specific polyfunctional CD4 and CD8 T cells after the second dose. Booster vaccination stimulated a notably enhanced innate immune response as compared to primary vaccination, evidenced by (1) a greater frequency of CD14+CD16+ inflammatory monocytes; (2) a higher concentration of plasma IFNγ; and (3) a transcriptional signature of innate antiviral immunity. Consistent with these observations, our single-cell transcriptomics analysis demonstrated an approximately 100-fold increase in the frequency of a myeloid cell cluster enriched in interferon-response transcription factors and reduced in AP-1 transcription factors, after secondary immunization. Finally, we identified distinct innate pathways associated with CD8 T cell and neutralizing antibody responses, and show that a monocyte-related signature correlates with the neutralizing antibody response against the B.1.351 variant. Collectively, these data provide insights into the immune responses induced by mRNA vaccination and demonstrate its capacity to prime the innate immune system to mount a more potent response after booster immunization.


Subject(s)
Adaptive Immunity , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Immunity, Innate , T-Lymphocytes/immunology , Vaccinology , Adult , Aged , Antibodies, Neutralizing/immunology , Autoantibodies/immunology , COVID-19 Vaccines/administration & dosage , Female , Humans , Immunization, Secondary , Male , Middle Aged , Single-Cell Analysis , Spike Glycoprotein, Coronavirus/immunology , Transcription, Genetic , Transcriptome/genetics , Young Adult
10.
JAMA Netw Open ; 4(7): e2116572, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1305100

ABSTRACT

Importance: Seroprevalence studies complement data on detected cases and attributed deaths in assessing the cumulative spread of the SARS-CoV-2 virus. Objective: To estimate seroprevalence of SARS-CoV-2 antibodies in patients receiving dialysis and adults in the US in January 2021 before the widespread introduction of COVID-19 vaccines. Design, Setting, and Participants: This cross-sectional study used data from the third largest US dialysis organization (US Renal Care), which has facilities located nationwide, to estimate SARS-CoV-2 seroprevalence among US patients receiving dialysis. Remainder plasma (ie, plasma that would have otherwise been discarded) of all patients receiving dialysis at US Renal Care facilities from January 1 to 31, 2021, was tested for SARS-CoV-2 antibodies. Patients were excluded if they had a documented dose of SARS-CoV-2 vaccination or if a residence zip code was missing from electronic medical records. Crude seroprevalence estimates from this sample (January 2021) were standardized to the US adult population using the 2018 American Community Survey 1-year estimates and stratified by age group, sex, self-reported race/ethnicity, neighborhood race/ethnicity composition, neighborhood income level, and urban or rural status. These data and case detection rates were then compared with data from a July 2020 subsample of patients who received dialysis at the same facilities. Exposures: Age, sex, race/ethnicity, and region of residence as well as neighborhood race/ethnicity composition, poverty, population density, and urban or rural status. Main Outcomes and Measures: The spike protein receptor-binding domain total antibody assay (Siemens Healthineers; manufacturer-reported sensitivity of 100% and specificity of 99.8%) was used to estimate crude SARS-CoV-2 seroprevalence in the unweighted sample, and then the estimated seroprevalence rates for the US dialysis and adult populations were calculated, adjusting for age, sex, and region. Results: A total of 21 464 patients (mean [SD] age, 63.1 [14.2] years; 12 265 men [57%]) were included in the unweighted sample from January 2021. The patients were disproportionately older (aged 65-79 years, 7847 [37%]; aged ≥80 years, 2668 [12%]) and members of racial/ethnic minority groups (Hispanic patients, 2945 [18%]; non-Hispanic Black patients, 4875 [29%]). Seroprevalence of SARS-CoV-2 antibodies was 18.9% (95% CI, 18.3%-19.5%) in the sample, with a seroprevalence of 18.7% (95% CI, 18.1%-19.2%) standardized to the US dialysis population, and 21.3% (95% CI, 20.3%-22.3%) standardized to the US adult population. In the unweighted sample, younger persons (aged 18-44 years, 25.9%; 95% CI, 24.1%-27.8%), those who self-identified as Hispanic or living in Hispanic neighborhoods (25.1%; 95% CI, 23.6%-26.4%), and those living in the lowest-income neighborhoods (24.8%; 95% CI, 23.2%-26.5%) were among the subgroups with the highest seroprevalence. Little variability was observed in seroprevalence by geographic region, population density, and urban or rural status in the January 2021 sample (largest regional difference, 1.2 [95% CI, 1.1-1.3] higher odds of seroprevalence in residents of the Northeast vs West). Conclusions and Relevance: In this cross-sectional study of patients receiving dialysis in the US, fewer than 1 in 4 patients had evidence of SARS-CoV-2 antibodies 1 year after the first case of SARS-CoV-2 infection was detected in the US. Results standardized to the US population indicate similar prevalence of antibodies among US adults. Vaccine introduction to younger individuals, those living in neighborhoods with a large population of racial/ethnic minority residents, and those living in low-income neighborhoods may be critical to disrupting the spread of infection.


Subject(s)
Dialysis/statistics & numerical data , SARS-CoV-2 , Seroepidemiologic Studies , Aged , Aged, 80 and over , COVID-19/epidemiology , COVID-19/virology , Cross-Sectional Studies , Dialysis/methods , Female , Humans , Male , Middle Aged , Plasma/virology , Surveys and Questionnaires , United States/epidemiology
11.
Cell Host Microbe ; 29(7): 1063-1075, 2021 07 14.
Article in English | MEDLINE | ID: covidwho-1272338

ABSTRACT

Antibodies, and the B cell and plasma cell populations responsible for their production, are key components of the human immune system's response to SARS-CoV-2, which has caused the coronavirus disease 2019 (COVID-19) pandemic. Here, we review findings addressing the nature of antibody responses against SARS-CoV-2 and their role in protecting from infection or modulating COVID-19 disease severity. In just over a year, much has been learned, and replicated in independent studies, about human immune responses to this pathogen, contributing to the development of effective vaccines. Nevertheless, important questions remain about the duration and effectiveness of antibody responses, differences between immunity derived from infection compared to vaccination, the cellular basis for serological findings, and the extent to which viral variants will escape from current immunity.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19 Vaccines/therapeutic use , COVID-19/immunology , SARS-CoV-2/immunology , Vaccination , Cross Reactions , Humans , Immunity , Immunity, Mucosal , Pandemics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
13.
Arch Pathol Lab Med ; 145(10): 1221-1227, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1261421

ABSTRACT

CONTEXT.­: The ongoing COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has elicited a surge in demand for serologic testing to identify previously infected individuals. In particular, antibody testing is crucial in identifying COVID-19 convalescent plasma, which has been approved by the Food and Drug Administration under the Emergency Use Authorization for use as passive immunotherapy for hospitalized patients infected with COVID-19. Currently, high-titer COVID-19 convalescent plasma can be qualified by Ortho's Vitros COVID-19 IgG antibody test. OBJECTIVE.­: To explore the use of an efficient testing method to identify high-titer COVID-19 convalescent plasma for use in treating COVID-19-infected patients and track COVID-19 positivity over time. DESIGN.­: We evaluated an enzyme-linked immunosorbent assay (ELISA)-based method that detects antibodies specific to the SARS-CoV-2 receptor binding domain (RBD) with individual and pooled plasma samples and compared its performance against the Vitros COVID-19 IgG antibody test. Using the pooled RBD-ELISA (P-RE) method, we also screened more than 10 000 longitudinal healthy blood donor samples to assess seroprevalence. RESULTS.­: P-RE demonstrates 100% sensitivity in detecting Food and Drug Administration-defined high-titer samples when compared with the Vitros COVID-19 IgG antibody test. Overall sensitivity of P-RE when compared with the Vitros COVID-19 IgG antibody test and our individual sample RBD-ELISA (I-RE) were 83% and 56%, respectively. When screening 10 218 healthy blood donor samples by P-RE, we found the seroprevalence correlated with the local infection rates with a correlation coefficient of 0.21 (P < .001). CONCLUSIONS.­: Pooling plasma samples can be used to efficiently screen large populations for individuals with high-titer anti-RBD antibodies, important for COVID-19 convalescent plasma identification.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Antibodies, Viral/blood , Blood Donors/statistics & numerical data , COVID-19/epidemiology , COVID-19/virology , Humans , Immunoglobulin G/blood , Pandemics/prevention & control , Reproducibility of Results , SARS-CoV-2/physiology , Sensitivity and Specificity , Seroepidemiologic Studies
14.
Science ; 372(6543): 738-741, 2021 05 14.
Article in English | MEDLINE | ID: covidwho-1180894

ABSTRACT

Vaccination and infection promote the formation, tissue distribution, and clonal evolution of B cells, which encode humoral immune memory. We evaluated pediatric and adult blood and deceased adult organ donor tissues to determine convergent antigen-specific antibody genes of similar sequences shared between individuals. B cell memory varied for different pathogens. Polysaccharide antigen-specific clones were not exclusive to the spleen. Adults had higher clone frequencies and greater class switching in lymphoid tissues than blood, while pediatric blood had abundant class-switched convergent clones. Consistent with reported serology, prepandemic children had class-switched convergent clones to severe acute respiratory syndrome coronavirus 2 with weak cross-reactivity to other coronaviruses, while adult blood or tissues showed few such clones. These results highlight the prominence of early childhood B cell clonal expansions and cross-reactivity for future responses to novel pathogens.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , Coronavirus/immunology , Immunologic Memory , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Aging , Child, Preschool , Cross Reactions , Ebolavirus/immunology , Female , Fetal Blood/immunology , Genes, Immunoglobulin , Humans , Immunoglobulin Class Switching , Immunoglobulin D/genetics , Immunoglobulin D/immunology , Immunoglobulin Heavy Chains/immunology , Immunoglobulin M/genetics , Immunoglobulin M/immunology , Infant , Lymph Nodes/immunology , Male , Middle Aged , Receptors, Antigen, B-Cell/immunology , Somatic Hypermutation, Immunoglobulin , Spleen/immunology , Young Adult
15.
J Clin Virol ; 139: 104818, 2021 06.
Article in English | MEDLINE | ID: covidwho-1164017

ABSTRACT

BACKGROUND: The coronavirus disease 2019 (COVID-19) endgame may benefit from simple, accurate antibody testing to characterize seroprevalence and immunization coverage. OBJECTIVES: To evaluate the performance of the lateral flow QIAreach anti-SARS-CoV-2 Total rapid nanoparticle fluorescence immunoassay compared to reference isotype-specific IgG, IgM, and IgA SARS-CoV-2 ELISA using S1 or receptor binding domain (RBD) as antigens. STUDY DESIGN: A diagnostic comparison study was carried out using 154 well-characterized heparin plasma samples. Agreement between assays was assessed by overall, positive, and negative percent agreement and Cohen's kappa coefficient. RESULTS: Overall agreement between the QIAreach anti-SARS-CoV-2 Total and any anti-spike domain (S1 or RBD) antibody isotype was 96.0 % (95 % CI 89.8-98.8), the positive percent agreement was 97.6 % (95 % CI 91.0-99.9), the negative percent agreement was 88.2 % (95 % CI 64.4-98.0). The kappa coefficient was 0.86 (95 % CI 0.72 to 0.99). CONCLUSION: The QIAreach anti-SARS-CoV-2 Total rapid antibody test provides comparable performance to high-complexity, laboratory-based ELISA.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , Fluorescent Antibody Technique/methods , SARS-CoV-2/immunology , Adult , Aged , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Nanoparticles
16.
Prehosp Emerg Care ; : 1-10, 2021 May 06.
Article in English | MEDLINE | ID: covidwho-1165151

ABSTRACT

Objective: Firefighter first responders and other emergency medical services (EMS) personnel have been among the highest risk healthcare workers for illness during the SARS-CoV-2 pandemic. We sought to determine the rate of seropositivity for SARS-CoV-2 IgG antibodies and of acute asymptomatic infection among firefighter first responders in a single county with early exposure in the pandemic. Methods: We conducted a cross-sectional study of clinically active firefighters cross-trained as paramedics or EMTs in the fire departments of Santa Clara County, California. Firefighters without current symptoms were tested between June and August 2020. Our primary outcomes were rates of SARS-CoV-2 IgG antibody seropositivity and SARS-CoV-2 RT-PCR swab positivity for acute infection. We report cumulative incidence, participant characteristics with frequencies and proportions, and proportion positive and associated relative risk (with 95% confidence intervals). Results: We enrolled 983 out of 1339 eligible participants (response rate: 73.4%). Twenty-five participants (2.54%, 95% CI 1.65-3.73) tested positive for IgG antibodies and 9 (0.92%, 95% CI 0.42-1.73) tested positive for SARS-CoV-2 by RT-PCR. Our cumulative incidence, inclusive of self-reported prior positive PCR tests, was 34 (3.46%, 95% CI 2.41-4.80). Conclusion: In a county with one of the earliest outbreaks in the United States, the seroprevalence among firefighter first responders was lower than that reported by other studies of frontline health care workers, while the cumulative incidence remained higher than that seen in the surrounding community.

17.
Clin Chem ; 67(7): 977-986, 2021 07 06.
Article in English | MEDLINE | ID: covidwho-1132473

ABSTRACT

BACKGROUND: Laboratory-based methods for SARS-CoV-2 antibody detection vary widely in performance. However, there are limited prospectively-collected data on assay performance, and minimal clinical information to guide interpretation of discrepant results. METHODS: Over a 2-week period, 1080 consecutive plasma samples submitted for clinical SARS-CoV-2 IgG testing were tested in parallel for anti-nucleocapsid IgG (anti-N, Abbott) and anti-spike IgG (anti-S1, EUROIMMUN). Chart review was conducted for samples testing positive or borderline on either assay, and for an age/sex-matched cohort of samples negative by both assays. CDC surveillance case definitions were used to determine clinical sensitivity/specificity and conduct receiver operating characteristics curve analysis. RESULTS: There were 52 samples positive by both methods, 2 positive for anti-N only, 34 positive for anti-S1 only, and 27 borderline for anti-S1. Of the 34 individuals positive for anti-S1 alone, 8 (24%) had confirmed COVID-19. No anti-S1 borderline cases were positive for anti-N or had confirmed/probable COVID-19. The anti-N assay was less sensitive (84.2% [95% CI 72.1-92.5%] vs 94.7% [95% CI 85.4-98.9%]) but more specific (99.2% [95% CI 95.5-100%] vs 86.9% [95% CI 79.6-92.3%]) than anti-S1. Abbott anti-N sensitivity could be improved to 96.5% with minimal effect on specificity if the index threshold was lowered from 1.4 to 0.6. CONCLUSION: Real-world concordance between different serologic assays may be lower than previously described in retrospective studies. These findings have implications for the interpretation of SARS-CoV-2 IgG results, especially with the advent of spike antigen-targeted vaccination, as a subset of patients with true infection are anti-N negative and anti-S1 positive.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , Immunoglobulin G/blood , Nucleocapsid/immunology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/immunology , Adult , Area Under Curve , COVID-19/virology , Case-Control Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , ROC Curve , Reagent Kits, Diagnostic , Retrospective Studies , SARS-CoV-2/isolation & purification
18.
Diagn Microbiol Infect Dis ; 100(3): 115365, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1116561

ABSTRACT

We present the case of an inpatient with pneumonia and repeatedly negative nasopharyngeal SARS-CoV-2 testing. In such challenging cases, alternative diagnostic options include lower respiratory tract and plasma SARS-CoV-2 RNA testing, of which the latter may be particularly useful where bronchoscopy is deferred due to clinical factors or transmission risk.


Subject(s)
COVID-19/diagnosis , Plasma/virology , SARS-CoV-2/isolation & purification , Adult , COVID-19 Nucleic Acid Testing , Humans , Male , Nasopharynx/virology , RNA, Viral/genetics , Specimen Handling
19.
Nat Immunol ; 22(1): 67-73, 2021 01.
Article in English | MEDLINE | ID: covidwho-1065904

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 infections can cause coronavirus disease 2019 (COVID-19), which manifests with a range of severities from mild illness to life-threatening pneumonia and multi-organ failure. Severe COVID-19 is characterized by an inflammatory signature, including high levels of inflammatory cytokines, alveolar inflammatory infiltrates and vascular microthrombi. Here we show that patients with severe COVID-19 produced a unique serologic signature, including an increased likelihood of IgG1 with afucosylated Fc glycans. This Fc modification on severe acute respiratory syndrome coronavirus 2 IgGs enhanced interactions with the activating Fcγ receptor FcγRIIIa; when incorporated into immune complexes, Fc afucosylation enhanced production of inflammatory cytokines by monocytes, including interleukin-6 and tumor necrosis factor. These results show that disease severity in COVID-19 correlates with the presence of proinflammatory IgG Fc structures, including afucosylated IgG1.


Subject(s)
COVID-19/immunology , Cytokines/immunology , Immunoglobulin G/immunology , Receptors, IgG/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , COVID-19/metabolism , COVID-19/virology , Child , Cytokines/metabolism , Female , Glycosylation , Humans , Immunoglobulin G/metabolism , Interleukin-6 , Male , Middle Aged , Receptors, IgG/metabolism , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Severity of Illness Index , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism
20.
Nat Med ; 27(1): 125-135, 2021 01.
Article in English | MEDLINE | ID: covidwho-1023963

ABSTRACT

Most of what we know about adaptive immunity has come from inbred mouse studies, using methods that are often difficult or impossible to confirm in humans. In addition, vaccine responses in mice are often poorly predictive of responses to those same vaccines in humans. Here we use human tonsils, readily available lymphoid organs, to develop a functional organotypic system that recapitulates key germinal center features in vitro, including the production of antigen-specific antibodies, somatic hypermutation and affinity maturation, plasmablast differentiation and class-switch recombination. We use this system to define the essential cellular components necessary to produce an influenza vaccine response. We also show that it can be used to evaluate humoral immune responses to two priming antigens, rabies vaccine and an adenovirus-based severe acute respiratory syndrome coronavirus 2 vaccine, and to assess the effects of different adjuvants. This system should prove useful for studying critical mechanisms underlying adaptive immunity in much greater depth than previously possible and to rapidly test vaccine candidates and adjuvants in an entirely human system.


Subject(s)
Influenza Vaccines/immunology , Palatine Tonsil/immunology , Adjuvants, Immunologic , B-Lymphocytes/cytology , B-Lymphocytes/immunology , COVID-19 Vaccines/immunology , Germinal Center/cytology , Hemagglutinin Glycoproteins, Influenza Virus , Humans , In Vitro Techniques , Lymphoid Tissue/immunology , Measles-Mumps-Rubella Vaccine/immunology , Organoids/cytology , Organoids/immunology , Rabies Vaccines/immunology , T-Lymphocytes/immunology
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