scholarly journals Serological Assessment of COVID-19 Patients in Brazil: Levels, Avidity, and Subclasses of IgG Against RBD

2021 ◽  
Author(s):  
Andrew Moura ◽  
Hernan H. da Costa ◽  
Victor Correa ◽  
Ana K. Lima ◽  
José A. Lindoso ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Vaccine Development ◽  
Immunological Response ◽  
Hospitalized Patients ◽  
Igg Antibody ◽  
Antibody Avidity ◽  
Mild Disease ◽  
Life Threatening ◽  
Antibody Levels

Abstract SARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still not available for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RDB IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8-14 and 15-21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RDB in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.

scholarly journals Assessment of avidity related to IgG subclasses in SARS-CoV-2 Brazilian infected patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew D. Moura ◽  
Hernan H. M. da Costa ◽  
Victor A. Correa ◽  
Ana K. de S. Lima ◽  
José A. L. Lindoso ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Vaccine Development ◽  
Immunological Response ◽  
Hospitalized Patients ◽  
Igg Antibody ◽  
Antibody Avidity ◽  
Mild Disease ◽  
Life Threatening ◽  
Antibody Levels

AbstractSARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still limited for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RBD IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8–14 and 15–21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RBD in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.

scholarly journals Detailed Multiplex Analysis of SARS-CoV-2 Specific Antibodies in COVID-19 Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Siggeir F. Brynjolfsson ◽  
Hildur Sigurgrimsdottir ◽  
Elin D. Einarsdottir ◽  
Gudrun A. Bjornsdottir ◽  
Brynja Armannsdottir ◽  
...  
Keyword(s):  
Antibody Response ◽  
Immunological Response ◽  
Receptor Binding Domain ◽  
Igg Antibody ◽  
Nucleocapsid Proteins ◽  
The Third ◽  
Antibody Isotypes ◽  
Iga Antibodies ◽  
Set Up ◽  
Antibody Levels

A detailed understanding of the antibody response against SARS-CoV-2 is of high importance, especially with the emergence of novel vaccines. A multiplex-based assay, analyzing IgG, IgM, and IgA antibodies against the receptor binding domain (RBD), spike 1 (S1), and nucleocapsid proteins of the SARS-CoV-2 virus was set up. The multiplex-based analysis was calibrated against the Elecsys® Anti-SARS-CoV-2 assay on a Roche Cobas® instrument, using positive and negative samples. The calibration of the multiplex based assay yielded a sensitivity of 100% and a specificity of 97.7%. SARS-CoV-2 specific antibody levels were analyzed by multiplex in 251 samples from 221 patients. A significant increase in all antibody types (IgM, IgG, and IgA) against RBD was observed between the first and the third weeks of disease. Additionally, the S1 IgG antibody response increased significantly between weeks 1, 2, and 3 of disease. Class switching appeared to occur earlier for IgA than for IgG. Patients requiring hospital admission and intensive care had higher levels of SARS-CoV-2 specific IgA levels than outpatients. These findings describe the initial antibody response during the first weeks of disease and demonstrate the importance of analyzing different antibody isotypes against multiple antigens and include IgA when examining the immunological response to COVID-19.

scholarly journals Immune Responses to Vi Capsular Polysaccharide Typhoid Vaccine in Children 2 to 16 Years Old in Karachi, Pakistan, and Kolkata, India

2014 ◽  
Vol 21 (5) ◽  
pp. 661-666 ◽  
Author(s):  
R. Leon Ochiai ◽  
M. Imran Khan ◽  
Sajid B. Soofi ◽  
Dipika Sur ◽  
Suman Kanungo ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Capsular Polysaccharide ◽  
Geometric Mean ◽  
Enzyme Linked Immunosorbent Assay ◽  
Typhoid Vaccine ◽  
Igg Antibody ◽  
Vi Capsular Polysaccharide ◽  
Cluster Randomized ◽  
Antibody Levels

ABSTRACTThe geometric mean concentration (GMC) and the proportion maintaining a protective level (150 enzyme-linked immunosorbent assay (ELISA) units [ELU]/ml) 2 years following a single dose of 25 μg of injectable Vi capsular polysaccharide typhoid vaccine was measured against that of the control hepatitis A vaccine in children 2 to 16 years old in cluster randomized trials in Karachi and Kolkata. The GMC for the Vi group (1,428 ELU/ml) was statistically significantly different from the GMC of the control hepatitis A vaccine group (86 ELU/ml) after 6 weeks. A total of 117 children (95.1%) in the Vi group and 9 (7.5%) in the hepatitis A group showed a 4-fold rise in Vi IgG antibody concentrations at 6 weeks (P< 0.01). Protective antibody levels remained significantly different between the two groups at 2 years (38% in the Vi vaccine groups and 6% in the hepatitis A group [P< 0.01]). A very small proportion of younger children (2 to 5 years old) maintained protective Vi IgG antibody levels at 2 years, a result that was not statistically significantly different compared to that for the hepatitis A group (38.1% versus 10.5%). The GMCs of the Vi IgG antibody after 2 years were 133 ELU/ml for children 2 to <5 years old and 349 ELU/ml for children 5 to 16 years old. In conclusion, Vi capsular polysaccharide typhoid vaccine is immunogenic in children in settings of South Asia where typhoid is highly endemic. The antibody levels in children who received this vaccine remained higher than those in children who received the control vaccine but were significantly reduced at 2 years of follow-up.

scholarly journals Seroprevalence of Aspergillus-Specific IgG Antibody among Mozambican Tuberculosis Patients

2021 ◽  
Vol 7 (8) ◽  
pp. 595
Author(s):  
Helmut J. F. Salzer ◽  
Isabel Massango ◽  
Nilesh Bhatt ◽  
Emelva Machonisse ◽  
Maja Reimann ◽  
...  
Keyword(s):  
Antibody Level ◽  
Hiv Positive ◽  
Igg Antibody ◽  
Tuberculosis Patients ◽  
Tb Treatment ◽  
Life Threatening ◽  
Specific Igg ◽  
Limited Health ◽  
Antibody Levels ◽  
Hiv Negative

Background: Chronic pulmonary aspergillosis (CPA) is a life-threatening sequel in patients with pulmonary tuberculosis (PTB). Aspergillus-specific IgG antibody is a useful diagnostic biomarker supporting CPA diagnosis, especially in countries with limited health recourses. Methods: We conducted a prospective pilot study to assess the seroprevalence of Aspergillus-specific IgG antibodies among 61 Mozambican tuberculosis patients before, during, and after the end of TB treatment. Aspergillus-specific IgG antibody levels were measured using the ImmunoCAP®. Results: In this study, 3 out of 21 HIV-negative PTB patients had a positive Aspergillus-specific IgG antibody level before, during, and after the end of TB treatment. Antibody levels were 41.1, 45.5, and 174 mg/L at end of treatment (EOT), respectively. Additionally, two HIV-negative PTB patients with negative Aspergillus-specific IgG antibody levels at baseline became seropositive at EOT (41.9 and 158 mg/L, respectively). Interestingly, none of the HIV-positive PTB patients (40/61) had a positive Aspergillus-specific IgG antibody level at any time, neither at baseline nor at EOT. Probable CPA was diagnosed in one HIV-negative patient (5%; 1/20). Conclusion: Seroprevalence of Aspergillus-specific IgG antibody may differ between HIV-negative and HIV-positive Mozambican PTB patients. Future studies evaluating post-tuberculosis lung disease should integrate CPA as a life-threatening sequel to PTB.

scholarly journals Antibody kinetics and clinical course of COVID-19 a prospective observational study

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248918
Author(s):  
Anna Bläckberg ◽  
Nils Fernström ◽  
Emma Sarbrant ◽  
Magnus Rasmussen ◽  
Torgny Sunnerhagen
Keyword(s):  
Observational Study ◽  
Prospective Observational Study ◽  
Severe Disease ◽  
Antibody Responses ◽  
University Hospital ◽  
Spike Protein ◽  
Serological Response ◽  
Igg Antibody ◽  
Mild Disease ◽  
Antibody Levels

Background Serological response and association to clinical manifestation is important for understanding the pathogenesis of COVID-19. Materials and methods A prospective observational study was conducted where antibody responses of IgG and IgA towards SARS-CoV-2 spike protein were studied over time in patients with COVID-19. Possible associations between antibody titers and outcome were analyzed. Results Forty patients with COVID-19, hospitalized at Skåne University hospital, Sweden, between April and June 2020 were included. IgG antibody responses were detected for all patients with the highest levels four weeks after COVID-19 diagnosis. Levels of IgA were generally higher at diagnosis and decreased towards baseline 4 weeks after confirmed COVID-19. Patients with severe COVID-19 had higher levels of antibodies directed against SARS-CoV-2 spike protein compared with patients with mild disease. Conclusion IgG and IgA antibodies towards the spike protein follow different kinetics during COVID-19 and patients with severe disease develop higher antibody levels.

scholarly journals Effect of Convalescent Plasma on Mortality among Hospitalized Patients with COVID-19: Initial Three-Month Experience

2020 ◽  
Author(s):  
Michael J Joyner ◽  
Jonathon W Senefeld ◽  
Stephen A Klassen ◽  
John R Mills ◽  
Patrick W Johnson ◽  
...  
Keyword(s):  
Antibody Level ◽  
Randomized Clinical Trials ◽  
Igg Antibody ◽  
Open Label ◽  
The Us ◽  
High Antibody Level ◽  
Life Threatening ◽  
Acute Care Facilities ◽  
Transfusion Guidelines ◽  
Antibody Levels

Importance: Passive antibody transfer is a longstanding treatment strategy for infectious diseases that involve the respiratory system. In this context, human convalescent plasma has been used to treat coronavirus disease 2019 (COVID-19), but the efficacy remains uncertain. Objective: To explore potential signals of efficacy of COVID-19 convalescent plasma. Design: Open-label, Expanded Access Program (EAP) for the treatment of COVID-19 patients with human convalescent plasma. Setting: Multicenter, including 2,807 acute care facilities in the US and territories. Participants: Adult participants enrolled and transfused under the purview of the US Convalescent Plasma EAP program between April 4 and July 4, 2020 who were hospitalized with (or at risk of) severe or life threatening acute COVID-19 respiratory syndrome. Intervention: Transfusion of at least one unit of human COVID-19 convalescent plasma using standard transfusion guidelines at any time during hospitalization. Convalescent plasma was donated by recently-recovered COVID-19 survivors, and the antibody levels in the units collected were unknown at the time of transfusion. Main Outcomes and Measures: Seven and thirty-day mortality. Results: The 35,322 transfused patients had heterogeneous demographic and clinical characteristics. This cohort included a high proportion of critically-ill patients, with 52.3% in the intensive care unit (ICU) and 27.5% receiving mechanical ventilation at the time of plasma transfusion. The seven-day mortality rate was 8.7% [95% CI 8.3%-9.2%] in patients transfused within 3 days of COVID-19 diagnosis but 11.9% [11.4%-12.2%] in patients transfused 4 or more days after diagnosis (p<0.001). Similar findings were observed in 30-day mortality (21.6% vs. 26.7%, p<0.0001). Importantly, a gradient of mortality was seen in relation to IgG antibody levels in the transfused plasma. For patients who received high IgG plasma (>18.45 S/Co), seven-day mortality was 8.9% (6.8%, 11.7%); for recipients of medium IgG plasma (4.62 to 18.45 S/Co) mortality was 11.6% (10.3%, 13.1%); and for recipients of low IgG plasma (<4.62 S/Co) mortality was 13.7% (11.1%, 16.8%) (p=0.048). This unadjusted dose-response relationship with IgG was also observed in thirty-day mortality (p=0.021). The pooled relative risk of mortality among patients transfused with high antibody level plasma units was 0.65 [0.47-0.92] for 7 days and 0.77 [0.63-0.94] for 30 days compared to low antibody level plasma units. Conclusions and Relevance: The relationships between reduced mortality and both earlier time to transfusion and higher antibody levels provide signatures of efficacy for convalescent plasma in the treatment of hospitalized COVID-19 patients. This information may be informative for the treatment of COVID-19 and design of randomized clinical trials involving convalescent plasma. Trial Registration: ClinicalTrials.gov Identifier: NCT04338360

scholarly journals SARS-CoV-2-directed antibodies persist for more than six months in a cohort with mild to moderate COVID-19

Infection ◽  
2021 ◽  
Author(s):  
Vivian Glück ◽  
Sonja Grobecker ◽  
Leonid Tydykov ◽  
Bernd Salzberger ◽  
Thomas Glück ◽  
...  
Keyword(s):  
Immune Responses ◽  
Time Course ◽  
Individual Variability ◽  
Igg Antibody ◽  
Severity Of Disease ◽  
Antibody Titers ◽  
Specific Igg ◽  
Antibody Levels ◽  
Specific Symptoms

Abstract Objective To follow serological immune responses of front-line healthcare workers after PCR-confirmed COVID-19 for a mean of 30 weeks, describe the time-course of SARS-CoV-2 spike protein-specific IgG, IgA and IgM levels and to identify associations of the immune response with symptoms, demographic parameters and severity of disease. Methods Anti-SARS-CoV-2 S protein-specific IgG, IgA and IgM antibodies were measured at three time points during the 30-week follow-up. COVID-19-specific symptoms were assessed with standardized questionnaires. Results 95% of the participants mounted an IgG response with only modest decline after week 12. IgG-type antibodies were still detectable in almost 90% of the subjects at 30 weeks. IgA and IgM responses were less robust and antibody titers decreased more rapidly. At 30 weeks, only 25% still had detectable IgA-type and none had IgM-type antibodies. Higher age and higher disease severity were independently associated with higher IgG antibody levels, albeit with wide variations. Conclusion Serological immune responses after COVID-19 show considerable inter-individual variability, but show an association with increasing age and higher severity of disease. IgG-type anti-SARS-CoV-2 antibodies remain positive in 90% of the individuals 30 weeks after onset of symptoms.

scholarly journals Protective characteristics of COVID-19 convalescent and post-vaccination IgG antibodies

2021 ◽  
Author(s):  
Melvin E Klegerman ◽  
Tao Peng ◽  
Ira Seferovich ◽  
Mohammad H. Rahbar ◽  
Manouchehr Hessabi ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Vaccine Development ◽  
Protective Efficacy ◽  
Critical Element ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Post Vaccination ◽  
Lack Of Information

Soon after commencement of the SARS-CoV-2 disease outbreak of 2019 (COVID-19), it became evident that the receptor-binding domain of the viral spike protein is the target of neutralizing antibodies that comprise a critical element of protective immunity to the virus. This study addresses the relative lack of information regarding actual antibody concentrations in convalescent plasma samples from COVID-19 patients and extends these analyses to post-vaccination samples to estimate protective IgG antibody (Ab) levels. Both sample populations were similar and a protective Ab level of 7.5 μg/ml was determined, based on 95% of the normal distribution of the post-vaccination population. The results of this study have implications for future vaccine development, projection of protective efficacy duration, and understanding of the immune response to SARS-CoV-2 infection.

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