Kinetics of anti-SARS-CoV-2 IgG antibody levels and potential influential factors in subjects with COVID-19: A 11-month follow-up study

ABSTRACTThe performance of a rapid and simple immunochromatographic test (ICT) with recombinant Em18 (rEm18) antigen for serological follow-up ofEchinococcus multilocularisinfection was evaluated by comparison with that of an enzyme-linked immunosorbent assay (ELISA) with rEm18, using serum samples from patients who underwent surgery and/or received antiparasitic chemotherapy. The degree of Em18-band intensity on the ICT correlated highly with the absorbance value obtained by the ELISA. The kinetics of antibody levels obtained by the ICT paralleled those of the ELISA. These data suggest that the ICT has high potential as an easy-to-handle, fast, and reliable follow-up tool to monitor the status of alveolar echinococcosis in different stages.

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Abstract 2425: Absence of Auto-Antibodies against Cardiac Troponin I Predicts Improvement of Left Ventricular Function after Acute Myocardial Infarction

Circulation ◽

10.1161/circ.118.suppl_18.s_724-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Florian Leuschner ◽

Jin Li ◽

Stefan Göser ◽

Lars Reinhardt ◽

Renate Öttl ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

Stroke Volume ◽

Antibody Titer ◽

Cardiac Troponin ◽

Troponin I ◽

Cardiac Troponin I ◽

Igg Antibody ◽

Follow Up Study

Application of antibodies against cardiac troponin I (cTnI-Ab) can induce dilation and dysfunction of the heart in mice. Recently, we demonstrated that immunization with cTnI induces inflammation and fibrosis in myocardium of mice. Others have shown that autoanti-bodies to cTnI are present in patients with acute coronary syndrome. But little is known about the clinical relevance of detected cTnI-Ab. First, anti-cTnI and anti-cTnT antibody titers were measured in sera from 272 patients with dilated- (DCM) and 185 with ischemic- (ICM) cardiomyopathy. Secondly, 108 patients with acute myocardial infarction (AMI) were included for a follow-up study. Heart characteristics were determined by magnetic resonance imaging 4 days and 6 –9 months after AMI. Altogether, in 7,0% of patients with DCM and in 9,2% with ICM an anti-cTnI IgG antibody titer ≥1:160 was measured. In contrast, only in 1,7% of patients with DCM and in 0,5% with ICM an anti-cTnT IgG antibody titer ≥1:160 was detected. Ten out of 108 patients included in the follow-up study were tested positive for cTnI-Ab with IgG Ab titers ≥1:160. TnI-Ab negative patients showed a significant increase in LVEF and stroke volume 6 –9 months after AMI. In contrast, there was no significant increase in LVEF and stroke volume in TnI-Ab positive patients. We demonstrate for the first time that the prevalence of cTnI-Abs in patients with AMI has an impact on the improvement of the LVEF over a study period of 6 –9 months.

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

Scientific Reports ◽

10.1038/s41598-021-95045-z ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 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.

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Viral and Antibody Kinetics of COVID-19 Patients with Different Disease Severities in Acute and Convalescent Phases: A 6-Month Follow-Up Study

Virologica Sinica ◽

10.1007/s12250-020-00329-9 ◽

2020 ◽

Author(s):

Xiaoyong Zhang ◽

Suwen Lu ◽

Hui Li ◽

Yi Wang ◽

Zhen Lu ◽

...

Keyword(s):

Follow Up Study ◽

Antibody Kinetics ◽

Kinetics Of

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Outbreak of human toxoplasmosis in a rural area. A three year serologic follow-up study

Memórias do Instituto Oswaldo Cruz ◽

10.1590/s0074-02761982000100004 ◽

1982 ◽

Vol 77 (1) ◽

pp. 29-36 ◽

Cited By ~ 7

Author(s):

Sergio Gomes Coutinho ◽

Anastácio Morgado ◽

Marina Wagner ◽

Renato Lobo ◽

Frits Sutmoller

Keyword(s):

Clinical Picture ◽

Clinical Evidence ◽

Toxoplasma Infection ◽

Igg Antibody ◽

Modes Of Transmission ◽

Follow Up Study ◽

Farm Population ◽

Antibody Titres ◽

Serologic Evidence

Thirty-six persons living on a farm located in the state of Minas Gerais (Brazil) were studied. Nine of them had the glandular form of toxoplasmosis, between May and August, 1976. These nine cases of toxoplasmosis were confirmed serologically by immunefluorescence-IF-, presenting IgG antibody titres between 1:4096 and 1:32000 and IgM antibody titres between 1:16 and 1:8000. Twelve out of thirty-six persons studied were considered to be "dubious cases". They were defined either by presenting a clinical picture compatible with acquired toxoplasmosis, yet having low serologic titres, or inversely they did not have a clear clinical picture but had serologic evidence of recent Toxoplasma infection. Fifteen out of thirty-six persons studied showed neither serologic nor clinical evidence of recent Toxoplasma infection. The epidemiologic information suggests two possible modes of transmission: a) poorly cooked pork at a barbecue party; b) farm vegetables and soil contaminated with Toxoplasma gondii oocysts (rat-cat cycle). Serologic follow-up nine months later in the human farm population demonstrated still high IgG titres, yet they tended to decline and IgM titres became negative. Three years later most of the IgG titres continued to decline and were almost compatible with the titres obtained in Brazilian population surveys.

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Gait kinetics of total hip replacement patients—A large scale, long-term follow-up study

Gait & Posture ◽

10.1016/j.gaitpost.2017.01.014 ◽

2017 ◽

Vol 53 ◽

pp. 173-178 ◽

Cited By ~ 10

Author(s):

Damien Bennett ◽

Paul Ryan ◽

Seamus O’Brien ◽

David E. Beverland

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Large Scale ◽

Total Hip ◽

Follow Up Study ◽

Long Term Follow Up ◽

Kinetics Of

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Comparative evaluation of three commercial Toxoplasma-specific IgG antibody avidity tests and significance in different clinical settings

Journal of Medical Microbiology ◽

10.1099/jmm.0.006668-0 ◽

2009 ◽

Vol 58 (3) ◽

pp. 358-364 ◽

Cited By ~ 21

Author(s):

Branko Bobić ◽

Ivana Klun ◽

Marija Vujanić ◽

Aleksandra Nikolić ◽

Vladimir Ivović ◽

...

Keyword(s):

Clinical Settings ◽

Igg Antibody ◽

Perfect Agreement ◽

Igg Avidity ◽

Resource Limited ◽

Specific Igg ◽

Set Up ◽

Kinetics Of

Determination of the avidity of specific IgG antibodies has become a generally accepted diagnostic aid for dating Toxoplasma infection. In this study, the Labsystems, VIDAS and EUROIMMUN Toxoplasma IgG avidity assays were compared on a series of 133 Toxoplasma IgG- and IgM-positive sera from symptomatic patients (n=28), from pregnant (n=43) and non-pregnant (n=26) women, and on 18 IgG-positive and IgM-negative sera from chronically infected patients. The results showed excellent concordance between the Labsystems and VIDAS tests in both the IgM-positive (r=0.82, κ=0.771) and IgM-negative (κ=0.609) sera, whilst the agreement of the EUROIMMUN assay with both the Labsystems and VIDAS tests in the IgM-positive sera was moderate (κ=0.575 and κ=0.525, respectively) and in the IgM-negative sera was poor (κ=0.000). Analysis of the kinetics of the maturation of avidity in 13 patients in whom follow-up sera were available showed that, despite a general trend of maturation, in two patients the avidity did not become high during 6 and 11 months of follow-up. In view of the clinical setting, in the symptomatic patients, despite one case of complete discrepancy and five cases of partial discrepancy, the Labsystems and VIDAS tests were in almost perfect agreement (κ=0.812), whilst the agreement in pregnant and non-pregnant women was substantial (κ=0.754 and κ=0.708, respectively). In conclusion, the Labsystems and VIDAS tests are equally reliable for the measurement of Toxoplasma IgG avidity; the choice of test should depend on the laboratory set-up. The EUROIMMUN test may be an acceptable alternative in resource-limited settings, but should be used prudently.

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Performance Evaluation of the Siemens SARS-CoV-2 Total Antibody and IgG Antibody Test

Laboratory Medicine ◽

10.1093/labmed/lmab027 ◽

2021 ◽

Author(s):

Lisa Florin ◽

Karel Maelegheer ◽

Wouter Vandewal ◽

Dirk Bernard ◽

Johan Robbrecht

Keyword(s):

Antibody Test ◽

Control Group ◽

Igg Antibody ◽

Antibody Assays ◽

Antibody Titers ◽

Polymerase Chain ◽

Kinetics Of ◽

Antibody Tests ◽

Positive Controls

Abstract Objective In this study, the performance of 2 commercially available SARS-CoV-2 antibody assays is evaluated. Methods The Siemens SARS-CoV-2 Total (COV2T) and IgG (COV2G) antibody tests were evaluated on a Siemens Atellica IM1300 analyzer. Imprecision was assessed with the CLSI EP15 protocol using positive controls. Ninety control group specimens were analyzed for specificity, and 175 specimens from 58 patients with polymerase chain reaction–confirmed SARS-CoV-2 were measured for the sensitivity and kinetics of the antibody response. Results Within-run and total imprecision were acceptable for both assays. Both tests showed a specificity of 100%. Sensitivity earlier in the disease state was greater for the COV2T assay than for the COV2G assay, but sensitivity >14 days after onset of symptoms approached 100% for both. For all patients, antibody titers remained above the seroconversion cutoff for all follow-up specimens. Conclusion This study shows acceptable performance for both the Siemens COV2T and COV2G test, although seroconversion occurs earlier with the COV2T test.

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Large-Scale Study of Antibody Titer Decay following BNT162b2 mRNA Vaccine or SARS-CoV-2 Infection

Vaccines ◽

10.3390/vaccines10010064 ◽

2021 ◽

Vol 10 (1) ◽

pp. 64

Author(s):

Ariel Israel ◽

Yotam Shenhar ◽

Ilan Green ◽

Eugene Merzon ◽

Avivit Golan-Cohen ◽

...

Keyword(s):

Large Scale ◽

Immune Protection ◽

Igg Antibodies ◽

Igg Antibody ◽

Exponential Decrease ◽

Previous Infection ◽

History Of ◽

Antibody Titers ◽

Antibody Levels ◽

Kinetics Of

Immune protection following either vaccination or infection with SARS-CoV-2 is thought to decrease over time. We designed a retrospective study, conducted at Leumit Health Services in Israel, to determine the kinetics of SARS-CoV-2 IgG antibodies following administration of two doses of BNT162b2 vaccine, or SARS-CoV-2 infection in unvaccinated individuals. Antibody titers were measured between 31 January 2021, and 31 July 2021 in two mutually exclusive groups: (i) vaccinated individuals who received two doses of BNT162b2 vaccine and had no history of previous infection with COVID-19 and (ii) SARS-CoV-2 convalescents who had not received the vaccine. A total of 2653 individuals fully vaccinated by two doses of vaccine during the study period and 4361 convalescent patients were included. Higher SARS-CoV-2 IgG antibody titers were observed in vaccinated individuals (median 1581 AU/mL IQR [533.8–5644.6]) after the second vaccination than in convalescent individuals (median 355.3 AU/mL IQR [141.2–998.7]; p < 0.001). In vaccinated subjects, antibody titers decreased by up to 38% each subsequent month while in convalescents they decreased by less than 5% per month. Six months after BNT162b2 vaccination 16.1% subjects had antibody levels below the seropositivity threshold of <50 AU/mL, while only 10.8% of convalescent patients were below <50 AU/mL threshold after 9 months from SARS-CoV-2 infection. This study demonstrates individuals who received the Pfizer-BioNTech mRNA vaccine have different kinetics of antibody levels compared to patients who had been infected with the SARS-CoV-2 virus, with higher initial levels but a much faster exponential decrease in the first group.

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