scholarly journals Examination of convalescents after West Nile fever for the specific IgM, IgG and neutralizing antibodies

2016 ◽  
Vol 21 (2) ◽  
pp. 82-86
Author(s):  
Alla R. Azaryan ◽  
A. A Kozlova ◽  
A. P Grishanova ◽  
E. I Ivashchenko ◽  
G. L Shendo ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Igg Antibodies ◽  
West Nile Fever ◽  
Serum Samples ◽  
West Nile ◽  
Negative Results ◽  
Igm Elisa ◽  
Control Research ◽  
Specific Igg ◽  
Specific Igg Antibodies

The examination was executed in the Astrakhan region over 2013-2014 with participation of three laboratories. In 26 convalescents after West Nile Fever (WNF) with the serological confirmed diagnosis of WNF blood sera were examined. Neurological form of WNF was observed in 8 cases, and febrile form - in 8 convalescents. Sera have been collected in 243-358 days, on average, in 308 days after the beginning of a disease. For their examination there were used IFA-IgM ELISA (MAC-ELISA), IgG ELISA methods as well as neutralization test in Vero E6 cell culture. The results of the examination in 24 of 26 patients (92, 3%) for IgM antibodies to the virus WNF were negative. In two convalescents according to the laboratories in Astrakhan and Moscow in sera there were observed low titers of IgM (1:400) with minor indices of sera optical density (0.3 to 0.4) and negative results in the Volgograd Plague Control Research Institute. Serum samples of other two convalescents were weakly positive or questionable in testing in Volgograd, but were negative when examined in the Institute of Virology. Specific IgG antibodies were detected in 23 of 26 convalescents (88.5%), neutralizing in 22 of 24 (91.7 %). These data confirm the adequacy of the criteria and tactics for WNF serodiagnosis adopted in Russia based on the application of the MAC -ELISA (IFA - IgM).

scholarly journals Endogenously Produced SARS-CoV-2 Specific IgG Antibodies May Have a Limited Impact on Clearing Nasal Shedding of Virus during Primary Infection in Humans

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 516
Author(s):  
Shuyi Yang ◽  
Keith R. Jerome ◽  
Alexander L. Greninger ◽  
Joshua T. Schiffer ◽  
Ashish Goyal
Keyword(s):  
Production Rate ◽  
Neutralizing Antibodies ◽  
Primary Infection ◽  
Natural Infection ◽  
Viral Clearance ◽  
Clinical Severity ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
Specific Igg ◽  
Specific Igg Antibodies

While SARS-CoV-2 specific neutralizing antibodies have been developed for therapeutic purposes, the specific viral triggers that drive the generation of SARS-CoV-2 specific IgG and IgM antibodies remain only partially characterized. Moreover, it is unknown whether endogenously derived antibodies drive viral clearance that might result in mitigation of clinical severity during natural infection. We developed a series of non-linear mathematical models to investigate whether SARS-CoV-2 viral and antibody kinetics are coupled or governed by separate processes. Patients with severe disease had a higher production rate of IgG but not IgM antibodies. Maximal levels of both isotypes were governed by their production rate rather than different saturation levels between people. Our results suggest that an exponential surge in IgG levels occurs approximately 5–10 days after symptom onset with no requirement for continual antigenic stimulation. SARS-CoV-2 specific IgG antibodies appear to have limited to no effect on viral dynamics but may enhance viral clearance late during primary infection resulting from the binding effect of antibody to virus, rather than neutralization. In conclusion, SARS-CoV-2 specific IgG antibodies may play only a limited role in clearing infection from the nasal passages despite providing long-term immunity against infection following vaccination or prior infection.

scholarly journals Broadly Neutralizing Hemagglutinin Stalk-Specific Antibodies Induce Potent Phagocytosis of Immune Complexes by Neutrophils in an Fc-Dependent Manner

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Caitlin E. Mullarkey ◽  
Mark J. Bailey ◽  
Diana A. Golubeva ◽  
Gene S. Tan ◽  
Raffael Nachbagauer ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Fc Receptor ◽  
Igg Antibodies ◽  
Specific Antibodies ◽  
Effector Functions ◽  
Iga Antibodies ◽  
Specific Igg ◽  
Optimal Protection ◽  
Specific Igg Antibodies

ABSTRACTBroadly neutralizing antibodies that recognize the conserved hemagglutinin (HA) stalk have emerged as exciting new biotherapeutic tools to combat seasonal and pandemic influenza viruses. Our general understanding of the mechanisms by which stalk-specific antibodies achieve protection is rapidly evolving. It has recently been demonstrated that broadly neutralizing HA stalk-specific IgG antibodies require Fc-Fcγ receptor (FcγR) interactions for optimal protectionin vivo. Here we examine the neutrophil effector functions induced by stalk-specific antibodies. As the most abundant subset of blood leukocytes, neutrophils represent a critical innate effector cell population and serve an instrumental role in orchestrating downstream adaptive responses to influenza virus infection. Yet, the interplay of HA stalk-specific IgG, Fc-FcγR engagement, and neutrophils has remained largely uncharacterized. Using anin vitroassay to detect the production of reactive oxygen species (ROS), we show that human and mouse monoclonal HA stalk-specific IgG antibodies are able to induce the production of ROS by neutrophils, while HA head-specific antibodies do not. Furthermore, our results indicate that the production of ROS is dependent on Fc receptor (FcR) engagement and phagocytosis. We went on to assess the ability of monoclonal HA stalk-specific IgA antibodies to induce ROS. Consistent with our findings for monoclonal IgGs, only HA stalk-specific IgA antibodies elicited ROS production by neutrophils. This induction is dependent on the engagement of FcαR1. Taken together, our findings describe a novel FcR-dependent effector function induced by HA stalk-specific IgG and IgA antibodies, and importantly, our studies shed light on the mechanisms by which HA stalk-specific antibodies achieve protection.IMPORTANCEThe present study provides evidence that broadly neutralizing HA stalk-specific antibodies induce downstream Fc-mediated neutrophil effector functions. In addition to their ability to neutralize, this class of antibodies has been shown to rely on Fc-Fc receptor interactions for optimal protectionin vivo. Curiously, neutralizing antibodies that bind the HA head domain do not require such interactions. Our findings build on these previous observations and provide a more complete picture of the relationship between stalk-specific antibodies and cells of the innate immune compartment. Furthermore, our data suggest that the ability of HA stalk-specific antibodies to mediate Fc-Fc receptor engagement is epitope dependent. Overall, this work will inform the rational design of improved influenza virus vaccines and therapeutics.

scholarly journals Contribution to canine babesiosis in the Czech Republic

2012 ◽  
Vol 81 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Jarmila Konvalinová ◽  
Ivo Rudolf ◽  
Silvie Šikutová ◽  
Zdeněk Hubálek ◽  
Vlasta Svobodová ◽  
...  
Keyword(s):  
Czech Republic ◽  
Dermacentor Reticulatus ◽  
Igg Antibodies ◽  
Canine Babesiosis ◽  
The Czech Republic ◽  
Negative Results ◽  
Working Dogs ◽  
Specific Igg ◽  
Polymerase Chain ◽  
Specific Igg Antibodies

From March to November 2010, a total of 68 samples of blood from 41 hunting and working dogs that never left the Czech Republic were examined. Some dogs were sampled repeatedly. Blood samples were examined by polymerase chain reaction for the presence of DNA of piroplasms with negative results. Specific IgG antibodies against Babesia canis were detected by indirect immunofluorescence test, and five dogs (12.21%) were seropositive. Titres ranged from 50 to 200. One dog was positive in two samplings within 3 months. The highest number of positive samples was taken in June. The results of this study suggest a likely contact of the examined dogs with the parasite; although in 2005, a total of 340 adult unfed Dermacentor reticulatus ticks in 34 pools screened by PCR for babesiae were negative.

scholarly journals Seroprevalence of SARS-CoV-2-specific IgG antibodies in Kashmir, India, 7 months after the first reported local COVID-19 case: results of a population-based seroprevalence survey from October to November 2020

BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e053791
Author(s):  
S Muhammad Salim Khan ◽  
Mariya Amin Qurieshi ◽  
Inaamul Haq ◽  
Sabhiya Majid ◽  
Javid Ahmad ◽  
...  
Keyword(s):  
Sampling Design ◽  
Final Analysis ◽  
Population Based ◽  
Secondary Outcome ◽  
Igg Antibodies ◽  
Serum Samples ◽  
History Of ◽  
Specific Igg ◽  
Index Value ◽  
Specific Igg Antibodies

ObjectivesWe designed a population-based survey in Kashmir to estimate the seroprevalence of SARS-CoV-2-specific IgG antibodies in the general population aged 18 years and above.SettingThe survey was conducted among 110 villages and urban wards across 10 districts in Kashmir from 17 October 2020 to 4 November 2020.ParticipantsIndividuals aged 18 years and above were eligible to be included in the survey. Serum samples were tested for the presence of SARS-CoV-2-specific IgG antibodies using the Abbott SARS-CoV-2 IgG assay.Primary and secondary outcome measuresWe labelled assay results equal to or above the cut-off index value of 1.4 as positive for SARS-CoV-2-specific IgG antibodies. Seroprevalence estimates were adjusted for the sampling design and assay characteristics.ResultsOut of 6397 eligible individuals enumerated, 6315 (98.7%) agreed to participate. The final analysis was done on 6230 participants. Seroprevalence adjusted for the sampling design and assay characteristics was 36.7% (95% CI 34.3% to 39.2%). Seroprevalence was higher among the older population. Among seropositive individuals, 10.2% (247/2415) reported a history of COVID-19-like symptoms. Out of 474 symptomatic individuals, 233 (49.2%) reported having been tested. We estimated an infection fatality rate of 0.034%.ConclusionsDuring the first 7 months of the COVID-19 epidemic in Kashmir Valley, approximately 37% of individuals were infected. The reported number of COVID-19 cases was only a small fraction of the estimated number of infections. A more efficient surveillance system with strengthened reporting of COVID-19 cases and deaths is warranted.

scholarly journals Antibody response to SARS-CoV-2 infection and BNT162b2 vaccine in Israel

2021 ◽  
Author(s):  
Guy Shapira ◽  
Ramzia Abu Hamad ◽  
Chen Weiner ◽  
Nir Rainy ◽  
Reut Sorek-Abramovich ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Host Cells ◽  
Spike Protein ◽  
Igg Antibodies ◽  
Age And Gender ◽  
Specific Igg ◽  
And Gender ◽  
Specific Igg Antibodies

Neutralizing antibodies targeting the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) block viral entry to host cells, preventing disease and further spread of the pathogen. The presence of SARS-CoV-2 antibodies in serum is a reliable indicator of infection, used epidemiologically to estimate the prevalence of infection and clinically as a measurement of an antigen-specific immune response. In this study, we analyzed serum Spike protein-specific IgG antibodies from 26,170 samples, including convalescent individuals who had coronavirus disease 2019 (COVID-19) and recipients of the BNT162b2 vaccine. We find distinct serological patterns in COVID-19 convalescent and vaccinated individuals, correlated with age and gender and the presence symptoms.

scholarly journals SEROPREVALENCE OF ANTI-MEASLES IGG IN THE POPULATION OF KHARKIV REGION IN 2018-2019

2019 ◽  
pp. 22-25
Author(s):  
Igor Yudin ◽  
Irina Kuchma ◽  
Andriy Voliansky
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Igg Antibodies ◽  
Prevention Strategies ◽  
Elisa Method ◽  
Negative Results ◽  
Specific Igg ◽  
Susceptible Populations ◽  
Vaccination Campaigns ◽  
Specific Igg Antibodies

Aim. The aim of this study was to evaluate herd immunity against measles in different age groups of the Kharkiv region of Ukraine’s population. Materials and methods. Seroprevalence of specific IgG antibodies was studied among different age groups of the Kharkiv region population from February 2018 to July 2019 by ELISA method. Results. A number of 6564 sera samples were processed. The overall seropositivity level was 91.3%; negative results were 5.3% and 3.3% equivocal. The highest seropositivity for IgG (> 98%) was in people aged 50 years and older. The lowest seropositivity rates were observed in the cohorts of 20-29 years (87.2%), 30-39 years (86.9%), and 40-49 years (91.1%). Conclusions. Measles-susceptible populations were identified for which new prevention strategies should be applied in the form of personalized vaccination campaigns to increase herd immunity.

scholarly journals SARS-CoV-2 seroprevalence in healthcare workers of dedicated-COVID hospitals and non–COVID hospitals of District Srinagar, Kashmir

2020 ◽  
Author(s):  
Muhammad Salim Khan ◽  
Inaamul Haq ◽  
Mariya Amin Qurieshi ◽  
Sabhiya Majid ◽  
Arif Akbar Bhat ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
High Risk Group ◽  
Infection Prevention And Control ◽  
Institutional Setting ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
Cross Sectional ◽  
Specific Igg ◽  
Specific Igg Antibodies

AbstractBackground and objectiveSARS-CoV-2 infection poses tremendous challenge to the healthcare system of nations across the globe. Serological testing for SARS-CoV-2 infection in healthcare workers, which form a high-risk group, helps in identifying the burden of hidden infection in an institutional setting.MethodsWe present the results of a cross-sectional serosurvey in healthcare workers from two different hospital settings based on their role in the management of SARS-CoV-2 patients in District Srinagar, Kashmir. In addition to testing for the presence of SARS-CoV-2 specific IgG, we collected information on influenza-like symptoms in the last four weeks and the status of RT-PCR testing. SARS-CoV-2 specific IgG antibodies were detected in serum samples using a sensitive and specific chemiluminescent microparticle immunoassay technology.Interpretation and ConclusionOf 2915 healthcare workers who participated in the study, we analysed data from 2905 healthcare workers. The overall prevalence of SARS-CoV-2 specific IgG antibodies was 2.5% (95% CI 2.0-3.1) in the healthcare workers of District Srinagar. Healthcare workers who had ever worked at a dedicated-COVID hospital had a substantially lower seroprevalence of 0.6% (95% CI: 0.2 - 1.9). Among healthcare workers who had tested positive for RT-PCR, seroprevalence was 27.6% (95% CI: 14.0 - 47.2).The seroprevalence of SARS-CoV-2 infection in healthcare workers of District Srinagar is low, reflecting that a high proportion of healthcare workers are still susceptible to the infection. It is crucial to lay thrust on infection prevention and control activities and standard hygiene practices by the healthcare staff to protect them from acquiring infection within the healthcare setting.

scholarly journals Depigmented Allergoids Reveal New Epitopes with Capacity to Induce IgG Blocking Antibodies

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Angeles López-Matas ◽  
Mayte Gallego ◽  
Víctor Iraola ◽  
Douglas Robinson ◽  
Jerónimo Carnés
Keyword(s):  
Birch Pollen ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Bet V 1 ◽  
Ige Binding ◽  
Linear Epitopes ◽  
Specific Igg ◽  
Allergen Extracts ◽  
Blocking Antibodies ◽  
Specific Igg Antibodies

Background. The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies.Methods. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined.Results. Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract.Conclusions. Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.

Immunity to measles in Italian children and adolescents: a persistent problem in view of measles elimination

2020 ◽  
Author(s):  
Serena Marchi ◽  
Martina Monti ◽  
Simonetta Viviani ◽  
Edmond J Remarque ◽  
Susanna Esposito ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Susceptible Population ◽  
Persistent Problem ◽  
Measles Elimination ◽  
Measles Vaccination ◽  
Specific Igg ◽  
Italian Children ◽  
Specific Igg Antibodies

Abstract Background Despite efforts to increase coverage by two doses of measles vaccine in Italy, measles continues to circulate, with over 13 000 cases of disease since 2013. This study aimed to evaluate immunity to measles in Italian children and adolescents. Methods A total of 378 serum samples from subjects aged 9 months–18 years were collected in Northern, Central and Southern regions of Italy between 2012 and 2016. Specific IgG antibodies against measles were measured by a commercial ELISA kit. Results The frequency of IgG-positive samples ranged from 10.5% in infants under 1 year to 98.3% in children aged 6–7 years. The frequency of IgG was 72.2% in subjects aged 1–2 years, 85.6% in those aged 3–5 years and 88.3 and 86.8% in those aged 8–10 and 11–18 years, respectively. In Northern Italy, IgG prevalence was consistent with data on vaccination coverage, whereas some differences were observed in samples from subjects aged more than 8 years in Central and Southern Italy. Conclusions Our findings confirm that a large proportion of children and adolescents in Italy are still susceptible to measles. While data on first- and second-dose measles vaccination are essential, they are not sufficient to identify susceptible population cohorts to be targeted by vaccination.

scholarly journals Application of immunoassay systems for diagnosis of dengue fever

2015 ◽  
Vol 20 (4) ◽  
pp. 8-12
Author(s):  
Yu. A Akinshina ◽  
V. F Larichev ◽  
S. G Mardanly ◽  
A. M Butenko ◽  
N. V Khutoretskaya ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Dengue Fever ◽  
Experimental Test ◽  
Igg Antibodies ◽  
West Nile Fever ◽  
West Nile ◽  
Cross Reactions ◽  
Test Systems ◽  
Tick Borne Encephalitis ◽  
Specific Igg

As a result of the application of experimental test systems "ELISA-IgM-dengue", "ELISA-IgM-WN" and "ELISA-IgM-TBE" when examining sera from patients with dengue fever (DF), West Nile fever (WNF) and tick-borne encephalitis (TBE) there was established the possibility of a clear differential diagnosis of these related flavivirus infections. Application of the ELISA-IgG test systems fail to provide such an opportunity due to cause of pronounced cross-reactions of group-IgG antibodies. In the article there are presented data on dynamics of IgM and IgG antibodies in patients with dengue fever. Detection of specific IgG in the first days of the disease may indicate to a secondary nature of infection and the possibility of the development of hemorrhagic syndrome.

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