scholarly journals Serological Survey of Hantavirus in Inhabitants from Tropical and Subtropical Areas of Brazil

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Felipe Alves Morais ◽  
Alexandre Pereira ◽  
Aparecida Santo Pietro Pereira ◽  
Marcos Lazaro Moreli ◽  
Luís Marcelo Aranha Camargo ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Atlantic Rain Forest ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Tropical Area ◽  
Forest Region ◽  
Human Sera ◽  
Tropical Areas ◽  
Antibody Levels ◽  
Recombinant Nucleocapsid Protein

Brazil has reported more than 1,600 cases of hantavirus cardiopulmonary syndrome (HPS) since 1993, with a 39% rate of reported fatalities. Using a recombinant nucleocapsid protein ofAraraquaravirus, we performed ELISA to detect IgG antibodies against hantavirus in human sera. The aim of this study was to analyze hantavirus antibody levels in inhabitants from a tropical area (Amazon region) in Rondônia state and a subtropical (Atlantic Rain Forest) region in São Paulo state, Brazil. A total of 1,310 serum samples were obtained between 2003 and 2008 and tested by IgG-ELISA, and 82 samples (6.2%), of which 62 were from the tropical area (5.8%) and 20 from the subtropical area (8.3%), tested positive. Higher levels of hantavirus antibody were observed in inhabitants of the populous subtropical areas compared with those from the tropical areas in Brazil.

scholarly journals Detection of diphtheria toxin antibodies in human sera in New Zealand by ELISA

1986 ◽  
Vol 96 (3) ◽  
pp. 415-418 ◽  
Author(s):  
R. C. H. Lau
Keyword(s):  
New Zealand ◽  
Diphtheria Toxin ◽  
Epidemiological Survey ◽  
Survey Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Age Group ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Human Sera ◽  
Antibody Levels

SUMMARYAn enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG antibodies to diphtheria toxin in human serum. Serum samples obtained from 557 normal persons aged 1–65 years from different areas in New Zealand showed maximum antibody levels in the 1–9 years age group (95·1%) and the least in the 60–65 years age group (38·1%). The indirect ELISA is suitable for sero-epidemiological survey study as it is simple to perform, economical and precise.

scholarly journals Stable IgG-antibody levels in patients with mild SARS-CoV-2 infection

2021 ◽  
Author(s):  
Thomas Akerlund ◽  
Katherina Zakikhany ◽  
Charlotta Lofstrom ◽  
Evelina Lindmark ◽  
Henrik Kallberg ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Spike Protein ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Time Period ◽  
Specific Igg ◽  
Antibody Levels ◽  
Over Time ◽  
Specific Igg Antibodies

More knowledge regarding persistence of antibody response to SARS-CoV-2 infections in the general population with mild symptoms is needed. We measured and compared levels of SARS-CoV-2 spike- and nucleocapsid-specific IgG-antibodies in serum samples from 145 laboratory-confirmed COVID-19 cases and 324 non-cases. The IgG-antibody levels against the spike protein in cases were stable over the time-period studied (14 to 256 days), while antibody levels against the nucleocapsid protein decreased over time.

scholarly journals Immunoglobulin G and A Antibody Responses to Bacteroides forsythus and Prevotella intermedia in Sera and Synovial Fluids of Arthritis Patients

2003 ◽  
Vol 10 (6) ◽  
pp. 1043-1050 ◽  
Author(s):  
Ketil Moen ◽  
Johan G. Brun ◽  
Tor Magne Madland ◽  
Turid Tynning ◽  
Roland Jonsson
Keyword(s):  
Immune Responses ◽  
Immunoglobulin G ◽  
Enzyme Linked Immunosorbent Assay ◽  
Prevotella Intermedia ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Iga Antibodies ◽  
Iga Antibody ◽  
Antibody Levels

ABSTRACT The objective of the present study was to investigate immunoglobulin G (IgG) and IgA antibody immune responses to Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, and Candida albicans in the sera of patients with rheumatoid arthritis (RA), the synovial fluid (SF) of patients with RA (RA-SF samples), and the SF of patients without RA (non-RA-SF samples). An enzyme-linked immunosorbent assay was used to determine IgG and IgA antibody levels in 116 serum samples from patients with RA, 52 RA-SF samples, and 43 non-RA-SF samples; and these were compared with those in SF samples from 9 patients with osteoarthritis (OA-SF samples) and the blood from 100 donors (the control [CTR] group). Higher levels of IgG antibodies against B. forsythus (P < 0.0001) and P. intermedia (P < 0.0001) were found in non-RA-SF samples than in OA-SF samples, and higher levels of IgG antibodies against B. forsythus (P = 0.003) and P. intermedia (P = 0.024) were found in RA-SF samples than in OA-SF samples. Significantly higher levels of IgA antibodies against B. forsythus were demonstrated in both RA-SF and non-RA-SF samples than in OA-SF samples. When corrected for total Ig levels, levels of IgG antibody against B. forsythus were elevated in RA-SF and non-RA-SF samples compared to those in OA-SF samples. Lower levels of Ig antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group for both IgG (P = 0.003) and IgA (P < 0.0001). When corrected for total Ig levels, the levels of IgG and IgA antibodies against B. forsythus were still found to be lower in the sera from patients with RA than in the plasma of the CTR group (P < 0.0001). The levels of antibodies against P. gingivalis and C. albicans in the sera and SF of RA and non-RA patients were comparable to those found in the respective controls. The levels of IgG and IgA antibodies against B. forsythus were elevated in SF from patients with RA and non-RA-SF samples compared to those in OA-SF samples. Significantly lower levels of IgG and IgA antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group. This indicates the presence of an active antibody response in synovial tissue and illustrates a potential connection between periodontal and joint diseases.

scholarly journals Transplacental Transfer of SARS-CoV-2 Antibodies

2020 ◽  
Author(s):  
Dustin D. Flannery ◽  
Sigrid Gouma ◽  
Miren B. Dhudasia ◽  
Sagori Mukhopadhyay ◽  
Madeline R. Pfeifer ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Transplacental Transfer ◽  
Antibody Levels

AbstractWe measured SARS-CoV-2 antibody levels in serum samples from 1,471 mother/newborn dyads and found efficient transplacental transfer of SARS-CoV-2 IgG antibodies in 72 of 83 seropositive pregnant women. Transfer ratios >1.0 were observed among women with an asymptomatic SARS-CoV-2 infection as well as those with mild, moderate and severe COVID-19. Our findings demonstrate the potential for maternally-derived antibodies to provide neonatal protection from SARS-CoV-2 infection.

scholarly journals Viral load and antibody levels in patients with COVID-19

2021 ◽  
Vol 8 (3) ◽  
pp. 010-018
Author(s):  
Iva Christova ◽  
Iva Trifonova ◽  
Teodora Gladnishka ◽  
Elena Dragusheva ◽  
Georgi Popov ◽  
...  
Keyword(s):  
Viral Load ◽  
High Viral Load ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
Weekly Basis ◽  
Specific Antibody Response ◽  
Viral Loads ◽  
Antibody Levels ◽  
Kinetics Of

Relations between viral load, antibody levels and COVID-19 severity are not well studied and results from such investigations are controversial. In this study, we investigated kinetics of viral load and antibody responses to SARS-CoV-2 in 20 patients with COVID-19 and analysed the association with disease severity. The patients were followed on weekly basis within the first month after the onset and then once per month for the next 4 months. Serum samples were tested for IgA, IgM, and IgG antibodies against SARS-CoV-2 using ELISA tests. SARS-CoV-2 viral load in nasopharyngeal swabs was measured by quantitative Realtime RT-PCR. For vast majority of the patients, the viral loads were at their highest levels at presentation and then declined gradually. Despite development of specific antibody response 7-11 days after the onset of COVID-19, SARS-CoV-2 RNA was still detected in nasopharyngeal swabs of most of the patients. There was no direct link between viral load and severity of COVID-19: some of mild and some of severe cases started with a high viral load. There was a relationship between the time from the onset of the disease and the viral load: the highest viral load was in the first days. In more severe cases, there was a tendency for slower reduction in viral load and longer detection of SARS-CoV-2 virus. Levels of the specific antibodies increased earlier and to higher levels and were present for longer time in patients with more severe manifestations of COVID-19 than in those with milder disease.

scholarly journals Seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in Tyrol, Austria: Large-scale study of 35,193 blood donors conducted between June 2020 and September 2021

2021 ◽  
Author(s):  
Anita Siller ◽  
Lisa Seekircher ◽  
Gregor A Wachter ◽  
Manfred Astl ◽  
Lena Tschiderer ◽  
...  
Keyword(s):  
Large Scale ◽  
Blood Donors ◽  
Participation Rate ◽  
Federal State ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Nucleocapsid Proteins ◽  
Antibody Levels ◽  
Prior Infection

Background: There is uncertainty about the seroprevalence of anti-SARS-CoV-2 antibodies in the general population of Austria, and about the extent to which antibodies elicited by vaccination or infection wane over time. Aim: To estimate seroprevalence, waning, and correlates of anti-SARS-CoV-2 IgG antibodies in the Federal State of Tyrol, Austria. Methods: We conducted a seroepidemiological study between June 2020 and September 2021, enrolling blood donors aged 18-70 years across Tyrol, Austria (participation rate 84.0%). We analysed serum samples for antibodies against spike or nucleocapsid proteins of SARS-CoV-2 with Abbott SARS-CoV-2 IgG assays. Results: We performed 47,363 serological tests among 35,193 individuals (median age 43.1 years [IQR: 29.3-53.7], 45.3% women, 10.0% with prior SARS-CoV-2 infection). Seroprevalence increased from 3.4% (95% CI: 2.8-4.2%) in June 2020 to 82.7% (95% CI: 81.4-83.8%) in September 2021, largely due to vaccination. Anti-spike IgG seroprevalence was 99.6% (99.4-99.7%) among fully vaccinated individuals, 90.4% (88.8-91.7%) among unvaccinated with prior infection, and 11.5% (10.8-12.3%) among unvaccinated without known prior infection. Anti-spike IgG levels were reduced by 44.0% (34.9-51.7%) at 5-6 months compared to 0-3 months after infection. In fully vaccinated individuals, they decreased by 31.7% (29.4-33.9%) per month. In multivariable adjusted analyses, both seropositivity among unvaccinated and antibody levels among fully vaccinated individuals were higher at young age (<25 years), higher with a known prior infection, and lower in current smokers. Conclusion: Seroprevalence in Tyrol increased to 82.7% in September 2021, with the bulk of seropositivity stemming from vaccination. Antibody levels substantially and gradually declined after vaccination or infection.

scholarly journals Testing IgG antibodies against the RBD of SARS-CoV-2 is sufficient and necessary for COVID-19 diagnosis

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241164 ◽  
Author(s):  
Victoria Indenbaum ◽  
Ravit Koren ◽  
Shiri Katz-Likvornik ◽  
Mayan Yitzchaki ◽  
Osnat Halpern ◽  
...  
Keyword(s):  
Igg Antibodies ◽  
Serum Samples ◽  
Igg Antibody ◽  
Past Exposure ◽  
Iga Antibodies ◽  
Global Spread ◽  
Diagnostic Capacity ◽  
Antibody Levels ◽  
Antibody Kinetics ◽  
Kinetics Of

The COVID-19 pandemic and the fast global spread of the disease resulted in unprecedented decline in world trade and travel. A critical priority is, therefore, to quickly develop serological diagnostic capacity and identify individuals with past exposure to SARS-CoV-2. In this study serum samples obtained from 309 persons infected by SARS-CoV-2 and 324 of healthy, uninfected individuals as well as serum from 7 COVID-19 patients with 4–7 samples each ranging between 1–92 days post first positive PCR were tested by an “in house” ELISA which detects IgM, IgA and IgG antibodies against the receptor binding domain (RBD) of SARS-CoV-2. Sensitivity of 47%, 80% and 88% and specificity of 100%, 98% and 98% in detection of IgM, IgA and IgG antibodies, respectively, were observed. IgG antibody levels against the RBD were demonstrated to be up regulated between 1–7 days after COVID-19 detection, earlier than both IgM and IgA antibodies. Study of the antibody kinetics of seven COVID 19 patients revealed that while IgG levels are high and maintained for at least 3 months, IgM and IgA levels decline after a 35–50 days following infection. Altogether, these results highlight the usefulness of the RBD based ELISA, which is both easy and cheap to prepare, to identify COVID-19 patients even at the acute phase. Most importantly our results demonstrate that measuring IgG levels alone is both sufficient and necessary to diagnose past exposure to SARS-CoV-2.

Evaluation of Visceral Larva Migrans by Radioimmunoassay Systems

PEDIATRICS ◽  
1975 ◽  
Vol 56 (3) ◽  
pp. 417-420
Author(s):  
Roy Patterson ◽  
Mary Roberts ◽  
Robert J. Hart ◽  
Carolyn C. Huntley
Keyword(s):  
Acute Phase ◽  
Solid Phase ◽  
Larva Migrans ◽  
Parasitic Diseases ◽  
Igg Antibodies ◽  
Visceral Larva Migrans ◽  
Serum Samples ◽  
Solid Phase Radioimmunoassay ◽  
Antibody Levels ◽  
Hyperimmunoglobulinemia E

A 9-year-old child with miliary pulmonary infiltrates, eosinophilia, and hyperimmunoglobulinemia E recovered rapidly over a four-week period. Subsequent analysis of serum samples by a solid phase radioimmunoassay technique demonstrated IgM, IgE, and IgG antibodies to Ascaris suum antigen which declined following the acute phase of the illness in parallel with a decline in serum IgM, IgE, and IgG concentrations. Precipitating antibodies in serum against Ascaris antigen were demonstrated. The diagnosis is considered to be toxocariasis or ascariasis. The application of sensitive radioimmunoassay techniques of this type should provide a method of earlier diagnosis and the demonstration of rapidly changing antibody levels a method of confirming the diagnosis in parasitic diseases.

Assessment of Anti-Streptokinase Antibody Levels in Human Sera Using a Microradioimmunoassay Procedure

1984 ◽  
Vol 52 (03) ◽  
pp. 281-287 ◽  
Author(s):  
D M Moran ◽  
R Standring ◽  
E A Lavender ◽  
G S Harris
Keyword(s):  
Ambient Temperature ◽  
Healthy Volunteers ◽  
Human Serum ◽  
High Capacity ◽  
Antibody Binding ◽  
Igg Antibodies ◽  
Antigenic Activity ◽  
Low Concentrations ◽  
Human Sera ◽  
Antibody Levels

SummaryA high capacity, quantitative radioimmunoassay procedure has been developed to measure IgG antibodies to streptokinase (SK) in human serum. Results showed that the use of low concentrations of 125I-SK (100 ng/ml) and ambient temperature incubation conditions minimised degradation of the target labelled antigen and afforded antibody binding values which could be confidently related to the native intact SK protein. SK-complexed to plasminogen was also shown to retain the equivalent antigenic activity of native SK. Comparison of the absolute anti-SK levels with streptokinase resistance titres demonstrated that the two measurements of antibody correlated statistically but afforded quantitatively poor agreements. A survey of IgG levels to SK in sera from 93 normal healthy volunteers showed that all individuals displayed readily measurable anti-SK antibodies, with some 80% having IgG concentration capable of binding in excess of 1 μg SK per ml serum.

scholarly journals Evaluation of Nucleocapsid and Spike Protein-Based Enzyme-Linked Immunosorbent Assays for Detecting Antibodies against SARS-CoV-2

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Wanbing Liu ◽  
Lei Liu ◽  
Guomei Kou ◽  
Yaqiong Zheng ◽  
Yinjuan Ding ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Early Stage ◽  
Disease Onset ◽  
High Sensitivity ◽  
Spike Protein ◽  
Nucleic Acid Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Positive Rate

ABSTRACT At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People’s Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness, 0 to 10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o., so it could be an important supplementary method for COVID-19 diagnosis.

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