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 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 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 tetanus toxoid antibodies in human sera in New Zealand by ELISA

1987 ◽  
Vol 98 (2) ◽  
pp. 199-202 ◽  
Author(s):  
R. C. H. Lau
Keyword(s):  
New Zealand ◽  
Human Serum ◽  
Immunosorbent Assay ◽  
Tetanus Toxoid ◽  
Indirect Elisa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Age Group ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Human Sera

SUMMARYAn enzyme-linked immunosorbent assay (ELISA) incorporating the sensitive biotin-streptavidin system was developed to detect IgG antibodies to tetanus toxoid in human serum. Serum samples obtained from 557 normal persons aged 1–65 years from different areas in New Zealand were tested. The proportion of those immune ranged from 60–93% in males, and from 46–86% in females. In the 1–9 years age group 85% were immune. The indirect ELISA is suitable for serological surveys as it is simple to perform, economical and reproducible.

STUDIES ON SULFATION FACTOR (SF) ACTIVITY OF HUMAN SERUM

1960 ◽  
Vol XXXV (III) ◽  
pp. 381-396 ◽  
Author(s):  
Sven Almqvist
Keyword(s):  
Human Serum ◽  
Normal Serum ◽  
Treatment Level ◽  
Response Curves ◽  
Normal Children ◽  
Significant Difference ◽  
Human Sera ◽  
Normal Humans ◽  
Pre Treatment ◽  
Dose Levels

ABSTRACT The sulfation factor (SF) activity of human sera has been estimated using a modification of the method of Daughaday et al. (1959). Each assay was statistically evaluated. The method had a mean precision of 0.14 and, used as an assay of GH of human serum, a sensitivity in three pituitary dwarfs of 0.1 to 0.6 μg of HGH/ml of serum. SF activity was found at all ages between 1 month and 75 years. There was a significantly lower mean SF activity below the age of half a year. Three cases of pituitary dwarfism had significantly low SF activities of sera. There was no significant difference between the SF activities of sera from untreated pituitary dwarfs and the sera from normal children below half a year of age. Dose-response curves with large volumes of sera from pituitary dwarfs and small volumes of sera from normal humans had the same slopes. Four mg of HGH prepared according to the method of Li & Papkoff (1956) resulted in a normal serum SF activity in each of the three dwarfs. A significant (P < 0.01) linear relationship was found between the concentration of SF activity of sera from these subjects and the logarithm of the dose of HGH given with dose levels of 1, 2 and 4 mg daily for three days. The decline of serum SF activity to the pre-treatment level following HGH in one dwarf suggested a half life not different from that indicated by others for growth hormone.

scholarly journals Application of Immunosignatures for Diagnosis of Valley Fever

2014 ◽  
Vol 21 (8) ◽  
pp. 1169-1177 ◽  
Author(s):  
Krupa Arun Navalkar ◽  
Stephen Albert Johnston ◽  
Neal Woodbury ◽  
John N. Galgiani ◽  
D. Mitchell Magee ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Random Sequence ◽  
False Negative ◽  
False Negative Rate ◽  
Peptide Array ◽  
Igg Antibodies ◽  
False Negatives ◽  
Peptide Microarray ◽  
Valley Fever ◽  
Antibody Levels

ABSTRACTValley fever (VF) is difficult to diagnose, partly because the symptoms of VF are confounded with those of other community-acquired pneumonias. Confirmatory diagnostics detect IgM and IgG antibodies against coccidioidal antigens via immunodiffusion (ID). The false-negative rate can be as high as 50% to 70%, with 5% of symptomatic patients never showing detectable antibody levels. In this study, we tested whether the immunosignature diagnostic can resolve VF false negatives. An immunosignature is the pattern of antibody binding to random-sequence peptides on a peptide microarray. A 10,000-peptide microarray was first used to determine whether valley fever patients can be distinguished from 3 other cohorts with similar infections. After determining the VF-specific peptides, a small 96-peptide diagnostic array was created and tested. The performances of the 10,000-peptide array and the 96-peptide diagnostic array were compared to that of the ID diagnostic standard. The 10,000-peptide microarray classified the VF samples from the other 3 infections with 98% accuracy. It also classified VF false-negative patients with 100% sensitivity in a blinded test set versus 28% sensitivity for ID. The immunosignature microarray has potential for simultaneously distinguishing valley fever patients from those with other fungal or bacterial infections. The same 10,000-peptide array can diagnose VF false-negative patients with 100% sensitivity. The smaller 96-peptide diagnostic array was less specific for diagnosing false negatives. We conclude that the performance of the immunosignature diagnostic exceeds that of the existing standard, and the immunosignature can distinguish related infections and might be used in lieu of existing diagnostics.

scholarly journals Immunoglobulin G antibodies directed against protein III block killing of serum-resistant Neisseria gonorrhoeae by immune serum.

1986 ◽  
Vol 164 (5) ◽  
pp. 1735-1748 ◽  
Author(s):  
P A Rice ◽  
H E Vayo ◽  
M R Tam ◽  
M S Blake
Keyword(s):  
Membrane Protein ◽  
Neisseria Gonorrhoeae ◽  
Human Serum ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Immune Serum ◽  
Igg Antibodies ◽  
Porin Protein ◽  
Blocking Activity ◽  
Normal Human

Neisseria gonorrhoeae that resist complement-dependent killing by normal human serum (NHS) are sometimes killed by immune convalescent serum from patients recovering from disseminated gonococcal infection (DGI). In these studies, killing by immune serum was prevented or blocked by IgG isolated from NHS. Purified human IgG antibodies directed against gonococcal protein III, an antigenically conserved outer membrane protein, contained most of the blocking activity in IgG. Antibodies specific for gonococcal porin (protein I), the major outer membrane protein, displayed no blocking function. In separate experiments, immune convalescent DGI serum which did not exhibit bactericidal activity was restored to killing by selective depletion of protein III antibodies by immunoabsorption. These studies indicate that protein III antibodies in normal and immune human serum play a role in serum resistance of N. gonorrhoeae.

scholarly journals Serosurvey of Rickettsia spp. in dogs and humans from an endemic area for Brazilian spotted fever in the State of São Paulo, Brazil

2008 ◽  
Vol 24 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Adriano Pinter ◽  
Maurício C. Horta ◽  
Richard C. Pacheco ◽  
Jonas Moraes-Filho ◽  
Marcelo B. Labruna
Keyword(s):  
Human Serum ◽  
Endemic Area ◽  
Spotted Fever ◽  
Sao Paulo ◽  
The State ◽  
The Other ◽  
São Paulo ◽  
Human Sera ◽  
Antibody Titers ◽  
Brazilian Spotted Fever

The present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for Brazilian spotted fever in the State of São Paulo, where the tick Amblyomma aureolatum is the main vector. Testing canine and human sera by indirect immunofluorescence against four Rickettsia antigens (R. rickettsii, R. parkeri, R. felis and R. bellii) showed that 16 (64%) of canine sera and 1 (2.8%) of human sera reacted to at least one of these rickettsial antigens with titers <FONT FACE=Symbol>³</FONT> 64. Seven canine sera and the single reactive human serum showed titers to R. rickettsii at least four times those of any of the other three antigens. The antibody titers in these 7 animals and 1 human were attributed to stimulation by R. rickettsii infection. No positive canine or human serum was attributed to stimulation by R. parkeri, R. felis, or R. bellii. Our serological results showed that dogs are important sentinels for the presence of R. rickettsii in areas where the tick A. aureolatum is the main vector of Brazilian spotted fever.

scholarly journals Development and Validation of 13-plex Luminex-Based Assay for Measuring Human Serum Antibodies to Streptococcus pneumoniae Capsular Polysaccharides

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. e00128-18 ◽  
Author(s):  
Danka Pavliakova ◽  
Peter C. Giardina ◽  
Soraya Moghazeh ◽  
Shite Sebastian ◽  
Maya Koster ◽  
...  
Keyword(s):  
Human Serum ◽  
Lower Limit ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Correlate Of Protection ◽  
Immune Correlate ◽  
Relative Standard ◽  
Limit Of Quantitation

ABSTRACT A Luminex-based direct immunoassay (dLIA) platform has been developed to replace the standardized pneumococcal enzyme-linked immunosorbent assay platform. The multiplex dLIA simultaneously measures the concentration of serum immunoglobulin G (IgG) antibodies specific for pneumococcal capsular polysaccharide (PnPS) serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F. The assay uses poly-l-lysine (PLL)-conjugated PnPS, chemically coupled to spectrally distinct Luminex microspheres. Assay validation experiments were performed using residual human serum samples obtained from 13-valent pneumococcal conjugate vaccine (13vPnC) clinical studies. Assay results are expressed as IgG antibody concentrations in micrograms per milliliter using the international reference serum, 007sp. The lower limit of quantitation (LLOQ) for all serotypes covered in the 13-plex dLIA fell within the range of 0.002 to 0.038 µg/ml serum IgG. The difference between the lower limit and upper limit of the assay range was >500-fold for all serotypes, and assay variability was <20% relative standard deviation (RSD) for all serotypes. IgG antibody measurements were shown to be serotype-specific (some cross-reactivity was observed only between the structurally related serotypes 6A and 6B as well as 19A and 19F), and no interference was observed between the serotypes when the assay was performed in the 13-plex format compared to the singleplex assays. The 13-plex dLIA platform developed by Pfizer Inc. generates up to 143 test results in a single 96-well plate and is a suitable replacement of the enzyme-linked immunosorbent assay (ELISA) platform for evaluating vaccine clinical trials. IMPORTANCE The pneumococcal enzyme-linked immunosorbent assay (ELISA) measures IgG antibodies in human serum, and it is an important assay that supports licensure of pneumococcal vaccines. The immune correlate of protection, 0.35 µg/ml of IgG antibodies, was determined by the ELISA method. Pfizer has developed a new Luminex-based assay platform to replace the ELISA. These papers describe the important work of (i) validating the Luminex-based assay and (ii) bridging the immune correlate of protection (0.35 µg/ml IgG) to equivalent values reported by the Luminex platform.

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