Measurement of Chlamydia pneumoniae-Specific Immunoglobulin A (IgA) Antibodies by the Microimmunofluorescence (MIF) Method: Comparison of Seven Fluorescein-Labeled Anti-Human IgA Conjugates in an In-House MIF Test Using One Commercial MIF and One Enzyme Immunoassay Kit

ABSTRACT For the serological diagnosis of acute Chlamydia pneumoniae infection, the microimmunofluorescence (MIF) test is the most commonly used method and also the “gold standard” for the measurement of immunoglobulin G (IgG) and IgM antibodies. The role of IgA antibodies in diagnosis has not been established. Commercially available fluorescein-labeled anti-human IgA conjugates have not been systematically compared to each other, and this situation may cause considerable variations in IgA results. Therefore, we tested 261 serum samples from 122 patients with pneumonia for IgA antibodies by using six α-chain-specific anti-IgA conjugates in our in-house MIF test, one commercial MIF test, and one enzyme immunoassay (EIA). Interfering IgG antibodies were removed with Gullsorb reagent before the measurement of IgA antibodies. Altogether, 14 significant IgA antibody increases in serum samples between the acute phase and the convalescent phase were detected by at least one of the conjugates in the MIF test, while no increases were found in the IgA EIA. Only one patient showed a significant IgA antibody increase with all of the fluorescein-labeled conjugates. Five significant titer changes were detected by at least two conjugates, and in nine instances, the titer increase was detected by one conjugate only. The titer agreement indicated by kappa coefficients was very good or good for all of the fluorescein-labeled conjugates and the EIA with low antibody titers but decreased with increasing titers.

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Interlaboratory Reliability of Microimmunofluorescence Test for Measurement of Chlamydia pneumoniae-Specific Immunoglobulin A and G Antibody Titers

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.3.615-617.2004 ◽

2004 ◽

Vol 11 (3) ◽

pp. 615-617 ◽

Cited By ~ 14

Author(s):

Alyson J. Littman ◽

Lisa A. Jackson ◽

Emily White ◽

Mark D. Thornquist ◽

Charlotte A. Gaydos ◽

...

Keyword(s):

Measurement Error ◽

Immunoglobulin G ◽

Chlamydia Pneumoniae ◽

Immunoglobulin A ◽

Specific Immunoglobulin ◽

Disease Associations ◽

Antibody Titers ◽

Iga Antibody ◽

Microimmunofluorescence Test

ABSTRACT To evaluate the reliability of Chlamydia pneumoniae-specific immunoglobulin G (IgG) and IgA antibody titers as measured by the microimmunofluorescence (MIF) test, we compared results from 392 individuals using a standard MIF protocol at two academic laboratories. The kappas for dichotomous titers (≥16 versus <16) were 0.39 for IgA and 0.53 for IgG. Measurement error likely attenuates C. pneumoniae-disease associations; the magnitude of attenuation can be estimated from results of studies such as this one.

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Use of Recombinant Nucleoproteins in Enzyme-Linked Immunosorbent Assays for Detection of Virus-Specific Immunoglobulin A (IgA) and IgG Antibodies in Influenza Virus A- or B-Infected Patients

Journal of Clinical Microbiology ◽

10.1128/jcm.36.12.3527-3531.1998 ◽

1998 ◽

Vol 36 (12) ◽

pp. 3527-3531 ◽

Cited By ~ 22

Author(s):

J. T. M. Voeten ◽

J. Groen ◽

D. van Alphen ◽

E. C. J. Claas ◽

R. de Groot ◽

...

Keyword(s):

Influenza Virus ◽

Clinical Symptoms ◽

Immunoglobulin A ◽

Influenza Viruses ◽

Igg Antibodies ◽

Serum Samples ◽

Influenza Virus A ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Immunosorbent Assays

The nucleoprotein genes of influenza virus A/Netherlands/018/94 (H3N2) and influenza virus B/Harbin/7/94 were cloned into the bacterial expression vector pMalC to yield highly purified recombinant influenza virus A and B nucleoproteins. With these recombinant influenza nucleoproteins, enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of influenza virus A- and B-specific immunoglobulin A (IgA) and IgG serum antibodies. Serum samples were collected at consecutive time points after the onset of clinical symptoms from patients with confirmed influenza virus A or B infections. Nucleoprotein-specific IgA antibodies were detected in 41.2% of influenza virus A-infected patients and in 66.7% of influenza virus B-infected patients on day 6 after the onset of clinical symptoms. In serum samples taken on day 21 (influenza virus A-infected patients) or day 28 (influenza virus B-infected patients), nucleoprotein-specific IgA antibodies could be detected in 58.8 and 58.3% of influenza virus A- and B-infected patients, respectively. At the same time, IgG antibody rises were detected in 88.2% of influenza virus A-infected patients and in 95.8% of influenza virus B-infected patients. On comparison, hemagglutination inhibition assays detected antibody titer rises in 81.3 and 72.7% of patients infected with influenza viruses A and B, respectively. In contrast to the detection of nucleoprotein-specific IgG antibodies or hemagglutination-inhibiting antibodies, the detection of nucleoprotein-specific IgA antibodies does not require paired serum samples and therefore can be considered an attractive alternative for the rapid serological diagnosis of influenza.

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Antibody in Middle Ear Fluid of Children Originates Predominantly from Sera and Nasopharyngeal Secretions

Clinical and Vaccine Immunology ◽

10.1128/cvi.05443-11 ◽

2012 ◽

Vol 19 (10) ◽

pp. 1593-1596 ◽

Cited By ~ 15

Author(s):

Ravinder Kaur ◽

Thomas Kim ◽

Janet R. Casey ◽

Michael E. Pichichero

Keyword(s):

Middle Ear ◽

Acute Otitis Media ◽

Secretory Iga ◽

Enzyme Linked Immunosorbent Assay ◽

Serum Samples ◽

Two Dimensional Gel Electrophoresis ◽

Middle Ear Fluid ◽

Iga Antibodies ◽

Iga Antibody ◽

Entire Array

ABSTRACTThe human middle ear is devoid of any immunocompetent cells in normal mucosa. We sought to determine the source of antibody present in the middle ear of children. Total IgG, IgA, and secretory IgA antibodies were determined by enzyme-linked immunosorbent assay from the nasopharyngeal, middle ear, and serum samples of children with acute otitis media. The two-dimensional gel electrophoresis pattern of the entire array of IgA antibodies in the nasal wash (NW) and middle ear fluid (MEF) was compared from the MEF and NW samples using isoelectric focusing and Western blotting. The total IgG and IgA antibodies in the MEF and NW samples of 137 children were compared. The ratio of IgG to IgA in the MEF was significantly different (P< 0.008) compared to NW because IgA levels were higher and IgG levels lower in NW. The IgG/IgA ratio of MEF resembled serum consistent with transudation to the MEF. Small amounts of secretory IgA were detected in MEF but the electrophoresis patterns of the entire array of IgA antibodies in the MEF and NW were virtually identical in each child evaluated; thus, IgA in MEF derived predominantly from serum and the nasopharynx by reflux via the Eustachian tube. The IgG/IgA antibody levels in the MEF and the same composition of IgA antibody in the MEF and NW identifies the predominant source of antibody in the MEF as a transudate of serum combined with nasal secretions refluxed from the nasopharynx in children.

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Diagnosis of Dengue Virus Infection by Detection of Specific Immunoglobulin M (IgM) and IgA Antibodies in Serum and Saliva

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.2.317-322.2003 ◽

2003 ◽

Vol 10 (2) ◽

pp. 317-322 ◽

Cited By ~ 83

Author(s):

Angel Balmaseda ◽

María G. Guzmán ◽

Samantha Hammond ◽

Guillermo Robleto ◽

Carolina Flores ◽

...

Keyword(s):

Dengue Virus ◽

Immunoglobulin M ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Serum Samples ◽

Diagnostic Modality ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Feasible Alternative

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.

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Seroepidemiology of Chlamydia Pneumoniae in Northern Greece

European Journal of Inflammation ◽

10.1177/1721727x0900700303 ◽

2009 ◽

Vol 7 (3) ◽

pp. 139-144

Author(s):

D. Chatzidimitriou ◽

M. Exidari ◽

G. Gioula ◽

P. Papakonstantinou ◽

A. Melidou ◽

...

Keyword(s):

Chlamydia Pneumoniae ◽

The Elderly ◽

Healthy Population ◽

Serum Samples ◽

Igg Antibody ◽

Northern Greece ◽

Specific Antibodies ◽

High Prevalence ◽

Iga Antibodies ◽

One Year

The prevalence of IgG and IgA antibodies to Chlamydia pneumoniae was evaluated in a group of an apparently healthy population in northern Greece. Serum samples were obtained over a period of one year (June 2006 to May 2007) from 530 individuals (300 males and 230 females, aged from 1 month to 90 years). The sera were tested for specific antibodies to C. pneumoniae by two commercial methods, an ELISA and a micro-IF assay based on the principles of MIF. The prevalence of IgG and IgA antibodies to C. pneumoniae was 53.2% and 45.9%, respectively, and was found to be unrelated to gender, even in the elderly >61 years old. The IgG antibody prevalence was low in children under 5 years old (7.7%), sharply increased by the age of 20 (40%) and continued to increase, gradually, to reach 80.1% in the elderly. IgA antibodies also increased with similar kinetics to IgG, although at a lower level (3.8–66.1%). Our results show that infection with C. pneumoniae is common in northern Greece. The high prevalence of IgA specific antibodies reported in the present study is due to primary infection at a young age, while in the elderly is probably due to infection or reinfection, although the option of persistence cannot be excluded.

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Immunoglobulin A Antibody Responses in Dengue Patients: a Useful Marker for Serodiagnosis of Dengue Virus Infection

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.12.10.1235-1237.2005 ◽

2005 ◽

Vol 12 (10) ◽

pp. 1235-1237 ◽

Cited By ~ 14

Author(s):

M. Nawa ◽

T. Takasaki ◽

M. Ito ◽

S. Inoue ◽

K. Morita ◽

...

Keyword(s):

Virus Infection ◽

Dengue Virus ◽

Immunoglobulin A ◽

Antibody Responses ◽

Enzyme Linked Immunosorbent Assay ◽

Virus Infections ◽

Serum Samples ◽

Dengue Virus Infection ◽

Iga Antibody ◽

Antibody Capture

ABSTRACT We determined the usefulness of an immunoglobulin A (IgA) antibody-capture enzyme-linked immunosorbent assay for serodiagnosis of dengue virus infections. The results indicate that the presence of IgA and IgM in serum samples assures recent primary dengue virus infection even with a single serum sample.

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Column enzyme immunoassay for secretory immunoglobulin A in serum.

Clinical Chemistry ◽

10.1093/clinchem/29.1.151 ◽

1983 ◽

Vol 29 (1) ◽

pp. 151-153 ◽

Cited By ~ 11

Author(s):

R Yamamoto ◽

S Kimura ◽

S Hattori ◽

Y Ishiguro ◽

K Kato

Keyword(s):

Enzyme Immunoassay ◽

Sodium Carbonate Solution ◽

Solid Phase ◽

Immunoglobulin A ◽

Enzyme Reaction ◽

Secretory Component ◽

Secretory Immunoglobulin A ◽

Serum Samples ◽

Sepharose 4B ◽

Secretory Immunoglobulin

Abstract This enzyme immunoassay for specific measurement of secretory immunoglobulin A concentrations in human serum involves use of a small chromatographic column as a solid-phase. Serum samples are incubated for 2 h with beta-D-galactosidase-labeled antibody to secretory component, then passed through a 0.1-mL Sepharose 4B column containing antibodies to human immunoglobulin A. After the column is washed to remove the unbound label, the buffer in the column is replaced by a solution of o-nitrophenyl-beta-D-galactoside (a beta-D-galactosidase substrate) and incubated at 25 degrees C overnight. The enzyme reaction is stopped by washing the column with sodium carbonate solution, and the absorbance of the eluate is measured at 420 nm. The concentration of secretory immunoglobulin A can be determined with a minimum detectable sensitivity of 3 mg/L, without interference from free immunoglobulin A and secretory component in the same samples.

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The Role of IgA in the Pathogenesis of IgA Nephropathy

International Journal of Molecular Sciences ◽

10.3390/ijms20246199 ◽

2019 ◽

Vol 20 (24) ◽

pp. 6199 ◽

Cited By ~ 3

Author(s):

Martina Perše ◽

Željka Večerić-Haler

Keyword(s):

Iga Nephropathy ◽

Genetic Factors ◽

Immunoglobulin A ◽

Symbiotic Relationship ◽

Biological Functions ◽

Antibody Isotype ◽

Microbial Invasion ◽

Iga Antibodies ◽

Interaction With Receptors

Immunoglobulin A (IgA) is the most abundant antibody isotype produced in humans, predominantly present in the mucosal areas where its main functions are the neutralization of toxins, prevention of microbial invasion across the mucosal epithelial barrier, and simultaneous maintenance of a physiologically indispensable symbiotic relationship with commensal bacteria. The process of IgA biosynthesis, interaction with receptors, and clearance can be disrupted in certain pathologies, like IgA nephropathy, which is the most common form of glomerulonephritis worldwide. This review summarizes the latest findings in the complex characteristics of the molecular structure and biological functions of IgA antibodies, offering an in-depth overview of recent advances in the understanding of biochemical, immunologic, and genetic factors important in the pathogenesis of IgA nephropathy.

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Longitudinal monitoring of SARS-CoV-2-specific immune responses

10.1101/2021.08.14.21262042 ◽

2021 ◽

Author(s):

Heike Rebholz ◽

Ralf J. Braun ◽

Titas Saha ◽

Oliver Harzer ◽

Miriam Schneider ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Immunoglobulin G ◽

Immunoglobulin A ◽

Comprehensive View ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Second Peak

The Lower Austrian Wachau region was an early COVID-19 hotspot of infection. As previously reported, in June 2020, after the first peak of infections, we determined that 8.5% and 9.0% of the participants in Weissenkirchen and surrounding communities in the Wachau region were positive for SARS-CoV-2-specific immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies, respectively. Here, we present novel data obtained eight months later (February 2021) from Weissenkirchen, after the second peak of infection, with 25.0% (138/552) and 23.6% (130/552) of participants that are positive for IgG and IgA, respectively. In participants with previous IgG/IgA positivity (June 2020), we observed a 24% reduction in IgG levels, whereas the IgA levels remained stable in February 2021. This subgroup was further analyzed for SARS-CoV-2-induced T cell activities. Although 76% (34/45) and 76% (34/45) of IgG positive and IgA positive participants, respectively, showed specific T cell activities, those were not significantly correlated with the levels of IgG or IgA. Thus, the analyses of antibodies cannot surrogate the measurement of T cell activities. For a comprehensive view on SARS-CoV-2-triggered immune responses, the measurement of different classes of antibodies should be complemented with the determination of T cell activities.

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