scholarly journals Quantification of IgG Antibodies to Aspergillus fumigatus and Pigeon Antigens by ImmunoCAP Technology: An Alternative to the Precipitation Technique?

2006 ◽  
Vol 52 (9) ◽  
pp. 1785-1793 ◽  
Author(s):  
Erna Van Hoeyveld ◽  
Lieven Dupont ◽  
Xavier Bossuyt
Keyword(s):  
Aspergillus Fumigatus ◽  
Hypersensitivity Pneumonitis ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Important Variable ◽  
Pulmonary Diseases ◽  
Igg Antibodies ◽  
Precipitation Technique ◽  
Measuring Techniques ◽  
Antibody Titers ◽  
Specific Igg

Abstract Background: We evaluated the ImmunoCAP technique for measurement of IgG specific to Aspergillus fumigatus and pigeon antigens. Methods: We used ImmunoCAP and precipitation technique to measure concentrations of IgG to A. fumigatus or pigeon antigens in sera from 265 patients and 42 controls. We also evaluated linearity, interference, imprecision, concordance, and diagnostic accuracy of the measuring techniques. Results: The precipitation and ImmunoCAP technique showed moderate concordance (κ, 0.46 for both A. fumigatus and pigeon antibodies). Specific IgG results for A. fumigatus and pigeon were linear (r = 0.98 and 0.97, respectively), with interrun reproducibility rates of 23% and 14% and maximal interference of 36.5% and 8% by lipid and 24% and 21% by hemolysis, respectively. A. fumigatus antibody concentrations were higher in patients with aspergillosis and allergic bronchopulmonary aspergillosis (ABPA) (median, 103 and 70.1 mgA/L, respectively) than in patients with other pulmonary diseases (median, 18.15–33.40 mgA/L). Antibodies to pigeon antigens were high in patients with hypersensitivity pneumonitis (median, 1024 mgA/L) but also in patients with other pulmonary diseases (median, 445 mgA/L). Antibody titers were substantially higher in patients with other pulmonary diseases and contact with pigeons (median, 1060 mgA/L) than in patients without antigen contact (median, 27.35 mgA/L) (P <0.004). Conclusions: Agreement between the precipitation and ImmunoCAP technique was 86% for A. fumigatus and 70% for pigeon antigens. Highest concentrations of specific IgG to A. fumigatus were found in patients with aspergillosis and ABPA. Our results suggest that antigen contact was the most important variable affecting the presence of antibodies to pigeon antigen.

scholarly journals Systemic and Mucosal Immunizations with Fibronectin-Binding Protein FBP54 Induce Protective Immune Responses against Streptococcus pyogenes Challenge in Mice

2001 ◽  
Vol 69 (2) ◽  
pp. 924-930 ◽  
Author(s):  
Shigetada Kawabata ◽  
Eiji Kunitomo ◽  
Yutaka Terao ◽  
Ichiro Nakagawa ◽  
Ken Kikuchi ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Binding Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Fibronectin Binding Protein ◽  
Specific Igg ◽  
Fibronectin Binding ◽  
Specific Igg Antibodies

ABSTRACT The purpose of this study was to examine the suitability of fibronectin-binding protein FBP54 as a putative vaccine forStreptococcus pyogenes infections. When the distribution of the fbp54 gene among the clinical isolates representing various M serotypes was tested by PCR and Southern blot assays, it was found that all of the strains possess this gene. Furthermore, a significant increase in immunoglobulin G (IgG) antibody titers against FBP54 was observed in sera from patients with S. pyogenesinfections compared with those from healthy volunteers (P < 0.005). Mice were immunized with FBP54 subcutaneously, orally, or nasally. An enzyme-linked immunosorbent assay revealed that antigen-specific IgG antibodies were induced in the sera of immunized mice, while high salivary levels of IgA antibodies were detected after oral and nasal immunizations. Mice subcutaneously or orally immunized with FBP54 survived significantly longer following the challenge with S. pyogenes than did nonimmunized mice (P < 0.001). These results indicate that FBP54 is a promising vaccine for the prevention of S. pyogenesinfections.

scholarly journals Prospective Evaluation of Aspergillus fumigatus-Specific IgG in Patients With Cystic Fibrosis

2021 ◽  
Vol 10 ◽  
Author(s):  
Patience Eschenhagen ◽  
Claudia Grehn ◽  
Carsten Schwarz
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Sensitivity And Specificity ◽  
Statistical Significance ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Control Group ◽  
Opportunistic Fungi ◽  
Significant Difference ◽  
Specific Igg

BackgroundIn Cystic Fibrosis (CF), the airways are often colonized by opportunistic fungi. The most frequently detected mold is Aspergillus fumigatus (Af). Af diseases are associated with significant morbidity and mortality. The most common clinical picture caused by Af is allergic bronchopulmonary aspergillosis (ABPA), triggered by an immunological reaction against Af. Af bronchitis and invasive aspergillosis rarely occur in CF as a result of spore colonization and germination. Since pulmonary mycoses and exacerbations by other pathogens overlap in clinical, radiological, and immunological characteristics, diagnosis still remains a challenge. The search for reliable, widely available biomarkers for Af diseases is therefore still an important task today.ObjectivesAf-specific IgG m3 is broadly available. Sensitivity and specificity data are contradictory and differ depending on the study population. In our prospective study on pulmonary Af diseases in CF, we determined specific IgG m3 in order to test its suitability as a biomarker for acute Af diseases and as a follow-up parameter.MethodsIn this prospective single center study, 109 patients with CF were screened from 2016 to 2019 for Af-associated diseases. According to diagnostic criteria, they were divided into four groups (control, bronchitis, ABPA, pneumonia). The groups were compared with respect to the level of Af-specific IgG (ImmunoCAP Gm3). We performed a receiver operating characteristic (ROC) curve analysis to determine cut-off, sensitivity and specificity. Twenty-one patients could be enrolled for a follow-up examination.ResultsOf the 109 patients, 36 were classified as acute Af-disease (Af bronchitis, ABPA, Af pneumonia). Of these, 21 patients completed follow up-screening. The median Af-specific Gm3 was higher in the acute Af-disease groups. There was a significant difference in Af-specific IgG m3 compared to the control group without acute Af-disease. Overall, there was a large interindividual distribution of Gm3. A cut-off value of 78.05 mg/L for Gm3 was calculated to discriminate controls and patients with ABPA/pneumonia with a specificity of 75% and a sensitivity of 74.6%. The follow up examination of 21 patients showed a decrease of Gm3 in most patients without statistical significance due to the small number of follow up patients.ConclusionAf specific IgG may be a useful biomarker for acute ABPA and Af pneumonia, but not for Af bronchitis in CF. However, due to the large interindividual variability of Gm3, it should only be interpreted alongside other biomarkers. Therefore, due to its broad availability, it could be suitable as a biomarker for ABPA and Af pneumonia in CF, if the results can be supported by a larger multicenter cohort.

scholarly journals Serum-IgG responses to SARS-CoV-2 after mild and severe COVID-19 infection and analysis of IgG non-responders

2020 ◽  
Author(s):  
Emelie Marklund ◽  
Susannah Leach ◽  
Hannes Axelsson ◽  
Kristina Nordström ◽  
Heléne Norder ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Neutralizing Antibodies ◽  
Infection Prevalence ◽  
Igg Antibodies ◽  
Domain Specific ◽  
Serum Igg ◽  
Protein Receptor ◽  
Antibody Titers ◽  
Specific Igg ◽  
True Infection

Background: To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset. Results: Forty-seven patients (mean age 49 years, 38% female) were included. All (15/15) patients with severe symptoms and 29/32 (90.6%) patients with mild symptoms of COVID-19 developed SARS-CoV-2-specific IgG antibodies in serum. Time to seroconversion was significantly shorter (median 11 vs. 22 days, P=0.04) in patients with severe compared to mild symptoms. Of the three patients without detectable IgG-responses after >90 days, all had detectable virus-neutralizing antibodies and in two, spike-protein receptor binding domain-specific IgG was detected with an in-house assay. Antibody titers were preserved during follow-up and all patients who seroconverted, irrespective of the severity of symptoms, still had detectable IgG levels >75 days post symptom onset. Conclusions: Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS-CoV-2-specific IgG than patients with mild symptoms. Of those patients who not develop detectable IgG antibodies, all have detectable virus-neutralizing antibodies, suggesting immunity. Our results showing that not all COVID-19 patients develop detectable IgG using two validated commercial clinical methods, even over time, are vital for the interpretation of COVID-19 seroprevalence surveys and for estimating the true infection prevalence in populations.

scholarly journals New Commercially Available IgG Kits and Time-Resolved Fluorometric IgE Assay for Diagnosis of Allergic Bronchopulmonary Aspergillosis in Patients with Cystic Fibrosis

2015 ◽  
Vol 23 (3) ◽  
pp. 196-203 ◽  
Author(s):  
Coralie Barrera ◽  
Bénédicte Richaud-Thiriez ◽  
Steffi Rocchi ◽  
Bénédicte Rognon ◽  
Sandrine Roussel ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Specific Ige ◽  
Enzyme Linked Immunosorbent Assay ◽  
Time Resolved ◽  
Content Type ◽  
Elisa Kit ◽  
Fungal Allergens ◽  
Specific Igg

ABSTRACTAllergic bronchopulmonary aspergillosis (ABPA) is difficult to diagnose; diagnosis relies on clinical, radiological, pathological, and serological criteria. Our aim was to assess the performance of two new commercially available kits and a new in-house assay: anAspergillus fumigatusenzyme-linked immunosorbent assay (ELISA) IgG kit (Bordier Affinity Products), anAspergillusWestern blotting IgG kit (LDBio Diagnostics), and a new in-house time-resolved fluorometric IgE assay (dissociation-enhanced lanthanide fluorescent immunoassay, or DELFIA) using recombinant proteins from anAspergillussp. recently developed by our laboratory for ABPA diagnosis in a retrospective study that included 26 cystic fibrosis patients.Aspergillus fumigatus-specific IgG levels measured by a commercial ELISA kit were in accordance with the level of precipitins currently used in our lab. The ELISA kit could accelerate and help standardize ABPA diagnosis.Aspergillus fumigatus-specific IgE levels measured by ImmunoCAP (Phadia) withA. fumigatusM3 antigen and by DELFIA with a purified protein extract ofA. fumigatuswere significantly correlated (P< 10−6). The results with recombinant antigens glucose-6-phosphate isomerase and mannitol-1-phosphate dehydrogenase were encouraging but must be confirmed with sera from more patients. The DELFIA is an effective tool that can detect specific IgE against more fungal allergens than can be detected with other commercially available tests.

The Relationship between Plasma Microparticles, Protein S and Anticardiolipin Antibodies in Patients with Human Immunodeficiency Virus Infection

1996 ◽  
Vol 76 (01) ◽  
pp. 038-045 ◽  
Author(s):  
Jean-Christophe Gris ◽  
Pierre Toulon ◽  
Sophie Brun ◽  
Claude Maugard ◽  
Christian Sarlat ◽  
...  
Keyword(s):  
Poor Prognosis ◽  
Anticardiolipin Antibody ◽  
Protein S ◽  
Anticardiolipin Antibodies ◽  
Protein S Deficiency ◽  
Free Protein ◽  
Precipitation Technique ◽  
S Deficiency ◽  
Immunodeficiency Virus ◽  
Antibody Titers

SummaryThe high prevalence of free protein S deficiency in human immunodeficiency virus (HlV)-infected patients is poorly understood. We studied 38 HIV seropositive patients. Free protein S antigen values assayed using the polyethylene-glycol precipitation technique (PEG-fS) were statistically lower in patients than in controls. These values using a specific monoclonal antibody-based ELISA (MoAb-fS) and the values of protein S activity (S-act) were not statistically different between patients and controls. C4b-binding protein values were not different from control values. In patients, PEG-fS values were lower than MoAb-fS values. Ten patients had a PEG-fS deficiency, 4 patients had a MoAb-fS deficiency and 8 had a S-act deficiency. Protein S activity and MoAb-fS were lower in clinical groups with poor prognosis and in patients with AIDS but PEG-fS was not. A trend for reduced S-act/MoAb-fS ratios was observed in patients. PEG-fS was negatively correlated with anticardiolipin antibody titers whereas MoAb-fS was not. The plasma of PEG-fS deficient HIV-patients contained high amounts of flow cytometry detectable microparticles which were depleted from plasma by PEG precipitation. The microparticles were partly CD42b and CD4 positive but CD8 negative. These microparticles were labelled by an anti free protein S monoclonal antibody. The observed differences between MoAb-fS and PEG-fS values were correlated with the amount of detectable plasma microparticles, just like the differences between MoAb-fS and S-act. Plasma microparticles correlated with anticardiolipin antibody titers.In summary, free protein S antigen in HIV infected patients is underestimated when the PEG precipitation technique is used due to the presence of elevated levels of microparticles that bind protein S. The activity of free protein S is also impaired by high levels of microparticles. The prevalence of free protein S deficiency in HIV positive patients is lower than previously published (4/38, -10%) and is correlated with poor prognosis. By implication, use of a PEG precipitation technique might give artefactually low free protein S antigen values in other patient groups if high numbers of microparticles are present. In HIV patients, high titers of anticardiolipin antibodies are associated with high concentrations of cell-derived plasma microparticles.

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