Allergen-specific IgE Research Articles

Epitope profiling of cow's milk allergen-specific antibodies with determining IgE content in epitopes-ALL, a 14-epitopes mixture

Allergen-specific antibodies (Abs), IgE, and IgG4 increase during the early phase of oral immunotherapy (OIT) of allergen food in patients; subsequently, IgE levels decrease and specific IgG4 levels increase after successful OIT treatment. The detailed profile of these Abs during OIT remains largely unclear. We developed a diagnostic tool to assess the OIT efficacy and extent of responsiveness based on a profiling method by identifying epitopes recognized by the Ab classes of IgE or IgG4.A peptide microarray followed by microplate analysis using synthetic peptides was used to identify 14 epitopes widely recognized by IgE and/or IgG4 in the serum samples of patients with OIT among the amino acid sequences of five major cow's milk allergens. The set of defined 14 epitopes clarified different epitope profiles of allergen-specific IgE and IgG4 in each patient's serum samples. Moreover, the total signal of Abs recognizing all 14 epitopes was equal to the sum of all individual epitope-specific Abs. It was further observed that the quantitative value of IgE concentrations of 14 epitopes-ALL correlated with the ImmunoCAP IgE value.These findings strongly imply that the quantity of IgE and IgG4 recognizing epitopes-ALL may easily be used to measure allergy severity. To investigate this potential, we developed an immunochromatographic method that can detect IgE and IgG4 levels in patient samples.This study clearly demonstrated the usefulness of the defined 14 epitopes and their mixture, “epitopes-ALL,” and that the simple and reliable methods of immunochromatography and microplate analyses demonstrating the epitope profile of allergen-specific Abs are applicable for diagnostic use at multiple disease stages and the OIT-treatment course in patients with cow's milk allergy.

Bee/Vespula venom-specific IgE ratio ≥5:1 indicates culprit insect in double-sensitized patients

BackgroundVenom-allergic patients are frequently double-sensitized to honeybee venom (BV) and Vespula venom (VV); genuine double allergy is uncommon. ObjectivesTo assess if quantitative comparison of BV and VV-specific IgE levels permits to identify the culprit venom in double-sensitized patients; to evaluate whether independent sensitization to BV- and VV-specific components corresponds to an indication for double immunotherapy. MethodsThis single centre observational study evaluates 1069 consecutive patients; 490 non-allergic controls were available for statistical comparison. The diagnosis (BV allergy, VV allergy, double allergy) based on a comprehensive allergological work-up including patient history, IgE serology, intradermal skin test, and – if required – basophil activation testing. Quantitative allergen-specific IgE to BV, VV, rApi m 1, rVes v 5 was retrospectively compared with the final diagnosis; the ratio of BV/VV-specific IgE levels was considered in double-sensitized venom-allergic patients. ResultsSensitization to whole venom preparations and components was frequent in patients and asymptomatic controls, with higher specific IgE levels in the patient group. An at least 5:1-dominance of the specific IgE to either BV or VV was documented in 239 (52.1 %) of 459 double-sensitized venom-allergic patients; 232 (97.1%) of these patients were diagnosed mono-allergic to only the venom they were dominantly sensitized to. ConclusionsFive:1-dominant specific IgE indicates the culprit venom in double-sensitized allergic patients. Additional component-resolved diagnostic testing can be restricted to cases with double sensitization to whole venoms at a ratio less than 5:1. Double sensitization to rApi m 1 and rVes v 5 per se does not justify double venom immunotherapy.

Expert consensus on the diagnosis and management of IgE mediated food allergy in children

The prevalence of food allergy in children is increasing, which seriously affects the quality of life of children and their families. Among children and adolescents, IgE-mediated food allergy is the most common type. In recent years, allergen specific IgE (sIgE) and skin prick testing (SPT) have been widely used in clinical practice, with component resolved diagnosis (CRD) also gaining traction for precise diagnosis of IgE-mediated food allergy. However, a challenge persists in clinical practice due to the tendency to over-interpret food allergen test results without considering the patient's clinical history. While food avoidance remains the most effective treatment for IgE-mediated food allergy, there are varying approaches to clinical management. Strict food avoidance for non-severe food allergies may increase the patient's burden and impact their quality of life. To address these challenges, a consensus on the diagnosis and management of IgE-mediated food allergy in children has been developed based on the latest guidelines and research evidence. This consensus aims to guide physicians in standardizing the management of IgE-mediated food allergy in children.

Prevalence of immunoglobulin E sensitisation to mites and pollens in 25,451 French dogs from 2016 to 2022.

Canine atopic dermatitis (cAD) is a common skin disorder in dogs, wherein allergens are presumed to exert a significant influence. The prevalence of allergen sensitisation in dogs with suspected cAD remains inadequately investigated in France. This study aimed to analyse allergen-specific immunoglobulin (Ig)E test results from French dogs with suspected cAD, exploring potential risk factors influencing sensitisation. The study included 25,451 client-owned dogs presented with clinical signs of cAD between January 2016 and December 2022. The study population consisted of 226 pure breeds and 915 cross-bred dogs of both sexes, with a mean age of 4.4 (±2.8) years. Data collection involved the compilation of results from canine serological allergen-specific IgE ELISA tests, using a 23 allergen composite panel. The influence of breed, sex, age, geographical area and sampling season on IgE test outcomes subsequently was analysed. Of the 25,451 analysed samples, 75.6% exhibited significant serum IgE concentrations in response to at least one of the tested allergens, with 67.9% testing positive for mites and 39.8% for pollens. Breed, sex, age, geographical area and sampling season were identified as significant risk factors influencing sensitisation patterns. This study provides insights into the prevalence and risk factors associated with allergen sensitisation in dogs with suspected cAD. Understanding these factors is crucial for effective diagnosis and tailored management strategies in veterinary practice. The findings underscore the need for personalised approaches in addressing cAD, considering individual patient characteristics.

Clinical study on the utility of allergy tests to detect IgE-mediated anaphylaxis after diclofenac etalhyaluronate administration.

This study was conducted to investigate factors involved in anaphylaxis related to diclofenac etalhyaluronate (DEH) [product name: Joyclu® (JCL)] (containing DEH and macrogol 400), which is used to treat patients with osteoarthritis. Patients with osteoarthritis were divided into two groups that had (experienced patients) or had not experienced anaphylactic symptoms after JCL administration (non-experienced patients). Five tests performed to assess factors related to anaphylaxis consisted of a skin prick test (SPT) as the primary endpoint and the other tests including basophil activation test, allergen-specific IgE (sIgE) tests using enzyme-linked immunosorbent assay or immunochromatographic kits, and genetic study were secondary endpoints. The SPT showed 4 (wheal)/7 (erythema) of 15 experienced patients and 0/3 of 19 non-experienced patients were positive for any of the test reagents containing DEH. The basophil activation test showed two experienced patients were positive for test reagents containing DEH. DEH- and diclofenac-sIgE were detected in 3 and 1 of 12 experienced patients, respectively. No clear results were shown in the other tests. DEH may be the main factor involved in the development of anaphylaxis. The SPT was more sensitive than the basophil activation and allergen-sIgE tests for identifying factors associated with anaphylaxis.

Validation of a Multiplex Molecular Macroarray for the Determination of Allergen-Specific IgE Sensitizations in Dogs.

Detecting IgE sensitizations in the serum of allergic dogs is commonly performed using allergen extracts, but these are difficult to standardize. This article details the development and validation of the Pet Allergy Xplorer (PAX; Nextmune, Stockholm, Sweden), the first multiplex macroarray for the detection of IgE sensitization in dogs using allergen extracts and molecular components; the PAX is derived from the Allergy Xplorer (ALEX2; MacroArray Diagnostics, Vienna, Austria). The selection of allergens, cartridge processing, strategy for identifying and blocking IgE directed against cross-reactive carbohydrate determinants (CCDs), and the method used for determining the positivity threshold are described. The validation of the PAX included evaluations of the specificity of its anti-IgE monoclonal antibody, specificity of IgE binding to target allergens, assay precision, and internal consistency. Additionally, the influence of possible confounding factors, such as sample type, the influence of hemolysis, lipemia, bilirubinemia, and elevated CCD-IgE, was tested. Finally, the sensitization rates of 23,858 European dogs to 145 environmental and Hymenoptera venom allergens were summarized. The PAX is accurate and reproducible and has a unique CCD-detection and blocking strategy; its molecular allergens offer a unique window on allergen cross-reactivity.

Microarray-based evaluation of selected recombinant timothy grass allergens expressed in E. Coli and N. Benthamiana

BackgroundTimothy grass (Phleum pratense) is a significant source of allergens, and recombinant allergens are increasingly used for diagnostic purposes. However, the performance of different recombinant allergen production systems in diagnostic assays needs further investigation to optimize their use in clinical settings.ObjectiveThe main objective of this study was to analyze and compare the diagnostic performance of recombinant timothy grass allergens produced in E. coli and N. benthamiana using a custom-made microarray chip.MethodsRecombinant timothy grass allergens Phl p 1, Phl p 2, Phl p 5, Phl p 6, Phl p 11, and Phl p 12 were produced in E. coli and/or N. benthamiana. A total of 113 patient serum samples were tested to evaluate the diagnostic sensitivity, specificity, inter-assay variability, and correlation of allergen-specific IgE detection compared to commercial multiplex tests (ALEX and ISAC). Additionally, the prevalence of sIgE to these allergens was assessed.ResultsPhl p 1, Phl p 2, Phl p 5, Phl p 6 and Phl p 11 showed high or very high positive correlation in immunoreactivity with other commercial multiplex tests. Notably, Phl p 11 fused with maltose-binding protein (MBP) demonstrated high diagnostic specificity and sensitivity, with a 0.3 arbitrary cut-off value. However, a high intra-assay variation was observed. The study also assessed specific IgE prevalence to timothy grass allergens within the tested patient cohort.ConclusionsRecombinant allergens from both E. coli and N. benthamiana demonstrated strong diagnostic potential on the microarray platform, with Phl p 11 (MBP-fused) showing particularly high performance. High intra-assay variation highlights the need for further optimization in allergen formulation and microarray storage conditions. These results highlight the potential of recombinant allergens for diagnostic applications, despite challenges with allergen stability in microarray formats. Specific IgE prevalence to timothy allergens revealed a sensitization profile consistent with findings from multiple studies.Graphical

B-067 Human IgE Monoclonal Antibodies as Unique Tools for Allergy Diagnostics

Abstract Background Current blood-based tests for allergy diagnosis rely on human sera or plasma as the source of IgE antibody for method validation and calibration. Obtaining human samples with sufficiently high levels of IgE presents challenges for researchers and diagnostic companies. Here, we present a unique panel of allergen-specific human IgE monoclonal antibodies (mAb) that target inhalant, food and alpha-gal allergens and offer novel approaches for investigation of IgE responses and standardization of allergy diagnostic reagents and methods. Methods Human IgE mAb (n=30) targeting inhalant allergens from dust mite, cat and dog; food allergens from peanut, egg, milk, walnut and cashew, and galactose-α-1,3-galactose, were generated from B cells from symptomatic allergic patients with rhinitis, asthma, atopic dermatitis or red meat allergy using hybridoma technology. Total and allergen-specific IgE were quantified by ImmunoCAP (whole allergen ImmunoCAP were also performed). Allergen binding profiles and mAb titers were determined by two-site immunoassay (ELISA). Antibody purity was assessed using SDS-PAGE and Western Blot. Results SDS-PAGE showed single heavy and light chain bands under reducing conditions. Antibody recognition of target allergens was confirmed by Western Blot. Allergen-specific IgE mAb concentrations for inhalant allergens ranged: 9,000-37,000 kU/L for dust mite (n=3), 2,100-53,000 kU/L for cat (n=4), 5,300-21,000 for dog (n=2). Food allergens ranged: 16,300-49,400 kU/L for peanut (n=14), 15,700-81,000 for egg (n=2), 41,600 for milk (n=1), 7,100 for walnut (n=1) and 37,000 for cashew (n=1). Alpha-gal IgE monoclonals (n=2) ranged in concentration from 15,700-81,000 kU/L. The ratios of specific IgE to total IgE measured by ImmunoCAP vary by allergen and by individual human IgE mAb. Ratios for the inhalant mAb ranged from 0.04-1.05, for the food mAb the ratios ranged from 0.33-0.99. The two alpha-gal mAb showed relatively lower specific IgE levels (average ratio was 0.14; range=0.08-0.20). Conclusions Monoclonal IgE antibodies derived from patients presenting with allergic symptoms may provide a reliable replacement for human sera to investigate allergic disease. IgE mAb to inhalant and food allergens, and to the alpha-gal carbohydrate epitope, provide unique diagnostic markers and will offer improved accuracy for assessing patient allergy by standardizing diagnostic reagents and methods. Crystal structures of several of the human IgE mAb epitopes have recently been reported (Pomés et al, J Allergy Clin Immunol, 2024). The current panel of human IgE mAb can be expanded to include additional allergen targets, which may lead to the development of improved allergy therapeutics.

B-059 Development and Validation of Multiplex Quantitative Allergy Tests based on Automated Flow Fluorescence Immunoassay Analyzer

Abstract Background Serological allergy tests measuring allergen-specific IgE (sIgE) are simpler and safer than skin prick tests, and the results are not influenced by skin condition or human factors. Quantitative detection of sIgE can also aid in evaluating patient allergies and aiding subsequent treatment. Dymind has researched and developed novel quantitative allergy tests based on the automated flow fluorescence immunoassay analyzer system (MF1280), enabling quantitative detection of multiple sIgE in just one test with one sample. Here, we present the performance of tIgE and two specific IgE test kits using the Dymind MF1280 system. Methods This study evaluated the performance of total IgE (tIgE) and two allergen-specific IgE (sIgE) panels of inhalant and food allergens, inhalant allergen panel including d1 (Dermatophagoides pteronyssinus), d2 (Dermatophagoides farina), i6 (Cockroach), e1 (Cat epithelium), e5 (Dog epithelium), w1(Common ragweed), and food allergen panel including f1 (Egg white), f2 (Cow’s milk), f3 (cod), f23 (Crab), 24 (Shrimp), and f27 (beef). Evaluation criteria included precision, linearity, limit of detection (LOD) and method comparison. As clinical performance of 425 clinical samples collected from 2 hospital laboratory in China was evaluated by both of Dymind allergen IgE MF1280 system and Phadia ImmunoCAP. Results The validated linearity of total IgE and sIgE were 2.0-5000.0 IU/mL and 0.1-100.0 IU/mL respectively. The LOD of total IgE and sIgE determined to be 2 IU/mL and 0.1 IU/mL respectively. The precision was evaluated by assaying a low and a high samples of every sIgE assay and the result of d1, d2, i6, e1, e5, w1, f1, f2, f3, f23, f24, f27 were 3.73% / 1.34% (low sample / high sample), 3.26% / 1.95%, 2.18% / 0.87%, 1.31% / 1.40%, 3.63% / 1.13%, 2.84% / 4.76%, 4.50% / 1.53%, 5.97% / 1.64%, 3.46% / 1.11%, 1.58% / 1.73%, 3.77% / 1.28%, 1.78% / 0.96% respectively. The total mean coefficient of measurements was below 7% to ensure high precision in multiplex quantitative analysis. Method comparison of 425 clinical samples between Phadia ImmunoCAP and Dymind allergen IgE showed total concordance rate was over 85% except f2 (over 80%). Conclusions The Dymind Allergen-specific IgE test kits on the automated flow fluorescence immunoassay analyzer system provide fast and accurate in vitro diagnostic detection of tIgE and sIgE for aiding diagnostics specific allergens sensitization and treatment for allergy patients, with good precision and excellent agreement compared to ImmunoCAP. The MF1280 system has advantages including random access, fully automated, multiplex quantitative detection of allergen sIgE with reducing assay time, sample consumption and lower costs.

B-056 Clinical and Analytical Performance Evaluation of Two Immunoassays for the Detection of Mite Specific Serum IgE for Allergy Diagnosis

Abstract Background IgE-mediated allergic diseases can be considered a modern epidemic, with exponential growth mainly in industrialized countries. Diagnosis is usually based on detailed medical history, physical examination, skin or challenge test and the determination of allergen-specific serum IgE - a laboratory test that has become a high-value tool in the allergy patient's journey over the last three decades. As the identification of specific immunoglobulin E (sIgE) for a given allergen is important to aid in the allergy diagnosis, several methods for detecting IgE in vitro are available worldwide and, in recent years, there have been several improvements in laboratory methodologies bringing greater advances in terms of clinical and analytical performance. The study aims to evaluate the clinical performance and correlation between two different sIgE assays (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and their concordance with Skin Prick Test (SPT) and clinical history. Methods This prospective study was conducted with approximately 130 consecutive patients who underwent evaluation of allergic diseases in different centers in Brazil. Clinical data, blood samples, and SPT results were collected. With the blood samples, the allergens D1, D2 and D201 were evaluated using both methods (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and the data were evaluated in a correlation study and clinical concordance analysis. Results Qualitatively evaluating the sIgE results between the two immunoassays, at the cutoff point considered clinically significant (≥ 0.35 KU/L), a total agreement of 95.2% (D1); 95.1% (D2), 91.7% (D201) and 96.8% (Derp2) was observed. Semi-quantitatively evaluating through reactive interpretation, an agreement of 89.5% (D1); 91.06% (D2); 87.60% (D201) and 93.33% (Derp2) was observed. Spearman's correlation between the analytical methods was 0.85 (D1), 0.93 (D2), 0.68 (D201) and 0.76 (Derp2). When compared with the SPT results, a total agreement of 78.7% and 80.1% was obtained for 3gAllergy and ImmunoCAP, respectively, with slightly higher positive agreement for both methods. Conclusions The two methods have good agreement with each other, with greater differences when evaluated quantitatively. However, when compared to clinical history and skin prick test results, both perform very similarly with a few differences that may be caused by the difference in the assay design.

A Case of the Anti-aquaporine-4 Antibody-negative Neuromyelitis Optica Spectrum Disorders Associated with Atopic Disease with High Concentration of Anti-IgE Autoantibody and HyperIgEemia

We report a 70-year-old male patient with the sero-negative neuromyelitis optica spectrum disorders (NMOSD) associated with atopic disease (AD). He was diagnosed with allergic rhinitis at the age of 20. When he was 61 years old, he subacutely developed orthostatic hypotension, bilateral optic neuritis, quadriparesis, urinary retention, and constipation. The laboratory results revealed allergen-specific IgE positivity for cryptomeria japonica and hinoki, hyperIgEemia, and Th (helper T cell) 1 dominance. The serological tests for autoantibodies revealed negative anti-aquaporine 4 antibody, and high concentration of anti-IgE autoantibody (anti-IgE AAb). Cerebrospinal fluid was negative for anti-myelin-oligodendrocyte glycoprotein antibody and glial fibrillary acidic protein antibody. Fluid-attenuated inversion recovery on brain magnetic resonance imaging (MRI) showed high signal intensities in bilateral cerebral deep white matter. T2 weighted image on spine MRI showed longitudinally extensive high signal intensities in the spinal cord, specifically involving C1 vertebral level to conus medullaris. Intravenous methylprednisolone (IVMP) and plasma exchange resulted in partial improvement. Following the onset of NMOSD, he had relapse of NMOSD four times. In each episode, IVMP was to be partially effective with anti-IgE AAb reduction. Anti-IgE AAb may be a reasonable clinical indicator of increased disease activity in the sero-negative NMOSD associated with AD.

Dendritic cell-specific deletion of PKCδ in offspring of allergic mothers prevents the predisposition for development of allergic lung inflammation in offspring.

In humans and in mice, maternal allergy predisposes offspring to development of allergy. In murine models, increased levels of maternal β-glucosylceramides are both necessary and sufficient for the development of allergic predisposition in offspring. Furthermore, increased numbers of CD11b+ dendritic cell subsets in the offspring of allergic mothers are associated with allergic predisposition. In vitro, β-glucosylceramides increase CD11b+ dendritic cell subset numbers through increased PKCδ signaling but it is not known if enhanced PKCδ signaling in dendritic cells is required in vivo. We demonstrate that dendritic cell-specific deletion of PKCδ prevents the β-glucosylceramide-induced increase in CD11b+ dendritic cell subset numbers both in vitro as well as in vivo in the fetal liver of offspring of mothers injected with β-glucosylceramides. Furthermore, dendritic cell-specific deletion of PKCδ in offspring prevents the maternal allergy-induced increase in CD11b+ dendritic cell subsets and decreases allergen-induced IL-5 and eosinophilia in lungs of offspring. However, loss of PKCδ in dendritic cells did not prevent development of allergen-specific IgE. Our study provides mechanistic insight into the function of PKCδ in the origins of allergic disease beginning in utero as well as the development of postnatal allergic lung inflammation.

A real-world data analysis of distribution and inconsistency between total serum IgE and allergen-specific IgE results in clinical practice.

The inconsistency between serum total IgE (tIgE) and allergen-specific IgE (sIgE) results is often encountered in clinical practice, but the distribution and influencing factors of the inconsistent results have not been fully understood. The aim of this study was to analyze the distribution and inconsistency between tIgE and sIgE test results. A retrospective study, from the electronic medical records of 2139 patients who underwent both tIgE and sIgE tests, from January to December 2023 was reviewed. The tIgE and sIgE results and their distribution, as well as their inconsistency, were analyzed based on sex, age, and disease subgroups. 36.2% of the patients had a positive sIgE, and 43.7% had an elevated tIgE level. sIgE and tIgE results were discordant in nearly 30% of patients, with no difference between genders, while individuals aged over 60 exhibited a significantly higher inconsistency rate than the other age groups, and the inconsistency rate between tIgE and sIgE results was significantly different among different tIgE levels, sIgE grades, positive allergen count and positive allergen types. In addition, patients with chronic urticaria (CU) had a higher inconsistency rate than those with other allergic diseases, but the difference was not statistically significant. The overall inconsistency rate between tIgE and sIgE results was about 30%. The elderly group older than 60 years old is more likely to have inconsistent results, and tIgE level, sIgE level, the number and type of positive allergens also affected the consistency of tIgE and sIgE results.

Atopy and asthma in children born to mothers at risk of gestational diabetes mellitus: a follow-up study

BackgroundGestational diabetes mellitus (GDM) is the most prevalent metabolic disturbance during pregnancy and is associated with adverse outcomes in offspring, including an elevated risk for developing atopic diseases in early childhood. Research is limited regarding only women at risk of GDM among whom some develop GDM while others do not. Information about adverse health outcomes in the offspring of these women is also lacking. The main aim was to assess whether maternal GDM increases the offspring’s risk of atopic dermatitis (AD), asthma and allergic rhinitis at 1, 2 and 5 years of age. The second aim was to analyze the association of other maternal health characteristics on the development of these disorders in offspring.MethodsThe follow-up study group of the Gestational Diabetes Study (GDS), conducted at Tartu University Hospital, Estonia, between 2014 and 2020, comprised 223 mother–child dyads. All women had at least one risk factor for GDM, of whom only some developed GDM. Information about the diagnoses of interest was obtained from Electronic Health Records. Allergen-specific IgE from children’s serum was measured using ImmunoCAP™ Phadiatop™ Infant, with results ≥ 0.35 kU/l considered positive. Statistical analysis was performed using the RStudio software (version 4.3.0).ResultsAccording to our results, only the cases of GDM requiring the use of antidiabetic medications were associated with the development of asthma and/or allergic rhinitis at 2 years of age (aOR 4.68, 95%CI 1.08–20.21, p = 0.039). Maternal obesity (BMI > 30) was associated with offspring´s asthma and/or allergic rhinitis diagnosis at 2 years of age (aOR 3.15, 95%CI 1.03–9.63, p = 0.045).Maternal abnormal weight gain during pregnancy was associated with asthma and/or allergic rhinitis at 5 years of age (aOR 2.76, 95%CI 1.04–7.31, p = 0.041).ConclusionAmong pregnant women at risk for GDM, maternal weight-related factors significantly influence the development of atopic diseases in their children between 1 and 5 years of age, regardless of the GDM diagnosis. This suggests that, besides women with GDM greater attention should also be paid to women at risk but who do not develop GDM, as their children seem to be at higher risk of atopic diseases.

IgE versus IgG and IgA: Differential roles of allergen-specific antibodies in sensitization, tolerization, and treatment of allergies.

The prevalence of asthma, rhinitis, and food allergies has increased dramatically over the last few decades. This increase originally started in western countries, but is now also evident in many other regions of the world. Given the fact that the increase is so quick, the noted increase cannot be linked to a genetic effect, and many environmental factors have been identified that are associated with increased or reduced prevalence of allergies, like changing dietary habits, increased urbanization, pollution, exposure to microorganisms and LPS, and the farming environment and raw milk consumption. Although the key role of allergen-specific IgE in allergies is well known, the role of allergen-specific IgG and IgA antibodies is less well defined. This review will provide an overview of the functions of allergen-specific IgE in allergy, the role of allergen-specific antibodies (IgG (4) and IgA) in allergen immunotherapy (AIT), the possibility to use allergen-specific antibodies for treatment of ongoing allergies, and the potential role of allergen-specific antibodies in tolerance induction to allergens in a preventive setting. In the last, more speculative, section we will present novel hypotheses on the potential role of allergen-specific non-IgE antibodies in allergies by directing antigen presentation, Th2 development, and innate immune training.

Allergen Testing: A Review of the Indications, Procedures, and Limitations in Ocular Allergy.

Allergen-based diagnostics are essential in the management algorithm of allergic diseases. Unlike systemic allergy, where the indications and interpretation of these diagnostic modalities are well established, their utility in ocular allergy is not well-defined. With the rising prevalence of ocular allergies and the need for personalized treatment strategies, there is a growing demand for precision allergen diagnostics. This review describes the commonly used tests with their indications, procedures, and limitations. A review of the literature was carried out on articles on allergen diagnostics in ocular allergy, and after excluding articles that were not relevant, 82 papers were included in the current review. IgE-mediated pathways contribute significantly to seasonal and perennial ocular allergy and partly to vernal keratoconjunctivitis. Most diagnostic techniques aim to detect IgE sensitization. In vivo tests include skin prick (SPT), intradermal, and patch tests. SPT is considered the gold standard and directly evaluates the presence of allergen-specific IgE in the skin. In vitro tests measure total and specific IgE from either tears or sera. Tear IgE measurement is relatively specific for allergic conjunctivitis and can provide insight into the potential allergens responsible for local sensitization. The conjunctival provocation test can help establish true allergy, especially in patients with polysensitization. This review also provides an overview of evidence in literature segregated based on the test employed. This includes 17 studies on only SPT; 42 studies on IgE measured in serum, tears, or both; and 20 studies which have evaluated both SPT and IgE. The pattern of allergen sensitization can guide recommendations for avoidance measures and immunotherapy. Thus, this could create a corticosteroid-sparing therapy avenue in these patients, reducing disease severity and resulting visual morbidity.

Analysis of the effectiveness of cross-reactive carbohydrate antigen determinant antibody adsorbents in identifying allergen-specific IgE antibodies

This study aimed to investigate the influence of anti-cross-reactive carbohydrate determinant IgE antibodies (anti-CCD IgE) on the detection of allergen-specific IgE (sIgE) antibodies, as well as the application value of anti-CCD IgE adsorbents in detecting allergen sIgE. In this cross-sectional study, a total of 2 636 test samples from patients who received treatment in West China Hospital of Sichuan University and tested allergen sIgE using the western blot method from October 2020 to May 2021 were analyzed. In these samples, 709 samples tested postive of allergen sIgE. 46 stochastic venous serum samples that tested positive in both sIgE and anti-CCD IgE and 1 serum sample that tested positive in sIgE but negative in anti-CCD IgE were collected. These samples were processed by anti-CCD IgE adsorbents, followed by allergen sIgE detection. The difference between the two detection results before and after adsorption was analyzed. The allergen test results showed that the positive rate of anti-CCD IgE in samples was 2.6% (69/2 636) during the period of sample collection. After treatment with anti-CCD IgE adsorbents, the top three allergen-sIgE of the positive rate changed from tree combination 2 (willow/poplar/elm), common ragweed and peanut to dust mite combination, cockroach and crab. The positive anti-CCD IgE results of 46 samples all turned negative and the total positive sIgE antibody dropped by 62.8%; the positive rate of sIgE antibodies with the class result ≥2 significantly decreased after treatment with anti-CCD IgE adsorbents, especially the positive rate of common ragweed dropped by 96.2%. The results of positive samples showed that multiple sIgE antibodies declined by different ranges, involving up to 11 antibodies with a maximum decline of 4 classes. Strongly positive sIgE antibodies (the class result ≥4) also had a high conversion rate of negative (25.0%-100%). The positive sIgE antibodies in about 60% of the samples decreased by more than 2, and the sIgE antibodies in 17.4% of the samples turned completely negative. There was no change in the allergen sIgE detection results of the sample with negative anti-CCD IgE after treatment. In conclusion, sIgE antibodies including targeting common ragweed, humulus, tree combination 2 (willow/poplar/elm), etc. are susceptible to false positives caused by anti-CCD IgE. Treatment of samples with anti-CCD IgE adsorbents can significantly reduce the risk of false positives caused by anti-CCD IgE. It is necessary to pretreat samples that were anti-CCD IgE positive with anti-CCD IgE adsorbents, which can make laboratory results more accurate and provide a reference for diagnosis and prevention of allergic diseases.

Clinical and Immunological Features of Bronchial Asthma Comorbid Chronic Urticaria: A Retrospective Study.

Asthma and chronic urticaria (CU) are two high prevalent diseases and often coexist. The underlying relationship and potential immunological mechanism between the two diseases are still unclear. The objective of this study was to investigate the clinical and immunological feature of asthma comorbid with CU. A retrospective study was conducted. Fifty patients with asthma comorbid CU, 50 patients with asthma, and 50 patients with CU alone were included. Age and sex of the patients enrolled were matched. Data of demographic characteristics, clinical manifestations including disease severity (frequency of symptoms, age of onset, disease duration, symptom score, complication with allergic rhinitis) as well as serum immunological index including total IgE (tIgE), allergen-specific IgE (sIgE), and food-specific IgG4 (FS-IgG4), were collected and analyzed. No significant differences in the frequency of symptoms, age of onset, and disease duration were found among the three groups. The score of asthma control test (ACT) in patients with asthma comorbid CU was significantly lower than that of asthma (p = 0.005); however, compared with patients with CU, the 7-day urticaria activity score (UAS7) of patients with asthma comorbid CU did not show obvious differences. Immunological index showed that the positive rates of tIgE, house dust mite (HDM)-sIgE, and FS-IgG4 were different among the three groups (p < 0.05). Patients with asthma comorbid CU had the highest rate of positive tIgE, moderate and severe positive sIgE to HDM. Egg-specific IgG4 (egg-sIgG4) had the highest positive rate in all groups. Patients of asthma comorbid CU obtained the highest rate of severe positive of egg-sIgG4. Our results demonstrated that patients with asthma comorbid CU have lower control level of asthma symptoms, higher tIgE and HDM-sIgE level, and highest rate of severe positive egg-sIgG4. These results indicate that comorbidity of CU in asthma obviously increases the severity of allergens.

Peripheral Inflammation Featuring Eosinophilia or Neutrophilia Is Associated with the Survival and Infiltration of Eosinophils within the Tumor among Various Histological Subgroups of Patients with NSCLC.

Immune activation status determines non-small cell lung cancer (NSCLC) prognosis, with reported positive/negative associations for T helper type 2 (TH2) responses, including allergen-specific IgE and eosinophils. Our study seeks to explore the potential impact of these comorbid immune responses on the survival rates of patients with NSCLC. Our retrospective study used data from the Data Warehouse of the German Center for Lung Research (DZL) and Lung Biobank at Thoraxklinik Heidelberg. We estimated the association of blood eosinophilia and neutrophilia on survival rates in an inflammatory cohort of 3143 patients with NSCLC. We also tested sensitization to food and inhalants and high-sensitivity C-reactive protein (hs-CRP) in a comorbidity cohort of 212 patients with NSCLC. Finally, we estimated the infiltration of immune-relevant cells including eosinophils, T-cells, and mast cells in a tissue inflammatory sub-cohort of 60 patients with NSCLC. Sensitization to at least one food or inhalant (sIgE) was higher in patients with adenocarcinoma (adeno-LC) than the non-adenocarcinoma (non-adeno-LC). Furthermore, hs-CRP was higher in non-adeno-LC compared with adeno-LC. Peripheral inflammation, particularly eosinophilia and neutrophilia, was associated with poor survival outcomes in NSCLC with a clear difference between histological subgroups. Finally, blood eosinophilia was paralleled by significant eosinophil infiltration into the peritumoral tissue in the lung. This study provides novel perspectives on the crucial role of peripheral inflammation, featuring eosinophilia and neutrophilia, with overall survival, underscoring distinctions between NSCLC subgroups (adeno-LC vs. non-adeno-LC). Peripheral eosinophilia enhances eosinophil infiltration into tumors. This sheds light on the complex interplay between inflammation, eosinophil infiltration, and NSCLC prognosis among various histological subtypes. Further studies are required to underscore the role of eosinophils in NSCLC among different histological subgroups and their role in shaping the tumor microenvironment.

Indirubin induces tolerogenic dendritic cells via aryl hydrocarbon receptor activation and ameliorates allergic asthma in a murine model by expanding Foxp3-expressing regulatory T cells

BackgroundAllergic asthma is a chronic bronchial inflammatory disease closely associated with abnormal immune responses of dendritic cells (DCs) and allergen-specific type 2 T helper (Th2) cells. Indirubin (IR), a natural aryl hydrocarbon receptor (AhR) ligand, exerts anti-inflammatory and immunomodulatory properties. PurposeIn this study, we aimed to clarify whether IR exhibits immunomodulatory action on DCs via AhR activation and investigated the antiallergic effects of IR in a mouse model of allergic asthma. MethodsLipopolysaccharide (LPS)-activated bone marrow-derived DCs were treated with IR. Their mRNA expressions, cytokine production, and phenotype patterns were determined by a quantitative real-time PCR, ELISA, flow cytometry, and RNA sequencing. The mixed lymphocyte reaction was utilized to evaluate the regulatory function of IR-treated DCs on T-cell differentiation. Moreover, mice with ovalbumin (OVA)-induced allergic asthma were treated with IR. Thereafter, the airway hyperresponsiveness (AHR), allergen-specific IgE production, cytokine levels, airway inflammation, and T-cell responses were evaluated. ResultsTreatment of LPS-stimulated DCs with 20 μM IR significantly reduced IL-12 and TNF-α production while increasing IL-10 secretion. Meanwhile, these DCs expressed decreased levels of CD80 but increased levels of Jagged 1 surface molecules. However, the effects of IR on DCs were reversed by pretreatment with the AhR antagonist, CH223191. Additionally, the coculture of these tolerogenic-like DCs with allogeneic CD4+T cells promoted the generation of Foxp3+ regulatory T (Treg) cells. A transcriptomic analysis identified several downregulated genes that are involved in regulating cell migration, cytokine secretion, and inflammatory responses in DCs after IR treatment. In an asthmatic murine model, oral administration of 25 mg kg-1 body weight of IR efficiently alleviated the development of AHR, OVA-specific IgE production, and levels of Th2-type cytokines (IL-4, IL-5, and IL-13) and the CCL11 chemokine. IR treatment also attenuated inflammatory cell recruitment and mucus production in the lungs. Notably, an enhanced frequency of Foxp3+ Treg cells and reduced effector T-cell proliferation associated with increased levels of IL-10 and TGF-β were observed in IR-treated mice. ConclusionIR can induce tolerogenic-like BMDCs which promote the differentiation of Treg cells. Importantly, the expansion of Foxp3+ Treg cells contributed to the therapeutic efficacy of IR against allergic asthma.