IgE Assays Research Articles

Comparison of Conventional IgE Assay and Measurement of Specific IgE to Haemocyanin for the Diagnosis of Adult Crab Allergy.

Five potential allergens of freshwater crab (Somanniathelphusa sinensis), including hemocyanin, have been discovered. Specific IgE to haemocyanin was increased in crab-allergic than in crab-tolerant patients. The add-on of specific IgE to hemocyanin to skin prick test enhanced the specificity of the crab allergy diagnosis. IgE, immunoglobulin E; rHM, recombinant haemocyanin; sIgE, specific IgE; SPT: skin prick test.

Real-Life Evidence of Mepolizumab Treatment in Chronic Rhinosinusitis with Nasal Polyps: A Multicentric Study

Background: The introduction of biological drugs in the management of chronic rhinosinusitis with nasal polyps (CRSwNP) is allowing new and increasingly promising therapeutic options. This manuscript aims to provide a multicenter trial in a real-life setting on Mepolizumab treatment for severe uncontrolled CRSwNP with or without comorbid asthma. Methods: A retrospective data analysis was jointly conducted at the Otolaryngology–Head and Neck Surgery departments of La Sapienza University and San Camillo Forlanini Hospital in Rome. Both institutions participated by sharing clinical information on patients with CRSwNP treated with Mepolizumab. Patients were evaluated before starting Mepolizumab, at six months and at twelve months from the first drug administration. During follow–up visits, patients underwent endoscopic evaluation, quality of life assessment, nasal symptoms assessment, and blood tests to monitor mainly neutrophils, basophils, eosinophils, and IgG, IgA, and IgE assay. Results: Twenty patients affected by CRSwNP and treated with Mepolizumab were enrolled (12 females and 8 males with a mean age of 63.7 years). Sixteen patients (80%) had concomitant asthma. During follow-up, a gradual improvement in nasal polyp score, quality of life and nasal symptoms, assessed by SNOT-22 and VAS and loss of smell measured by olfactory VAS, was found. Regarding blood tests, eosinophils decreased gradually, while other blood parameters showed no statistically significant changes. Conclusions: Mepolizumab has been shown to be effective in the therapeutic management of patients with CRSwNP. Further studies are needed to support our findings and better understand the underlying immune pathways to predict patients’ response to biological treatment in CRSwNP.

Seasonal Patterns and Allergenicity of Casuarina Pollen in Sydney, Australia: Insights from 10 Years of Monitoring and Skin Testing

Casuarina (Australian pine, She-oak) is native to Australia and South East Asia and is known for its abundant wind-borne pollen. Despite not being considered a major aeroallergen, some patients report respiratory symptoms upon exposure, with positive skin prick tests (SPT) to Casuarina pollen extract. This study investigates Casuarina pollen dispersal patterns in Sydney, Australia, over a 10-year period, from 2008 to 2018, revealing a bimodal distribution of pollen from September to October (southern hemisphere spring) and February to March (mid-late summer). Analysis of historical SPT data shows 20% of individuals with respiratory allergies reacting positively to Casuarina pollen extract, with almost 90% of these also reacting to grass pollen, suggesting potential cross-reactivity. Notably, there are no exclusive reactions to Casuarina pollen. Understanding the prolonged pollen season underscores the importance of year-round monitoring for accurate characterization. Currently lacking are commercially available skin test extracts or specific IgE assays for Casuarina sensitization, necessitating challenge studies to confirm clinical symptoms directly attributable to Casuarina pollen. By elucidating the seasonal dynamics and meteorological drivers of Casuarina pollen dispersion, alongside the potential allergenicity suggested by skin prick tests, this study paves the way for improved management of Casuarina-related allergies and highlights the critical need for further research on native Australian plant allergens.

Discrepancies between two total IgE assays and difference in reference intervals in healthy adults

ObjectiveTo compare total immunoglobulin (Ig) E assay performance characteristics between Abbott Architect and Siemens Immulite test systems. Reference intervals were also determined for both platforms in an American population of healthy adults. MethodsAgreement of the two total IgE assays was evaluated in a cohort of 331 subjects with normal complete blood count (CBC) and comprehensive metabolic panel (CMP) results. Reference intervals were established in 302 subjects after exclusion of atopic individuals on the Abbott Architect and Siemens Immulite test systems. ResultsWe demonstrated a 32% positive bias for total IgE quantitation on the Siemens Immulite platform compared to the Abbott Architect, despite both methods calibrated against the same WHO international reference material (75/502), Furthermore, the upper limit of the reference interval (95th percentile) was determined to be higher for the Siemens Immulite assay compared to the Abbott Architect (132 and 102 IU/mL, respectively). ConclusionDespite the use of a common WHO reference material for total IgE assay calibration, significant differences in quantitation was observed between two FDA-cleared test systems. Given that, it is warranted for clinical laboratories to verify vendor established reference intervals and adjust accordingly based on internal assessment of the normal range.

Mammalian Meat Allergy and IgE to Alpha-Gal in Central Virginia: Findings From a COVID-19 Vaccine and Patient Cohort

IgE to galactose-alpha-1,3-galactose (alpha-gal) is linked to tick bites and an important cause of anaphylaxis and urticarial reactions to mammalian meat. The alpha-gal syndrome (AGS) is recognized as being common in the southeastern United States. However, prevalence studies are lacking and open questions remain about risk factors and clinical presentation of alpha-gal sensitization. Here we characterized the prevalence as well as the presentation and risk factors of AGS and alpha-gal IgE sensitization in adults in central Virginia recruited without regard to the history of allergic disease. Adults in central Virginia, primarily University of Virginia Health employees, were recruited as part of a COVID-19 vaccine study. Subjects provided at least one blood sample and answered questionnaires about medical and dietary history. We used ImmunoCAP for IgE assays and assessed the ABO blood group by reverse typing using stored serum. We also investigated biobanked serum from COVID-19 patients. Median age of the 267 enrollees was 42 years, 76% were female, and 43 (16%) were sensitized to alpha-gal (cutoff of 0.1 IU/mL), of which mammalian meat allergy was reported by seven (2.6%). Sensitized subjects (1) were older, (2) had higher total IgE levels but a similar frequency of IgE to common respiratory allergens, and (3) were more likely to report tick bites than were nonsensitized subjects. Among those who were sensitized, alpha-gal IgE levels were higher among meat-allergic than nonallergic subjects (geometric mean, 9.0 vs 0.5 IU/mL; P< .001). Mammalian meat and dairy consumption was common in individuals with low-level sensitization. In central Virginia, AGS is a dominant cause ofadult food allergy with a prevalence approaching or exceeding2%.

L’allergie alimentaire aux lentilles : une entité méconnue chez l’enfant

Introduction: Food allergies affect about 6-8 % of children. Legumes are the most common ingredients in the Mediterranean diet. They occupy the fifth place among the foods responsible for allergic reactions that can be severe and cause anaphylaxis. Lentils are most involved in IgE-mediated food allergies in children. However, little information is available on lentil allergens.Objectives: The aim of this study is to describe the clinical and biological picture of food allergy to lentils in order to raise awareness of this emerging allergen among pediatricians.Patients and Methods: We report 4 cases of food allergy to lentils in children aged 3 to 6 years, 2 of whom were male. Clinical symptoms occurred within 2 hours of ingestion or inhalation of lens vapor. Three patients consulted for localized or generalized urticarial reactions, including one with angioedema of the face. One patient had consulted on several occasions for unexplained discomfort after meals. A personal or family atopic background was found in 3 patients. Two of these patients had other associated food allergies: to fish (2 cases), peanut (1 case), egg (2 cases) and shrimp (1 case). One of our patients was found to be underweight (-2 SD). Prick tests to the native allergen were very positive in two children and confirmed the diagnosis. They were doubtful in one case and were not performed in a child with a very severe clinical picture. The specific IgE assay was very positive in one case. The evolution was favorable in all cases. The management consisted of a strict avoidance of raw or cooked lentils as well as other foods in the context of a cross-food allergy.Conclusion: Allergy to lenses is rare in our context. Its diagnosis is based on a suggestive anamnesis, followed in case of doubt by an oral provocation test. It is essentially due to the major allergen vicilin Len c 1. It may be associated with hypersensitivity to other legumes belonging to the same family, notably peas. In the majority of cases, the disease evolves favorably and tolerance is acquired.

Establishment of fluorescence multi-flow cytometric immunoassay for the simultaneous quantitative detection of six allergen-sIgE antibodies

BackgroundThe in vitro specific IgE (sIgE) assays now commonly used in clinical laboratories are not only time-consuming and expensive but also require many serum samples. To address these limitations, a novel fluorescent microsphere-based multiplex flow cytometric immunoassay was developed. This innovative assay enables rapid and simultaneous quantitative detection of multiple allergen-sIgE antibodies. ObjectiveTo establish a new method for the simultaneous quantitative detection of 6 allergen-sIgE antibodies based on fluorescence multiplex flow cytometry. MethodsSix different encoded fluorescent microspheres were selected to covalently couple 6 allergens, and their antigen-coupling activities were verified. After optimizing the multiplexing procedure and reaction conditions, including the concentration of microspheres encapsulated by allergens, reaction temperature, and reaction time, standard curves were established to quantify the 6 allergen-sIgE, and their performance was evaluated according to clinical guidelines. ResultsThe chosen analytical mode was optimized for the detection of the 6 allergens-sIgE for 70 minutes. The established coefficients of variation for multiplex flow cytometry reproducibility and intermediate precision were less than 10%. Linear regression analysis showed a highly significant quantitative correlation between the results of the multiple analyses of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Artemisia, and cat hair allergens and ImmunoCAP (Thermo Fisher Scientific): the r2 values ranged from 0.85 to 0.97 (P < .0001). In addition, there was a high correlation between the results of the multiplex analysis of dog hair allergens and the capture enzyme-linked immunosorbent assay (r2 = 0.92, P < .0001). ConclusionA high-throughput system called multiplex flow cytometry has been developed for the simultaneous detection of 6 inhalant allergens. The method has the advantage of being rapid and using less serum. Furthermore, it has the potential to be expanded to include other allergens and biologic agents.

IgE Antibody Assay-Based Allergen Database(CLSI-IL/A-37)

There are 8 established allergen databases (IUIS/WHO ANDB, Allergome, AllFam, AllergenOnline, SDAP, COMPARE, IEDB and AllerBase).None of these provide a comprehensive listing of the internationally-accepted nomenclature codes and Linnean system descriptors of the~1000 extract and molecular allergens used world-wide in diagnostic single-and multi-plex IgE antibody assays. The new Diagnostic Allergen DataBase (DADB) has been prepared by an international scientific committee of the Clinical and Laboratory Standards Institute to specifically provide these data together in a readily-searchable Excel database. Using peanut as an example, the DADB lists the allergens’ unique assay working codes (F13), general category (food), principal IgE antibody assay method(s) where the allergen specificity is available, common name (peanut), taxonomical name (Arachis hypogaea), and the NCBI, NPU, LOINC, Allergome and IUIS/WHO descriptor codes for allergens and their assays. The DADB benefits manufacturers of allergen-specific IgE assays by providing unambiguous specificity descriptors. With the DADB, allergen extract manufacturers will have clearly defined specificity targets for allergenic product development. Government regulators will have clarity on the specificity of new allergen reagents that are being submitted for clearance. IgE antibody proficiency testing programs (e.g. CAP) will be able to clearly define the IgE antibody specificities being measured in their challenge sera. The clinician will precisely know the allergen specificity of IgE antibody that is measured in their reference laboratory. Finally, the allergic patient will be assured that their allergic sensitization is being assessed in an assay with a well-characterized allergen reagent.

Retrospective Analysis of Allergen Distribution Dynamics in Central Taiwan.

Introduction: Allergy is a type Ⅰ hypersensitivity reaction to certain substances (allergens) such as environmental factors, food and drugs. Allergies are a significant public health issue, and therefore, understanding the distribution patterns of allergens in specific regions is important. This study aimed to retrospectively analyse allergen distribution patterns in Central Taiwan over a 5years period (2018-2022). Methods: Data of patients who had allergen sensitization testing using the OPTIGEN® Allergen-Specific IgE Assay from the 1st of January 2018 to the 31st of December 2022 were reviewed retrospectively. Statistical analyses were performed to determine the prevalence and distribution of allergens in our study population. Results: A total of 8,444 patients (3,784 males and 4,660 females) who attended the Asia University Hospital for allergen detection were enrolled in this study. Dermatophagoides farina (41.8%), Dermatophagoides pteronyssinus (37.9%), house dust (24.6%), cockroach mix (17.7%), crab (12.6%), clam (9.8%), shrimp (9.1%), cat dander (8.1%), pig weed (8%) and peanut (7.8%) were identified as the ten allergens that most commonly induced sensitization in our study population. Additionally, crab, clam, shrimp, peanut and beef were the five most common food allergens. Conclusion: In summary, our findings contribute significantly to the knowledge on allergen distribution in Central Taiwan. Our identification of prevalent allergens may contribute to an improved understanding of the epidemiology of allergies in this region.

Epitope-Based IgE Assays and Their Role in Providing Diagnosis and Prognosis of Food Allergy.

With advances in molecular and computational science, epitope-specific IgE antibody profiling has been developed and recently brought into clinical practice. Epitope-based testing detects IgE antibodies that directly bind to antigenic sites of an allergen, providing increased resolution specificity and fewer false-positive results for diagnosing food allergy. Epitope-binding profiles may also serve as prognostic markers of food allergy and help predict quantities of allergen that would provoke a reaction (ie, eliciting dose, possible severity of a reaction after allergen ingestion, and outcomes of treatment options such as oral immunotherapy [OIT]). Future studies are under way to discover additional applications of epitope-specific antibodies for multiple food allergens.

Epitope-Based IgE Assays and Their Role in Providing Diagnosis and Prognosis of Food Allergy

Epitope-Based IgE Assays and Their Role in Providing Diagnosis and Prognosis of Food Allergy

B-059 Allergen-specific IgE Measurement for Peanut Ara h 2*

Abstract Background Legumes such as peanuts are a major source of food allergies among children and adults. Ingestion is the primary route of exposure, although inhalation may also trigger an allergic response in patients with known hypersensitivity. Allergic reactions to peanut can include atopic dermatitis, angioedema, vomiting, diarrhea, and anaphylaxis. Several allergenic peanut proteins have been identified and linked with variable severity of patient symptoms. Ara h 2 is one of the proteins uniquely associated with severe peanut allergy. In this study, we evaluate the analytical performance of the Ara h 2 allergen containing reagent for use in the IMMULITE® 2000 3gAllergy® Specific IgE assay. Methods Serum samples were collected from 13 patient samples with documented histories of tree nut or legume-related allergies. The samples were analyzed for specific IgE reactivity to a commercially available recombinant Ara h 2 (rAra h 2) using the IMMULITE 2000 3gAllergy Specific IgE assay (Siemens Healthcare Diagnostics Inc., Tarrytown, NY). Precision, linearity, limit of detection, and endogenous interference were assessed. Results Repeatability and within-lab precision at all levels tested were less than 10% over a 20-day study. Regression analysis was performed following linearity assessment and resulted in a slope 95% CI of 0.9251–1.0492 (range 0.3–24 kU/L). Limit of blank and limit of detection were 0.02 kU/L and 0.08 kU/L, respectively. Endogenous interference testing showed &amp;lt;10% difference when spiked with hemoglobin (1000 mg/dL), intralipid (3000 mg/dL), and unconjugated bilirubin (40 mg/dL). Conclusion rAra h 2 allergen containing reagent for use in the IMMULITE 2000 3gAllergy Specific IgE assay is sensitive and capable of quantitatively measuring IgE in patients with clinical history of nut allergy. *Assay under development. Not available for sale. Future availability cannot be guaranteed.

Assessing IgE sensitization profiles to birch and timothy grass pollen allergens in birch pollen allergic blood donors using an oligoplex specific IgE assay

IgE sensitization profiles to single birch allergens in birch-sensitized patients differ among European countries. The aim of this study was to determine the distribution of specific IgE antibodies to major and minor birch pollen allergens in a population of allergic Norwegian individuals by using a birch allergic blood donor population as a surrogate sample. Sixty blood donors were recruited and sampled based on birch allergy symptoms such as rhinitis, rhinoconjunctivitis and/or mild asthma in previous seasons. All sera were collected before start of the pollen season and tested using a line blot assay (Euroimmun AG, Lübeck, Germany) for IgE to birch and timothy pollen. Both extracts, single allergens, and cross-reacting carbohydrate determinants (CCD) were analysed. Only donors with specific IgE to birch and/or timothy grass were further evaluated. Specific IgE to birch pollen extract was found in 52 sera, and sensitization to timothy grass in 40 sera. Specific IgE to Bet v 1 was predominant in contrast to Bet v 4 which was absent. However, sensitization to the minor allergens Bet v 2 and 6 was always found together with high levels of IgE to Bet v 1. Subjects sensitized to the profilin Bet v 2 from birch were also sensitized to Phl p 12 from timothy grass. In conclusion, there was predominantly Bet v 1 sensitization in this cohort and low sensitization to minor allergens and cross-reactive allergens (Bet v 2, Bet v 4, Phl p 7 and Phl p 12).

Comparison of Skin Prick Tests (SPT), Intradermal Tests (IDT) and In Vitro Tests in the Characterization of Insect Bite Hypersensitivity (IBH) in a Population of Lusitano Horses: Contribution for Future Implementation of SPT in IBH Diagnosis.

Thirty controls (C) and 30 IBH-affected (T) Lusitano horses were evaluated. T horses were included based on anamnesis and physical examination, supported by questionnaires. All horses were submitted to skin tests, Intrademal (IDT) and Skin Prick Tests (SPT), on the neck with 14 specific allergens, 13 recombinant proteins (r-proteins) from Culicoides nubeculosus (Cul n) and Culicoides obsoletus (Cul o) salivary glands and Culicoides nubeculosus Whole Body Extract (Cul n WBE). Addicionally, a cluster of six T and six C horses were also tested with Cul n 3 and Cul n 4 produced in insect cells and barley, as well as E. coli produced Cul o 3 and Cul o WBE. Allergen concentrations were 10 µg/mL for IDT and 100 µg/mL for SPT, and wheal diameters assessed at 20 min, 6 and 48 h. IDTs were considered positive when wheal diameter was ≥50% of the histamine wheal and SPT's ≥ 0.9 cm. In vitro tests, allergen-specific serum IgE and sulfidoleukotriene (sLT) release assay were also carried out. Results showed that Cul n WBE, Cul n 7, 8, 9, Cul o1P and Cul o 2P were the best performing allergens for SPTs (p ≤ 0.0001) for the 1st allergen panel and Cul o WBE, Cul n 3 Bar and Cul n 4 Bac (p ≤ 0.05) for the 2nd, presenting a higher discriminatory diagnostic potential than IDTs, at a concentration of 100 µg/mL, with readings assessed at 20 min. Regarding in vitro tests overall, the sLT release assay performed best.

Improving In Vitro Detection of Sensitization to Lipid Transfer Proteins: A New Molecular Multiplex IgE Assay.

LTP-syndrome is characterized by sensitization (IgE) to multiple non-specific lipid transfer proteins (nsLTPs) with a variable clinical outcome. The treatment is primarily based on offending food avoidance. However, the determination of Pru p 3-specific IgE is currently the main diagnostic tool to assess sensitization to nsLTPs. Herein, the study evaluates improvement of LTP-syndrome diagnosis and clinical management using a new IgE multiplex-immunoblot assay with a high diversity of food nsLTPs. An EUROLINE-LTP strip with 28 recombinant nsLTPs from 18 allergenic sources is designed. In total the study investigates 38 patients with LTP-syndrome and compares results from the nsLTPs (LTP-strip) with the respective food extracts of Prick-by-prick (PbP) testing. The agreement exceeds 70% for most nsLTPs, e.g., Pru p 3 (100%), Mal d 3 (97%), Pru av 3 (89%), Pha v 3 isoforms (87%/84%), Ara h 9 (82%), Cor a 8 (82%), and Jug r 3 (82%). The functionality and allergenic relevance of nine recombinant nsLTPs are proven by Basophil activation testing (BAT). The new IgE multiplex-immunoblot nsLTP assay shows a good diagnostic performance allowing culprit food assessment. Negative results from LTP-strip may indicate potentially tolerable foods, improving diet intervention and patients' quality of life.

Allergy to Hymenopter Venins: About Two Cases

The prevalence of allergic diseases has increased significantly, Hymenoptera allergy is one of the most frequent causes of anaphylaxis. The most common species are Wasps and Bees. The fatal risk has been known since antiquity. We report the study of two observations of allergy to hymenoptera venom collected in the respiratory diseases department of the Ibn Rochd University Hospital of Casablanca. A man and a woman, victims of a hymenoptera sting, presented severe allergic reactions requiring treatment with allergenic immunotherapy. The clinical examination was unremarkable. The blood count showed hypereosinophilia. Skin tests were positive for bee venom. The specific IgE assay for bee venom was positive. The diagnosis chosen was that of allergy to bee venom. Our patients were classified as Mueller stage III. The bee venom desensitization protocol was started according to the Ultra Rush protocol with clinical monitoring of the desensitization sessions.

INMUNOCAT study: The impact of molecular diagnosis on immunotherapy prescription in pollen polysensitized patients from Catalonia.

Recognition of specific allergens triggering immune response is key for the appropriate prescription of allergen-specific immunotherapy (SIT). This study aimed at evaluating the impact of using the commercially available microarray ImmunoCAPTM ISAC 112 (Thermo Fisher Scientific) on the etiological diagnosis and SIT prescription compared to the conventional diagnostic methods in patients with allergic rhinitis/rhinoconjunctivitis and/or asthma. 300 patients with respiratory allergic disease, sensitized to three or more pollen aeroallergens from different species, as assessed by a skin prick test (SPT) and specific IgE assays (sIgE), were included in this multicentric, prospective observational study. SPT and a blood test were performed to all patients. Total serum IgE and sIgE (ImmunoCAPTM) for allergens found positive in the SPT and sIgE allergen components (ImmunoCAPTM ISAC 112) were measured. According to SPT results, the most prevalent pollen sensitizers in our population were Olea europaea followed by grass, Platanus acerifolia and Parietaria judaica. The molecular diagnosis (MD) revealed Ole e 1 as the most prevalent pollen sensitizer, followed by Cup a 1, Phl p 1, Cyn d 1, Par j 2, Pla a 1, 2, and 3 and Phl p 5. Immunotherapy prescription changed, due to MD testing, in 51% of the cases, with an increase of prescription of SIT from 39% to 65%. The identification of the allergen eliciting the respiratory disease is essential for a correct immunotherapy prescription. The advances in allergen characterization using methods, such as the commercial microarray ImmunoCAPTM ISAC 112, can help clinicians to improve SIT prescription.

Early exposure to farm dust in an allergic airway inflammation rabbit model: Does it affect bronchial and cough hyperresponsiveness?

Over the past 50 years, the prevalence of allergic respiratory diseases has been increasing. The Hygiene hypothesis explains this progression by the decrease in the bio-diversity of early microbial exposure. This study aims to evaluate the effect of early-life farm exposure on airway hyperresponsiveness and cough hypersensitivity in an allergic airway inflammation rabbit model. A specific environment was applied to pregnant rabbits and their offspring until six weeks after birth. Rabbits were housed in a pathogen-free zone for the control group and a calf barn for the farm group. At the end of the specific environmental exposure, both groups were then housed in a conventional zone and then sensitized to ovalbumin. Ten days after sensitization, the rabbit pups received ovalbumin aerosols to provoke airway inflammation. Sensitization to ovalbumin was assessed by specific IgE assay. Cough sensitivity was assessed by mechanical stimulation of the trachea, and bronchial reactivity was assessed by methacholine challenge. The farm environment was characterized by endotoxin measurement. A total of 38 rabbit pups were included (18 in the farm group). Endotoxin levels in the farm environment varied from 30 to 1854 EU.m-3. There was no significant difference in specific IgE values to ovalbumin (p = 0.826) between the two groups. The mechanical threshold to elicit a cough did not differ between the two groups (p = 0.492). There was no difference in the number of cough (p = 0.270) or the intensity of ventilatory responses (p = 0.735). After adjusting for age and weight, there was no difference in respiratory resistance before and after methacholine challenge. Early exposure to the calf barn did not affect cough sensitivity or bronchial reactivity in ovalbumin-sensitized rabbits. These results suggest that not all farm environments protect against asthma and atopy. Continuous exposure to several sources of microbial diversity is probably needed.

Sensibilisation allergénique et asthme sévère en France : résultats de l’étude FASE-CPHG

IntroductionSevere asthma is a disease with many phenotypes. In this new subanalysis of the results of the FASE-CPHG study, one objective was to describe the allergenic sensitization profile of patients with severe asthma and to compare this profile with phenotyping in the same population. MethodsThe FASE-CPHG study is an observational, descriptive, and multicenter study investigating a population of patients with severe asthma cared for in 70 general hospitals in France between March 2016 and July 2017. ResultsOf the 1,502 patients included, 1,465 could be analyzed and their data were used for this study. An allergy assessment was undertaken: a skin test in 71% of the patients, and specific IgE assays in 37% of the patients. When the skin tests were done, 71.2% were positive for at least one allergen (sensitization to dust mites, 79%; grasses, 48%; cats, 40%; Betulaceae, 15.5%; cockroaches, 7.1%; Alternaria, 10.9%). A blood eosinophilia count was performed in 75% of the patients (count > 300/mm3 in 53% of the cases). Five severe asthma phenotypes were identified: early allergic asthma (sensitization to at least one allergen in 87% of the cases), obesity and asthma (sensitization in 64%), late-onset obstructive asthma (sensitization in 14%), late-onset eosinophilic asthma (sensitization in 43%), asthma and intolerance to aspirin (sensitization in 66%). ConclusionThis study demonstrated that in daily practice the allergy assessment was only carried out in 80% of patients who had severe asthma. An allergy assessment seems desirable for any phenotype of severe asthma; the prevalence of allergenic sensitization is also important within late-onset asthma phenotypes that are reputed to be non-allergic.

Trajectories of cough without a cold in early childhood and associations with atopic diseases.

Although children can frequently experience a cough that affects their quality of life, few epidemiological studies have explored cough without a cold during childhood. The objective of the study was to describe the latent class trajectories of cough from one to 10 years old and analyse their association with wheezing, atopy and allergic diseases. Questions about cough, wheeze and allergic diseases were asked at 1, 1.5, 2, 3, 4, 5, 6 and 10 years of age in the European prospective cohort of Protection against Allergy: STUdy in Rural Environment (PASTURE). Specific IgE assays were performed at 10 years of age. Questions regarding a cough without a cold were used to build a latent class model of cough over time. Among the 961 children included in the study, apart from the never/infrequent trajectory (59.9%), eight trajectories of cough without a cold were identified: five grouped acute transient classes (24.1%), moderate transient (6.8%), late persistent (4.8%) and early persistent (4.4%). Compared with the never/infrequent trajectory, the other trajectories were significantly associated with wheezing, asthma and allergic rhinitis. For asthma, the strongest association was with the early persistent trajectory (ORa =31.00 [14.03-68.51]), which was inversely associated with farm environment (ORa =0.39 [0.19-0.77]) and had a high prevalence of cough triggers and unremitting wheeze. Late and early persistent trajectories were also associated with food allergy. Atopic sensitization was only associated with the late persistent trajectory. Late and early persistent coughs without a cold are positively associated with atopic respiratory diseases and food allergy. Children having recurrent cough without a cold with night cough and triggers would benefit from an asthma and allergy assessment. Growing up on a farm is associated with reduced early persistent cough.