Allergenic Profile Research Articles

Component resolved diagnosis by recombinant allergens in patients with allergies to inhalants.

Molecular characterization of IgE reactivity of specific individual components of allergenic extracts is now possible due to the technology of recombinant allergens derived from studies of molecular biology of allergic pathology. The identification of the immunoreactivity to single allergenic components in allergic subjects allows to specifically define her/his allergic profile and obtain the so-termed Component Resolved Diagnosis (CRD). Molecular allergens can be classified into those that induce the respiratory allergic reactivity and those that identify the food-related allergic pathology. It is also essential to identify those molecular allergens whose immunoreactivity is able to connect the two clinical conditions: respiratory symptoms and food allergy symptoms. The present study was conducted on 50 patients with a clinical history of hypersensitivity to pollen and/or allergy and positivity to Skin Prick Test. The sera were analyzed in our laboratories and the panel of recombinant allergens was applied in the case of positivity of the specific IgE. Of the 50 patients enrolled, 31 were selected as positive to 4 main pan-allergen Bet v1, Par j2, Art v1 and Phl p1; among these, 14 subjects showed one allergen-specific IgE towards natural extracts of tested foods even in absence of clinical history. CRD allows for an increased accuracy in allergy diagnosis and prognosis and plays an important role in: a) resolving genuine vs cross-reactive sensitization in poly-sensitized patients, b) assessing, in selected cases, the risk of severe, systemic vs mild, local reactions in food allergy, and c) identifying patients and triggering allergens for specific immunotherapy (ITS). In light of our results, we believe that the transition from a diagnostic based on the use of allergenic extracts to another one based on the use of single allergenic molecules that is able to define the specific allergenic profile of each patient, seems to be able to revolutionize the allergy diagnosis.

Allergen profile of rhinitis and asthma among Iraqi patients

ObjectiveAllergic rhinitis (AR) and bronchial asthma (AS) are two related clinical types of allergic respiratory diseases, and there is a necessity to define both allergies in terms of the associated allergens. Accordingly, a cross-sectional observational study was conducted to examine the allergen profile in AR and AS of Iraqi patients, in whom the data are not well-elaborated. MethodsDuring January 2014–April 2017, 653 AR and 521 AS patients were ascertained and their sera were assessed for total and specific IgE. ResultsThe 16–45 years was the most encountered age group in AR and AS patients (79.1 and 75.1%, respectively). For total IgE, AS patients at all age groups had a significantly higher level than in AR cases of both genders. However, total IgE level showed no significant variation between age groups with the exception of total AS patients in the age group >45 years who had the lowest IgE level (338 ± 269 IU/ml). Screening the sera for eight allergen types (animal dander, grasses, house dust, insects, mites, molds, trees and weeds) depicted that molds were the most frequent allergen in AR and AS patients (8.7 and 19.6%, respectively), but mixed sources of allergens were much more frequently encountered. ConclusionThe age range 16–45 years is an important target for AR and AS. Molds (Alternaria alternate spores) as well as mixed allergens were the mostly encountered types in Iraqi AR and AS patients.

Characterization and Identification of Allergen Protein in Shrimp Before and After Heated with SDS-PAGE Method

Food allergies are one of the most common allergies in Indonesian society. Generally, when children aged 5-6 years food allergies will disappear, except peanut allergies and allergies to seafood, such as fish, shellfish and crustaceans. This study aims to determine the pattern of separation of allergen proteins in shrimp using anion exchange column chromatography method and identify allergen proteins in shrimp using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. Protein extraction from shrimp using Phosphate buffer saline (PBS) pH 7.2 and centrifuged at 10,000 rpm for 10 min at 4�C. Protein separation was carried out by anion-exchange column chromatography method, and the fraction obtained was measured at 280nm wavelength. The highest yield at absorbance was identified by using SDS-PAGE. Polyacrylamide gel electrophoresis was used to determine the protein profile and molecular weight of shrimp extract. Coloring of protein bands using silver staining. Data were analyzed descriptively based on the migration value of the sample protein bands compared to the marker protein band (Rf). The results of protein allergen profile analysis on shrimp using SDS-PAGE showed that the shrimp contained a protein band with a molecular weight of 37.77 kDa for cooked shrimp and 37.03 kDa for fresh shrimp.

The level of allergens in dust samples collected from selected schools in Shiraz, Iran and its asthma-risk implications

BackgroundBoth home and school are important places where children are exposed to various indoor allergens. This study aimed to identify the profile of indoor allergens in schools and its impact on asthma development. MethodsA total of 104 classrooms from 52 schools were selected for dust collection during the fall of 2017. The levels of indoor allergens including dust mite (Der f1, Der p1), cat (Fel d1), cockroach (Bla g1) and mouse (Mus m1) were measured by enzyme linked immunosorbent assay (ELISA). The diagnosis of asthma was made in all students of the selected classes by the allergist. The collected data were analyzed using SPSS version 21.0. ResultsOut of 2816 students in the selected classes, 180 students were involved with asthma. Students were mostly exposed to Bla g1 (83.1%), followed by Der f1 (51.5%), Mus m 1 (45.5%), Der p1 (8.9%) and Fel d1 (7.9%) in the dust collected from 101 classrooms. Although levels of all studied allergens in the settled dust of the classrooms were low, there was a relationship between Fel d1 in the classroom dust and development of asthma. ConclusionThis study showed considerable levels of cockroach allergens in schools. Exposure to cat allergen in our schools played an important role in asthma development; further school-based investigations require evaluating the role of classroom allergen on asthma development.

Similar Allergenicity to Different Artemisia Species Is a Consequence of Highly Cross-Reactive Art v 1-Like Molecules.

Background and objectives: Pollens of weeds are relevant elicitors of type I allergies. While many Artemisia species occur worldwide, allergy research so far has only focused on Artemisia vulgaris. We aimed to characterize other prevalent Artemisia species regarding their allergen profiles. Materials and Methods: Aqueous extracts of pollen from seven Artemisia species were characterized by gel electrophoresis and ELISA using sera from mugwort pollen-allergic patients (n = 11). The cDNA sequences of defensin–proline-linked proteins (DPLPs) were obtained, and purified proteins were tested in a competition ELISA, in rat basophil mediator release assays, and for activation of Jurkat T cells transduced with an Art v 1-specific TCR. IgE cross-reactivity to other allergens was evaluated using ImmunoCAP and ISAC. Results: The protein patterns of Artemisia spp. pollen extracts were similar in gel electrophoresis, with a major band at 24 kDa corresponding to DPLPs, like the previously identified Art v 1. Natural Art v 1 potently inhibited IgE binding to immobilized pollen extracts. Six novel Art v 1 homologs with high sequence identity and equivalent IgE reactivity were identified and termed Art ab 1, Art an 1, Art c 1, Art f 1, Art l 1, and Art t 1. All proteins triggered mediator release and cross-reacted at the T cell level. The Artemisia extracts contained additional IgE cross-reactive molecules from the nonspecific lipid transfer protein, pectate lyase, profilin, and polcalcin family. Conclusions: Our findings demonstrate that DPLPs in various Artemisia species have high allergenic potential. Therefore, related Artemisia species need to be considered to be allergen elicitors, especially due to the consideration of potential geographic expansion due to climatic changes.

Investigation of the protein profile of silkworm (Bombyx mori) pupae reared on a well-calibrated artificial diet compared to mulberry leaf diet.

BackgroundSilkworm pupae is the main by-product of the sericulture industry with an interesting nutritional profile, especially in terms of proteins. In consideration of its possible use as a food or food ingredient in Western countries, a comparative proteomic experiment has been performed to investigate the differences of the protein profile of male and female silkworm pupae reared on mulberry leaves or on an artificial diet.MethodsThe nutritional profile of lyophilized silkworm pupae in terms of dry matter and ash was evaluated according to the AOAC procedures, the total nitrogen content was determined by a nitrogen analyzer and the silkworm pupae gross energy value was measured using an adiabatic calorimetric bomb. The comparative proteomic analysis was performed on male and female silkworm pupae reared on mulberry leaves or on the artificial diet. Proteins were separated by two-dimensional electrophoresis and, after a multivariate statistical analysis, the differentially expressed proteins were identified by LC-MS/MS.ResultsThe comparative proteomic approach highlighted 47 silkworm pupae proteins differentially expressed comparing diet and gender. PCA analysis showed that seven proteins were more effective in discriminating the sex and five were more effective in discriminating the diet type. In spite of the above-mentioned differences in the silkworm pupae protein profile, no strong alteration of the pupa physiological traits have been demonstrated, suggesting a general silkworm pupae flexibility to adapt to a well-balanced artificial diet. Differences in lipid transport and metabolism were found among the experimental groups, that might have a relevant effect on the timing and on hormone secretion. This aspect may also affect silk production, as univoltine strains are the most productive. The proteomic data provided in this work, may offer a contribution in understanding also the influence of gender and farming strategy on the allergen profile of Bombyx mori, when used as food or as a food ingredient. Female silkworm pupae reared on mulberry leaves seemed to contain lower levels of known allergens than those reared in the other experimental conditions; these findings will have to be taken into account when farming B. mori for food production purposes. However, our results need to be supported by further characterization of the allergenic potential of B. mori.

Allergens in dog extracts: Implication for diagnosis and treatment.

Five to ten percent of the population in affluent countries are allergic to dog. Diagnosis and treatment is based on allergen extracts from natural sources where composition and concentration are poorly defined. We aimed to quantify six dog allergens (Can f 1-6) in commercial skin prick test (SPT) solutions and to determine individual allergen profiles in dogs. The allergen content of SPT solutions from five vendors and allergen source material from three anatomical sites were analyzed. Fur and saliva samples were collected from a mixed population of 120 dogs. Can f 1-6 were quantified by inhibition ELISA using purified recombinant or natural allergens and polyclonal or monoclonal antibodies. Allergenicity was analyzed by basophil activation test. Extensive variation in allergen composition was observed in commercial SPT vials resulting in a patient-dependent ability to activate basophils. Extract heterogeneity depended on collection site and allergen composition in individual dogs and source materials. Can f 2 and Can f 6 exhibited low levels in fur and SPT solutions, whereas Can f 4, which was the dominating allergen in fur samples, did not display similar high proportions in SPT solutions. Can f 3 varied most among SPT solutions. There is a great variation of dog allergens in natural extracts raising questions of source, sampling, processing and ultimately of standardization and minimum allergen levels for accurate diagnosis and treatment.

Investigation on the allergen profile of the soluble fraction of autoclaved peanuts and its interaction with Caco-2 cells

Peanuts are a source of proteins and fats but they are also considered a harmful food for individuals who are allergic to them due to their ability to trigger severe and life-threatening reactions. Strict avoidance of peanuts is the most effective means to prevent the development of an allergic reaction. Physical or chemical strategies employing autoclaving can represent a valid alternative to produce a final food with a decreased allergenic power as in the case of peanuts. Thermal processing might induce protein modifications in foods and affect protein digestibility or absorption of nutrients across the intestinal mucosa. Besides, the type of processing could also alter food protein allergenicity thus influencing the interplay with the biological system at the gut level. In this paper, we investigated the influence of autoclaving based treatments on the proliferation of epithelial cells at the intestinal level. Extractable proteins of raw and autoclaved peanuts were analysed by SDS-PAGE and untargeted LC-high resolution-MS/MS to investigate the peptide composition. Our findings show that when raw peanuts were assayed on Caco 2 cell lines, an antiproliferative effect was observed. By contrast, peanuts subjected to hydration and autoclaving did not show an inhibition of proliferation on Caco-2 cells. In parallel, extensive fragmentation induced by autoclaving treatments on the original peanut proteins was also recorded by LC-MS/MS analysis with a consequent increase in the number of peptides detected. These results indicate that the processing applied to peanuts can have an influence on both the nutritional and allergological sides, and more investigations will be required on this issue to understand the alteration of inflammatory mediators induced by the treatment applied.

Clinical Profile and Allergens in Pigmented Cosmetic Dermatitis and Allergic Contact Dermatitis to Cosmetics in India.

Pigmented cosmetic dermatitis (PCD) is frequently encountered in dark-skinned individuals as gradual hyperpigmentation on the face without preceding erythema or itching. Little is known about the allergen profile in PCD. The aim of the study was to describe the clinical profile and common allergens in PCD and allergic contact dermatitis (ACD) to cosmetics in Delhi. Records of patients suspected of PCD and ACD to cosmetics were analyzed. All patients were patch tested with the Indian standard series, Indian cosmetic and fragrance series, and personal cosmetics and, in relevant cases, hairdresser series. One hundred six patients were analyzed. Patch test was positive in 77 cases (72.6%). Cetrimonium, gallate mix, thiomerosal, and skin lightening creams were more frequently positive in cases of PCD (P = 0.019-0.003), whereas p-phenylenediamine, toluene-2,5 diamine sulfate, p-aminophenol, m-aminophenol, and nitro-p-phenylenediamine were predominantly positive in ACD to cosmetics (P < 0.001). Preservatives, antioxidants, and skin lightening creams seem to play a role in causation of PCD, whereas hair dye allergens cause ACD to cosmetics in India.

Immunogenic and allergenic profile of wheat flours from different technological qualities revealed by ion mobility mass spectrometry

A two-step extraction of soluble (AG) and gluten (GLU) proteins was performed on nine common wheat flours of different technological qualities, low (LW), medium (MD), and superior (SP). The immunogenic and allergenic peptides were identified and relatively quantified by a non-targeted multiplexed MS-MS method that used a Triticum aestivum database (UniProt) and ProPepper™. Collectively, 3603 and 91,609 peptides were identified, and, after clustering and filtering for this study, approximately 450 and 1708 peptides from GLU and AG fractions, respectively, were obtained from all samples. Approximately 19% of the identified peptides showed immunogenic action associated with prolamins. For the most part, 60% of the peptides belonged to high-molecular-weight glutenins. The immunogenic peptides were more expressed in LW than in SP and MD flours. Low quality flours also contained the highest number of epitopes (28) associated with CD and wheat allergies. The major proteins from AG associated with respiratory allergies were α-amylase inhibitors and serpins. Two serpins were found more expressed in LW flours. This paper offers the most comprehensive immunogenic profile of wheat proteins based on proteomics to date. These results indicate that low quality wheat flours are a more conceivable cause of immunological reactions.

Bedroom exposure to airborne allergens in the Chicago area using a patient-operated sampling device

BackgroundIn current practice, allergens in vacuum-collected dust are used as surrogates for inhalable allergens. We developed an air-sampling device that can be used by patients for direct measurement of airborne allergen concentrations in their own homes. ObjectiveTo demonstrate the use of this device to establish allergen concentration reference ranges in a target population and to evaluate associations between patient-reported information and measured allergen concentrations. MethodsPatients from 5 allergist's practices in the Chicagoland region were provided with instructions, questionnaires, informed consent forms, and samplers to run for 5 days in their bedrooms. Samples were collected from cartridges and assayed by multiplex immunoassays for 12 common household allergens and enzyme-linked immunosorbent assay for ragweed. ResultsUnique allergen profiles were obtained for 102 patient homes. Samples with allergen concentrations above the limit of detection were as follows: total dust mite, 28%; cat, 61%; dog, 64%; mouse, 12%; rat, 0%; cockroach, 4%; Alternaria, 6%; Aspergillus, 21%; birch pollen 1%; grass, 8%; and ragweed, 5%. Of those, 75 completed questionnaires, providing meta-data for further analysis. Pet allergens correlated significantly with number of pets owned. Humidity correlated with dust mite allergens, open windows with Alternaria and mouse allergens, and high-efficiency particulate air filter use with reduced levels of several allergens. Many other variables showed no significant correlations. ConclusionThe combination of ease of use, high air-sampling rate, and sensitive immunoassays permitted the measurement of airborne allergen concentrations in homes and establishment of reference ranges. Patient-reported information permitted identification of factors that could relate to allergen concentrations and suggested remedial measures.

Profils clinique et allergénique des pollinoses en Tunisie

BackgroundPollinosis is a public health problem due to its prevalence, morbidity, impact on quality of life and cost. The objective of our study was to describe the clinical and allergenic profiles of pollen allergy in Tunisia. Patients and methodsWe conducted a descriptive retrospective study including all patients investigated for pollen allergy at the allergology department of the La Marsa internal security forces hospital in Tunis between 1993 and 2015. ResultsPollen sensitization involved 45.8% of the patients tested with a total of 2490 patients. Rhinitis was the most common manifestation (87.1%), followed by asthma (59.9%) and conjunctivitis (50.4%). Asthma was more common in children, while rhinitis and conjunctivitis were more common in adults. Clinical manifestations were most often associated (75.4%). An association between asthma and rhino conjunctivitis (24.5%) was the most frequent, followed by an association between asthma and rhinitis (24%). The allergenic profile showed predominance of sensitization to grass pollen (54.4%), followed by sensitization to tree pollen (48.8%) and grass pollen (48.1%). Parietaria was the most sensitizing grass pollen, with olive pollen being the most sensitizing tree pollen (35.5%). Polysensitization to pollen was found in 55.5% of patients. ConclusionPollinosis is extremely common among allergic subjects in Tunisia. Rhinitis is the most common clinical manifestation. Weed pollens are the most sensitizing with a high frequency of pollen polysensitization.

Molecular allergen profiling in horses by microarray reveals Fag e 2 from buckwheat as a frequent sensitizer.

BackgroundCompanion animals are also affected by IgE‐mediated allergies, but the eliciting molecules are largely unknown. We aimed at refining an allergen microarray to explore sensitization in horses and compare it to the human IgE reactivity profiles.MethodsCustom‐designed allergen microarray was produced on the basis of the ImmunoCAP ISAC technology containing 131 allergens. Sera from 51 horses derived from Europe or Japan were tested for specific IgE reactivity. The included horse patients were diagnosed for eczema due to insect bite hypersensitivity, chronic coughing, recurrent airway obstruction and urticaria or were clinically asymptomatic.ResultsHorses showed individual IgE‐binding patterns irrespective of their health status, indicating sensitization. In contrast to European and Japanese human sensitization patterns, frequently recognized allergens were Aln g 1 from alder and Cyn d 1 from Bermuda grass, likely due to specific respiratory exposure around paddocks and near the ground. The most prevalent allergen for 72.5% of the tested horses (37/51) was the 2S‐albumin Fag e 2 from buckwheat, which recently gained importance not only in human but also in horse diet.ConclusionIn line with the One Health concept, covering human health, animal health and environmental health, allergen microarrays provide novel information on the allergen sensitization patterns of the companion animals around us, which may form a basis for allergen‐specific preventive and therapeutic concepts.

Extensive Cross-reactivity Between Salsola kali and Salsola imbricata.

There are no studies on cross-reactivity between Salsola kali and Salsola imbricata pollens. The main goals of the present study were to compare the degree of the cross-reactivity between S kali and S imbricata and to compare the various allergenic components shared by S kali and S imbricata. erum samples were obtained from rhinitis patients with or without asthma living in Kuwait and presenting with a positive skin test result to S kali. SDS-PAGE/IgE Western blot and ELISA inhibition assay were performed. The study population comprised 37 patients. The most frequent IgE proteins against S imbricata weighed around 12, 15, 18, 37, and 50+55 kDa. 2D electrophoresis revealed a correlation between S kali and S imbricata at 40, 60, and 75 kDa, with similar isoelectric points. ELISA inhibition revealed an Ag50 value of 1.7 μg/mL for S kali and 500.5 μg/mL for S imbricata when the solid phase was S kali and an Ag50 value of 1.4 μg/mL for S kali and 3.0 μg/mL for S imbricata when the solid phase was S imbricata. ELISA inhibition revealed strong cross-reactivity between S kali and S imbricata. This finding might be clinically relevant for the efficacy of allergen-specific immunotherapy. We report, for the first time, the allergenic profile of S imbricata and potentially allergenic proteins for S kali and S imbricata.

Development and characterization of an allergoid of cat dander for immunotherapy

BackgroundAllergy to cats is a frequent cause of sensitization to indoor allergens and currently there are few alternatives to specific immunotherapy with cat native extracts. The objective is to develop and characterize a new allergoid to increase the tools available for use in clinical practice. MethodsThe allergoid cat dander extract (ACD) was developed from a native cat dander extract (NCD) by modification with glutaraldehyde, and the optimal process control was determined by SDS-PAGE, DOT BLOT and determination of free amine groups. The ACD was characterized in protein profile by SDS-PAGE, size exclusion chromatography (SEC) and peptide footprint. The allergenic profile of ACD was determined by immunoblot, IgE CAP inhibition and IgG competition ELISA. The major allergen content in NCD was obtained by the ELISA sandwich protocol and was extrapolated to ACD. ResultsThe control process determined the optimal development of the allergoid. The ACD obtained contains 182.28μg/mg of protein and 11.90μg/mg of Fel d 1. SDS-PAGE and SEC confirmed the presence of high molecular weight proteins in ACD, and the peptide footprint showed the presence of Fel d 1 and Fel d 7. The high degree of polymerization was evidenced with the determination of the reduction of lysine residues in the allergoid, resulting 91.96%. The ACD showed a significant loss of allergenicity respect to NCD, while the IgG-binding capacity was maintained. ConclusionsThe ACD obtained presents a good safety profile, so would be a good alternative for treatment of cat allergy.

Characterization of Rask1 a novel major allergen in Indian mackerel and identification of parvalbumin as the major fish allergen in 33 Asia-Pacific fish species.

Fish is a well-recognized cause of food allergy and anaphylaxis. The evolutionary and taxonomic diversity of the various consumed fish species pose a challenge in the identification and characterization of the major fish allergens critical for reliable diagnostics. Globally, fish is a rising cause of food allergy complicated by a large under-investigated variety of species as well as increasing global tourism and trade. This is the first comprehensive study on allergen profiles of heat-processed fish from Vietnam. The aim of this study was to identify the major heat-stable allergens from frequently exported Asia-Pacific freshwater and marine fish and to characterize the major allergen parvalbumin (PV) from one of the most consumed and exported fish species from Asia, the Indian mackerel (Rastrelliger kanagurta). Heated protein extracts from 33 fish species were separated by gel electrophoresis. PV isoforms were identified by immunoblotting utilizing 3 different PV-specific monoclonal and polyclonal antibodies and further characterized by mass spectrometry. IgE reactivity was investigated using sera from 21 patients with confirmed fish allergy. Heat-stable IgE-reactive PVs, with up to 5 isoforms per species, were identified in all 33 analysed fish species. In the Indian mackerel, 7 PV isoforms were identified by 2D-gel electrophoresis combined with mass spectrometric analyses. The amino acid sequence deduced from cDNA of the most expressed isoform showed a high identity (>90%) to PVs from 2 other mackerel species. Different PVs were identified as the major heat-stable allergens in all 33 analysed freshwater and marine fish species from Vietnam, many of which are exported world-wide and 21 species that have never been investigated before. The Indian mackerel PV represents a novel fish allergen, now officially registered as Rask1. Improved diagnostics for fish allergy against Asia-Pacific species should be developed with focus on PV.

Comparison of microbiota and allergen profile in house dust from homes of allergic and non-allergic subjects- results from the GUSTO study

Background The prevalence of allergic diseases, such as asthma, allergic rhinitis, eczema and food allergy, has been increasing worldwide, as shown in a large number of studies, including the International Study of Asthma and Allergies in Childhood (ISAAC). However, there is significant variation in the prevalence of these diseases in different regions, suggesting that there may be location-specific factors such as environment and microbial exposure affecting allergic disease prevalence. Hence, in this study we determine if there is a difference in microbiota composition and allergen concentration of household dust collected from the homes of non-allergic and allergic subjects from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort.Methods From the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort, 25 allergic subjects and 25 non-allergic subjects were selected at the year 5.5 follow up. Definitions of allergic outcomes were standardized in the questionnaires administered at 3, 6, 9, 12, 15, 18, 24, 36, 48 and 60 months to ensure consistency during interviews and home visits. Allergen sensitization was determined by skin prick testing (SPT) at 18, 36 and 60 months. Dust samples were collected from the subject’s bed, sofa, and play area. DNA extraction was carried out and V3-V4 hypervariable regions of bacterial 16S rRNA gene were sequenced. Protein extraction was performed and allergens assayed by using multiplex assay and ELISA.Results The most abundant phyla in house dust were Actinobacteria (29.8%), Firmicutes (27.7%), and Proteobacteria (22.4%). Although there were no differences in bacteria abundance and diversity between house dust samples of allergic and non-allergic subjects, the relative abundance of Anaplasmataceae, Bacteroidaceae, and Leptospiraceae were significantly higher in dust samples of allergic subjects as compared to non-allergic subjects in 2 or more locations. The concentration of Der p 1 was significantly lower in bed dust samples of allergic subjects (Median [Interquartile range], 174 ng/g [115–299 ng/g]) as compared to non-allergic subjects (309 ng/g [201–400 ng/g]; P < 0.05). The concentration of tropomyosin was significantly higher in sofa dust samples of allergic subjects (175 ng/g [145–284 ng/g] as compared to non-allergic subjects (116 ng/g [52.8–170 ng/g]; P < 0.05).Conclusion In conclusion, we found a differential microbiota and allergen profile between homes of allergic and non-allergic subjects.Trial registrationNCT01174875 Registered 1 July 2010, retrospectively registered.

Preclinical safety and immunological efficacy of Alternaria alternata polymerized extracts.

Introduction Alternaria alternata is a widespread fungi whose allergy is a risk factor for asthma development. The use of a polymerized allergen extract (allergoid) may be safer than native extract based treatments while maintaining efficacy. The objective of this study was to characterize biochemically and immunochemically a new Alternaria alternata allergoid.MethodsCharacterization of native and allergoid extracts was performed by determination of protein content, protein and allergenic profile, biological potency, identification of Alternaria allergens, and Alt a 1 quantification. Safety was evaluated in toxicological assays (Ames test, limit test, and fish embryo acute toxicity test in zebrafish, and maximum tolerated dose and Dose‐range finding study in rats). Efficacy was evaluated as the capacity to induce IgG antibodies that block IgE‐binding to the allergen and cytokine induction (IFN‐γ, IL‐4, IL‐6, IL‐10, and TNF‐α) in PBMC from atopic donors.ResultsProtein and antigenic profiles showed significant modification of the depigmented allergoid with respect to the native extract, inducing a lower IgE binding capacity. Alt a 1, Alt a 3, Alt a 6, and Alt a 8 allergen sequences were identified in the polymer. No toxicological nor genotoxicity effects were observed. The polymer induced IgG antibodies that blocked human IgE binding epitopes, and it induced higher IL‐10 levels and similar levels of the other cytokines than native extract in PBMC.ConclusionsThis new A. alternata allergoid could be an effective immunotherapy treatment leading to cytokine stimulation and inducing synthesis of IgG antibodies able to block IgE binding to the allergen. In addition, no toxicological effect was observed, and it may be safer than native extract due to its lower IgE binding capacity and cytokine induction that suggest tolerance induction via T cell shift to Treg (IL‐10).

Crossreactive allergen-specific IgE in children with birch pollen allergic rhinitis

Objective. The aim of this study was to research a sIgE allergen profile of birch pollen and to evaluate a contribution of some homologous food allergens as well as latex allergen to the development of sensibility in allergic rhinitis (AR) / rhinoconjunctivitis patients, in focus of cross-reactivity and oral allergy syndrome.. Methods. Blood sera of 21 AR/rhinoconjunctivitis patients (at the age of 3 to 16) and 20 healthy persons without allergy symptoms were used. sIgE to birch pollen, soybean, latex, apple and celery as well as the total IgE levels were measured by the ImmunoCAP method (Phadia, Sweden) and the ELISA kits (Alkorbio, Russia). Results. We detected high total IgE levels, sIgE to allergens of birch pollen, apple, celery, as well as to recombinant allergens of birch Bet v 1, Bet v 2 and soybean - Gly m 4 in AR patients. Correlation analysis of IgE humoral response to homologous proteins showed the direct valid dependence between the sIgE levels to birch isoallergen Bet v 1 and soy isoallergen Gly m 4 (r=0,84; p

Mite-Induced Asthma and IgE Levels to Shrimp, Mite, Tropomyosin, Arginine Kinase, and Der p 10 Are the Most Relevant Risk Factors for Challenge-Proven Shrimp Allergy

Background: Shrimp sensitization is common in the general population, but the presence of symptoms is only moderately related to sensitization. A point still at issue is which in vivo and/or in vitro tests (food challenge, component-resolved diagnosis, house dust mite [HDM] sensitization) can help in distinguishing shrimp-allergic subjects from subjects that are sensitized but tolerant. Methods: The aim of this study was to evaluate the role of IgE to the different shrimp and mite allergens in distinguishing shrimp challenge-positive from challenge-negative patients. Subjects with suspected hypersensitivity reactions to shrimp, positive skin prick tests (SPTs), and/or anti-shrimp IgE were submitted to open and double-blind placebo-controlled food challenges (DBPCFC). Specific IgE to shrimp, mites, and the recombinants rPen a 1, rDer p 1, 2, and 10 were tested using ImmunoCAP-FEIA. IgE immunoblotting was performed to identify the patients' allergenic profiles. Results: In total, 13 out of 51 (25.5%) patients with reported reactions to shrimp were truly shrimp allergic (7 DBPCFC positive and 6 with documented severe reactions). These patients had significantly higher skin test wheal diameters than nonallergic patients, as well as higher levels of IgE to rPen a 1 and rDer p 10. HDM-induced asthma and the simultaneous presence of anti-nDer p 1, 2, and 10 IgE levels increased the risk of true shrimp allergy. Conclusion: Food challenge tests are mandatory for the diagnosis of shrimp allergy. Tropomyosin is associated with clinical reactivity. HDM-induced asthma and anti-mite IgE are risk factors for shrimp allergy.