sIgE Determination Research Articles

Optimization of Basophil Activation Test in the Diagnosis and Qualification for Allergen-Specific Immunotherapy in Children with Respiratory Allergy to the House Dust Mite Dermatophagoides pteronyssinus.

The aim of this study was to optimize a basophil activation test in the detection of allergy to the house dust mite Dermatophagoides pteronyssinus in children with allergic respiratory diseases. This study involved 32 cases, 13 girls and 19 boys aged 4-17 years, with perennial asthma or allergic rhinitis caused by D. pteronyssinus. The control group consisted of 13 girls and 19 boys aged 4-17 years with seasonal allergic asthma or rhinitis provoked by Timothy or birch pollen. House dust mite (HDM) allergy was excluded in the controls based on their medical history, skin prick test (SPT) results and sIgE determination. In all patients, a basophil activation test (BAT) was performed with five dilutions of D. pteronyssinus allergen (the dilution series ranged from 22.5 to 0.00225 ng/mL). The results were analyzed by using the receiver operating characteristics (ROC) to determine the optimal allergen concentrations, outcome measures and cut-off points that would differentiate most accurately between HDM-allergic and non-allergic patients. As a "gold standard", criteria for allergen-specific immunotherapy with D. pteronyssinus or respective pollens were applied by an experienced pediatric allergist following the guidelines of the European Academy of Allergy and Clinical Immunology. The highest diagnostic efficiency was yielded by the protocol assuming a cut-off value of 9.76% activated basophils after activation with a single allergen concentration of 2.25 ng/mL (sensitivity 90.6%, specificity 100%). This protocol yielded 3 (4.7%) misclassifications, all false negative, when compared with the "gold standard". There was a strong correlation with the BAT results at 22.5, 2.25 and 0.225 ng/mL (respectively r = 0.90 and r = 0.78, p < 0.001), as well as between the BAT at 2.25 ng/mL and SPT (r = 0.82, p < 0.001) and between the SPT and sIgE levels (r = 0.78, p < 0.001). High cross-reactivity between D. pteronyssinus and D. farinae was confirmed based on the BAT at 22.5 ng/mL (r = 0.82, p < 0.001). In conclusion, the BAT showed very good concordance with the result of a meticulous process of decision-making that combined validated allergy tests (SPT, sIgE) with expert guidelines, specialist knowledge and experience. Facing the risk of the incorrect qualification of patients for costly, long-lasting and potentially risky allergen-specific immunotherapy, the inclusion of a basophil activation test into diagnostic process seems fully justified.

Hybridization of ellipsometry and XPS energy loss: Robust band gap and broadband optical constants determination of SiGe, HfON and MoOx thin films

In this study, we compare the robustness of optical constants and optical band gap determination of three different materials: SiGe, N-doped HfO2 and MoOx, using the combination of two techniques: spectroscopic ellipsometry, and energy loss signal (ELS) of X-ray photoelectron spectroscopy (XPS). The determination of such physical properties is achieved through the hybridization of the two techniques based on multiple Tauc-Lorentz model, applied on the whole energy range of measurement.Such use of hybridized data demonstrates a new robust method to determine the band gap of the studied materials, together with the optical indices (refractive index and extinction coefficient) on a wide energy range (up to 40 eV). This method provides an extension of determination of the relevant physical quantities compared to each technique on their own.Moreover, this algorithm is tested on limit conditions, where the energy ranges of measurement of the two respective techniques presented no overlap. Yet the use of a unique physical model still allows us to calculate the different physical quantities even on the energy range where no measurement is performed, validating the semi-predictive nature of the hybrid technique. Additional measurements under different experimental configurations validate the extended scope of such hybrid technique.

Algorithm for selecting patients for house dust mite allergen specific immunotherapy in children with bronchial asthma and allergic rhinitis

Objective. Based on literature data and own research, on the selection of pediatric patients for the treatment of allergen immunotherapy (AIT) with house dust mite (HDM) allergens, to develop an Algorithm for selecting patients for AIT with HDM allergens in children with bronchial asthma (BA) and allergic rhinitis (AR). &#x0D; Methods. Data from our own studies included 420 patients with AR and complaints indicating domestic sensitization (256 boys, 164 girls), aged 5 to 17,.9 years (mean age 8,.44 ± 3.,06), of which 176 have had BA. Patients underwent skin prick tests (SPT) with household allergens, determination of sIgE for HDM allergens by the ImmunoCAP method, and nasal provocative test (NPT) with HDM. If the results were negative, the allergological examination was repeated again in 12-–18 months. &#x0D; Results: The Patient Selection Algorithm was constructed on the basis of the obtained data on the significance of the examination methods used. The primary role of SPT, the possibility of repeating the examination in case of negative results, indications for NPT with HDM allergens were taken into account. The algorithm makes it possible to organize an examination of a patient with HDM allergy in order to develop indications for AIT.

Consistency of Determination of sIgE and the Basophil Activation Test in Vespa velutina nigrithorax Allergy.

Consistency of Determination of sIgE and the Basophil Activation Test in Vespa velutina nigrithorax Allergy.

Basophil Activation Test for Allergy Diagnosis.

The basophil activation test (BAT) is a complementary in vitro diagnostic test that can be used in addition to clinical history, skin test (ST), and specific IgE (sIgE) determination in the evaluation of IgE-mediated allergic reactions to food, insect venom, drugs, as well as some forms of chronic urticaria. However, the role of this technique in the diagnostic algorithms is highly variable and not well determined. BAT is based on the determination of basophil response to allergen/drug cross-linking IgE activation through the measurement of activation markers (such as CD63, CD203c) by flow cytometry. This test can be a useful and complementary tool to avoid controlled challenge teststo confirm allergy diagnosis, especially in subjects experiencing severe life-threatening reactions. In general, the performance of BAT should be considered if i) the allergen/drug produces false positive results in ST; ii) there is no allergen/drug source to use for ST or sIgE determination; iii) there is discordance between patient history and ST or sIgE determination; iv) symptoms suggest that ST may result in systemic response; v) before considering a CCT to confirm the culprit allergen/drug. The main limitations of the test are related to non-optimal sensitivity, especially in drug allergy, the need to perform the test no longer than 24 h after sample extraction, and the lack of standardization between laboratories in terms of procedures, concentrations, and cell markers.

Features of sensitization to molds and its role in development of respiratory allergic diseases

Over recent decades, a steady increase in the number of allergic diseases has been shown. Current evidence demonstrate a close association between their emergence and exposure to fungal allergens. In this regard, the aim of the present study was to identify frequency and structure of sensitization to the most clinically significant molds in the patients with respiratory allergic diseases. In blood serum of 283 patients with allergic rhinitis and bronchial asthma, we determined total IgE and sIgE to the mold allergens: Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatus and Alternaria alternata by the ImmunoCAP method (Phadia, Sweden). Statistical analysis was carried out by nonparametric methods. The total IgE levels (420 (225.5-641) kU/l) were higher (p 0.05) in patients with sensitization to fungal allergens than in general group (296 (129- 530) kU/l). Multiple sensitization to respiratory allergens was revealed in the patients with allergic rhinitis and bronchial asthma, and sensitization to fungal allergens was associated with increasingly severe manifestations of the disease. In the patients with fungal allergies, sIgE to Alternaria alternata was most often detected (92.5%), with average level of 3.52 (0.635-19.525) kUA/l. Sixteen patients (40%) were sensitized to Aspergillus fumigatus (0.14 (0.06-0.63) kUA/l). In 19 patients (47.5%), we found increased levels of sIgE to Cladosporium herbarum (0.29 (0.045-1.005) kUA/l). Sensitization to Penicillium notatum was detected in 12 patients (30%), the sIgE levels were 0.125 (0.01-0.5) kUA/l. Detection rates in the total group of fungus-allergic patients with respiratory allergies were as follows: Penicillium notatum, 4.2%; Cladosporium herbarum, 6.7%; Aspergillus fumigatus, 5.6%; Alternaria alternata, 13.07%. We found a significant correlation (p 0.05) between the sIgE contents to different fungal allergens. The levels of IgE antibodies to Alternaria alternata correlated with the levels of sIgE to other fungi (Aspergillus fumigates, r = 0.45; Cladosporium herbarum, r = 0.39; Penicillium notatum, r = 0.39). These findings allow us to suggest that sensitization to Alternaria alternata (13.07%) and Cladosporium herbarum (6.7%) is most common among the patients with allergic rhinitis and bronchial asthma, whereas fungal sensitization aggravates clinical course of these diseases. Determination of sIgE to Alternaria alternata can serve as a marker for the presence of potential cross-sensitization to other fungal allergens, i.e., Aspergillus fumigatus, Cladosporium herbarum, and Penicillium notatum.

Use of a comprehensive diagnostic algorithm for Anisakis allergy in a high seroprevalence Mediterranean setting.

Background.Diagnosis of anisakis allergy (AA) is based on the skin prick test (SPT) and specific IgE (sIgE) determination. Anyway, false positivity cases are due to cross reactivity with numerous allergens. The aim of the study was to evaluate the reliability of a comprehensive diagnostic algorithm for the AA. Methods.An observational study was conducted on a sample of consecutive subjects accessing the allergology outpatient ambulatories of two hospitals located in Western Sicily. All the recruited outpatients were tested by Skin Prick Test performed using anisakis extracts by ALK-Abellò (Madrid, Spain). Specific IgE dosage for anisakis extracts was then performed by using ImmunoCAP250 (Immunodiagnostics Uppsala, Sweden). Consequently, outpatients who tested positive to first line tests underwent sIgE testing for ascaris and tropomyosin. Lastly, outpatients positive to the first line were invited to be further tested by basophil activation test (BAT) by using Flow CAST kit and anisakis commercial extract (Bühlmann Laboratories AG, Schönenbuch, Switzerland), as confirmatory analysis. Results.One hundred and eleven outpatients with an anamnesis suggestive of sensitization to anisakis (AS) and 466 subjects with chronic urticaria (CU) were recruited in the study. Of these, 22 with AS and 41 with CU showed a sensitization to anisakis allergens. The diagnostic algorithm revealed that 8.8% of outpatients who tested positive to sIgE determination were affected by CU, while 82.5% of all the sIgE positivity was related to cross-reactivity. Overall, a genuine anisakis seroprevalence of 2.3% was documented. Within a sub-sample of 15 subjects with clinical symptoms related to AA, n. 8 showed a real positivity after BAT. A greater response to A. pegreffii allergens as compared to A. simplex was reported. Conclusions.Our preliminary findings support the high clinical specificity of BAT for AA diagnosis, suggesting implementing this method in a comprehensive diagnostic algorithm.

Importance of wasp and honey bee recombinant allergens in the diagnosis of hymenoptera venom anaphylaxis

Background: Hymenoptera venom-allergic patients frequently present multiple sensitisations. Objectives: To define the allergic profile by components in Hymenoptera venom allergic patients. To study the usefulness of specific IgE to components in cases of negative results of sIgE to the venoms. Patients (n = 86) with a diagnosis of allergic systemic reaction following honey bee or wasp stings were included in the study. Skin prick tests (SPT) and intradermal reaction were performed. sIgE to complete extracts of honey bee (Apis mellifera), Vespula (Vespula spp.), venom and recombinant allergens rApi m1, rApi m 5; rVes v5 and rVes v1 5 were analysed by ImmunoCAP (Phadia). sIgE concentration higher than 0.35 kU/l were considered positive. Results: 86 patients (40 male, 46 female) were included. No sIgE to Honey bee/Vespula was detected in 15 patients. In 7 of them only component diagnosis (Api m1 and Ves v5) confirmed hymenoptera allergy. Positive correlation between severity of anaphylactic reaction and sIgE to rVes v1 concentration was observed (r = 0,85; p < 0.05) and sIgE to rApi m1 (r = 0.87; p < 0.05). None such correlation was observed with specific IgE to other venom components. Conclusions: Components analysis can be useful to make diagnosis more accurate. Determination of sIgE towards phospholipase A2 (Apis mellifera) and phospholipase A1 (Vespula spp.) may reflects severity of allergic reaction after hymenoptera sting.

Allergen-specific IgE to recombinant latex allergens in occupational allergy diagnostics.

ObjectivesSpecific challenge tests (SICs) are considered reference tests for allergic occupational diseases diagnosis. However, in numerous cases, SICs cannot be carried out in the diagnosis of allergy to latex due to the risk of generalized reactions. The aim of the study was to evaluate the usefulness of sIgE determination to recombinant latex allergens in diagnostics of occupational respiratory allergy.Materials and MethodsThe study group comprised 44 healthcare workers (HCW) suspected of suffering from occupational respiratory allergy to latex (they underwent a physical examination, skin‐prick tests (SPTs) to common and latex allergens, spirometry and SIC) and 17 controls not occupationally exposed to latex, with a positive sIgE against latex. Each serum was tested for allergen‐specific IgE to aeroallergens, latex, eight recombinant latex allergens and CCD‐markers.ResultsSpecific IgE against Hev b5, 6.01, and 6.02 were significantly more frequently detected in HCWs and their mean serum levels were higher compared with the control group. In 26 HCWs with occupational asthma (OA), sensitization to Hev b5, Hev b6.01, Hev b6.02 was significantly more frequent than in 18 HCWs with work‐exacerbated asthma (WEA); they had positive results SPT to latex significantly more frequently in comparison with subjects with WEA.ConclusionsTest for recombinant latex allergens is much more accurate in recognition of latex allergy than test for latex extract, which seems to produce false‐positive results in patients with pollen allergy. The measurements of sIgE against recombinant latex allergens Hev b 6.01, 6.02, 5, and 8 are useful in differentiating OA from WEA.

Predictors of efficacy of allergen immunotherapy in children with seasonal allergic rhinoconjunctivitis and pollen-food allergy syndrom

Objective of the research. To study predictors of efficacy of AIT in relation to the symptoms of seasonal ARC and PFAS in children with different IgE profiles. Materials and methods. Open prospective observational study of 161 patients aged 5 to 17 years with clinical symptoms of ARC (the annual escalation in April-May, duration of the disease is not less than 2 years, the need for symptomatic therapy in the flowering season of cause-significant plants) and PFAS for products of plant origin. The examination included skin testing, as well as sIgE determination of birch pollen allergen extract, cross-food allergens of plant origin (apple, pear, cherry, peach, carrot) and recombinant birch pollen allergens allergens (rBet v 1, rBet v 2, rBet v 4, rBet v 6) on the automatic analyzer ImmunoCAP250. All patients received two courses of AIT, sublingual administration. Assessment of efficacy was performed using the modified scheme A.D. Ado and diagnostic introduction earlier unbearable product. Conclusion. Monosensitization to rBet v 1 is a clinical and laboratory marker of the high efficacy of AIT in children with seasonal ARC and PFAS. Conclusion. Monosensitization to rBet v 1 is a clinical and laboratory marker of the high efficacy of ACIT in children with pollinosis and cross-PAS. Daily high-dose immunotherapy with standardized extract of birch pollen allergen has a good therapeutic effect, including in relation to the manifestations ofPFAS.

The potential of component-resolved diagnosis in laboratory diagnostics of allergy.

The initial laboratory approach in the diagnosis of allergies is to detect the type of allergic reaction, i.e. whether the patient’s allergy is mediated by immunoglobulin E (IgE) or not. For this purpose, the concentration of total serum IgE (tIgE) and specific IgE (sIgE) are determined. Progress in laboratory diagnostics is the use of component-resolved diagnosis (CRD) which implies determination of sIgE against purified native and recombinant allergenic molecules. Component-resolved diagnosis is used in laboratory practice as singleplex and multiplex assays. The choice of allergen for singleplex assay is based on anamnesis, clinical findings of a patient and on skin prick test results. Multiplex-microarray assays simultaneously determine multiple sIgE’s against numerous allergens. The goal of CRD is to distinguish the true allergens from the cross-reactive allergen molecules. Component-resolved diagnosis allows predicting the risk of severe symptoms, as well as anticipating the development of allergies. Thus, determination of sIgE against allergenic components may significantly improve current diagnostics of allergy. Since this method is applied in laboratory practice just a few years, it is necessary to acquire new knowledge and experience, to establish good co-operation between specialist in medical biochemistry and laboratory medicine and the specialist allergologist, so that the method can be applied in a rational manner. Component-resolved diagnosis will significantly improve the diagnostics of IgE-mediated allergy in the future. The aim of this article is to present potentials of CRD in the laboratory diagnostics of allergy mediated by IgE.

Comparison of specific IgE detection by immunoblotting and fluorescence enzyme assay with in vivo skin prick test

Diagnostic tools to identify allergens that cause allergic symptom is important part in the care of allergic patients. Detection of causative allergen can be performed by in vivo skin prick test (SPT) or in vitro tests for detection serum specific immunoglobulin E (sIgE). The common methods used are fluorescent enzyme assay and immunoblotting assay. We aim to evaluate performance of the two sIgE determination systems, immunoblotting assay (Euroline) and fluorescent enzyme assay (ImmunoCAP) in comparison with SPT. Two hundred and two participants with allergic diseases were enrolled. Sensitization to common allergens was identified using skin prick test and serum specific IgE assays with Euroline and ImmunoCAP. Both systems provide the result in the same unit and the same cut-off value (0.35 kUA/L). The specific IgE levels of 4 aeroallergens, 6 food allergens and 3 food allergen components were analyzed to evaluate the performance of both sIgE assays with SPT. When compared with the result of SPT, ImmunoCAP has 63.9-93.2% agreement and Euroline has 68.4-86.2% agreement for allergen detection. Both sIgE assays have significant correlation in measuring sIgE of almost all allergens (r=0.626-0.901, p< 0.001) except for dog. For food allergen components, both sIgE tests have outstanding correlation and agreement (r=0.816-0.952, p< 0.001; agreement =87.0-92.9%, respectively). The receiver-operating characteristic curve analysis indicated slight discrepancy of both sIgE assays. Both sIgE determination systems demonstrate fair to good performance when compared to SPT depending on type of allergens. The two sIgE determination systems had favorable correlation and agreement.

Comparison of detection methods of allergen specific IgE

The determination of serum specific IgE (sIgE) plays an important part in the diagnosis of allergen in vitro, which has been widely used. All kinds of diagnostic methods have both advantages and disadvantages. The sIgE determination in this paper, commonly used at present in China was introduced and the comparative study among the methods in recent years was reviewed, which would help physicians to understand the test results correctly.(Chin J Lab Med, 2016, 39: 814-816) Key words: Allergens; Immunoglobulin E; Enzyme-linked immunosorbent assay; Immunoblotting; Immunoassay

English

Local allergic rhinitis (LAR) is a phenotype of allergic rhinitis characterized by the presence of a localized immune response in the nasal mucosa of patients with negative skin prick test (SPT) results and undetectable serum specific IgE (sIgE). It unknown whether LAR is limited to areas with low or moderate aeroallergen exposure. To explore the presence of LAR and the clinical and immunological characteristics of this entity in geographic areas with high grass pollen loads. A cross-sectional observational study was carried out in 2 hospitals in central Spain (Madrid and Ciudad Real). Sixty-one patients with seasonal rhinitis and negative SPT results and undetectable serum sIgE were evaluated using a clinical questionnaire, determination of serum total IgE, and a nasal allergen provocation test (NAPT) with Phleum species. The response to NAPT was monitored using assessment of nasal symptoms, acoustic rhinometry, and determination of sIgE, tryptase, and eosinophil cationic protein in the nasal cavity. Seasonal LAR was detected in 37 patients (61%) using the techniques described above. Eleven percent of patients with LAR were adolescents or children, and 14% reported onset of rhinitis in childhood. Most patients reported persistent-moderate seasonal nasal symptoms, and 41% reported worsening of the disease during the last 2 years. Conjunctivitis was the most common comorbidity, affecting 95% of cases. LAR to grass pollen is relevant in patients with seasonal symptoms indicative of allergic rhinitis but with a negative skin test result who live in areas with high allergenic pollen loads. This entity should be included the differential diagnosis of rhinitis.

English

Component-based diagnosis on multiplex platforms is widely used in food allergy but its clinical performance has not been evaluated in nut allergy. To assess the diagnostic performance of a commercial protein microarray in the determination of specific IgE (sIgE) in peanut, hazelnut, and walnut allergy. sIgE was measured in 36 peanut-allergic, 36 hazelnut-allergic, and 44 walnut-allergic patients by ISAC 112, and subsequently, sIgE against available components was determined by ImmunoCAP in patients with negative ISAC results. ImmunoCAP was also used to measure sIgE to Ara h 9, Cora 8, and Jug r 3 in a subgroup of lipid transfer protein (LTP)-sensitized nut-allergic patients (positive skin prick test to LTP-enriched extract). sIgE levels by ImmunoCAP were compared with ISAC ranges. Most peanut-, hazelnut-, and walnut-allergic patients were sensitized to the corresponding nut LTP (Ara h 9, 66.7%; Cor a 8, 80.5%; Jug r 3, 84% respectively). However, ISAC did not detect sIgE in 33.3% of peanut-allergic patients, 13.9% of hazelnut-allergic patients, or 13.6% of walnut-allergic patients. sIgE determination by ImmunoCAP detected sensitization to Ara h 9, Cor a 8, and Jug r 3 in, respectively, 61.5% of peanut-allergic patients, 60% of hazelnut-allergic patients, and 88.3% of walnut-allergic patients with negative ISAC results. In the subgroup of peach LTP-sensitized patients, Ara h 9 sIgE was detected in more cases by ImmunoCAP than by ISAC (94.4% vs 72.2%, P < .05). Similar rates of Cora 8 and Jug r 3 sensitization were detected by both techniques. The diagnostic performance of ISAC was adequate for hazelnut and walnut allergy but not for peanut allergy. sIgE sensitivity against Ara h 9 in ISAC needs to be improved.

Development of hydrogel biochip for in vitro allergy diagnostics

A hydrogel biochip was developed for the simultaneous quantitative determination of sIgE for 21 allergens and total IgE in human serum. The biochips are manufactured by photoinduced copolymerization of different molecules (allergens and antibodies) with gel-forming monomers resulting in the formation of three-dimensional hydrogel elements (1nl gel drops). After incubation of the biochip with the serum, the results are visualized using fluorescently labeled anti-IgE antibodies. Using biochips, serum samples from allergic patients and healthy donors were analyzed and good correlation with the results obtained using commercial EIA test systems of generally recognized quality (Dr. Fooke Laboratorien GmbH, Germany) was observed.

Is the Determination of Specific IgE against Components Using ISAC 112 a Reproducible Technique?

BackgroundThe ImmunoCAP ISAC 112 is a fluoro-immunoassay that allows detection of specific IgE to 112 molecular components from 51 allergenic sources. We studied the reliability of this technique intra- and inter- assay, as well as inter-batch- and inter-laboratory-assay.MethodsTwenty samples were studied, nineteen sera from polysensitized allergic patients, and the technique calibrator provided by the manufacturer (CTR02). We measured the sIgE from CTR02 and three patients' sera ten times in the same and in different assays. Furthermore, all samples were tested in two laboratories and with two batches of ISAC kit. To evaluate the accuracy of ISAC 112, we contrasted the determinations of CTR02 calibrator with their expected values by T Student test. To analyse the precision, we calculated the coefficient of variation (CV) of the 15 allergens that generate the calibration curve, and to analyse the repeatability and the reproducibility, we calculated the intraclass coefficient correlation (ICC) to each allergen.ResultsThe results obtained for CTR02 were similar to those expected in 7 of 15 allergens that generate the calibration curve, whereas in 8 allergens the results showed significant differences. The mean CV obtained in the CTR02 determinations was of 9.4%, and the variability of sera from patients was of 22.9%. The agreement in the intra- and inter-assay analysis was very good to 94 allergens and good to one. In the inter-batch analyse, we obtained a very good agreement to 82 allergens, good to 14, moderate to 5 allergens, poor to one, and bad to 1 allergen. In the inter-laboratory analyse, we obtained a very good agreement to 73 allergens, good to 22, moderate to 6 and poor to two allergens.ConclusionThe allergen microarray immunoassay, ISAC 112, is a repeatable and reproducible in vitro diagnostic tool for determination of sIgE beyond the own laboratory.

Immunological cross-reactivity between olive and grass pollen: implication of major and minor allergens

Background Grasses and olive trees are the most common sources of allergenic pollen worldwide. Although they share some allergens, there are few studies analyzing the in vitro cross-reactivity between them. The aim was to define the cross-reactivity between Olea europaea and Phleum pratense using well-characterized sera of allergic children from Madrid, Spain.Methods 66 patients (mean age 10.32+/−4.07 years) were included in the study. All suffered from rhinoconjuntivitis and/or asthma and had a positive skin test and/or specific IgE determination to olive and grass pollen. Serum sIgE to individual allergens was conducted and sIgE against different grass species and olive was also determined by ELISA. Inhibition assays were performed using two serum sources, containing, or not, sIgE to minor allergens. Mass spectrometry analysis was performed in both extracts.Results 59/66 (89.39%) children had a positive sIgE determination by ELISA to grasses and 57/66 (86.36%) to olive pollen. There was no significant correlation between sIgE levels to grass and olive. Inhibition assays demonstrated no cross-reactivity between P. pratense and olive pollen when using the pool containing mainly sIgE to major allergens, whereas minimal to moderate cross-reactivity was detected when the serum contained high sIgE titers to minor allergens. Proteomic analyses revealed the presence of 42 common proteins in grasses and olive pollens.Conclusion No in vitro cross-reactivity was observed when sIgE was mainly directed to major allergens. In our population, sensitization to olive and grasses is not due to cross-reactivity. The contribution of the major allergens seems to be determinant.

Features of sensitization to widespread allergens in residents of St. Petersburg and the Leningrad region with common allergic deseases

Background. To identify differences in sensitization to widespread allergens in patients with common allergic diseases: allergic rhinitis, bronchial asthma, angioedema, allergic urticaria and atopic dermatitis. Materials and methods. Determination of sIgE in serum using commercial and domestic reagent kits («AllergoI-FA-specific IgE» and biotinylated allergens of «Alcor Bio», St. Petersburg) was conducted in patients with allergic rhinitis, bronchial asthma, angioedema, allergic urticaria and atopic dermatitis. Results. There was a significant similarity between the spectrum of sensitization in patients with allergic rhinitis and asthma In atopic dermatitis patients the increasing of frequency of food and especially mold sensitization was estimated. The high degree of correlation between the moulds, plants and food allergens in atopic dermatitis was observed. Conclusion. The results obtained in the study can be interesting for physicians in allergological examination and for the researchers to identify new cross-reactive allergens.

Determination of sIgE to rPhl p 1 is sufficient to diagnose grass pollen allergy

New diagnostic tools such as the basophil activation test (BAT) and component-resolved diagnosis (CRD) are promising for Hymenoptera venom or food allergy. A clear benefit for inhalant allergens has not yet been shown. Our aim was to compare new and established tests for grass pollen allergy. Forty-nine patients with grass pollen allergy and 47 controls were prospectively enrolled in the study. A symptom score was calculated for each patient. Conjunctival provocation tests (CPT), skin prick tests (SPT), BAT, and sIgE determination including CRD were performed. Sensitivity and specificity were compared and results were correlated with the symptom score. Single determination of sIgE to rPhl p 1 showed the best balance between sensitivity (98%) and specificity (92%). Use of additional components, such as rPhl p 2 and 5, did not increase sensitivity. Generally, sensitivity of tests was high: SPT 100%, ISAC-112 100%, sIgE to timothy grass 98%, BAT 98%, ISAC-103 84%, and CPT 83%. Specificity ranged from 79% (SPT) to 96% (CPT). All test results and calculated values (e.g. ratio sIgE/tIgE) did not correlate with symptom severity. Asymptomatic sensitization to timothy grass in controls was rare in the CAP (11%) and predominantly due to Phl p 1 sensitization. rPhl p 1 was sufficient to diagnose grass pollen allergy, and sIgE patterns were the same in symptomatically and asymptomatically sensitized subjects. The testing of multiple components was of minor importance, and no test correlated with symptom severity.