Utility of Gal d 1-Specific IgE Levels in Predicting Reactivity to Boiled Egg in Chinese Children

<b><i>Background:</i></b> Many researchers have reported predicting the outcome of oral food challenges (OFCs) on the basis of specific IgE (sIgE) levels. However, the clinical usefulness of the determination of IgE antibodies to egg allergen components in Chinese children with suspected boiled egg allergy is not well studied. <b><i>Objective:</i></b> Our objective was to assess the diagnostic performance of sIgE to egg white and Gal d 1, 2, 3, and 5 based on the open challenge outcome for boiled egg. <b><i>Methods:</i></b> A total of 48 child patients with a suspect of boiled egg allergy were included. Serum egg white and Gal d 1, 2, 3, and 5 sIgE were measured by ImmunoCAP. Diagnostic value was assessed by area under the receiver operating characteristic curves (AUC). <b><i>Results:</i></b> Using the OFC results as the reference parameter, Gal d 1 sIgE had the highest AUC (0.84) compared with egg white (0.77) and other investigated components (ranging from 0.51 to 0.71). The clinical sensitivity and specificity for the sIgE to Gal d 1 at optimal cutoff (6.15 kU_A/L) were 73.7% and 96.7%, respectively. Sensitization to Gal d 1 with a cutoff value of &#x3e;7.48 kU_A/L indicated a 90% probability of positive challenge. <b><i>Conclusion:</i></b> Quantitative measurements of Gal d 1 sIgE antibodies using ImmunoCAP are useful in the management of boiled egg allergy in Chinese children.

Exercise induced anaphylaxis in kiwi allergic patient: case report

Background An allergy to kiwi is rare in Poland. Most (65–72%) of the patients who are allergic to kiwi report symptoms of an oral allergy syndrome (OAS); however, systemic manifestations (18–28%) have also been reported. Case report A 27-year-old male patient, previously not suffering from chronic diseases, exercised in the gym. He began with isometric training and then continued with aerobic exercise on a treadmill. After exercise, he ate 2 kiwi (Actinidia deliciosa) fruits. He experienced a swelling of the lips after eating the fruit, followed by an itchy scalp and a swollen face. Approximately 60 min later, the symptoms worsened: the patient suffered from generalized hives, general weakness and a "rumbling" sensation in ears. The patient's condition improved upon the consumption of antihistamines. However, the swelling of the face persisted for 24 h despite previously eating a kiwi without any side effects. By means of diagnostics based on allergen components, an allergy to grass allergen components, especially timothy grass—Phl p 1, Phl p 2 and Phl p 5, was confirmed. The presence of IgE that is specific for Act d 2 kiwi was also found. The patient had an oral food challenge with kiwi fruit at rest and after exercise provocation test. The challenge was negative at rest and positive after exercise. A food-dependent exercise-induced anaphylaxis gathered with a kiwi sensitization was diagnosed. Conclusion To our knowledge, this case is the first report of a kiwi-allergic patient in whom exercise was a necessary cofactor to induce an anaphylactic reaction.

Analysis of allergen components and identification of bioactivity of HSP70 in pollen of Populus deltoides

Background Allergies caused by pollen from Populus deltoides are common, but the allergic components are still unclear. Methods The total proteins in pollen of P. deltoides were analyzed by proteomics, and the potential allergens were identified via the WHO/IUIS database and the allergenOnline database retrieval. One target protein was screened by bioinformatics and expressed in Escherichia coli. The biological activity of the expressed product was verified by animal experiments. Results The total of 3929 proteins in pollen of P. deltoides were identified, and 46 potential allergens belonging to 10 protein families were recognized by database retrieval. B9N9W6 protein of Hsp70 family was screened by bioinformatics analysis and expressed successfully. ELISA showed that B9N9W6 can stimulate the immune system to produce specific IgE and promote the generation of IL-4. Flow cytometry showed that B9N9W6 can significantly stimulate the proliferation of CD4+ T cells and promote the polarization of Th2 cells. The pathological sections of mice lung tissues indicated that alveolar destruction was more severe in the B9N9W6 group than that of extract group, and there were more inflammatory cells infiltration, mucus exudation and bleeding. Conclusion B9N9W6 is an important antigenic substance in the pollen of P. deltoides. Due to the conserved structure of Hsp70 family, more attention should be paid to the possibility of sensitization when Hsp70 from any pathogenic species is administered.

Distinct differences in analytical performance of two commercially available assays for specific IgE to egg white and house dust mite allergens

Background Measurements of allergen-specific IgE antibodies with different manufacturers’ assays show modest or poor agreement. This study compares analytical performance of specific IgE tests for whole allergen extracts and individual allergen components of two assay systems, IMMULITE and ImmunoCAP, using human sera as well as monoclonal antibodies. Methods Comparisons were performed for specific IgE to house dust mite (HDM, n = 44), egg white (EW, n = 36) and the allergen components rDer p 1, rDer p 2, nGal d 1, nGal d 2 and nGal d 4 in human sera and with monoclonal mouse/human chimeric IgE antibodies specific for the same allergen components. Competitive interference with IgE measurement was investigated using allergen-specific monoclonal IgG and IgG4 antibodies. Results Measurements of IgE to HDM and EW in serial dilutions of human sera revealed weaker dilution linearity with IMMULITE than with ImmunoCAP. Analysis of five different monoclonal IgE antibodies with total and specific IgE assays, expected to return similar levels, gave an average specific/total IgE ratio of 0.96 (range 0.71–1.14) with ImmunoCAP and 1.89 (range 0.76–2.85) with IMMULITE, indicating overestimation of specific IgE by IMMULITE. With the EW IgE tests of both assay systems, measurements of a chimeric anti-Gal d 2 IgE antibody were unaffected by a competing mouse IgG antibody. While the same was true for measurement of a chimeric anti-Der p 1 IgE antibody using the HDM test in ImmunoCAP, a suppression of measured concentrations by up to 42% was observed in IMMULITE. Similarly, measurement of HDM-specific IgE in human sera by ImmunoCAP was unaffected by a competing monoclonal anti-Der p 2 IgG4 antibody while IMMULITE displayed a reduction of HDM-specific IgE values by up to 30%. Conclusions In this evaluation of analytical performance of two widely used assay systems, ImmunoCAP showed higher accuracy in quantitation of specific IgE and greater resistance against competing allergen-specific non-IgE antibodies which may arise through natural or dietary exposure, or as a result of allergen immunotherapy treatment.

Assessment of TSLP, IL 25 and IL 33 in patients with shrimp allergy

Background Shrimp allergy is a growing problem among the European population. TSLP, IL-25 and IL-33 are involved in the pathophysiology of allergic diseases, including asthma and atopic dermatitis, as they activate the Th2-dependent immune response. Methods Thirty-seven patients (18 male and 19 female) with a positive history of symptoms associated with shrimp consumption were selected. All patients had blood samples taken to assess the concentration of allergen-specific IgE (sIgE) to house dust mites (HDM) and shrimp (Singleplex, quantitative method with cut off value > 0,35 kAU/L) as well as the level of allergen components using the ImmunoCap ISAC method (Microarray test, semi-quantitative with cut off value > 0,3 ISU-E). The concentrations of TSLP, IL-25 and IL-33 in the patients’ blood serum was assessed using the ELISA method (Cusabio). Twenty patients with negative allergy history of allergic disease tests were included in the control group. Results Among the 37 shrimp-allergic patients, ImmunoCap ISAC was identified the presence of sIgE to the available shrimp allergen components in only 14 cases (37.8%). TSLP and IL25 levels were significantly higher in the study group. No statistically significant correlation was found between the concentration of analyzed alarmins and the concentration of sIgE level to shrimp or HDM between the study and control groups. No statistically significant correlation was found between poly-sensitization occurring in patients and levels of TSLP, IL-25 and IL-33 . Conclusion In shrimp-allergic patients, the concentrations of TSLP and IL-25 were significantly higher than in the control group (1.33 vs. 0.49 and 157 vs. 39.36, respectively). There was no correlation between the concentrations of TSLP, IL-25 and IL-33 and the concentration of sIgE in the patients or the number of allergen components that the patients were sensitized to. Trial registration: Bioethics Committee 147/2015, 11.03.2015.

Analysis of Allergen Components and Identification of Bioactivity of HSP70 in Pollen of Populus Deltoides

Background: Allergies caused by pollen from Populus deltoides are common, but the allergic components are still unclear. Methods: The total proteins in pollen of P. deltoides were analyzed by proteomics, and the potential allergens were identified via the WHO/IUIS database and the allergenOnline database retrieval. The target protein was screened by bioinformatics and expressed in Escherichia coli. The biological activity of the expressed product was verified by animal experiments. Results: 3929 total proteins in pollen of P. deltoides were identified, and 49 potential allergens belonging to 10 protein families were recognized by database retrieval. B9N9W6 protein of Hsp 70 family was screened by bioinformatics analysis and expressed successfully. ELISA showed that B9N9W6 can stimulate the immune system to produce specific IgE and promote the generation of IL-4. Flow cytometry showed that B9N9W6 can significantly stimulate the proliferation of CD4+ T cells and promote the polarization of Th2 cells. The pathological sections of mice lung tissues indicated that alveolar destruction was more severe in the B9N9W6 group than that of extract group, and there were more inflammatory cells infiltration, mucus exudation and bleeding. Conclusion: B9N9W6 is an important antigenic substance in the pollen of P. deltoides. Due to the conserved structure of Hsp 70 family, more attention should be paid to the possibility of sensitization when HSP 70 from any pathogenic species is administered.