Variation in the Allergenicity of Scrambled, Boiled, Short-Baked and Long-Baked Egg White Proteins.

BACKGROUND: Hen's egg white (HEW) is the most common cause of food allergy in children which induces mild to fatal reactions. The consultation for a proper restriction is important in HEW allergy. We aimed to identify the changes in HEW allergenicity using diverse cooking methods commonly used in Korean dishes. METHODS: Crude extract of raw and 4 types of cooked HEW extracts were produced and used for sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), and ELISA inhibition assays using 45 serum samples from HEW allergic and tolerant children. Extracts were prepared; scrambled without oil for 20-30 seconds in frying pan without oil, boiled at 100°C for 15 minutes, short-baked at 180°C for 20 minutes, and long-baked at 45°C for 12 hours with a gradual increase in temperature up to 110°C for additional 12 hours, respectively. RESULTS: In SDS-PAGE, the intensity of bands of 50-54 kDa decreased by boiling and baking. All bands almost disappeared in long-baked eggs. The intensity of the ovalbumin (OVA) immunoglobulin E (IgE) bands did not change after scrambling; however, an evident decrease was observed in boiled egg white (EW). In contrast, ovomucoid (OM) IgE bands were darker and wider after scrambling and boiling. The IgE binding reactivity to all EW allergens were weakened in short-baked EW and considerably diminished in long-baked EW. In individual ELISA analysis using OVA+OM+ serum samples, the median of specific IgE optical density values was 0.435 in raw EW, 0.476 in scrambled EW, and 0.487 in boiled EW. Conversely, it was significantly decreased in short-baked (0.406) and long-baked EW (0.012). Significant inhibition was observed by four inhibitors such as raw, scrambled, boiled and short-baked HEW, but there was no significant inhibition by long-baked HEW (IC50 > 100 mg/mL). CONCLUSION: We identified minimally reduced allergenicity in scrambled EW and extensively decreased allergenicity in long-baked EW comparing to boiled and short-baked EW as well as raw EW. By applying the results of this study, we would be able to provide safer dietary guidence with higher quality to egg allergic children.

Component resolved diagnosis of walnut allergy in young children: Jug r 1 as a major walnut allergen.

BACKGROUND: Walnuts (WN) are one of the main causes of tree nut allergies. However, the potential value of component resolved diagnosis (CRD) for WN allergy is controversial. OBJECTIVE: We analyzed the clinical and immunological features of clinical WN allergy and the usefulness of CRD in young children. METHODS: Forty-one participants with a history of ingesting WN who were assessed for serum-specific IgE to WN (WNsIgE) using CRD (ImmunoCAP ISAC 112) at the Department of Pediatrics in Ajou University Hospital were enrolled and their demographic profiles, clinical symptoms, and laboratory findings were evaluated. RESULTS: A total of 32 patients were diagnosed with clinical WN allergy, of which 31 had specific immunoglobulin E antibodies to Jug r 1 (Jug r1-sIgE). The Jug r 1-sIgE levels were higher in WN-allergic patients than in WN-tolerant patients and significantly higher in patients with anaphylaxis than in the WN-tolerant patients. Receiver-operating characteristic curves demonstrated that the Jug r 1-sIgE level was much better in discriminating between clinical WN allergy and WN tolerance in young children than the WN-sIgE level. CONCLUSIONS: Jug r 1 is the major component allergen in young children with clinical WN allergy. To measure Jug r 1-sIgE appears to be a promising approach for both diagnosis and predicting severity in young children with a history of suspected WN allergy.

A randomized trial of Lactobacillus rhamnosus IDCC 3201 tyndallizate (RHT3201) for treating atopic dermatitis.

BACKGROUND: Probiotic therapies, mainly live bacteria, have been proven to be effective in treating atopic dermatitis (AD) with some controversies. Killed probiotics or postbiotics would have immunomodulatory effect in allergic diseases including AD. This study was performed to evaluate the therapeutic effect and safety of tyndallized Lactobacillus rhamnosus (IDCC 3201, isolated from the feces of a Korean breastfed infant, repeated heat-treated and incubated, RHT3201) in children with AD. METHODS: In a randomized, double-blind, placebo-controlled study, RHT3201 at a dose of 1.0 × 1010  CPU/d or placebo was given in children (aged 1-12 years) with moderate AD for 12 weeks. SCORing of AD (SCORAD) scores, allergic inflammatory markers, and safety parameters were evaluated. RESULTS: For evaluating the therapeutic effects of RHT3201, 33 subjects in each group were analyzed. The change of SCORAD total score at 12 weeks (primary outcome) from baseline was significantly greater in the RHT3201 group (-13.89 ± 10.05) compared to the control group (-8.37 ± 9.95). Levels of eosinophil cationic protein (ECP) and interleukin (IL)-31 showed tendency to decrease in the RHT3201 group and significant decreases in subgroup analysis in AD for ≥50 months. For safety analysis, a total of 100 subjects (50 in the treated group and 50 in the control group) were evaluated, and there were no significant differences in safety parameters between two groups. CONCLUSION: In children with moderate AD, oral administration of RHT3201 showed the therapeutic effect on AD, the effects in part correlated with decrement of ECP and IL-31, and the effect was more remarkable in subgroup analysis.

Clinical and Laboratory Findings of Barley Allergy in Korean Children: a Single Hospital Based Retrospective Study.

BACKGROUND: Barley is a grain that is consumed in various forms in Asia. Studies on barley allergy are limited to a few case reports about hypersensitivity reactions to beer, but there is no barley allergy study in children. This study aimed to identify the phenotype and immunologic findings in Korean children with barley allergy. METHODS: Forty-two participants with a history of ingesting barley who underwent serum specific immunoglobulin E to barley (barley-sIgE) assay at the Department of Pediatrics in Ajou Medical Center were enrolled through a retrospective analysis of medical records from March 2008 to February 2018. The demographic characteristics, symptoms, and immunologic parameters of the patients were assessed. RESULTS: Twenty subjects presented with clinical barley allergy (B-allergic group), and 22 were atopic controls without allergic reactions after the ingestion of barley (B-tolerant group). The median ages of the B-allergic and B-tolerant groups were 1 and 3 years, respectively. In the B-allergic group, the cutaneous system (90.0%) was most frequently affected, followed by the respiratory system (40.0%). Anaphylaxis was observed in 35.0% of the B-allergic group. The median level of barley-sIgE was 13.90 kUA/L (range, 0.14-101.00 kUA/L) in the B-allergic group, and this value was significantly higher (P < 0.001) than that of the B-tolerant group (0.30 kUA/L; range, 0.01-24.40 kUA/L), with an optimal cutoff level of 1.24 kUA/L (sensitivity, 85.0%; specificity, 86.4%). A positive correlation was found between the serum levels of barley-sIgE and wheat-sIgE in the B-allergic group with clinical wheat allergy. CONCLUSION: Barley is an important allergen for children in Korea. This study showed the clinical characteristics of barley allergy and suggested optimal cut-off levels of barley-sIgE for clinical barley allergy. Clinically, cross-reactivity or co-sensitization is often observed between barley and wheat.

IgE recognition profile of aeroallergen components in young children sensitized to dogs.

BACKGROUND: Pet ownership is increasing rapidly and as growing numbers of dogs in household, clinicians are facing more allergic patients and so as in young children. OBJECTIVE: This study aims to profile the IgE recognition patterns to aeroallergen components in young children sensitized to dogs. METHODS: Through retrospective chart reviews, we evaluated the clinical, environmental, and laboratory findings of patients sensitized to dogs in early life. We further evaluated specific IgE to dog component allergens (Can f 1, Can f 2, and Can f 3) and other aeroallergens using a microarray. RESULTS: The median age of 28 patients sensitized to dogs (dog-specific IgE ≥ 0.35 kU/L; 0.38-101 kU/L) was 61 months and underlying diseases included doctor diagnosed atopic dermatitis (n = 17), asthma (n = 7), and allergic rhinitis (n = 5). Twenty patients (71.4%) had experienced self-reported dog allergy and 70.0% of them were symptomatic after exposed to dogs from others. Component-resolved diagnosis was performed on 18 patients. Can f 1 positivity was the most common (77.8%) but had no value in symptom prediction. The most common cosensitized aeroallergen was house dust mites (44.5%). The symptomatic group tended to be poly-sensitized to Can f 1, Can f 2, and Can f 3. CONCLUSION: Can f 1 was dominantly detected and poly-sensitized to Can f 2 and/or Can f 3 simultaneously tend to develop hypersensitivity to dogs in young children. Most of them were exposed to dogs not living with.

Immunoglobulin E-binding Proteins of Cooked Walnuts in Korean Children.

PURPOSE: The immunological characteristics of young Korean children with walnut (WN) allergy and the influence of different cooking methods on WN proteins have not been evaluated to date. This study aimed to evaluate the major WN allergens identified among Korean children, together with changes in WN antigenicity caused by common cooking methods. METHODS: We enrolled children under the age of 13 years with WN serum-specific immunoglobulin (Ig) E concentrations. The protein fractions of dry-fried and boiled WN extracts were compared with those of raw WNs using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), 2-dimentional gel electrophoresis (2DE) and a proteomic analysis using electrospray ionization (liquid chromatography-mass spectrometry [LC-MS]). An immunoblotting analysis was conducted to examine IgE reactivity toward raw WNs using serum samples from 6 children with a clinical WN allergy. To determine the processed WN proteins with IgE-binding capacity, a 2D-immunoblotting analysis was performed using the pooled sera of 20 WN-sensitized children. RESULTS: Protein bands from raw WNs were identified at 9, 16, 28, 52, 58, and 64 kDa via SDS-PAGE. The 9- and 16-kDa protein bands were enhanced by boiling, whereas the 52- and 64-kDa bands were considerably diminished. On LC-MS analysis, of the 66 IgE-binding proteins present in raw WNs, 57 were found in dry-fried WNs, but only 4 in boiled WNs. The sera of 5 out of 6 participants reacted with the 52-kDa protein bands and those of 4 out of 6 participants reacted with the 16- and 28-kDa protein bands, respectively. Meanwhile, a 2D-immunoblotting result confirmed the presence of different binding patterns among children who consumed cooked WNs. CONCLUSIONS: The protein profile of boiled WNs is substantially different from that of raw WNs. However, 4 proteins including prolamins remained stable after dry-frying or boiling. Further studies are needed to evaluate the clinical relevance of these findings.

Cross-reactivity of Can f 1 with Syrian hamster and Fel d 1 in children

Introduction and objectives: With increasing pet allergies among pediatric patients, the need for precise environmental care is increasing. We investigated the clinical, immunological, and environmental characteristics of pediatric patients sensitized to a dog to evaluate the cross-antigenicity of canine lipocalin Can f 1 with feline lipocalin Fel d 1 and Syrian hamster extract. Materials and methods: The protein fractions of the processed and commercial Syrian hamster extracts were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An enzyme-linked immunosorbent assay (ELISA) inhibition test was performed on Can f 1, Fel d 1, and processed Syrian hamster extract, and the antigen-specific immunoglobulin E (IgE)-binding capacity for each antigen was analyzed using serum samples from patients. Results: Twelve of 19 patients with a median age of 40.5 months were symptomatic when exposed to dogs. Eleven (91.7%) patients showed a positive IgE response to Can f 1. Two patients were positive for Fel d 1-specific IgE antibody, and one was positive for hamster-specific IgE antibody. SDS-PAGE confirmed the presence of different patterns of protein bands between the commercial and processed hamster extracts. There was no cross-antigenicity among Can f 1, Fel d 1, and processed Syrian hamster extract. Conclusions: Since the standard commercial hamster extract did not contain Syrian hamster antigens that were diverse enough, caution should be taken when using it. In children allergic to cats and dogs, sensitization to isolated Can f 1 or Fel d 1 is unlikely to cause cross-reactivity to Syrian hamster hair and epithelium (AU)

Sensitization patterns of cow's milk and major components in young children with atopic dermatitis.

BACKGROUND: Cow's milk (CM) is one of the most common food allergens in children with atopic dermatitis (AD), and the component-specific immunoglobulin E (component-IgE) measurement has recently become available. OBJECTIVE: This study aimed to investigate the sensitization patterns to CM and 3 major components and their clinical values in young Korean children with AD. METHODS: Cow's milk-specific IgE (CM-IgE), α-lactalbumin-specific IgE (ALA-IgE), ß-lactoglobulin-specific IgE (BLG-IgE), and casein-specific IgE (Cas-IgE) levels from the sera of patients with AD were measured using the UniCAP™ system (Thermo Fisher Scientific, Sweden) and collected from January 2004 to December 2010. Patients ≥ 4 years of age were excluded from the analysis. RESULTS: A total of 950 patients diagnosed with AD were ultimately enrolled in the study. Among them, 471 (49.6%) patients were sensitized to CM (CM-IgE[+], > 0.35 kU/L). Sensitization to casein (n = 349, 74.1%) was most common, followed by ALA (n = 283, 60.1%), and BLG (n = 245, 52.5%). Meanwhile, 95 patients had at least 2 follow-up tests. Eighty (84.2%) of these patients tested positive to CM, and the casein sensitization rate was the highest (n = 65, 81.3%). In addition, 479 (50.4%) patients were not sensitized to CM (CM-IgE[-], ≤ 0.35 kU/L) but 35 (7.3%) patients were sensitized to at least one component. Among them, a telephone survey was accessible in 21 cases. A total of 8 (38.1%) patients still suffered from adverse reactions after consuming milk and/or dairy foods. CONCLUSION: Casein was the most commonly and persistently sensitized component in CM-IgE(+) children with AD. Measuring CM component IgE antibodies, especially Cas-IgE, is helpful for evaluating problematic allergens in young children with AD.