[A CASE OF FOOD-DEPENDENT EXERCISE-INDUCED ANAPHYLAXIS DUE TO POLISHED RICE].

A 14-year-old girl presented to our hospital with food-dependent exercise-induced anaphylaxis (FDEIA), possibly caused by rice. Despite experiencing four previous episodes of suspected FDEIA, she did not seek medical attention at her own discretion. On the fifth occurrence of symptoms, the general practitioner suspected FDEIA and referred the patient to our hospital. The only common factor in all five episodes was the consumption of rice, leading to the examination of the patient under suspicion of FDEIA caused by rice. Skin prick test results were positive for bran and polished rice, and exercise after consumption of polished rice resulted in anaphylaxis. Therefore, we diagnosed FDEIA caused by polished rice. Immunoblotting confirmed the presence of immunoglobulin E reacting with 14-16kDa rice bran protein in the patient's serum. The immunoblot inhibition test suggested that the rice bran protein to which the patient's serum reacted was also present in polished rice and no wash rice. As the patient may experience FDEIA after ingestion of no wash rice or rice flour, she was advised to eliminate these from her diet, treating them similarly to brown rice or polished rice.

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.

Anaphylaxis due to potato starch (possibly caused by percutaneous sensitization).

An 8-year-old boy with poor control of atopic dermatitis could eat potato products such as French fries without restrictions until 21 months of age. However, he developed generalized urticaria after eating potato products at the same age. Therefore, potatoes were excluded from his diet; nevertheless, he continued to consume a very small amount of potato starch but was without symptoms until the age of 8 years. At this age, he developed anaphylaxis after consuming potato starch and required administration of intramuscular epinephrine. He tested positive for potato-specific immunoglobulin E, skin prick test, and basophil activation test. He developed severe eczema with dry skin and erosion. We later discovered that potato starch had been used for play clay at his nursery school. Although he discontinued using potato starch play clay, it remained present in his surroundings for 6 years. His potato allergy may have developed and continued to worsen as a result of making indirect contact with surfaces that had previously been exposed to the allergen. Two-dimensional Western blot analysis on potato starch revealed the presence of proteins binding to the immunoglobulin E of the patient. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis findings showed that 5 of the 6 protein bands had a similar molecular weight as that of potato proteins. Thus far, there are no reports of anaphylaxis due to potato starch. Children with atopic dermatitis or damaged skin may have sensitivity to potato starch and could develop anaphylaxis as noted in this case.

Evaluation of cross-reactivity between casein components using inhibition assay and in silico analysis.

BACKGROUND: We previously reported that the specific IgE levels to αs1-casein (CN) and ß-CN in patients with cow's milk allergy decreased with similar dynamics during oral immunotherapy. Therefore, we hypothesized that αs1- and ß-CN have strong cross-reactivity among CN components, despite the low similarity in the full-length amino acid sequences. METHODS: The αs1-, ß-, and κ-CN were purified from commercial cow's milk. We recruited 39 patients with cow's milk allergy, and the serum IgE levels for each CN component were measured by enzyme-linked immunosorbent assay (ELISA). Cross-reactivity between CN components was investigated by competitive ELISA against αs1-CN. Sequence homology between CN components at the peptide level was calculated using in silico analysis and quantified by the property distance (PD) value. RESULTS: The αs1-CN-specific IgE levels exhibited a strong positive correlation with the ß-CN-specific IgE (r = 0.945, P < .001). Complete competition was observed by ß-CN against αs1-CN, suggesting the presence of common epitopes between them. In silico analysis detected 24 peptide sets with PD values lower than 10 between αs1- and ß-CN, and 14 sets between αs1- and κ-CN. The amino acid sequences of αs1-CN (E61-E70) and ß-CN (I12-E21) that showed the lowest PD value (5.30) were present in the characteristic sequence known as casein phosphopeptide (CPP). CONCLUSION: We detected strong cross-reactivity between CN components. Furthermore, we found highly homologous sequences in the CPP region, which contains a core sequence of "SSSEE" with phosphorylated serine residues.

Changes in passively-sensitized basophil activation to αS1-casein after oral immunotherapy.

INTRODUCTION: Immune response to cow's milk allergen (CMA) has been analyzed mostly using crude milk antigen or a mixture of various caseins. This study aimed to assess the changes in the immunological response against αS1-casein during oral immunotherapy (OIT) and to investigate the mechanism of tolerance. METHODS: We have performed rush OIT to 39 patients with CMA and obtained the serum samples up to 3 years after OIT. Immunoglobulin E (IgE) and IgG4 antibodies specific to highly purified αS1-casein as well as passively-sensitized basophil activation were evaluated using the serial samples. Furthermore, we examined whether basophil activation led by the pre-OIT serum was suppressed by the post-OIT serum, or by the tolerant serum obtained from naturally outgrown patients. RESULTS: Specific IgE to αS1-casein was significantly reduced after OIT. Specific IgG4 (sIgG4) to αS1-casein was also detected in most of the pre-OIT sera, which was not significantly increased after OIT. Activation of passively-sensitized basophils to αS1-casein was significantly reduced after 2 years (14% ± 19%) and 3 years (19% ± 18%) post-OIT compared with pre-OIT (%CD63high basophils; 51% ± 27%). Furthermore, the addition of post-OIT or tolerant serum to pre-OIT serum significantly suppressed the basophil activation. This suppression was abrogated by washing the supernatant after passive sensitization, but not by depleting IgG antibodies from post-OIT or tolerant sera, nor by blocking FcγRIIb using an anti-FcγR antibody. CONCLUSIONS: αS1-casein-sIgG4 plays a minor role in tolerance mechanisms in cases of CMA; humoral factors other than antigen-sIgG4 may be involved.

Exercise-induced allergic reactions on desensitization to wheat after rush oral immunotherapy.

BACKGROUND: The effect of oral immunotherapy (OIT) on wheat allergy is promising in terms of the potential to obtain desensitization; however, the frequency of exercise-induced allergic reactions on desensitization (EIARDs) and the associated risk factors remain to be determined. METHODS: Twenty-five patients underwent rush OIT for wheat allergy, and 21 achieved the full-dose intake of wheat products (5 g of wheat protein). Exercise-provocation tests were repeatedly performed after the ingestion of a full-dose wheat product. The time-course of the levels of the specific IgEs (sIgE) to wheat extract, total gliadin, deamidated gliadin, recombinant gliadin components (α/ß-, γ- and ω-5-), and glutenin (high and low molecular weight) components was analyzed using ImmunoCAP® , ELISA, or IgE immunoblotting. RESULTS: Fourteen patients (66.7%) were diagnosed as EIARD+, which remained 5 years after rush OIT in 11 patients (52.4%). There were no differences in the clinical backgrounds of the EIARD+ and EIARD- patients. However, EIARD+ patients showed significantly higher sIgE levels to all gliadin and glutenin components than EIARD- patients before OIT. The sIgE levels to each component decreased equally after 1 and 2 years of OIT. On IgE immunoblotting, sera from all patients reacted to the multiple gluten bands, and some reacted to the water-soluble bands. The intensity of all IgE-reactive bands also became equally lighter after OIT. CONCLUSIONS: EIARDs were frequently observed and remained for a long period after successful OIT for wheat allergy. None of the specific wheat components were found to contribute to EIARDs.

[ORAL AND SYSTEMIC SYMPTOMS IN CHILDREN WITH FRUIT ALLERGY].

BACKGROUND AND PURPOSE: The principal aim of this study was to clarify the clinical profile of pediatric patients with fruit allergies. SUBJECTS AND METHODS: We assigned 265 pediatric patients with fruit allergies who were receiving outpatient treatment at Aichi Children's Health and Medical Center and 32 who underwent kiwi or banana oral food chal- lenge (OFC) test to an oral symptom group or a systemic symptom group and retrospectively examined their clinical profiles and prognosis from their medical records. RESULTS: The most common cause of fruit allergy was kiwi (139 patients, 21% of all patients). Watermelon had the highest oral symptom induction rate (97%), whereas banana had the highest systemic reaction induction rate (46%). In the oral symptom group, the prevalence of hay fever was 54% and 66% of patients showed aller- gic reaction to multiple fruits. In contrast, in the systemic symptom group, the prevalence of pollen allergies was 24% and 77% of patients showed allergic reaction to a single fruit only. The results revealed that 65% of patients allergic to bananas had infant-onset allergy and seven among 20 patients were confirmed acquisition of tolerability by the OFC test. CONCLUSION: Our data suggest that there is a difference in the clinical profile and disease type between patients with oral symptoms and those with primarily systemic symptoms. It is important to differentiate between these patients for accurate diet guidance, safety management, and prognosis estimation.

INSOLUBILITY AND ALTERATION OF ALLERGENIC ACTIVITY OF WHEAT PROTEINS IN PROCESSED FOODS.

BACKGROUND: Food processing causes decomposition, denaturation or polymerization of protein, which may alter an allergic reaction. This study aimed to investigate the insolubility and alteration of wheat allergens in processed foods and the reactivity to patient sera. METHODS: We extracted proteins from wheat flour, udon and bread using different extracts and conducted SDS-polyacrylamide gel electrophoresis. IgE-immunoblotting was also conducted using sera from children with wheat allergy. RESULTS: Soluble protein was extracted from wheat flour, and gluten fractions were also extracted by adding SDS. However, no proteins were able to be extracted from udon or bread witout severing the disulfide bonds under reducing condition. Only trace amounts of protein were detected in the water after boiling udon noodles. The reactivity of IgE antibody to the extracted protein did not differ among the different processed food types. CONCLUSIONS: Wheat allergens became strongly insolubilized after gluten formation and heating. However, the reactivity of IgE antibody to each allergen was not affected by food processing. Further studies are needed for the effects on clinical symptoms.