A case of white bean allergy.

White bean allergy is uncommon and rarely reported. Herein, we report a case of white bean allergy in a patient with Down syndrome. A 7-year-old girl with Down syndrome experienced allergic symptoms twice after eating white bean and visited our hospital for a food allergy investigation. An ImmunoCAP assay revealed a white bean-specific IgE (13.4 kUA/L) in the patient's serum. In addition, her skin prick test result was positive. Moreover, ingestion of 2 g of boiled white beans in an oral food challenge test induced intermittent cough, desaturation, generalized urticaria, abnormal sleep, and mild hypotension. Thus, we diagnosed the patient with white bean allergy. We performed western blotting and mass spectrometric analysis and detected the following allergens: Phytohemagglutinin, group 3 late embryogenesis abundant protein, lipoxygenase, and legumin. In addition, we detected several candidate allergenic proteins for the first time. White bean, runner bean, or azuki bean was considered the primary source of sensitization because although immunoblotting inhibition tests revealed that the abovementioned beans inhibited other legumes, soybean, which she tolerates, showed little inhibition of the other legumes. However, we could not confirm whether the patient could ingest legumes other than soybean or white bean because her family did not wish to continue with further testing. This is the first report of a case of systemic allergic reactions to white bean in a child with Down syndrome. Further studies are needed to identify white bean allergens and understand the relationship between Down syndrome and white bean allergy.

Alpha/Beta Gliadin MM1 Is a Novel Antigen for Wheat-Dependent Exercise-Induced Anaphylaxis.

INTRODUCTION: Screening for ω-5 gliadin specific IgE antibody (sIgE) has high diagnostic utility in cases of suspected wheat-dependent exercise-induced anaphylaxis (WDEIA); however, negative cases may require confirmatory tests, such as the oral challenge test. Thus, newly identified allergens that can be used for the serological diagnosis of WDEIA are needed. This study aimed to identify additional sIgE biomarkers of WDEIA. METHODS: Forty-two patients with WDEIA (5 negative/37 positive for ω-5 gliadin sIgE) were enrolled. For comparison, 8 patients with immediate-type wheat allergy without WDEIA and 20 healthy controls without wheat allergy were also enrolled. Extracted wheat proteins were separated by 2D-PAGE. Proteins that reacted with serum IgE antibody in 2D Western blotting (2D-WB) were identified using mass spectrometry. Recombinant proteins were synthesized in Escherichia coli, and the antigenicity was tested using ELISA and the basophil activation test. RESULTS: In 2D-WB, nine proteins reacted with the serum IgE antibody from at least 60% of patients with WDEIA (n ≥ 25/42). ELISA revealed that alpha/beta gliadin MM1 exhibited the highest positive immunoreactivity in 23 of 26 patients who were positive for ω-5 gliadin sIgE (88%) and in 5 of 5 patients who were negative for ω-5 gliadin sIgE (100%). Alpha/beta gliadin MM1 exhibited significantly higher basophil activation in 14 patients with WDEIA when compared to 5 individuals without a wheat allergy. CONCLUSIONS: Alpha/beta gliadin MM1 sIgE exhibited the highest seropositivity, even among patients who were negative for ω-5 gliadin sIgE. The inclusion of alpha/beta gliadin MM1 in allergen-sIgE tests may improve the sensitivity for diagnosing WDEIA.

Nattokinase (Bac s 1), a subtilisin family serine protease, is a novel allergen contained in the traditional Japanese fermented food natto.

BACKGROUND: Immediate allergy caused by natto, a popular Japanese food prepared by fermenting soybeans with Bacillus subtilis var. natto, has been reported. Polygamma glutamic acid (PGA) in the sticky substance around natto beans has been reported to be a causative allergen of natto allergy. However, some of our patients with natto allergy were negative for PGA in the skin prick test (SPT). The sticky substance of natto beans contains a subtilisin family serine protease, nattokinase, along with PGA. In this study, we aimed to examine the antigenicity of nattokinase in natto allergy. METHODS: Eight patients, who developed symptoms after ingesting natto and positively reacted to natto (seven to the sticky substance in natto and one to the whole natto product) in their SPT, were enrolled in this study. To analyze IgE reactivity, we performed immunoblotting, ELISA, and SPT for natto (bean and sticky substance), and/or PGA, and/or nattokinase and/or cultured B. subtilis var. natto extract. RESULTS: In the SPT, four cases each were PGA-positive and PGA-negative. Immunoblotting of the sera from PGA-negative patients showed a protein band at 30 kDa, which was identified as nattokinase. Three PGA-negative cases, but not three PGA-positive cases, showed a positive reaction to nattokinase in the SPT and had a history of atopic dermatitis. The ELISA for nattokinase revealed a positive reaction of PGA-negative cases and negative reaction of PGA-positive cases in the SPT. CONCLUSIONS: We identified a subtilisin family serine protease, nattokinase, as a novel allergen in natto allergy patients unsensitized to PGA.

Food-Dependent Exercise-Induced Anaphylaxis Caused by Carrots: A Case Report.

Background: Most cases of food-dependent exercise-induced anaphylaxis (FDEIA) are caused by eating wheat or crustaceans. However, fruits or vegetables may rarely act as allergens for FDEIA. We report a rare case of FDEIA caused by eating carrots. Case Presentation: An 8-year-old boy developed an anaphylactic reaction while playing, after eating lunch that included cooked carrots. Serum carrot-specific immunoglobulin E level was 0.19 UA/mL. The prick-by-prick test for raw carrots was positive (wheal diameter: 4 mm). The patient developed urticaria after exercise provocation tests following ingestion of raw carrots. Carrot proteins were analyzed by 2-dimensional Western blotting to identify the causative allergens. Nine proteins were identified as candidate antigens at 21-66 kDa. Conclusions: Our patient presented with FDEIA symptoms after ingesting both raw and cooked carrots. Both raw and cooked carrots contain 9 proteins that may induce FDEIA.

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.

[THE CASE REPORT OF A 8 YEARS OLD BOY WITH COCHINEAL ALLERGY].

BACKGROUND: Cochineal dyes are used as additives in various foods for the purpose of red coloration. On the other hand, although it has been reported as a causative agent of immediate allergy, most of them are adult women. We report a case of an 8-year-old boy who developed a cochineal allergy.Current disease history: He has been suffering from atopic dermatitis, bronchial asthma, and food allergies since childhood. At the age of seven, he experienced an unknown anaphylaxis reaction twice. When he was 8 years old, he ate a frankfurter containing hypoallergenic cochineal for the first time; cold sweat, intraoral discomfort, respiratory distress, and urticaria appeared throughout the body. His skin prick tests were positive, with a result of 2+to frankfurter and cochineal dyes (color value 0.1 and 0.01). In the immunoblot assay, binding of IgE antibody was observed with CC38K (the main component of cochineal) and a protein of approximately 80-200 kDa in the high molecular weight region. DISCUSSION: We report a case of anaphylaxis with hypoallergenic cochineal onset in a school-age boy.

Cochineal dye-induced immediate allergy: Review of Japanese cases and proposed new diagnostic chart.

BACKGROUND: Cochineal dye is used worldwide as a red coloring in foods, drinks, cosmetics, quasi-drugs, and drugs. The main component of the red color is carminic acid (CA). Carmine is an aluminum- or calcium-chelated product of CA. CA and carmine usually contain contaminating proteins, including a 38-kDa protein thought to be the primary allergen. Severe allergic reactions manifest as anaphylaxis. The aim of this study was to review all Japanese reported cases and propose useful diagnostic chart. METHODS: All reported Japanese cases of cochineal dye-induced immediate allergy were reviewed, and newly registered cases were examined by skin prick test (SPT) with cochineal extract (CE) and measurement of CE and carmine-specific serum IgE test. Two-dimensional (2D) western blotting using patient serum was conducted to identify the antigen. RESULTS: Twenty-two Japanese cases have been reported. SPT and the level of specific IgE test indicated that six cases should be newly registered as cochineal dye allergy. All cases were adult females, and all cases except three involved anaphylaxis; 13 cases involved past history of local symptoms associated with cosmetics use. Japanese strawberry juice and fish-meat sausage, and European processed foods (especially macarons made in France) and drinks were recent major sources of allergen. 2D western blotting showed that patient IgE reacted to the 38-kDa protein and other proteins. Serum from healthy controls also weakly reacted with these proteins. CONCLUSIONS: SPT with CE and determination of the level of CE and carmine-specific IgE test are useful methods for the diagnosis of cochineal dye allergy.