Comparison of the ImmunoCAP Assay and AdvanSure™ AlloScreen Advanced Multiplex Specific IgE Detection Assay

PURPOSE: The AdvanSure™ AlloScreen assay is an advanced multiplex test that allows for simultaneous detection of specific IgE (sIgE) against multiple allergens. For precise identification of causative allergens in allergic patients, we compared this new multiplex sIgE assay with the ImmunoCAP assay, which is currently the gold-standard method for sIgE detection. MATERIALS AND METHODS: Serum samples from 218 Korean allergic disease patients were used to compare the ImmunoCAP and AlloScreen assays with respect to the following 13 allergens: Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat and dog dander, Alternaria, birch, oak, ragweed, mugwort, rye grass, and food allergens (egg white, cow's milk, peanuts). RESULTS: A total of 957 paired tests using the 13 allergens were compared. The total agreement ratio ranged from 0.74 (oak) to 0.97 (Alternaria). With respect to class association analyses, the gamma index ranged from 0.819 (rye grass) to 0.990 (Alternaria). The intra-class correlation coefficients for house dust mites, cat and dog dander, Alternaria, birch, ragweed, egg white, cow's milk, and peanut sIgE titers were >0.8. CONCLUSION: The AlloScreen and ImmunoCAP assays exhibited similar diagnostic performance. However, due to methodological differences between the two systems, careful interpretation of their results is needed in clinical applications.

Clinical Significance of Component Allergens in Fagales Pollen-Sensitized Peanut Allergy in Korea

PURPOSE: Clinical features of peanut allergy can range from localized to systemic reactions. Because peanut and birch pollen have cross-reactivity, peanut can lead to localized allergic reaction in Fagales pollen-sensitized oral allergy syndrome (OAS) patients without peanut sensitization per se. The purpose of this study was to discriminate true peanut food allergy from cross-reactive hypersensitivity in birch-sensitized peanut allergy. METHODS: Birch-sensitized (n=81) and peanut anaphylaxis patients (n=12) were enrolled. Peanut-related allergic reactions and sensitization profiles were examined. Specific IgE to Fagales tree pollens (birch, oak), peanut, and their component allergens (Bet v 1, Bet v 2, Ara h 1, Ara h 2, Ara h 3, Ara h 8, and Ara h 9) were evaluated. Based on these specific IgEs and clinical features, the patients were classified into 4 groups: group 1 (Fagales pollen allergy without OAS), group 2 (Fagales pollen allergy with OAS), group 3 (OAS with peanut anaphylaxis), and group 4 (peanut anaphylaxis). RESULTS: After peanut consumption, one-third of OAS patients experienced oral symptoms not associated with peanut sensitization. Ara h 1 or Ara h 2 was positive in peanut anaphylaxis patients, whereas Ara h 8 was positive in OAS patients. There were 4 patients with both peanut anaphylaxis and OAS (group 3). Both Ara h 2 and Ara h 8 were positive in these patients. Foods associated with OAS in Korea showed unique patterns compared to Westernized countries. CONCLUSIONS: Ara h 2 and Ara h 8 may be important component allergens for discriminating peanut allergy.

Oral allergy syndrome associated with weed pollinosis

Oral allergy syndrome (OAS) is caused by cross-reactivity between certain pollens and plant foods, including vegetables, nuts, or fruits. Here, we experienced 2 cases of OAS patients associated with mugwort pollinosis without sensitization to Fagales. A 54-year-old female repeatedly experienced skin rashes, perioral edema, nasal obstruction after eating fresh vegetables (celery, lettuce, chicory, radish sprouts, ginseng, etc.). She had suffered from allergic rhinitis worsening in autumn for 5 years. Specific IgE (sIgE) titers to ragweed and mugwort were elevated to 54.1 and 24.9 kU/L, respectively. With regard to the allergen component of pollens, sIgE to Art v 1 (mugwort) and Amb a 1 (ragweed) were elevated to 21.9 and 36.1 kU/L, respectively. Birch sIgE (including Bet v 1 and Bet v 2) was not detected. A 35-year-old male suffered from abdominal pain, skin rashes after eating mango and kiwi. In addition, systemic allergic reaction developed after consumption of tomato and ginseng. He had chronic rhinitis. The sIgE levels to ragweed, mugwort, and tomato were elevated to 0.55, 6.39, and 0.78 kU/L, respectively. The sIgE test results were all negative for Amb a 1, Bet v 1, and Bet v 2 sIgE. Specific IgE levels to Art v 1, Art v 2 sIgE were 3.51 and 4.46 kU/L, respectively. Based on the history and sIgE test results, 2 cases OAS were related to mugwort. We experienced 2 cases of weed pollinosis related to OAS. Culprit foods of OAS can vary depending on their cuisine cultures.