Abstract
BACKGROUND: The clinical importance of sensitization to Arachis hypogaea 6 (Ara h 6) in Japanese children remains unelucidated. We aimed to quantitatively evaluate the clinical importance of sensitization to Ara h 6 in managing peanut allergy in Japanese children. METHODS: We retrospectively analyzed the data of children with or without symptoms induced by an oral food challenge or home dosing of up to 3 g of peanuts. The specific immunoglobulin E (sIgE) levels against peanuts, Ara h 2, and Ara h 6 were quantified using an ImmunoCAP assay. RESULTS: We examined 273 patients aged 4.6-9.8 years (median 6.3); 189 (69%) were male, 187 (68%) had allergies to peanuts, and 43 (16%) had anaphylactic reactions to peanuts. Ara h 6 and Ara h 2 co-sensitization was observed in 224 patients (82%). Ara h 6-sIgE levels were significantly associated with the probability of allergic reactions and anaphylaxis. The 95% probability of allergic reactions to peanuts was obtained at 44.5 kU(A)/L of Ara h 6-sIgE, but the 95% probability of anaphylaxis could not be calculated. A combination of Ara h 6 and Ara h 2 could not improve diagnostic accuracy for allergic reactions and anaphylaxis to peanuts. CONCLUSION: Sensitization to Ara h 6 played an important role in managing peanut allergy in Japanese children, and sIgE levels provided valuable predictive information for allergic reactions to peanuts. However, the measurement of Ara h 6 did not improve the diagnostic accuracy of anaphylaxis, and Ara h 2 alone might be sufficient for clinical evaluation in peanut allergy.