Kyohei Takahashi

Reactions of Buckwheat-Hypersensitive Patients during Oral Food Challenge Are Rare, but Often Anaphylactic

Background: Buckwheat (BW) is a common cause of life-threatening allergy in Asia. Few have examined oral food challenges (OFCs) using BW. We here describe the OFC outcomes for the diagnosis or confirmation of tolerance acquisition and clarify risk factors for positive OFCs. Methods: Between July 2005 and March 2014, we retrospectively reviewed data from children who underwent OFCs using 3,072 mg of BW protein at Sagamihara National Hospital. Children were suspected of having BW allergy because of positive results for BW-specific IgE or because they had been previously diagnosed with BW allergy owing to immediate reactions to BW. Results: Of 476 such patients, we analyzed 419 aged 1-17 years (median age 6.7 years). Forty-four (10.5%) reacted to the BW OFC and 24 (54.5%) experienced anaphylaxis. Among patients with suspected BW allergies (n = 369), 30 (8.1%) reacted to OFC. However, among patients with definitive BW allergies (n = 50) who underwent OFCs a median of 7.0 years after their last immediate reaction, 14 (28.0%) reacted to OFC. Among 12 patients with past anaphylactic reactions to BW, 8 exhibited tolerance to BW. A history of immediate reaction to BW and high BW-specific IgE levels were significant risk factors for a positive OFC. Conclusions: BW allergies are rare among children suspected of having BW allergies due to positivity for BW-specific IgE. Most children with definitive BW allergies can tolerate BW, even after anaphylactic reactions. Nevertheless, careful observation is needed when performing BW OFCs, considering the high incidence of anaphylactic reactions.

Increasing specific immunoglobulin E levels correlate with the risk of anaphylaxis during an oral food challenge

Oral food challenges (OFCs) are necessary to diagnose food allergies; however, these tests can cause anaphylaxis. Higher specific immunoglobulin E (sIgE) levels to causative food have been associated with a positive OFC. To date, no data have been found to indicate the factors associated with severe symptoms or anaphylaxis among challenge‐positive patients. This study aimed to clarify the association of sIgE with causative foods and anaphylaxis during OFC among the whole study population and challenge‐positive patients.

Salmon roe-specific serum IgE predicts oral salmon roe food challenge test results.

cutoffs in all the hazelnut-tolerant children. Unfortunately, the prick-to-prick method has not been properly standardized and there may be a significant inter-operator variability. Although promising, our results need to be interpreted bearing in mind that they come from a tertiary referral highly selected population of children sensitized to hazelnut, in most cases with concomitant food allergies. Caution is therefore needed before extending our considerations to other clinical settings. In conclusion, our study showed that the component Cor a 14 can play an important part in identifying Italian children with symptomatic hazelnut allergy. The simultaneous presence of Cor a 14-specific IgE and prick-to-prick test positivity might possibly even further improve the accuracy of the former as a predictor of symptomatic hazelnut allergy.

Risk Factors and Clinical Features in Cashew Nut Oral Food Challenges

Background: Cashew nuts (CN) are capable of causing severe allergic reactions. However, little has been reported about the details of CN oral food challenges (OFC). Methods: CN-specific IgE (sIgE) levels were measured for 1 year in 66 patients who underwent an OFC with >3 g CN for diagnosis or confirmation of tolerance acquisition between June 2006 and August 2014. We retrospectively analyzed the OFC and patient background. Results: The median (IQR) age of the 66 patients (48 boys/men and 18 girls/women) was 7.0 years (5.7-8.8). Twelve patients (18.2%) had a positive OFC result; 6 of 8 (75%) patients with a history of an immediate reaction to CN failed the OFC. Anaphylaxis was experienced by 5 of these 12 (42%) patients. A history of an immediate reaction to CN and the CN sIgE levels were significantly different for patients with a positive or negative OFC result (p < 0.01). Among patients without a previous immediate reaction to CN, the 95% positive predictive value (PPV) for the CN sIgE level for a positive OFC result was 66.1 kUA/L. Conclusions: A history of an immediate reaction to CN and high CN sIgE were risk factors for a positive OFC result. The number of positive OFC results was relatively low, but there was a high probability of anaphylaxis. We should consider the indication of OFC carefully for patients with a history of immediate reactions to CN and avoid OFC for patients without such a history whose CN sIgE values are >66.1 kUA/L (95% PPV).

Specific IgE for Fag e 3 Predicts Oral Buckwheat Food Challenge Test Results and Anaphylaxis: A Pilot Study

Background: Buckwheat (BW) is the source of a life-threatening allergen. Fag e 3-specific serum IgE (sIgE) is more useful than BW-sIgE for diagnosis; however, it is unknown whether Fag e 3-sIgE can predict oral food challenge (OFC) results and anaphylaxis. This study aimed to clarify the efficacy of Fag e 3-sIgE in predicting OFC results and anaphylaxis. Methods: We conducted a retrospective review of BW- and Fag e 3-sIgE data obtained using the ImmunoCAP® assay system and fluorescent enzyme-linked immunosorbent assay from children who underwent OFC using 3,072 mg of BW protein between July 2006 and March 2014 at Sagamihara National Hospital, Kanagawa, Japan. Results: We analyzed 60 patients aged 1.9–13.4 years (median 6.0 years); 20 (33%) showed objective symptoms upon BW OFC. The patients without symptoms had significantly lower Fag e 3-sIgE than those with non-anaphylactic (p < 0.001) and anaphylactic reactions to BW (p = 0.004). Fag e 3-sIgE was the only tested factor that significantly predicted positive OFC results (odds ratio 8.93, 95% confidence interval 3.10–25.73, p < 0.001) and OFC-induced anaphylaxis (2.67, 1.12–6.35, p = 0.027). We suggest that a threshold Fag e 3-sIgE level of 18.0 kUE/L has 95% probability of provoking a positive reaction to BW. Conclusions: Fag e 3-sIgE predicted OFC results and OFC-induced anaphylaxis. We further emphasize paying careful attention to the risk of BW OFC-induced anaphylaxis.

Measurement of Exhaled Nitric Oxide in Children: A Comparison Between NObreath® and NIOX VERO® Analyzers

Purpose Few studies have compared fractional exhaled nitric oxide (FeNO) measurement by NIOX VERO® (NOV) and other devices in children. Moreover, there is no agreement between differences in FeNO values obtained using different devices in adults. Here, we compared FeNO values obtained using NOV and NObreath® (NOB) systems to derive a correction equation for children. Methods Eighty-eight participants (age 7–15 years) who were diagnosed with atopic bronchial asthma and visited Sagamihara National Hospital as outpatients between January and April of 2017 were included. We measured FeNO values obtained using NOB and NOV, and analyzed them using Wilcoxon tests and Altman-Bland plots. Results The median age of the participants was 11.5 years, and the scored Asthma Control Test (ACT) or Childhood ACT (C-ACT) was 25 (interquartile range, 24–25) or 26 (24–27). NOB and NOV values were significantly different (31 [14–52] versus 36 [20–59] ppb; P = 0.020) and strongly correlated (r = 0.92). An equation to convert NOB values into NOV values was derived using linear regression as follows: log NOV = 0.7329 × log NOB + 0.4704; NOB for 20, 40, 58, 80 and 100 ppb corresponded to NOV for 27, 44, 59, 73 and 86 ppb. Thus, NOB < 58 ppb suggested NOB < NOV, whereas NOB > 58 ppb suggested NOB > NOV. Conclusions NOB and NOV values were strongly correlated. Participants whose FeNO values were relatively low represented NOB < NOV, whereas those whose FeNO values were relatively high represented NOB > NOV.

Negative Act d 8 indicates systemic kiwifruit allergy among kiwifruit-sensitized children.

Kiwifruit allergy appears to be increasing (1). Symptoms of kiwifruit allergy vary from localized oral symptoms to life-threatening anaphylaxis (2, 3). Kiwifruit allergy is generally diagnosed based on medical history, positive specific immunoglobulin E (IgE) to kiwifruit, and oral food challenge (OFC). It is important to identify biomarkers to differentiate severe symptoms from localized oral symptoms. However, commercially available in vitro tests for specific IgE antibodies to crude kiwifruit extracts cannot predict severe kiwifruit allergy (4, 5). Although the prick by prick test has high sensitivity, it has low specificity and cannot predict severe symptoms (2). This article is protected by copyright. All rights reserved.