Cross-reactivity of each fraction among cereals in children with wheat allergy

Background: Cross-reactivity between wheat and other cereals is an essential issue in the management of wheat allergy. Few studies have reported in vitro cross-reactivity in immediate-type wheat allergy. This study aimed to examine cross-reactivity of the three fractions (albumin/globulin, gliadin, and glutenin fractions) among cereals in children with wheat allergy. Methods: Sera from 128 children with immediate-type wheat allergy were collected. We measured specific immunoglobulin E (sIgE) levels against each fraction of wheat, barley, and rye by using an enzyme-linked immunosorbent assay (ELISA). Cross-reactivities of each fraction among wheat, barley, and rye were examined via inhibition ELISA. Results: All subjects were sensitized to all the fractions of wheat, and also those of barley and rye. The wheat sIgE levels were significantly higher than those of barley and rye in all the fractions (p ≤ 0.001) and were significantly correlated with sIgE levels to them in each fraction (r = 0.887–0.969, p < 0.001). On inhibition ELISA, wheat inhibited the IgE binding to most of the solid phases at the lower protein levels compared to barley and rye in all fractions. Conclusions: In children with immediate-type wheat allergy, sensitization to all the three fractions of wheat was observed. In addition, they showed sensitization to barley and rye caused by in vitro cross-reactivity with wheat in each fraction. When managing children with wheat allergy, sensitization to barley and rye caused by the cross-reactivities should be considered.

A Simple and Rapid Light-Initiated Chemiluminescence Assay for Quantitation of Artemisia-Specific Immunoglobulin E

<b><i>Background:</i></b> Light-initiated chemiluminescence assay (LICA) is a homogeneous assay that has been successfully used for the quantitation of food allergen-specific immunoglobulin E (sIgE), but not inhaled allergen-sIgE. Simultaneously, current assays used to detect allergen-sIgE are serum consuming and/or time consuming. Hence, we established a method for the quantitation of <i>Artemisia</i>-sIgE based on LICA and verified its performance according to the clinical guideline documents, laying a foundation for the quantitation of inhaled and food allergen-sIgE in parallel on LICA. <b><i>Methods:</i></b> The assay was established after optimizing the first incubation time and the dilutions of <i>Artemisia</i>-coated chemibeads, biotinylated goat anti-human IgE, and serum. In order to quantitate <i>Artemisia</i>-sIgE, the calibration curve was established with a high positive serum of known concentration. The assay performance was confirmed per the clinical guideline documents. In addition, the correlation between the results of LICA and capture enzyme-linked immunosorbent assay was evaluated. <b><i>Results:</i></b> The developed LICA’s coefficients of variation of repeatability and intermediate precision were 3.20%, 2.14%, and 3.85% and 4.30%, 4.00%, and 4.40%, respectively. The limit of detection was 0.10 kU_A/L, and the limit of quantitation was 0.11 kU_A/L. The range of linearity was from 0.27 kU_A/L to 97.53 kU_A/L (<i>r</i> = 0.9968). The correlation coefficient (<i>r</i>) for the correlation analysis between results of LICA and capture ELISA was 0.9087. This assay was successfully applied in 64 human serum samples, showing good sensitivity (82.20%) and specificity (100%). <b><i>Conclusion:</i></b> An <i>Artemisia</i>-sIgE quantitation assay based on LICA was successfully established. Its performance satisfied the clinical requirements and could be widely used in clinical laboratories.

The influence of acetylsalicylic acid and alcohol on absorption kinetics of hen ́s egg white in a human passive cutaneous anaphylaxis model

Background: Despite the well-known fact that acetylsalicylic acid (ASA) can induce anaphylaxis in patients susceptible to wheat-dependent exercise-induced anaphylaxis, few studies have sought to investigate the effects of cofactors on type-1 food allergy and none with ASA and hen’s egg and hen’s egg and alcohol combined. Methods and results: We applied the experimental model of ‘passive cutaneous anaphylaxis’ in humans to study whether the absorption kinetics of egg white is altered while being treated with ASA or under the influence of alcohol. Donor sera from four egg allergic patients with specific immunoglobulin E (s-IgE) to ovalbumin (0.1–8.87–19.5–170 kUA/L) were injected intracutaneously into the forearm of 12 healthy volunteers who were then challenged separately to: 1) egg white 2) egg white + ASA and 3) egg white + alcohol. ‘Time to wheal’ and ‘wheal size’ were compared among the three experiments. We saw that ‘time to wheal’ with both ASA (P = 0.001) and alcohol (P = 0.019) added as cofactor significantly decreased compared with baseline. Conclusion: In this passive cutaneous anaphylaxis model, ASA and alcohol affected both reaction time and size of reactions elicited after egg ingestion. This suggests that patients with egg allergy could have faster and more severe reactions during ASA treatment or under alcohol influence.

Pulmonary eosinophilia may indicate onset stage of allergic bronchopulmonary aspergillosis

Background Allergic bronchopulmonary aspergillosis (ABPA) and chronic eosinophilic pneumonia (CEP) both display peripheral eosinophilia as well as pulmonary infiltration, together described as pulmonary eosinophilia, and differentiation is sometimes problematic. This study therefore examined the distinctions between ABPA with and without CEP-like shadows. Methods This retrospective cohort study from a single center included 25 outpatients (median age, 65 years) with ABPA diagnosed between April 2015 and March 2019, using criteria proposed by the International Society of Human and Animal Mycology (ISHAM), which focuses on positive specific IgE for Aspergillus fumigatus. Patients were assigned to either the eosinophilic pneumonia (EP) group or Non-EP group, defined according to findings on high-resolution computed tomography (HRCT). The EP group included patients with HRCT findings compatible with CEP; i.e., the presence of peripheral consolidation (p-consolidation) or ground-glass opacities (GGO), with no evidence of high-attenuation mucus. The Non-EP group comprised the remaining patients, who showed classical findings of ABPA such as mucoid impaction. Differences between the groups were analyzed. Results Baseline characteristics, frequency of a history of CEP (EP, 50% vs. Non-EP, 26%) and tentative diagnosis of CEP before diagnosis of ABPA (67% vs. 16%) did not differ significantly between groups. Although elevated absolute eosinophil count and Aspergillus-specific immunoglobulin E titers did not differ significantly between groups, the Non-EP group showed a strong positive correlation between these values (R = 0.7878, p = 0.0003). The Non-EP group displayed significantly higher levels of the fungal marker beta-D glucan (median, 11.7 pg/ml; interquartile range, 6.7–18.4 pg/ml) than the EP group (median, 6.6 pg/ml; interquartile range, 5.2–9.3 pg/ml). Both groups exhibited frequent recurrence of shadows on X-rays but no cases in the EP group had progressed to the Non-EP group at the time of relapse. Conclusions The ABPA subgroup with imaging findings resembling CEP experienced frequent recurrences, as in typical ABPA. In pulmonary eosinophilia, even if there are no shadows indicating apparent mucous change, the Aspergillus-specific immunoglobulin E level is important in obtaining an accurate diagnosis and in the selection of appropriate therapies for this type of ABPA.

Legume and sesame oral food challenge outcomes

Background: Legume and sesame are emerging food allergens. The utility of specific immunoglobulin E (sIgE) testing to predict clinical reactivity to these allergens is not well described. Objective: To describe clinical outcomes and sIgE in sesame and legume oral food challenges (OFC). Methods: We performed a retrospective review of 74 legume and sesame OFCs between 2007 and 2017 at the Ann and Robert H. Lurie Children’s Hospital of Chicago. Clinical data, OFC outcome, and sIgE to legume and sesame were collected. Receiver operating characteristic curves and logistic regression models that predicted OFC outcome were generated. Results: Twenty-eight patients (median age, 6.15 years) passed legume OFC (84.9%), and 25 patients (median age, 5.91 years) passed sesame OFC (61.0%). The median sIgE to legume was 1.41 kUA/L and, to sesame, was 2.34 kUA/L. In patients with failed legume OFC, 60.0% had cutaneous symptoms, 20.0% had gastrointestinal symptoms, and 20.0% had anaphylaxis. Of these reactions, 80.0% were controlled with antihistamine alone and 20.0% required epinephrine. In patients for whom sesame OFC failed, 50.0% had cutaneous symptoms, 12.5% had gastrointestinal symptoms, and 37.50% had anaphylaxis. Of these reactions, 6.3% required epinephrine, 31.3% were controlled with diphenhydramine alone, and 63.50% required additional epinephrine or prednisone. Conclusion: Most OFCs to legumes were passed and reactions to failed legume OFCs were more likely to be nonsevere. Sesame OFC that failed was almost twice as likely compared with legume OFC that failed, and reactions to sesame OFC that failed were often more severe. Sesame sIgE did not correlate with OFC outcome.