Food Specific IgE Levels in Children Should Be Interpreted in Context of Total IgE

Objective: In this study, we: (1) evaluated the correlation between total IgE and the presence of specific IgE; (2) compared the characteristics of patients with positive specific IgE to those with negative specific IgE; and, (3) analyzed the allergic testing results of patients on omalizumab and reported the effect of omalizumab on forced expiratory volume (FEV1) and asthma control test (ACT) results. Methods: Data from patients diagnosed with allergic asthma and seen at Florida Lung, Asthma & Sleep Specialists (FLASS) between January 2016 and June 2019 were analyzed. Parameters evaluated were total IgE, and levels of specific IgE to antigens in the ImmunoCAP test and skin prick test (SPT). Additional parameters for patients on omalizumab therapy for at least 6 months were FEV1, % predicted FEV1 and ACT results. Results: A total of 475 patients (114 males, 361 females) met the inclusion criteria. The mean age was 53 years (range: 17 to 89 years). Of these, 36 patients were not included in the analysis due to incomplete data. Mean total IgE was higher in patients with positive ImmunoCAP results compared to those with negative results (396 KU/L vs. 81.3 KU/L). There was a significant positive correlation between total IgE and levels of positive specific IgE in the ImmunoCAP test (p<0.0001, r=0.36, n=213 patients). The correlation between total IgE and levels of positive allergens in SPT was not significant (p=0.15, n=44 patients) Two positive reactions to allergens were seen in 22% of ImmunoCAP tests and 13% of SPT tests. There was no statistically significant improvement in FEV1 (p=0.097, CI -0.17 to 0.02) and % predicted FEV1 (p=0.109, CI -6.63 to 0.70) in patients who used omalizumab for at least 6 months. There was a statistically significant improvement in ACT scores (p=0.031, CI -4.21 to -0.21) in patients who used omalizumab for at least 6 months. Conclusion: Allergic asthma could be seen in patients who had an absence of specific IgE in ImmunoCAP and a negative reaction to SPT. The benefit of omalizumab therapy is not limited to allergic asthma patients with positive specific IgE.

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Addressing Common Misconceptions in Food Allergy: A Review

Children ◽

10.3390/children8060497 ◽

2021 ◽

Vol 8 (6) ◽

pp. 497

Author(s):

Aikaterini Anagnostou

Keyword(s):

Food Allergy ◽

The United States ◽

Specific Ige ◽

Oral Immunotherapy ◽

Food Allergies ◽

Allergy Prevention ◽

Diagnosis And Management ◽

Skin Prick Tests ◽

Food Specific Ige ◽

Common Misconceptions

Background: Food allergies are common, affecting 1 in 13 school children in the United States and their prevalence is increasing. Many misconceptions exist with regards to food allergy prevention, diagnosis and management. Objective: The main objective of this review is to address misconceptions with regards to food allergies and discuss the optimal, evidence-based approach for patients who carry this diagnosis. Observations: Common misconceptions in terms of food allergy prevention include beliefs that breastfeeding and delayed introduction of allergenic foods prevent the development of food allergies. In terms of diagnosis, statements such as ‘larger skin prick tests or/and higher levels of food-specific IgE can predict the severity of food-induced allergic reactions’, or ‘Tryptase is always elevated in food-induced anaphylaxis’ are inaccurate. Additionally, egg allergy is not a contraindication for receiving the influenza vaccine, food-allergy related fatalities are rare and peanut oral immunotherapy, despite reported benefits, is not a cure for food allergies. Finally, not all infants with eczema will develop food allergies and epinephrine auto-injectors may unfortunately be both unavailable and underused in food-triggered anaphylaxis. Conclusions and relevance: Healthcare professionals must be familiar with recent evidence in the food allergy field and avoid common misunderstandings that may negatively affect prevention, diagnosis and management of this chronic disease.

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Food antigen-specific IgE in dogs with suspected food hypersensitivity

Tierärztliche Praxis Ausgabe K Kleintiere / Heimtiere ◽

10.1055/a-1274-9210 ◽

2020 ◽

Vol 48 (06) ◽

pp. 395-402

Author(s):

Sandra A. Baumann ◽

Cornelius Fritz ◽

Ralf S. Mueller

Keyword(s):

Clinical Relevance ◽

Specific Ige ◽

Elimination Diet ◽

Cross Reactivity ◽

Food Hypersensitivity ◽

Strong Correlations ◽

Odds Ratios ◽

Cross Reactions ◽

Ige Reactivity ◽

Food Specific Ige

Abstract Objective Knowledge of cross-reactions in food-sensitive dogs will influence the choice of elimination diets and the long-term management of those patients. The objective of this study was to evaluate food allergen-specific IgE tests of suspected allergic dogs for concurrent positive reactions as possible evidence for cross reactions between allergens. Material and methods Results of serum IgE tests from 760 suspected allergic dogs submitted to 2 laboratories were evaluated statistically. After the tested allergens were grouped by their phylogenetic relationship, odds ratios as well as a sensitivity analysis of the odds ratios were performed to evaluate if concurrent positive IgE results to 2 allergens occurred more often than expected. Results Within related allergen pairs 27% (laboratory 1) and 72% (laboratory 2) of the pairs could be considered as associated. For the unrelated allergen pairs only 6.8% and 10.6% of the analyzed pairs were considered associated respectively. Strong correlations were shown in the group of ruminant allergens, especially beef and lamb, and grain allergens. High rates of concurrent reactions were also detected in the poultry group, especially between chicken and duck, as well as between pork and ruminant allergens, and soy and grain allergens. Conclusion As our results showed not only correlations within related but also between non-related allergens, the possible relevance of carbohydrate moieties as well as panallergens for canine hypersensitivities warrants further study. Further investigations are necessary to distinguish co-sensitization from cross-reactions and determine the clinical relevance of food-specific IgE reactivity. Clinical relevance Due to possible cross reactivity related allergens, especially beef and lamb as well as grain allergens, should not be used for an elimination diet to avoid false results.

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