Cross-reactive LTP sensitization in food-dependent exercise-induced urticaria/anaphylaxis: a pilot study of a component-resolved and in vitro depletion approach

Food-Dependent Exercise-Induced Wheals, Angioedema, and Anaphylaxis: A Systematic Review

BACKGROUND

Food-dependent exercise-induced wheals, angioedema, and anaphylaxis remain insufficiently characterized.

OBJECTIVE

We systematically reviewed the literature on clinical manifestations, laboratory investigations, culprit foods, triggering exercise, comorbidities, and treatment outcomes.

METHODS

Using predefined search terms and Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations, we searched 3 electronic databases to identify relevant literature published before July 2021.

RESULTS

Of 722 patients (median age 25 years; 55.4% male) from 231 studies (43 cohort studies, 15 cases series, and 173 case reports), 79.6% and 3.7% had anaphylaxis with and without wheals and/or angioedema, respectively. The remaining 16.6% had wheals and/or angioedema without anaphylaxis. The duration from eating to exercising and from exercising to symptom onset ranged from 5 minutes to 6 hours (median 1 hour) and from 5 minutes to 5 hours (median 30 minutes), respectively, and virtually all patients exercised within 4 hours after eating and developed symptoms within 1 hour after exercising. Wheat was the most common culprit food. Running was the most common trigger exercise. Most patients were atopic, and 1 in 3 had a history of urticaria. Aspirin and wheat-based products were the most frequent augmenting factors. On-demand antihistamines, corticosteroids, and epinephrine were commonly used and reported to be effective. Patients who stopped eating culprit foods before exercise no longer developed food-dependent exercise-induced allergic reactions.

CONCLUSIONS

Food-dependent exercise-induced allergic reactions are heterogeneous in their clinical manifestations, triggers, and response to treatment. Patients benefit from avoidance of culprit foods before exercise, which highlights the need for allergological diagnostic workup and guidance.

Lipid transfer protein allergy: A review of current controversies

Sensitization to lipid transfer protein (LTP), the most frequent cause of food allergy in southern Europe, still shows several controversial, but also intriguing, aspects. Some of these include the degree of cross-reactivity between LTPs from botanically distant sources, the definition of risk factors, the role of some cofactors, clinical outcomes, geographical differences and the identification of the primary sensitizer in different areas. This review article tries to analyse and comment on these aspects point by point suggesting some explanatory hypotheses with the final scope to stimulate critical thoughts and elicit the scientific discussion about this issue in the readership.

Helminth infection induces non-functional sensitization to house dust mites

BACKGROUND

IgE characterizes the humoral response of allergic sensitization but less is known about what modulates its function and why some patients present clinical symptoms for a given IgE level and others do not. An IgE response also occurs during helminth diseases, independently of allergic symptoms. This response could be a model of non-functional IgE.

OBJECTIVE

To study the IgE response against environmental allergens induced during natural helminth infection.

METHODS

In 28 non allergic subjects from the periphery of Ho Chi Minh city with (H+, n = 18) and without helminth infection (H-, n = 10), we measured IgE and IgG4 against several components of Dermatophagoïdes pteronyssinus (Dpt) and Ascaris (a marker of immunization against nematodes), and determined the IgE component sensitization profile using microarray ISAC biochips. The functional ability of IgE to induce degranulation of cultured mast cells was evaluated in the presence of Dpt.

RESULTS

Non allergic H+ subjects exhibited higher levels of IgE against Dpt compared to H- subjects. Dpt IgE were not functional in vitro and did not recognize usual Dpt major allergens. IgE recognized other component allergens that belong to different protein families, and most were glycosylated. Depletion of IgE recognizing carbohydrate cross-reactive determinant (CCD) did not induce a reduction in Dpt IgE. The Dpt IgG4 were not significantly different.

CONCLUSION

Helminth infections induced IgE against allergens such as Dpt and molecular components that belong to different sources as well as against CCD (such as β-1,2-xylose and/or ⍺-1,3-fucose substituted N-glycans). Dpt IgE were not able to induce degranulation of mast cells and were not explained by sensitization to usual major allergens or N-glycans.

Diagnosis and prevention of food-dependent exercise-induced anaphylaxis

Introduction: Food-dependent, exercise-induced anaphylaxis (FDEIA) is a rare type of anaphylaxis with a growing incidence. Although the precise mechanism by which the patient reacts only in a combination of a culprit food and cofactors are not currently understood, many advances in diagnosis and management have been made since their first description. Areas covered: A literature search in PubMed was performed to review the diagnosis and management of FDEIA. Clinicians should have a high level of suspicion for identification of the culprit foods and the cofactors involved. Component-resolved diagnosis and more accurate provocation tests have revolutionized the diagnosis accuracy. Management is not easy and involves educating the patient to evict the combination of exposure to the culprit foods and the cofactors that elicit anaphylaxis, and how to act and treat if a reaction occurs. Expert opinion: FDEIA is currently misdiagnosed and the authors believe that there are many FDEIA patients labelled as idiopathic anaphylaxis with unnecessary evictions and with a poor quality of life because of the fear of an imminent reaction. Due to recent advances in diagnostic tools and the use of monoclonal antibodies for prophylaxis in persistent cases, FDEIA can have a better prognosis improving the quality of life of the patients and their families.

How to manage food dependent exercise induced anaphylaxis (FDEIA)

PURPOSE OF REVIEW

In recent years, the number of reports on food-dependent exercise-induced anaphylaxis (FDEIA) has been increasing. This review aims to describe the standard management of FDEIA including provocation tests and identify the issues that remain unclear.

RECENT FINDINGS

Provocation tests with aspirin for FDEIA enable us to confirm the definitive diagnosis and to make differential diagnosis. In some cases, FDEIA symptoms can be induced by aspirin and the causative food without exercise. Exercise may only be an augmenting factor of FDEIA, similar to aspirin or alcohol.

SUMMARY

The mechanisms of FDEIA development remain unclear. It has been suggested that in FDEIA, exercise lowers the threshold of a food allergy. Further research is needed to elucidate the mechanism of FDEIA and to establish strategies for effective disease management.

Component-resolved diagnosis in allergic disease: Utility and limitations

Component resolved diagnosis (CRD) is a microarray-based diagnostic solution capable of simultaneously analysing specific IgE antibodies against 112 allergenic components, providing sensitivity patterns for multi-sensitised or complex patients. The CRD is indicated for these patients, especially those with concomitant respiratory and food allergies. This study reivews the method, its utility, limitations, and our experience in allergic diseases with difficult etiologic diagnosis (eosinophilic esophagitis, occupational asthma and drug allergy).