Evolution of Food Protein-Induced Enterocolitis Syndrome (FPIES) Index Trigger Foods and Subsequent Reactions After Initial Diagnosis

Association of myeloid cell reactivity patterns with safe food predictions in FPIES patients

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is an understudied non-IgE-mediated food allergy, which is distinct from and lacks diagnostic testing akin to IgE testing. FPIES affects infants and toddlers but can persist into adulthood. As there are no extant methods to identify safe foods for FPIES patients, food ingestion trials are performed at home and often lead to reactions and development of food aversions, which may lead to failure-to-thrive and gastric feeding tube requirements. We hypothesized that foods that fail to elicit responses in immune cells of FPIES patients would be safe to ingest, which could support development of a diagnostic method to headstart safe food identification in patients.

METHODS

We developed an ex vivo model of FPIES using food-stimulated white blood cells (WBCs) from pediatric FPIES patients and controls by defining a 9-gene panel representative of FPIES ex vivo responses and conducted a single-arm pilot clinical trial.

RESULTS

Myeloid cells of FPIES patients displayed variable individual-specific myeloid cell reactivity patterns (iMCRPs) to different foods. Foods that failed to elicit repsonses in patients' immune cells were safe to ingest with a negative predictive value of 98.5%. This, when utilized in prospective predictions, reduced newly introduced food reaction rates from 19.5 to 0% while increasing food repertoire diversity.

CONCLUSIONS

iMCRPs represent a novel and potentially useful tool that associates with safe food ingestion in FPIES patients for foods that fail to elicit immune cell reactions. Trial Registration The trial has been registered at registered at ClinicalTrials.gov # NCT04644783.

Food allergy endotypes revisited

In the last century, food allergy has become recognized as an increasingly prevalent and heterogeneous condition. Advances in biomedical technology have revealed complex genetic, environmental, immune, and metabolic pathways underlying the pathogenesis of food-allergic disorders. These findings permit classification of distinct food allergy endotypes with unique pathophysiologic features. In this review, we suggest that these endotypes of food-allergic disorders should be defined on the basis of (1) whether or not the allergic antibody IgE plays an essential role in disease pathogenesis, (2) the molecular features of the allergen (protein vs carbohydrate), and (3) the molecular markers associated with prognosis, severity, or clinical presentation. Beyond these broad categories, additional subtypes with unique mechanistic characteristics are discussed.

Severity Trend of Recurrence in Pediatric Food Protein-Induced Enterocolitis Syndrome

BACKGROUND

Reintroduction of the offending food in pediatric patients affected by food protein-induced enterocolitis syndrome (FPIES) is carried out in hospitals with an oral food challenge (OFC), which leads to a long waiting time and increases the societal burden of medical cost and human resources.

OBJECTIVE

To assess the severity trend of acute FPIES adverse reactions over time in the same patient for possible outpatient or home reintroduction of the offending food.

METHODS

All children (aged <18 years) with a diagnosis of acute FPIES referred to two Italian pediatric allergy clinics were retrospectively enrolled. To determine whether home or outpatient clinic reintroduction of trigger food was possible, a risk of severe reactions of 5% or less was arbitrarily considered acceptable.

RESULTS

Of202 patients enrolled, 23 (11.4%) had increasing severity from mild to moderate up to severe episodes. No variables analyzed in these patients (sex, age at onset, and the interval between the first and severe episodes) had a statistically significant influence on the risk of more severe reactions. Of all patients who initially presented with mild or moderate episodes, 15.2% and 13.9% later manifested severe episodes over time, respectively. Of patients with cow's milk FPIES that started with a mild episode, 5.5% later experienced a severe episode.

CONCLUSIONS

Performing OFC for acute FPIES is not safe enough at home because the probability of severe adverse reaction is greater than 5%. However, it could be considered to perform OFC in an outpatient clinic in patients with cow's milk FPIES who started with a mild episode and if a rapid transfer plan to emergency department is available.

Cost-effectiveness of shared decision-making in determining challenge setting for nonsevere food protein-induced enterocolitis syndrome

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) affects approximately 0.5% of US children. Oral food challenges (OFCs) are frequently conducted to assess FPIES resolution in an observed setting, given the risk of severe reactions. However, it is unclear whether the observed OFC is universally cost-effective in all contexts vs gradually titrated home OFCs when caregivers are willing to accept a risk-to-benefit tradeoff.

OBJECTIVE

To characterize the health and economic benefits of at-home vs supervised reintroduction OFC in patients with a history of mild-moderate index FPIES.

METHODS

Cohort analyses evaluated the cost-effectiveness of a gradually titrated home vs clinical or hospital OFC using population simulations (n = 200,000 patients) and simulations in a rural New England population (n = 105). Severe FPIES reactions were defined as necessitating intravenous fluids. Fatality rates were defined as occurring approximately in 1/1,000,000 FPIES OFCs. Motor vehicle fatality rates were applied based on the travel distance to the OFC site. The cost-effectiveness threshold was set at $10,000,000 per fatality prevented.

RESULTS

In the population simulation, the supervised OFC costs reached $411,088,445, with 18,680 severe reactions occurring (per-patient mean 0.093, SD 0.025), at a cost-per-fatality prevented of $124,233,328. In a simulation of a rural New England population with FPIES, the cost per severe reaction ranged from $11,790 to $46,304.

CONCLUSION

A requirement for universally conducting FPIES challenges in an office-based or in-hospital setting is not cost-effective given extremely low FPIES reaction fatality rates, especially when compared with travel-based motor vehicle fatality rates. A shared decision-making approach may be appropriate to determine the challenge setting for patients with lower risk of severe reactions.

Current status and future directions in food protein-induced enterocolitis syndrome: An NIAID workshop report of the June 22, 2022, virtual meeting

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food allergy characterized by delayed, protracted vomiting and accompanied by lethargy and pallor, usually 1 to 4 hours after ingesting the food allergen. The pathophysiology of FPIES remains unknown, and currently there are no diagnostic biomarkers available to assess disease activity or its resolution. Over the last 2 decades, FPIES has become increasingly recognized in both pediatric and adult patients. Forty years after the initial FPIES description, the first FPIES code appeared in the International Classification of Diseases, Tenth Revision (ICD-10), and the first international consensus guidelines for the diagnosis and management of FPIES were published. On June 22, 2022, the National Institute of Allergy and Infectious Diseases (NIAID) held its first virtual multidisciplinary workshop on FPIES. Various clinical and translational aspects of FPIES as well as important areas of unmet needs were discussed as priorities for future research during this 2-day virtual workshop. Our report provides a summary of content of the workshop, including updated literature on the topic areas, and also provides critical commentary on the state of FPIES.

Food protein induced enterocolitis syndrome: French practices assessment in children

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a specific non IgE-mediated food allergy. The international consensus guidelines defined diagnosis criteria and management plan in 2017.

OBJECTIVES

To assess practices regarding FPIES in France and in French-speaking countries, according to those guidelines.

METHODS AND SETTING

We carried out a 22-question online survey to assess practices of specialised physicians (paediatricians, allergists, gastroenterologists, members of 2 French-speaking learning societies and/or working at hospitals in paediatric allergy units) following patients with FPIES between August 2019 and February 2022.

RESULTS

We received 92 replies to our survey, mostly from hospital practitioners following less than 10 patients with FPIES. Oral rehydration solution and/or Ondansetron were largely prescribed in the emergency kit (61/72, 84.7 % and 47/72, 65.3 % respectively). 20 practitioners declared never prescribing an emergency kit. There was some confusion when distinguishing between FPIES and an IgE-mediated food allergy, as suggested by the unnecessary prescription of an antihistamine (18/72, 25.0 %) and/or epinephrine (11/72, 15.3 %) in the emergency kit. An explanatory FPIES emergency management letter to physicians in case of allergic reactions was provided in 83.7 % (77/92) of patients. Oral food challenge (OFC) practices varied greatly concerning doses: most respondents used several doses (52/92, 56.5 %) during the same day (33/52, 63.4 %). Eleven responders (12.0 %) used the same protocol as for an IgE-mediated food allergy.

CONCLUSION

Our survey showed that practices of FPIES management in France are generally aligned with the international consensus guidelines. There are still pending issues to be standardised, such as the emergency kit prescription and its contents, as well as OFC management strategies. This work confirms the need for continuous training of physicians regarding FPIES management. Further guidelines are needed to improve standardisation of FPIES management.

Contribution of T cell subsets to different food allergic diseases

Food allergies occur due to a lack of tolerance to the proteins found in foods. While IgE- and non-IgE-mediated food allergies have different clinical manifestations, epidemiology, pathophysiology, and management, they share dysregulated T cell responses. Recent studies have shed light on the contributions of different T cell subsets to the development and persistence of different food allergic diseases. This review discusses the role of T cells in both IgE- and non-IgE-mediated food allergies and considers the potential future investigations in this context.

Differences in Characteristics Between Patients Who Met or Partly Met the Diagnostic Criteria for Food Protein-Induced Enterocolitis Syndrome (FPIES)

BACKGROUND

Some patients with food protein-induced enterocolitis (FPIES)-like allergy do not completely fulfill the diagnostic criteria of the international consensus guideline for FPIES. However, it is unclear whether such FPIES-like patients represent a completely different population from FPIES.

OBJECTIVE

This study aimed to clarify differences in characteristics between patients with FPIES who fully met diagnostic criteria and those who partly met them.

METHODS

This was a cross-sectional study using data at the time of registration in multicenter, prospective studies of patients with FPIES in Japan. Children who had delayed emesis within 1 to 4 hours and/or diarrhea within 5 to 10 hours after ingestion of food were recruited between March 2020 and February 2022. We examined their compatibility with the diagnostic criteria of the international consensus guideline and their detailed clinical characteristics, including trigger foods, the serving size that elicited symptoms, and antigen-specific IgE antibody titers.

RESULTS

Of the 225 patients with FPIES, 140 fully met the diagnostic criteria whereas 79 patients did not fully meet them but demonstrated reproducible symptoms. The frequencies of pallor, lethargy, and diarrhea were significantly higher in those who met the criteria fully, whereas the age at onset, trigger foods, comorbidity, and perinatal information were comparable. Analysis of patients with FPIES to hen's egg revealed significantly higher levels of egg white- and egg yolk-specific IgE in patients who partly met criteria, whereas the serving size eliciting symptoms was comparable.

CONCLUSIONS

Patients who partly met the diagnostic criteria may have a milder phenotype of FPIES, but this needs to be validated in further studies using biomarkers reflecting the pathophysiology.

Current and future perspectives on the consensus guideline for food protein-induced enterocolitis syndrome (FPIES)

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy presenting with delayed onset of projectile vomiting in the absence of cutaneous and respiratory symptoms. The pathophysiology of FPIES remains poorly characterized. The first international consensus guidelines for FPIES were published in 2017 and provided clinicians with parameters on the diagnosis and treatment of FPIES. The guidelines have served as a resource in the recognition and management of FPIES, contributing to an increased awareness of FPIES. Since then, new evidence has emerged, shedding light on adult-onset FPIES, the different phenotypes of FPIES, the recognition of new food triggers, center-specific food challenge protocols and management of acute FPIES. Emerging evidence indicates that FPIES impacts both pediatric and adult population. As a result, there is growing need to tailor the consensus guidelines to capture diagnoses in both patient groups. Furthermore, it is crucial to provide food challenge protocols that meet the needs of both pediatric and adult FPIES patients, as well as the subset of patients with atypical FPIES. This review highlights the evolving clinical evidence relating to FPIES diagnosis and management published since the 2017 International FPIES Guidelines. We will focus on areas where recent published evidence may support evolution or revision of the guidelines.

Heterogeneity of food protein-induced enterocolitis syndrome (FPIES)

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with gastrointestinal symptoms such as vomiting and diarrhea. The development of international consensus guidelines for the diagnosis and management of FPIES in 2017 enabled us to compare patients worldwide, regardless of geographic variation in disease features. As a result, it has become clear that there is heterogeneity among patients with FPIES or that there are cases that partly fit the diagnostic criteria for FPIES but have different characteristics. This review highlights the heterogeneity in FPIES characteristics in terms of trigger foods, the age of onset, differences in geographic regions, and symptoms; it further proposes four disease entities, including acute FPIES in children, acute FPIES in adults, chronic FPIES, and early-onset neonatal FPIES, depending on the age of onset and presumed pathophysiology. The major symptoms at onset and trigger foods differ in acute FPIES in children, acute FPIES in adults, and chronic FPIES, whereas the disease entities may share a similar pathophysiology. Early-onset neonatal FPIES may have a different pathophysiology than acute or chronic FPIES, and may not necessarily fulfil the full diagnostic criteria for acute or chronic FPIES described in the international consensus guidelines. Due to the similarity in symptoms, early-onset neonatal FPIES may sometimes be misdiagnosed as necrotizing enterocolitis. We aim to increase awareness of FPIES among medical staff in pediatrics, neonatology, and internal medicine and promote research, to gain a better understanding of the heterogeneity and pathophysiology of FPIES.

Food protein-induced enterocolitis syndrome (FPIES): Beyond the guidelines

Background

Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E (IgE) cell mediated food allergy that can cause severe symptoms and is considered an allergic emergency.

Objective

To describe FPIES epidemiology and appraise the approach to diagnosis and management.

Methods

A review of the relevant articles published in the peer-reviewed journals since the publication of the First International FPIES Consensus Guidelines in 2017.

Results

FPIES is estimated to affect 0.51-0.9% of children and 0.22% of adults in the United States. It typically presents with protracted, projectile vomiting, which occurs within 1-4 hours of ingesting culprit foods, sometimes followed by diarrhea within 24 hours of ingestion. In ∼15-20% of severe cases, patients go into hypovolemic or distributive shock. In chronic FPIES, infants may have failure to thrive and weight loss. The most common triggers include cow's milk, oat, rice, and avocado, with egg and peanut being more frequently reported. Examples of other common fruit and vegetable triggers include banana, apple, and sweet potato. FPIES can be classified into acute, chronic, adult-onset, or atypical subtypes. FPIES is associated with comorbid atopic conditions of IgE-mediated food allergy, atopic dermatitis, asthma, allergic rhinitis, and eosinophilic esophagitis. The natural history of infantile FPIES is generally favorable, with the exception of fish FPIES. Seafood FPIES in adults has low rates of resolution over 3-5 years. Correctly identifying FPIES can be challenging because there are no specific biomarkers for diagnosis and the constellation of symptoms may mimic those of infectious enteritis or sepsis. Management relies on dietary food avoidance, periodic re-evaluations for tolerance with oral food challenges, and management of acute reactions with rehydration and antiemetic ondansetron. Although the pathophysiology of FPIES remains poorly understood, underlying mechanisms such as cytokine release, leukocyte activation, and impaired gastrointestinal mucosal barrier function may act as cornerstones for further research.

Conclusion

Prevention, laboratory diagnostic testing, and strategies to accelerate tolerance development are urgent unmet needs in FPIES.