Gastrointestinal food allergy in infants

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.

Research progress on the mechanism of probiotics regulating cow milk allergy in early childhood and its application in hypoallergenic infant formula

Some infants and young children suffer from cow's milk allergy (CMA), and have always mainly used hypoallergenic infant formula as a substitute for breast milk, but some of these formulas can still cause allergic reactions. In recent years, it has been found that probiotic nutritional interventions can regulate CMA in children. Scientific and reasonable application of probiotics to hypoallergenic infant formula is the key research direction in the future. This paper discusses the mechanism and clinical symptoms of CMA in children. This review critically ex- amines the issue of how probiotics use intestinal flora as the main vector to combine with the immune system to exert physiological functions to intervene CMA in children, with a particular focus on four mechanisms: promoting the early establishment of intestinal microecological balance, regulating the body's immunity and alleviating allergic response, enhancing the intestinal mucosal barrier function, and destroying allergen epitopes. Additionally, it overviews the development process of hypoallergenic infant formula and the research progress of probiotics in hypoallergenic infant formula. The article also offers suggestions and outlines potential future research directions and ideas in this field.

Outcomes and factors associated with tolerance in infants with non-IgE-mediated cow's milk allergy with gastrointestinal manifestations

OBJECTIVES

To evaluate outcomes of oral food challenge (OFC) test to assess tolerance in infants with non-IgE-mediated cow's milk allergy (CMA) with gastrointestinal manifestations and explore clinical data predictive of these outcomes.

METHODS

Single-center retrospective study including infants (age < 12 months) who were referred for CMA between 2000 and 2018 and underwent OFC on follow-up. A univariate logistic regression test was performed to evaluate variables associated with the outcomes of the follow-up OFC test.

RESULTS

Eighty-two patients were included, 50% were male. Eighteen patients had a positive OFC test (22%). Most patients had presented with hematochezia (77%). The median age of symptom onset was 30 days. Two-thirds of the patients were on appropriate infant formula (extensively hydrolyzed or amino acid-based formula), exclusively or in association with breastfeeding. The median time on an elimination diet before the OFC test was 8 months (Q1 6 - Q3 11 months). All cases with positive follow-up OFC tests (n = 18) had been exposed to cow's milk-based formula before the first clinical manifestation of CMA. Five out of eight cases with Food Protein-Induced Enterocolitis Syndrome (FPIES) had positive OFC tests. Exposure to cow's milk-based formula before diagnosis, a history of other food allergies, hematochezia and diarrhea were predictors of a positive OFC test.

CONCLUSIONS

In infants with non-IgE-mediated CMPA with gastrointestinal manifestations, the use of cow's milk-based formula, a history of other food allergies, and hematochezia and diarrhea upon initial presentation were associated factors for the later achievement of tolerance.

Specific and nonspecific nutritional interventions enhance the development of oral tolerance in food allergy

The goal of food allergy (FA) prevention and treatment is to induce oral tolerance (OT). Appropriate nutritional interventions are essential to induce OT to food allergens. This review introduces the mechanism of OT and the importance of early nutritional interventions, and then firstly summarizes specific nutritional factors to induce the development of OT of FA, including proteins, vitamins, fatty acids, saccharides and probiotics. The regulatory mechanism mainly induces the development of tolerance by increasing local or systemic protective regulatory T cells (Tregs) to suppress FA, while the gut microbiota may also be changed to maintain intestinal homeostasis. For allergens-specific OT, the disruption to the structure of proteins and epitopes is critical for the induction of tolerance by hydrolyzed and heated proteins. Vitamins (vitamin A, D), fatty acids, saccharides and probiotics as allergens nonspecific OT also induce the development of OT through immunomodulatory effects. This review contributes to our understanding of OT in FA through nutritional interventions. Nutritional interventions play an important role in the induction of OT, and offer promising approaches to reduce allergy risk and alleviate FA. Moreover, due to the importance and diversity of nutrition, it must be the future trend of induction of OT in FA.

Mast cells-fetal mast cells crosstalk with maternal interfaces during pregnancy: Friend or foe?

Mast cells (MC) are hematopoietic immune cells that play a major role during allergic reactions in adults by releasing a myriad of vasoactive and inflammatory mediators. MC seed all vascularized tissues and are most prominent in organs with a barrier function such as skin, lungs, and intestines. These secreted molecules cause mild symptoms such as localized itchiness and sneezing to life-threatening symptoms (i.e., anaphylactic shock). Presently, despite the extensive research on Th2-mediated immune responses in allergic diseases in adults, we are still unable to determine the mechanisms of the role of MC in developing pediatric allergic (PA) disorders. In this review, we will summarize the most recent findings on the origin of MC and discuss the underappreciated contribution of MC in the sensitization phase to maternal antibodies during pregnancy in allergic reactions and other diseases such as infectious diseases. Then, we will lay out potential MC-dependent therapeutic strategies to be considered in future investigations to understand the remaining gaps in MC research for a better quality of life for these young patients.

Children with Delayed-Type Cow's Milk Protein Allergy May Be at a Significant Risk of Developing Immediate Allergic Reactions Upon Re-introduction

Background

Cow's Milk Protein Allergy (CMPA) is the most common food allergy in children. The reaction is classified into IgE-mediated immediate reaction and delayed-onset, according to the underlying immune mechanism, and hence, the timing of the symptoms. Case reports suggest that children, with delayed CMPA reactions on elimination diet, may develop severe immediate reactions on reintroduction.

Aim

The objective of this study was to evaluate the incidence and the risk factors of developing immediate reactions to milk and dairy products in children with CMPA whose initial presentations were of delayed type.

Methods

A retrospective chart review of children, aged 0-12 years, presented with delayed type CMPA reactions to the allergy-clinical immunology clinics, was performed. The diagnosis was made clinically, and with appropriate allergy tests when indicated.

Results

Sixty children were included. Males:female ratio was 1.7:1. Family history of atopy was in 72%, and 57% had personal history of atopy. Sixty percent were not breast fed. The most common concomitant food allergy was egg. The most common initial presentation was diarrhea without protein loss or bleeding followed by exacerbation of atopic dermatitis upon exposure to dairy products. Immediate reactions developed in 21.6% upon re-exposure. There were significant associations with concomitant food allergy (OR 56.6 (3.15-1016.1) P<0.0001), especially eggs (OR 12.85 (3.09-53.5) P<0.01).

Conclusion

Children with CMPA, who present with delayed-type allergic reactions, may be at a significant risk of developing immediate reactions upon reintroduction. Evaluation of possible IgE-mediated allergic reactions before reintroduction may be advisable.

Food protein-induced enterocolitis syndrome due to buckwheat: A case report

Buckwheat is a rare causative food for food protein-induced enterocolitis syndrome (FPIES). To date, it is unknown what laboratory data patients with FPIES caused by buckwheat show. We report a 4-year-old female with FPIES caused by buckwheat and the laboratory results. Skin prick, specific IgE antibody, and basophil activation tests were negative; however, the lymphocyte stimulation test (LST) revealed a 10.2-fold increase in activation compared with the negative control. In an open-label oral food challenge (OFC) of 80 g boiled buckwheat noodles, 3 hours after ingestion, vomiting occurred four times in a 2-hour duration. Therefore, we diagnosed the patient with FPIES caused by buckwheat. Her neutrophil count, C-reactive protein, and thymus and activation-regulated chemokine were elevated after the OFC. Moreover, the patient had a positive reaction to the LST, which may theoretically be useful in diagnosing non-immunoglobulin E-mediated gastrointestinal food allergies. FPIES caused by buckwheat is rare; however, we found that the same laboratory results were observed in a comparison of FPIES cases caused by other foods.

Assessment of intracellular zinc levels in infants with food protein-induced allergic proctocolitis

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is characterized by bloody stools in well-appearing infants. Zinc is a micronutrient that plays a crucial role in immune modulation and is essential for cellular function during immune response. Although there are studies on the assessment of intracellular zinc levels in allergic diseases, no data is available on erythrocyte zinc levels of patients with FPIAP.

OBJECTIVE

This study aimed to assess the erythrocyte zinc levels of children with allergic proctocolitis and compare zinc levels with clinical and demographic characteristics.

METHODS

This was a case-control study that prospectively compared 50 patients with FPIAP and 50 healthy children without malnutrition. The erythrocyte zinc levels of children were determined using atomic absorption spectrophotometry.

RESULTS

Fifty patients with FPIAP, including 28 (51%) girls, with median age of 7.1 ± 2.9 (3-14) months and 50 healthy children, including 26 (53.1%) girls, with median age of 7.7 ± 2.8 (3-13) months were included in the study. Seventy percent (n = 35) of the patients with FPIAP started to have symptoms while they were exclusively breastfeeding. Offending allergen foods were cow's milk (78%), egg (40%), sesame (10%), hazelnut (8%), almond (6%), beef (6%), and peanuts (6%, n = 3). Intracellular (erythrocyte) zinc levels in patients with FPIAP were lower than in the healthy control group (495.5 ± 134 µg/dL, 567.3 ± 154.4 µg/dL, respectively, P = 0.01). Patients with FPIAP aged younger than 6 months had lower intracellular zinc levels compared with those aged above 6 months (457 ± 137 µg/dL; 548 ± 112 µg/dL, respectively, P = 0.01). There was no relationship between zinc levels and time of symptom onset, presence of concomitant disease, being allergic to multiple foods, and family history of atopy (P > 0.05).

CONCLUSIONS

FPIAP is a food allergy with limited information on its pathogenesis. Considering the beneficial effects on gastrointestinal system epithelia, zinc may be involved in the pathogenesis of FPIAP. Future comprehensive prospective research on this subject is of importance.

Food Protein-induced Enterocolitis Syndrome Due to Rice in a Japanese Infant: A Case Report

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food allergy characterized by repetitive vomiting within 1-4 h and/or diarrhea within 24 h after ingesting the causative food. We herein report a rare Japanese case of rice-induced FPIES. A six-month-old, female, Japanese patient presented to the emergency room (ER) with the complaint of vomiting after feeding. Postprandial vomiting had occurred occasionally since she started ingesting solid food at the age of 5 months. Rice-induced FPIES was suspected only after the fourth ER visit based on the characteristic history of recurrent vomiting occurring 1-2 h after ingesting food containing rice. Allergen-specific IgE testing and a skin prick test with an allergen scratch extract were both negative for rice. During an oral food challenge test (OFC), vomiting was observed after the patient ingested 2 g of rice porridge. Based on the OFC results and the entire clinical course, FPIES due to rice was diagnosed. A lymphocyte stimulation test with rice revealed a significantly elevated stimulation index. Rice-induced FPIES is rarely reported among Japanese infants despite rice being a staple in the Japanese diet. The prevalence of rice-induced FPIES differs greatly among populations, suggesting a multifactorial cause associated with its development. Delays in diagnosis are common in FPIES, and our case demonstrates the importance of obtaining a dietary history of food ingested prior to symptom onset in cases of infantile repetitive vomiting.

The challenging diagnosis of food protein-induced enterocolitis syndrome: A case report series

Food protein-induced enterocolitis syndrome (FPIES) is a type of non-immunoglobulin E (IgE)-mediated food allergy. However, in addition to vomiting and diarrhea, IgE-mediated skin or respiratory symptoms may be comorbidities in some patients with FPIES. We described four unusual cases of neonates with FPIES, whose clinical presentations were variable and misleading. All patients experienced vomiting, diarrhea or other gastrointestinal symptoms, and three of them developed IgE-mediated food allergy. Case 1 was admitted to the hospital with convulsions and then developed severe sepsis and necrotizing enterocolitis (NEC)-like appearance. Case 2 was wrongly diagnosed with Stevens-Johnson syndrome due to a severe extravasation rash of the skin and mucous membranes and a systemic inflammatory response. There was unexplained cholestasis in case 3, which might be attributed to food allergy. Asymptomatic elevation of C-reactive protein was the only hint at early-stage FPIES in case 4. Moreover, there were increased serum food-specific IgG values in three of the above cases. After eliminating the offending food, all of the above clinical manifestations rapidly improved in the four cases; thus, we believe that the most correct diagnosis in the described four cases was FPIES. This case report series should further draw clinicians' attention to FPIES with variable and atypical symptoms. The usefulness of IgG levels in identifying the presence of FPIES is uncertain.

Can fecal calprotectin levels be used to monitor infant milk protein allergies?

Background

Milk protein allergy is one of the most common food allergies in infants. We aimed to test whether fecal calprotectin can be used to monitor food allergies in infants by comparing the fecal calprotectin levels in infants with a milk protein allergy before and after an intervention treatment.

Methods

The study was designed as a prospective case–control trial. Stool samples were collected at follow-up, and the concentration of fecal calprotectin was determined using an enzyme-linked immunosorbent assay. The infant’s weight and length were measured.

Results

The allergic group comprised 90 milk-allergic infants (41 boys, 49 girls), and the nonallergic group comprised 90 nonallergic infants (51 boys, 39 girls). Compared with the fecal calprotectin level in the nonallergic group (median: 141 μg/g), that in the allergic group (median: 410 μg/g) was significantly higher (z = − 9.335, p < 0.001). After two dietary interventions and treatments, the fecal calprotectin levels of the infants with a milk protein allergy at the first (median: 253 μg/g) and second follow-up visits (median: 160 μg/g) were significantly lower than those before the intervention (z = − 7.884, p < 0.001 and z = − 8.239, p < 0.001, respectively). The growth index values (LAZ and WAZ) of the infants with a milk protein allergy at the first and second follow-up visits were significantly higher than those before dietary intervention (p < 0.05). Fecal calprotectin was negatively and significantly correlated with the WLZ and WAZ at the second follow-up visit (Spearman’s rho = − 0.234, p = 0.01 and Spearman’s rho = − 0.193, p = 0.03, respectively).

Conclusion

The level of fecal calprotectin in infants with a milk protein allergy decreased after dietary intervention and seems to be a promising biological indicator for monitoring intestinal allergies.

Induction of food tolerance is dependent on intestinal inflammatory state

Food allergies are usually managed by food avoidance. Hidden allergens in food, due to cross-contamination and/or allergenic additives added during production, place an important concern in today's increasing food allergy cases worldwide. Previous studies showed that the introduction of unacquainted food components, in an inflamed intestine, results in sensitization to this food. Thus, our aim was to evaluate the kinetics of multiple food allergy induction. Adult male C57BL/6 mice were divided into five groups, four of which were submitted to an intestinal inflammation induction protocol to peanuts. Egg white (OVA) diluted 1:5 v/v in distilled water was instilled by gavage 6h-before (PRIOR), concomitant (AT) and 6h-after (DURING) the onset of the peanut challenge diet. Positive control (POS CONT) and NEG CONT received saline per gavage. Finally, animals were challenged with subcutaneous injections of OVA. Results showed no changes in diet intake were observed. Anti-OVA polyisotypic IgG antibody titers significantly increased in AT. Flow cytometry revealed significant decrease in CD4⁺CD25⁺Foxp3⁺ and significant increase in TCD8⁺ in AT. Histomorphometrically, AT and DURING were classified as Infiltrative and Partial Destruction stages. PRIOR was classified as Infiltrative, while POS CONT was classified as Partial Destruction. NEG CONT was classified as Normal. Together, our results confirm that the introduction of unfamiliar food only a few hours before the initiation of a gut inflammation process is able to induce oral tolerance, however the introduction of a dietary protein concomitant to the onset or during an ongoing gut inflammation may induce multiple allergies.

Non-IgE- or Mixed IgE/Non-IgE-Mediated Gastrointestinal Food Allergies in the First Years of Life: Old and New Tools for Diagnosis

non-IgE and mixed gastrointestinal food allergies present various specific, well-characterized clinical pictures such as food protein-induced allergic proctocolitis, food protein-induced enterocolitis and food protein-induced enteropathy syndrome as well as eosinophilic gastrointestinal disorders such as eosinophilic esophagitis, allergic eosinophilic gastroenteritis and eosinophilic colitis. The aim of this article is to provide an updated review of their different clinical presentations, to suggest a correct approach to their diagnosis and to discuss the usefulness of both old and new diagnostic tools, including fecal biomarkers, atopy patch tests, endoscopy, specific IgG and IgG4 testing, allergen-specific lymphocyte stimulation test (ALST) and clinical score (CoMiss).

Feeding-based treatment of allergic proctocolitis and associated clinical outcomes

BACKGROUND

Allergic colitis (AC) is one of the most common etiologies of rectal bleeding in infants aged one to six months.

AIM

The aim of this study is to apply step-by-step dietary restrictions in the mother's diet or change of infant formula fed thereby, to evaluate the subsequent clinical response.

METHODS

Sixty healthy infants whose clinical and evaluation results indicated proctocolitis in our outpatient gastroenterology clinic were included in this. They were divided into three groups according to the type of feeding; group 1 were exclusively breast fed, group 2 were exclusively formula fed and group 3 were fed with combination of both. In breast feeding women, discontinuation was allergenic food was studied in four stages; cow-related dairy products, soy, sesame and fast food (stage A), egg (stage B), corn, nuts and fish (stage C) and wheat (stage D).

RESULTS

Sixty newborns with age at symptom onset 3 days-20 days participated in the study. Up to the time of our initial evaluation, the mean age and weight of infants was 73.34 ± 1.00 day and 3292.71 ± 367.93 g, respectively. There was no significant difference in sex and the type of labor between the groups. Thirty-three infants had a history of eczema and the parents of 47 infants had a history of allergy, with the greatest prevalence in group one. Rectal bleeding in 50% of infants was halted after the elimination of allergenic feed in mother (15 in stage A, 8 in stage B and 7 in stage C). Ten infants needed extensive hydrolyzed formula and 20 needed amino acid-based formulas.

CONCLUSIONS

There is no need for immediate use of amino acid or extensive hydrolyzed formulas in the first stage of blood in stool, perhaps discontinuing allergenic food in mothers could be the primary measure.

Risk Factors Influencing Tolerance and Clinical Features of Food Protein-induced Allergic Proctocolitis

OBJECTIVE

Continued progress in our understanding of the food protein-induced allergic proctocolitis (FPIAP) will provide the development of diagnostic tests and treatments. We aimed to identify precisely the clinical features and natural course of the disease in a large group of patients. Also, we investigated the predicting risk factors for persistent course since influencing parameters has not yet been established.

METHODS

Infants who were admitted with rectal bleeding and had a diagnosis of food protein-induced allergic proctocolitis in 5 different allergy or gastroenterology outpatient clinics were enrolled. Clinical features, laboratory tests, and prognosis were evaluated. Risk factors for persistent course were determined by logistic regression analyses.

RESULTS

Among the 257 infants, 50.2% (n = 129) were girls and cow's milk (99.2%) was the most common trigger. Twenty-four percent of the patients had multiple food allergies and had more common antibiotic use (41.9% vs 11.8%), atopic dermatitis (21% vs 10.2%), wheezing (11.3% vs 1.5%), colic (33.8% vs 11.2%), and IgE sensitization (50% vs 13.5%) compared to the single-food allergic group (P < 0.001, P = 0.025, P = 0.003, P < 0.001, respectively). In multivariate logistic regression analysis, presence of colic (odds ratio [OR]: 5.128, 95% confidence interval [CI]: 1.926-13.655, P = 0.001), IgE sensitization (OR: 3.964, 95% CI: 1.424-11.034, P = 0.008), and having allergy to multiple foods (OR: 3.679, 95% CI: 1.278-10.593, P = 0.001] were found to be risk factors for continuing disease after 1 year of age.

CONCLUSION

Although most children achieve tolerance at 1 year of age, IgE sensitization, allergy to multiple foods, and presence of colic were risk factors for persistent course and late tolerance. In this context, these children may require more close and extended follow-up.

The diagnostic value of APT for food allergy in children: a systematic review and meta-analysis

BACKGROUND

The role of atopy patch test (APT) in the diagnosis of food allergy (FA) remains largely controversial. In our meta-analysis, we aimed to evaluate the accuracy of APT for diagnosing FA in children.

METHODS

Pubmed, Embase and Cochrane Library were searched for studies regarding the diagnostic value of APT for FA in children compared to oral food challenge (double-blind placebo-controlled food challenge and/or open food challenge). The last search was conducted on November 11, 2017. Two reviewers independently screened relevant studies and assessed the quality by QUADAS-2. Meta-analysis was performed to calculate the pooled sensitivity, specificity, DOR (diagnostic odds ratio), PLR (positive likelihood ratio), NLR (negative likelihood ratio) with their 95% confidence intervals (CIs). Subgroup analyses were conducted according to different food allergens, atopic dermatitis, gastrointestinal symptoms, and age younger than 3 years.

RESULTS

Forty-one studies were included in the meta-analysis. The pooled sensitivity, specificity, PLR, NLR and DOR were 50.30% (95% CI 48.40%-52.30%), 86.60% (95% CI 85.30%-87.80%), 3.405 (95% CI 2.594-4.470), 0.545 (95% CI 0.469-0.634) and 7.528 (95% CI 5.507-11.206), respectively. However, for children with FA-related gastrointestinal symptoms, the pooled sensitivity and specificity were 57.40% (95% CI 52.10%-62.50%) and 91.50% (95% CI 88.30%-94.10%) respectively.

CONCLUSIONS

Our findings suggest that APT is specific but not sensitive for diagnosing FA in children, especially in children with FA-related gastrointestinal symptoms.

Mechanisms by which gut microorganisms influence food sensitivities

Finely tuned mechanisms enable the gastrointestinal tract to break down dietary components into nutrients without mounting, in the majority of cases, a dysregulated immune or functional host response. However, adverse reactions to food have been steadily increasing, and evidence suggests that this process is environmental. Adverse food reactions can be divided according to their underlying pathophysiology into food intolerances, when, for instance, there is deficiency of a host enzyme required to digest the food component, and food sensitivities, when immune mechanisms are involved. In this Review, we discuss the clinical and experimental evidence for enteric infections and/or alterations in the gut microbiota in inciting food sensitivity. We focus on mechanisms by which microorganisms might provide direct pro-inflammatory signals to the host promoting breakdown of oral tolerance to food antigens or indirect pathways that involve the metabolism of protein antigens and other dietary components by gut microorganisms. Better understanding of these mechanisms will help in the development of preventive and therapeutic strategies for food sensitivities.

Higher Polygenetic Predisposition for Asthma in Cow's Milk Allergic Children

Cow’s milk allergy (CMA) is an early-onset allergy of which the underlying genetic factors remain largely undiscovered. CMA has been found to co-occur with other allergies and immunological hypersensitivity disorders, suggesting a shared genetic etiology. We aimed to (1) investigate and (2) validate whether CMA children carry a higher genetic susceptibility for other immunological hypersensitivity disorders using polygenic risk score analysis (PRS) and prospective phenotypic data. Twenty-two CMA patients of the Dutch EuroPrevall birth cohort study and 307 reference subjects were genotyped using single nucleotide polymorphism (SNP) array. Differentially genetic susceptibility was estimated using PRS, based on multiple P-value thresholds for SNP inclusion of previously reported genome-wide association studies (GWAS) on asthma, autism spectrum disorder, atopic dermatitis, inflammatory bowel disease and rheumatoid arthritis. These associations were validated with prospective data outcomes during a six-year follow-up in 19 patients. We observed robust and significantly higher PRSs of asthma in CMA children compared to the reference set. Association analyses using the prospective data indicated significant higher PRSs in former CMA patients suffering from asthma and related traits. Our results suggest a shared genetic etiology between CMA and asthma and a considerable predictive sensitivity potential for subsequent onset of asthma which indicates a potential use for early clinical asthma intervention programs.

Gastrointestinal food allergy in Ghanaian children: a case series

Background

Food allergy is an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food. Food allergies are classified into three types: Ig(immunoglobulin)E mediated, mixed IgE and cell mediated and cell-mediated non IgE mediated. Gastrointestinal (GIT) food allergy has classically encompassed a number of different clinical entities: food protein-induced enterocolitis syndrome (FPIES), food protein-induced proctocolitis (FPIP), food protein-induced enteropathy and eosinophilic gastrointestinal disorders (EGID).

Case presentations

These are 5 cases of infants and toddlers who presented with various features of gastrointestinal food allergies, the commonest of which is lower gastrointestinal bleed. Two infants on exclusive breast feeding, presented with lower gastrointestinal bleeding and these resolved with maternal dietary milk and all dairy elimination. The third infant had rectal bleeding at age 6 months after the introduction of infant formula. The bleeding and eczema resolved with the introduction of hydrolyzed formula. One of the toddlers presented with severe eczema and malnutrition which improved with 6 food elimination. The last case had massive lower gastrointestinal bleed which resulted in hemicolectomy with no improvement until dietary elimination was instituted.

Conclusion

Gastrointestinal food allergy is not uncommon in children in Ghana. A high index of suspicion is required to make the right diagnosis, to minimize morbidity and unnecessary therapy.

Source of funding

None.

Tolerance development in food protein-induced allergic proctocolitis: Single centre experience

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is characterised by inflammation of the distal colon in response to one or more food proteins. It is a benign condition of bloody stools in a well-appearing infant, with usual onset between one and four weeks of age.

OBJECTIVE

Our objective was to examine the clinical properties of patients with FPIAP, tolerance development time as well as the risk factors that affect tolerance development.

METHODS

The clinical symptoms, offending factors, laboratory findings, methods used in the diagnosis and tolerance development for 77 patients followed in the Paediatric Allergy and Gastroenterology Clinics with the diagnosis of FPIAP during January 2010-January 2015 were examined in our retrospective cross-sectional study.

RESULTS

The starting age of the symptoms was 3.3±4.7 months (0-36). Milk was found as the offending substance for 78% of the patients, milk and egg for 13% and egg for 5%. Mean tolerance development time of the patients was 14.7±11.9 months (3-66 months). Tolerance developed before the age of one year in 40% of the patients. Tolerance developed between the age of 1-2 years in 27%, between the age of 2-3 years in 9% and after the age of 3 years in 5% of the patients.

CONCLUSIONS

Smaller onset age and onset of symptoms during breastfeeding were found associated with early tolerance development. In the majority of the patients, FPIAP resolves before the age of one year, however in some of the patients this duration may be much longer.

International consensus guidelines for the diagnosis and management of food protein-induced enterocolitis syndrome: Executive summary-Workgroup Report of the Adverse Reactions to Foods Committee, American Academy of Allergy, Asthma & Immunology

Food protein-induced enterocolitis (FPIES) is a non-IgE cell- mediated food allergy that can be severe and lead to shock. Despite the potential seriousness of reactions, awareness of FPIES is low; high-quality studies providing insight into the pathophysiology, diagnosis, and management are lacking; and clinical outcomes are poorly established. This consensus document is the result of work done by an international workgroup convened through the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology and the International FPIES Association advocacy group. These are the first international evidence-based guidelines to improve the diagnosis and management of patients with FPIES. Research on prevalence, pathophysiology, diagnostic markers, and future treatments is necessary to improve the care of patients with FPIES. These guidelines will be updated periodically as more evidence becomes available.

Phenotypic and Genotypic Characterisation of Inflammatory Bowel Disease Presenting Before the Age of 2 years

OBJECTIVES

Inflammatory bowel disease [IBD] presenting in early childhood is extremely rare. More recently, progress has been made to identify children with monogenic forms of IBD predominantly presenting very early in life. In this study, we describe the heterogeneous phenotypes and genotypes of patients with IBD presenting before the age of 2 years and establish phenotypic features associated with underlying monogenicity.

METHODS

Phenotype data of 62 children with disease onset before the age of 2 years presenting over the past 20 years were reviewed. Children without previously established genetic diagnosis were prospectively recruited for next-generation sequencing.

RESULTS

In all, 62 patients [55% male] were identified. The median disease onset was 3 months of age (interquartile range [IQR]: 1 to 11). Conventional IBD classification only applied to 15 patients with Crohn's disease [CD]-like [24%] and three with ulcerative colitis [UC]-like [5%] phenotype; 44 patients [71%] were diagnosed with otherwise unclassifiable IBD. Patients frequently required parenteral nutrition [40%], extensive immunosuppression [31%], haematopoietic stem-cell transplantation [29%], and abdominal surgery [19%]. In 31% of patients, underlying monogenic diseases were established [EPCAM, IL10, IL10RA, IL10RB, FOXP3, LRBA, SKIV2L, TTC37, TTC7A]. Phenotypic features significantly more prevalent in monogenic IBD were: consanguinity, disease onset before the 6th month of life, stunting, extensive intestinal disease and histological evidence of epithelial abnormalities.

CONCLUSIONS

IBD in children with disease onset before the age of 2 years is frequently unclassifiable into Crohn's disease and ulcerative colitis, particularly treatment resistant, and can be indistinguishable from monogenic diseases with IBD-like phenotype.

Cow milk protein allergy presenting as feeding intolerance and eosinophilia: case reports of three preterm neonates

Three preterm infants with cow milk protein allergy (CMPA) presented with feeding intolerance, sepsis-like episodes and persistent moderate-to-severe eosinophilia. After eliminating cow milk, the clinical symptoms improved significantly. CMPA can cause common manifestations in sick preterm infants such as feeding intolerance and eosinophilia.

Cow's milk allergy in Dutch children: an epigenetic pilot survey

Background

Cow’s milk allergy (CMA) is a common disease in infancy. Early environmental factors are likely to contribute to CMA. It is known that epigenetic gene regulation can be altered by environmental factors. We have set up a proof of concept study, aiming to detect epigenetic associations specific with CMA.

Methods

We studied children from the Dutch EuroPrevall birth cohort study (N = 20 CMA, N = 23 controls, N = 10 tolerant boys), age and gender matched. CMA was challenge proven. Bisulfite converted DNA (blood) was analyzed using the 450K infinium DNA-methylation array. Four groups (combined, girls, boys and tolerant boys) were analysed between CMA and controls. Statistical analysis and pathway-analysis were performed in “R” using IMA, Minfi and the global-test package. Differentially methylated regions in DHX58, ZNF281, EIF42A and HTRA2 genes were validated by quantitative amplicon sequencing (ROCHE 454^®).

Results

General hypermethylation was found in the CMA group compared to control children, while this effect was absent in the tolerant group. Methylation differences were, among others, found in regions of DHX58, ZNF281, EIF42A and HTRA2 genes. Several of these genes are known to be involved in immunological pathways and associated with other allergies.

Conclusion

We show that epigenetic associations are involved in CMA. Although, the statistical power of our study is limited and our sample was based on whole blood, we were still able to detect feasible loci and pathways. Therefore our findings might contribute to future diagnostic or therapeutic interventions for specific CMA. Further studies have to confirm the findings of our study.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-016-0105-z) contains supplementary material, which is available to authorized users.

Role of specific IgE to β-lactoglobulin in the gastrointestinal phenotype of cow's milk allergy

Rationale

The prevalence of many phenotypes of food allergy is increasing. Specific gastrointestinal (GI) phenotype of food allergy (GI allergy) is also increasing but it is difficult to know the prevalence because of many entities.

Methods and Results

A 1 year retrospective study of pediatric patients complaining exclusively gastrointestinal symptoms after cow’s milk consumption and at least one positive specific IgE (sIgE) to cow’s milk (CM) proteins (CMP) was done (n = 39). The most prevalent symptom was abdominal cramps in 35 patients (90 %), discomfort or abdominal distention in 30 patients (75 %), diarrhea in 10 patients (25 %) and constipation in 5 patients (12 %). IgA anti-transglutaminase antibodies were absent and lactose intolerance was ruled out in all patients. Average of total IgE on this group was 288 UI/ml. sIgE against β-lactoglobulin was the dominant with an average of 4.14 kU/l. sIgE to casein (CAS), which is the dominant protein in systemic anaphylaxis was 1.74 kU/l; sIgE to α-lactoalbumin, the other whey protein, was 0.83 kU/l and sIgE levels to CM were 0.78 kU/l. The quotient sIgE CAS/sIgE β-lactoglobulin in these patients was always lower than 1. Patients experienced an improvement of their symptoms after a CM free diet. An open oral challenge with CM did mimic their initial symptoms in all patients. However, the open oral challenge with dairy products was well tolerated.

Conclusions

Patients with a specific phenotype of GI allergy with CM have specific IgE against β-lactoglobulin, as a dominant sIgE. These patients could beneficiate of a diet with dairy products.

Mesenteric IL-10-producing CD5+ regulatory B cells suppress cow's milk casein-induced allergic responses in mice

Food allergy is a hypersensitive immune reaction to food proteins. We have previously demonstrated the presence of IL-10-producing CD5(+) B cells and suggested their potential role in regulating cow's milk casein allergy in humans and IgE-mediated anaphylaxis in mice. In this study, we determined whether IL-10-producing CD5(+) regulatory B cells control casein-induced food allergic responses in mice and, if so, the underlying mechanisms. The induction of oral tolerance (OT) by casein suppressed casein-induced allergic responses including the decrease of body temperature, symptom score, diarrhea, recruitment of mast cells and eosinophils into jejunum, and other biological parameters in mice. Notably, the population of IL-10-producing CD5(+) B cells was increased in mesenteric lymph node (MLN), but not in spleen or peritoneal cavity (PeC) in OT mice. The adoptive transfer of CD5(+) B cells from MLN, but not those from spleen and PeC, suppressed the casein-induced allergic responses in an allergen-specific and IL-10-dependent manner. The inhibitory effect of IL-10-producing CD5(+) B cells on casein-induced allergic response was dependent on Foxp3(+) regulatory T cells. Taken together, mesenteric IL-10-producing regulatory B cells control food allergy via Foxp3(+) regulatory T cells and could potentially act as a therapeutic regulator for food allergy.

Characteristics and Prognosis of Allergic Proctocolitis in Infants

OBJECTIVES

The dietary protein proctocolitis, also known as allergic proctocolitis (AP), is characterized by the presence of mucoid, frothy, and bloody stools in an otherwise healthy infant. The aim of this study was to describe a group of children with AP, diagnosed according to the criterion-standard method, food challenge to provide clinicians with more information on typical presentation, and an overview on nutritional management strategies and prognosis.

METHODS

We collected data on infants with AP in our allergy and gastroenterology outpatient clinics. Any other conditions that may cause bloody diarrhea were ruled out. Skin prick tests and atopy patch tests were performed for diagnosis, and patients were studied for resolution. To the patients whose rectal bleeding did not recover with oligoantigenic maternal diet in addition to amino acid-based formula, endoscopic evaluation was performed to confirm the diagnosis and to exclude other reasons of rectal bleeding.

RESULTS

Sixty patients were diagnosed as having AP. The age of onset was 1.7 ± 1.32 months. All of the patients were triggered by milk, 6.6% with milk and egg, 3.3% with milk and chicken, 1.7% with milk and wheat, 1.7% with milk and potato, and 3.3% had multiple food allergy. 53.3% (n = 32) acquired tolerance by age 1, 25.0% (n = 15) by 2 years, 5% (n = 3) by 3, and 1.7% (n = 1) by 4 years.

CONCLUSIONS

Milk was a triggering factor for all of the patients. Resolution of AP is usually within 1 year but symptoms of some patients may continue even longer. An extension of the follow-up period is required according to our study.

Review article: the diagnosis and management of food allergy and food intolerances

BACKGROUND

Adverse reactions to food include immune mediated food allergies and non-immune mediated food intolerances. Food allergies and intolerances are often confused by health professionals, patients and the public.

AIM

To critically review the data relating to diagnosis and management of food allergy and food intolerance in adults and children.

METHODS

MEDLINE, EMBASE and the Cochrane Database were searched up until May 2014, using search terms related to food allergy and intolerance.

RESULTS

An estimated one-fifth of the population believe that they have adverse reactions to food. Estimates of true IgE-mediated food allergy vary, but in some countries it may be as prevalent as 4-7% of preschool children. The most common food allergens are cow's milk, egg, peanut, tree nuts, soy, shellfish and finned fish. Reactions vary from urticaria to anaphylaxis and death. Tolerance for many foods including milk and egg develops with age, but is far less likely with peanut allergy. Estimates of IgE-mediated food allergy in adults are closer to 1-2%. Non-IgE-mediated food allergies such as Food Protein-Induced Enterocolitis Syndrome are rarer and predominantly recognised in childhood. Eosinophilic gastrointestinal disorders including eosinophilic oesophagitis are mixed IgE- and non-IgE-mediated food allergic conditions, and are improved by dietary exclusions. By contrast food intolerances are nonspecific, and the resultant symptoms resemble other common medically unexplained complaints, often overlapping with symptoms found in functional disorders such as irritable bowel syndrome. Improved dietary treatments for the irritable bowel syndrome have recently been described.

CONCLUSIONS

Food allergies are more common in children, can be life-threatening and are distinct from food intolerances. Food intolerances may pose little risk but since functional disorders are so prevalent, greater efforts to understand adverse effects of foods in functional disorders are warranted.

Genetic susceptibility for cow's milk allergy in Dutch children: the start of the allergic march?

BACKGROUND

Cow's milk allergy (CMA) is the most common allergic disease in infancy. It is not clear, whether infants with CMA have an increased risk of developing other allergic diseases later in life, the so-called "allergic march". We aimed to detect genetic associations of CMA using reported single nucleotide polymorphisms (SNP) in other allergic diseases and genetic mutations within the filaggrin (FLG) gene. Both to investigate possible causes of CMA, which also suggests an "allergic march".

METHODS

Thirty children from the Dutch EuroPrevall birth cohort study with CMA in infancy and twenty-three healthy controls were studied. Six candidate SNPs were selected (minor allele frequency 10-50 % combined with a large effect) based on the literature. Thirteen FLG candidate mutations were selected spread over repeats 1, 3, 4, 5, 6, 7, 9 and 10 respectively.

RESULTS

We found two SNP's, rs17616434 (P = 0.002) and rs2069772 (P = 0.038), significantly associated with CMA. One is located near the toll like receptor 6 (TLR6) gene, which functionally interacts with toll-like receptor 2, and is associated with an increased risk of other allergic diseases. One is located at the Interleukin 2 (IL2) locus. Twelve FLG amplicons were analyzed, but showed no significant enrichment. Nevertheless, we did observe more FLG mutations in the CMA-group compared to controls.

CONCLUSION

We significantly associated two SNPs with CMA, suggesting that variation in the TLR6 and IL2 genes contribute to the expression of CMA. In addition, since TLR6 and IL2 were earlier associated with other later onset allergies, this also favours the "allergic march" hypothesis. We observed more FLG mutations in the CMA-group, albeit we found no statistical significant enrichment of FLG mutations. Further studies are necessary to investigate the role of common variants and FLG or other skin barrier gene mutations in CMA.

Peyer's patches and mesenteric lymph nodes cooperatively promote enteropathy in a mouse model of food allergy

Background and Objective

To improve the efficacy and safety of tolerance induction for food allergies, identifying the tissues responsible for inducing intestinal inflammation and subsequent oral tolerance is important. We used OVA23-3 mice, which express an ovalbumin-specific T-cell receptor, to elucidate the roles of local and systemic immune tissues in intestinal inflammation.

Methods and Results

OVA23-3 mice developed marked enteropathy after consuming a diet containing egg white (EW diet) for 10 days but overcame the enteropathy (despite continued moderate inflammation) after receiving EW diet for a total of 28 days. Injecting mice with anti-IL-4 antibody or cyclosporine A confirmed the involvement of Th2 cells in the development of the enteropathy. To assess the individual contributions of Peyer’s patches (PPs), mesenteric lymph nodes (MLNs), and the spleen to the generation of effector CD4⁺ T-cells, we analyzed the IL-4 production, proliferation in response to ovalbumin, and CD4⁺ T-cell numbers of these tissues. EW feeding for 10 days induced significant IL-4 production in PPs, the infiltration of numerous CD4⁺ T-cells into MLNs, and a decrease in CD4⁺ T-cell numbers in spleen. On day 28, CD4⁺ T-cells from all tissues had attenuated responses to ovalbumin, suggesting tolerance acquisition, although MLN CD4⁺ T-cells still maintained IL-4 production with proliferation. In addition, removal of MLNs but not the spleen decreased the severity of enteropathy and PP-disrupted mice showed delayed onset of EW-induced inflammatory responses. Disruption of peripheral lymphoid tissues or of both PPs and MLNs almost completely prevented the enteropathy.

Conclusions

PPs and MLNs coordinately promote enteropathy by generating effector T-cells during the initial and exacerbated phases, respectively; the spleen is dispensable for enteropathy and shows tolerogenic responses throughout EW-feeding. The regulation of PPs may suppress the initiation of intestinal inflammation, subsequently restricting MLNs and inhibiting the progression of food-allergic enteropathy.

Evaluation of a free amino acid-based formula in infants with presumptive food protein-induced proctocolitis

Objective:

Food protein–induced proctocolitis usually occurs early in life and is characterized by blood-streaked stools and pain during defecation in an otherwise healthy infant. While many infants with food protein–induced proctocolitis respond well to a casein hydrolysate formula, some require an amino acid–based formula. The objective of the study was to measure the change in physician-rated symptom score from enrollment to study completion in infants with presumptive food protein–induced proctocolitis fed with a specific amino acid-based formula.

Methods:

In this study, infants ≤6 months of age diagnosed with presumptive food protein–induced proctocolitis received an amino acid-based formula for 42 days. Intake, stool patterns, weight, stool occult blood, and questionnaires assessing infant feeding and stool patterns and parental formula satisfaction were collected.

Results:

The full analysis set included 43 infants. The mean age at enrollment was 59 ± 5 days. A significant improvement was observed from enrollment to exit in physician-rated symptom score (9.1 ± 0.5 to 4.8 ± 0.5, p < 0.0001), the number of infants with occult blood in stool, and weight-for-age Z-scores during the study. Parental satisfaction with the formula was high.

Conclusion:

The results confirm that the amino acid-based formula studied is efficacious for managing symptoms of presumptive food protein–induced proctocolitis.

Clinical presentation and referral characteristics of food protein-induced enterocolitis syndrome in the United Kingdom

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a pediatric non-IgE-mediated allergic reaction to foods. The diagnosis of FPIES is clinical, with children presenting typically 2 to 4 hours after ingestion of a food protein. The most striking symptoms are vomiting, lethargy, and pallor. Misdiagnosis and delay in presentation to an allergist or gastroenterologist are common.

OBJECTIVES

To investigate the pathway of patients with FPIES presenting to a specialist clinic in the United Kingdom to ascertain whether they experienced delays or misdiagnoses and to investigate their symptoms and triggers.

METHODS

All patients with FPIES presenting over a 3-year period (2010-2013) in a tertiary pediatric allergy clinic in London were analyzed retrospectively. This was performed by searching electronically for all patients with a diagnosis of FPIES and manually reviewing paper notes. Presenting symptoms and management pathways were collated.

RESULTS

Fifty-four patients were identified, with an average age of onset at 8 months. They initially presented to medical professionals other than an allergist or gastroenterologist. The most frequent presenting symptom was vomiting followed by signs suggesting shock or hypotension and diarrhea. Differential diagnoses included gastroenteritis, sepsis, and surgical abnormalities. The main eliciting foods were cow's milk, fish, egg, soy, and wheat.

CONCLUSION

In the United Kingdom, FPIES typically has its onset at 8 months. Patients experience a delay of 12 months in the diagnosis of FPIES and frequently have multiple episodes and interim diagnoses. A great need remains for enhanced education of medical practitioners dealing with children about the varied presentations of FPIES.